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Head & Neck

Disclaimer

  • This manual is not a substitute for consultation with an appropriate specialist.
  • The contents of this manual have been developed through consensus of a Provincial Tumour Group. Please note the various update dates for each section as some of the content of the manual may not be up to date.



1. Tumor Site/Type Demographics

Updated: May 2003

In British Columbia, incidence of cancers of the head and neck region is 22.9/100,000 in males and 14.9/100,000 in females. Head and neck cancers are a heterogeneous group of tumours, consisting predominantly of squamous cancers of the lip, mouth, pharynx, larynx and cervical esophagus, adenocarcinomas of the major and minor salivary glands and thyroid and occasional tumours of connective tissue origin. Head and neck cancers are more frequent among males than females for most subgroups (ratio ranges from 1.6:1 for the tongue to 3.8 to 1 for the larynx), the only exception being thyroid cancers where the ratio is 0.3 to 1.

Etiological agents vary with the subgroup. Squamous cell carcinomas are most commonly found in those who use tobacco, particularly smokers, and/or those with a high alcohol intake. A synergistic effect is observed when both tobacco and alcohol use are combined. Human papilloma virus is the most likely etiological factor in those who do not use tobacco or drink alcohol.

Nasopharyngeal carcinoma is a tumour of epithelial origin with distinctive epidemiological features. These include a predilection for certain ethnic groups particularly those from Hong Kong and adjacent provinces of southern China, persons from the Middle East and Mediterranean basin and the Inuit. It is strongly associated with exposure to Epstein-Barr virus and some other environmental factors that have not been conclusively identified. There is little or no causal association with tobacco and alcohol consumption in endemic areas.

Some data indicate that various industrial exposures may be related to cancer of the paranasal sinus and nasal cavity.

Exposure to ionising radiation is well known to be associated with an increased risk of thyroid cancer, although most patients with thyroid cancer have no history of radiation exposure. The etiology of most salivary tumours is unknown.

Another indication of the multifactorial nature of cancers in the head and neck region is the possibility that genetic factors may play a role. Such factors might include a variation in the capacity of individuals to metabolize carcinogens (such as those present in tobacco) so that they can be safely excreted from the body. Alternatively, genetically determined variation in efficiency of repair of DNA damaged by carcinogens, might prevent or facilitate mutation to critical genes required for cancer development. This area of research is rapidly developing.

Second primary tumours

It is well recognised that patients who have had one squamous carcinoma of the upper aero-digestive tract have an increased risk of developing a second primary if the first is cured. The actuarial risk is between 3 and 5% per year. This risk is highest in those who continue to smoke.

2. Predisposing Factors/Prevention

Updated: May 2003

With respect to prevention, several studies have concluded that there is a rapid reduction in risk of oral and laryngeal cancers following cessation of smoking, suggesting that this is an effective method of reducing cancer risk at these sites. Another possibility that is receiving attention is "chemoprevention". This approach is experimental, and involves the use of non-toxic agents on premalignant lesions, to prevent them from developing into cancers. This is an active field of research in British Columbia.

Thyroid Malignancies – History of Radiation Exposure

The risk of subsequent development of thyroid cancer after radiation therapy in childhood has been estimated at 7%, that is 1.5-4.5 per 10 subjects per rad per year, the latent period being reported from 4 to 30 years. It is important to recognize that radiation to the head and neck or chest not only results in an increased risk of thyroid cancer but also leads to an increased occurrence of benign changes within the thyroid gland such a colloid nodules and cysts, thereby the importance of following these patients very closely.

3. Screening/Early Detection

Updated: May 2003

To date there is no evidence to support screening of asymptomatic patients for head and neck cancer, but, not infrequently, asymptomatic potentially premalignant lesions are found by dentists and their staff at routine oral examinations. 10% of leukoplakia (white mucosal patches) may develop into a carcinoma if left untreated. Inflamed red patches (erythroplakia) is potentially more sinister with a 30% of chance of developing malignancy.

4. Diagnosis

Updated: August 2006

4.1 Clinico-pathologic Considerations

Malignancy should be suspected in the following situations and further investigation undertaken:

  • An area of ulceration or induration in the oral cavity without obvious cause and not quickly responding to symptomatic treatment
  • Pain in the mouth, jaw or ear without obvious cause
  • Unexplained malfunction of swallowing or speech
  • Areas of ulceration produced, in theory, by ill-fitting dentures or jagged teeth that do not resolve quickly when potential irritants are removed
  • Tonsillitis, especially unilateral, that does not resolve rapidly with treatment
  • Unexplained, enlarged lymph nodes in the neck
  • Solitary masses in the thyroid or changes in pre-existing goiters
  • Palpable lesions in salivary glands, especially when they are asymptomatic.

4.2 Diagnostic and Treatment Planning Considerations

Primary Tumour

Biopsy of the primary lesion is the first procedure and, following diagnosis, treatment planning can be decided in consultation. Molecular markers are becoming increasingly more important in the development of management plans for individual patients. The tests used to identify these markers require adequate tissue samples so it is important that as much tissue as is reasonably attainable is taken at the initial biopsy.

Patients presenting with enlarged neck nodes

The subsequent management of a patient may be compromised if tissue planes in the neck are disrupted by a diagnostic open biopsy, so this should only be done when all other methods of diagnosis have failed.

There are pathologists throughout the province who can give a high rate of accurate diagnosis of lymph node abnormalities on fine needle aspiration. This is especially so for metastatic squamous carcinoma. A high degree of accuracy is also possible in salivary gland tumours and thyroid nodules. If, however, a lesion is clinically suspicious of malignancy and fine needle aspiration does not confirm this, repeat aspiration or other means of biopsy must be undertaken. There is also the possibility of a false positive diagnosis and, if fine needle aspiration indicates a diagnosis of malignancy in a clinically benign situation, the biopsy should be repeated before planning treatment.

Detailed imaging of the primary tumour and regional lymph node drainages areas is usually invaluable in the pretreatment assessment of all but the earliest tumours. The relative indications for currently available imaging modalities are as follows.

Thyroid Malignancies

Adequate initial diagnosis is essential to determine whether surgical intervention or only conservative management is required. Following history and physical examination, the following diagnostic pathway is proposed.

The differentiation between a cystic and solid thyroid nodule can be made by a fine needle aspiration biopsy (FNA) or by ultrasonography. The advantage of an early FNA is that material can be obtained from all lesions for cytological analysis and should be preferred in all cases. If malignant cells are detected or interpreted as follicular neoplasia, surgical intervention should be recommended without unnecessary delay. If the cytology is suspicious or non-diagnostic, a repeat FNA may be done. If diagnosis is still unclear then radioactive isotope uptake and scanning should be done to determine whether the nodule is either hot or cold. If the nodule is hot, (a solitary autonomous nodule), then the patient could be merely observed and have medical treatment as required. On the other hand, if the nodule is not hot (cold), surgical intervention should be recommended. Repeat fine needle aspiration biopsy may be recommended if the thyroid nodule fails to regress. If again this proved to be suspicious then surgery should be recommended.

4.3 Radiology/Imaging

Plain radiographs

These have limited value in most cases, but are useful for demonstrating gross bony involvement or soft tissue swelling, for following sinusitis (esp. maxillary sinusitis) and evaluating the gross position of brachytherapy implants.

Computed Tomography (CT)

CT is presently the primary modality for the assessment of primary ENT tumours and nodal metastases. CT has inherently higher patient throughput compared to MRI and equal (or better) spatial resolution. It is the best modality for assessing the extent of lytic skull base involvement. A disadvantage is the marked artifact from dental amalgam and implanted orthopedic metal which may render parts of the study almost uninterpretable. These problems can be minimized by using different imaging planes. In addition, CT ENT assessment is moderately dependent on the use of iodinated contrast and contrast allergy may be a problem.

The Radiologist will decide on the exact protocol based on the information provided by the clinician and data from previous studies. It is therefore essential that appropriate information is provided for the radiologist. However, in most cases of head and neck cancer assessment of the primary tumour and regional nodes requires scans with IV iodinated contrast with axial 3mm cuts taken from the base of skull to the clavicles.

If enhanced visualization of structures whose long axis is parallel to the transverse plane is required, then 3mm coronal cuts are also helpful. This would include tumours involving the skull base, cavernous sinus, floor of the sphenoid sinus or nasopharyngeal roof, or the palate. Coronal views are also helpful for assessing the 3-dimensional relationships of complex tumours involving multiple structures. They can not be used for patients who are unable to extend their neck due to arthritis or instability.

MRI

Compared to CT, MRI relies on completely different physical mechanisms to obtain an image – the MR signal is obtained from mobile protons in water and fat whereas CT images are based on electron density. Soft tissue contrast is generally better in MRI, particularly close to bone where there is often some degradation of the soft tissue imaging with CT – in general subtle lesions are easier to see. Hence MRI is better for seeing structures around the pituitary fossa, or soft tissue lesions invading the cavernous sinus, the skull base and its foramina, sphenoid floor and nasopharyngeal roof, the palate and within the spinal canal. MRI is indicated for lesions with complex 3-D topology, such as some tongue cancers, where demonstration of bony margins is not of prime importance. This holds true even when no MRI contrast (gadolinium) is used. Occasionally malignant tissue is more easily differentiated from an inflammatory process (eg: in differentiating between tumour and benign inflammatory mucosal disease in cranial air sinuses).

Imaging can be performed in any plane the operator desires (CT is restricted to transverse and coronal planes). Vessels can be imaged non-invasively using "MR-angiography" protocols. MRI contrast agent (gadolinium) has several advantages. The incidence of contrast allergy is extremely low. Gadolinium is excreted primarily in the liver hence it can be used in patients with impaired renal function.

Disadvantages: MRI does not image bone directly and is poor for following lytic bony lesions. Some people cannot be placed in the MRI magnet bore (eg. they are claustrophobic, or have a pacemaker, etc.). They must be able to lie perfectly still for 4-8 minutes at a time; otherwise the image quality is degraded. CT requires the patient to lie still for approx. 30 seconds. Occasionally embedded ferromagnetic foreign bodies can produce marked artifact which makes image interpretation difficult or impossible.

Positron Emission Tomography

The use of positron emission tomography (PET) is becoming more widespread worldwide in the management of patients with cancer. Numerous studies have demonstrated that squamous cell carcinomas of the head and neck region are well imaged by PET and there is accumulating evidence supporting its use for a number of indications in head and neck cancers.

Effective August 16, 2005, the Functional Imaging Department has expanded the clinical indications for referral within the framework of the evidence-based BCCA guidelines for FDG-PET. PET/CT scan referrals will now be accepted at our facility for certain indications in adult oncology patients. To view the referral guideline, please go to the Functional Imaging page.

There is support in the literature for the use of PET in three main areas:

  1. In the initial staging of head and neck tumours where there is some uncertainty as to how extensive initial surgery or radiotherapy should be.
  2. As an additional procedure in the diagnosis of carcinoma of unknown primary presenting as a nodal neck mass.
  3. In the detection of recurrent disease post therapy where standard investigations are equivocal and further salvage therapy is feasible.

5. Staging

​Updated January 2012

TNM Staging for head and neck cancers should be done in accordance with the 7th Edition of the AJCC Cancer Staging Handbook.

Staging Diagrams (PDF):

6. Management


Updated: May 2003

Referral information for the new patient visit.

ENT Conference is held every Monday from 11.00 a.m. - noon.

Thyroid Conference is held on the 1st Thursday of the month from 8.00-9.15 a.m.

Tertiary Triage Criteria (who should be referred to a regional cancer centre)

  • all patients currently on protocol studies
  • all head & neck and ENT cases

Although the majority of physicians and dentists will encounter few patients with cancer of the oral cavity, larynx, pharynx, thyroid or salivary glands, it is essential that the possibility of malignancy should be considered when an abnormality in these areas is encountered. If cancers of the oral cavity, pharynx and larynx are seen when small and before lymph node metastases have occurred, the majority can be cured. If diagnosis is delayed until the lesion is large or has metastasized to lymph nodes in the neck, the many will die of their disease.

There appear to be misconceptions as to the significance of thyroid cancer. When seen in young people, thyroid cancer usually has a very favorable outcome but many do not appreciate that differentiated thyroid cancer in older patients may be lethal.

The treatment of head and neck cancer should be the responsibility of a team of surgeons, radiation oncologists, medical oncologists and dentists. Many patients also require the services of dietitians, physiotherapists and speech therapists. The aim of treatment is to give the best possible chance of cure while reducing functional and cosmetic disability to a minimum. As these types of cancers are not commonly seen, a few specialists across the province have developed a special interest and their advice should be sought.

Many early squamous cell carcinomas of the mouth and oropharynx can be cured by excision, but some form of radiation therapy is the usual preferred primary treatment for early tumours at other sites. Multidisciplinary assessment is mandatory for patients with more advanced cancers. When there is metastatic lymph node involvement, surgical dissection of the lymph nodes is usually required. In selected patients when radiation has failed as a primary treatment, radical surgical excision may still be possible and offer a significant chance of cure with acceptable functional and cosmetic results.

When radiotherapy is prescribed, this usually requires the construction of an immobilization device and subsequent CT based treatment planning which make take 7-10 days before treatment can be started.

6.1 Chemotherapy

​Updated: May 2003

Chemotherapy may be part of either the curative or palliative treatment of patients with head and neck cancer. Used alone, chemotherapy has not been shown to cure established squamous cell carcinomas, however, when used concurrently with radiation it is has been shown to increase both control of disease in the head and neck and increase survival rates. In patients with incurable disease, chemotherapy may be sufficiently effective to produce a significant reduction in tumour size that will relieve symptoms and improve quality of life.

Several different drugs may be used either alone or in combination, the side effects will depend on the drugs that are used.

6.2 Radiotherapy Techniques

​Updated: May 2003

The following types of radiation therapy may be recommended depending on the individual circumstances of the patient.

Interstitial radiotherapy (brachytherapy)

This technique is usually reserved for accessible, small tumours often in the mouth or oropharynx. Radioactive sources are placed in and/or around the tumour. The sources may be removed once the tumour has received the appropriate dose or they may remain in place potentially forever thereafter. In the latter case the sources lose their radioactivity in a matter of weeks and then present no risk to the patient or those around them. The initial part of the implant usually requires sedation or a general anesthetic and a short admission to hospital.

External beam radiotherapy

This is the most common form of radiotherapy. A beam, or combination of beams, of either X rays or electrons is directed at the tumour and/or surrounding tissues. Treatments are given once or twice daily (twice daily treatments are given approximately 6 hours apart), each treatment lasts for approximately 10 minutes. Most treatment courses last for between 4 and 7 weeks.

The volume of tissue treated may be confined to the tissues immediately adjacent to the tumour (such as for early cancers of the larynx) or may include both the primary tumour and the lymph nodes on both sides of the neck as in the treatment of most cancers of the nasopharynx.

Immobilisation

In order to give high doses of radiation to the target volume while at the same time limiting the dose to adjacent normal tissues, patient movement must be kept to a minimum. To achieve this, a custom made immobilisation mask is produced for most patients. The mask is worn for any treatment planning scans and for each radiation treatment.

3-D conformal and stereotactic radiotherapy

An external beam radiotherapy technique in which multiple beams are used to shape the high dose of radiation around the tumour. Stereotactic radiotherapy is a conformal technique in which multiple small fields are used to treat tumours that are very close to critical structures such as the optic chiasm. Special immobilisation devices are needed for stereotactic treatment.

Intensity modulated radiotherapy (IMRT)

An external beam radiotherapy technique in which the usual uniform intensity of the beam is changed so that the intensity varies across the beam. In certain circumstances this produces a better dose distribution around the tumour and greater sparing of the adjacent normal tissues than conformal radiotherapy.

6.3 Radiation Reactions

Updated: May 2003

Radiation therapy inevitably causes damage to the normal tissues in the path of the beam(s). This damage is referred to as the radiation reaction. When it occurs during and immediately after treatment it is called an early or acute reaction or acute. When it occurs more than 3 months after treatment it is referred to as the late reaction or damage.

Acute reactions

The acute reaction from treating oral cavity, oropharyngeal, nasopharyngeal, hypopharyngeal or laryngeal tumours will be similar and individual symptoms will largely depend on the tissues that have been treated.

Functional changes due to inflammation caused by the radiation will depend on the tissue involved, for example most patients will develop transient hoarseness if their larynx is irradiated and pain or difficulty eating if the mouth is treated. During a five or six week course of treatment, few symptoms will develop in the first 2 weeks except that the saliva may become thicker and more difficult to clear. Then the treated tissues will start to become inflamed and the patient will develop a painful mucositis. The reaction will usually reach its peak in the last 2 weeks of treatment and persist largely unchanged for about 2 weeks after the treatment has finished. Then it usually heals quite quickly and most symptoms should have resolved within four weeks of the completion of treatment. When chemotherapy has been combined with radiation or a twice daily radiation treatment schedule has been used, the reaction may be more severe and take longer to heal.

Treatment

  1. Reassurance
  2. Maintenance of fluid intake with oral fluids or intravenous infusion if necessary.
  3. Maintenance of adequate nutrition. Dietary supplements are often required. A feeding gastrostomy may be required and patients who are to be treated with regimens that usually produce severe mucositis will be offered prophylactic insertion of a feeding gastrostomy.
  4. Most patients require analgesics such as acetaminophen and codeine, occasionally some require stronger narcotics. Effective analgesia is often essential to maintain adequate fluid and calorie intake and patients should try to time their meals so that they have taken some analgesic about half an hour before eating. Mucaine or xylocaine viscous taken shortly before meals may assist swallowing.
  5. Some patients will develop oral candidiasis which should be treated with Nystatin oral suspension. Thrush can be difficult to differentiate from the fibrinous mucositis caused by the treatment, but typical colonies are usually seen in unirradiated tissue. Occasionally patients will also require treatment with a broad spectrum antibiotic. Although some trials have suggested that prophylactic administration of antibiotics and antifungals reduces the severity of mucositis, other trials have failed to show an effect and the situation at this stage is unclear.

Skin Reaction

Erythema progressing to dry, and sometimes moist, desquamation is usual. This starts to heal within 2 weeks of completing treatment. The treated area is often pigmented for some months and eventually returns to normal with or without some depigmentation and telangiectasia. When hair bearing skin is in the entry or exit beam of one or more radiation fields, it is likely that there will be epilation. If the dose exceeds the tolerance of the hair follicles, this epilation will be permanent, if not, the hair will regrow starting approximately 3 months after the completion of treatment.

Treatment

  1. Avoid irritation from rubbing, clothing and excessive heat or cold
  2. Leave open to the air.
  3. Where necessary, apply steroid creams without antibiotics
  4. Where possible, allow to dry and crust and allow the crusts to fall off spontaneously
  5. If infection develops, treat with appropriate systemic antibiotics
  6. If there is significant moist desquamation, daily topical treatment with 1% Flamazine often speeds the healing and prevents infection.

Late radiation damage

This is mainly due to damage to the microvasculature which is present in subclinical levels in nearly all patients but only progresses to radiation necrosis in bone or soft tissue in approximately 5% of cases. It is more common in patients with conditions that also damage small blood vessels such as diabetes. It may be caused or exacerbated by any form of trauma, e.g., dental extraction, biopsy, injury or infection (see dental section below). Treat conservatively, wherever possible by minimising aggravating factors such as a rough tooth or an ill fitting denture. Where possible, avoid biopsy which may cause further damage. Antibiotics may be helpful in bone necrosis. Some patients may be referred for hyperbaric oxygen therapy which appears to increase the blood supply to irradiated tissue and promote healing of necrotic areas.

6.4 General Principles of Treatment

Updated: May 2003

Squamous Cell Carcinoma of All Sites Except Nasopharynx

Dysplasia and squamous cell carcinoma in situ

Precipitating or aggravating factors should be removed and where possible the area excised with clear margins. Persistent mild dysplasia may be treated with topical Vitamin A acid gel 0.01-0.05% applied QID. Topical Bleomycin or laser excision may be used to treat mild to severe dysplasia. When the lesion is inaccessible or recurs repeatedly after apparently adequate surgical management and/or topical treatment, radiation therapy may be considered.

Early invasive squamous cell carcinoma T1-2 N0-1

Surgery and radiation therapy both offer a high chance of cure. Surgery is usually chosen for tumours of the mouth and oropharynx that can be resected with a good functional outcome. Radiation therapy is chosen for most laryngeal and pharyngeal tumours or when the patient declines surgery. If the tumour recurs following radiation therapy, most patients will still be eligible for resection.

Most of these patients can be cured by using a once daily radiation therapy schedule. If the tumour is more bulky then a twice daily schedule may be recommended.

More advanced tumours - T3-4 or N2-3

These patients require a multidisciplinary assessment prior to definitive treatment and referral to a regional cancer centre is strongly recommended. Some may be curable by surgery or radiotherapy alone, but most will require a combined modality approach such as radiation therapy followed by a neck dissection, or surgery followed by postoperative radiation therapy. In many cases, surgery is likely to require sophisticated reconstructive expertise.

Patients with larger, node negative tumours and other tumours with involved lymph nodes that are all in close proximity to the primary tumour, will usually be offered a twice daily radiation therapy schedule. Those with widespread lymphadenopathy will be offered a combined chemotherapy/radiation therapy regimen.

Patients presenting with distant metastases or unresectable recurrence

Treatment for these patients is not usually curative. Management must be tailored for each individual to provide the best chance of symptom relief and improved quality of life. Most patients will be considered for chemotherapy, many will also require palliative radiotherapy either to the primary tumour or symptomatic metastases.

Carcinoma of the nasopharynx T1-4,N1-3,M0

These tumours are treated with primary radiotherapy using either daily or twice daily radiotherapy or combined chemotherapy and radiation. Patients with more advanced disease are currently offered the chance to participate in an international multicentre clinical trial which is coordinated by the Hong Kong Nasopharyngeal Cancer Study Group.

Patients presenting with distant metastases

The principles are the same as those stated above for squamous cell carcinoma.

Benign and malignant tumours of major or minor salivary glands

The treatment of choice for all but the most advanced of these tumours is surgery. Unresectable tumours may be treated with radiotherapy and, where appropriate, patients with advanced tumours may referred for treatment with neutron irradiation which appears to be particularly effective for these tumours.

Surgery alone is sufficient for most salivary carcinomas, but patients with high grade salivary carcinomas should be offered postoperative radiotherapy. This may also be recommended for pleomorphic adenomas that have been incompletely excised.

6.5 Lip

Updated: May 2003

Most of these cancers are squamous cell carcinomas and the primary treatment is by radiotherapy or surgery with primary closure. Resection with reconstruction is reserved for recurrent carcinomas or advanced primary lesions involving bone and/or with regional metastases.

Radiotherapy for early stage lip cancers usually consists of a 2 week course of treatment with a relatively superficial beam with appropriate shielding of the adjacent tissues.

Lymph Node Metastases

Only 10% of patients with carcinoma of the lip will ever develop lymphatic metastases, but it is from this group that deaths due to lip cancer occur. The management of the clinically negative neck in patients with lip cancer is expectant, with careful routine examination of the regional nodes. Please see section 4: Dia​gnosis.

Lymph node metastases usually appear in the first two years and may enlarge rapidly. They are usually treated with a neck dissection. Patients presenting with lymph node metastases require a multidisciplinary assessment. Inoperable lymph node metastases may be treated where possible with primary radiotherapy.

6.6 Oral Cavity

​Updated: May 2003

Carcinoma in situ

Surgical or laser excision are used for localized lesions. A gold seed implant or radioactive iridium implant could be also employed in selected cases. External beam irradiation is occasionally used for widespread lesions that cannot be controlled by other means.

Invasive carcinoma

Most of these cancers are squamous cell carcinomas and the primary treatment of curable disease is surgical resection and/or radiation therapy. Adenocarcinomas of minor salivary gland origin, connective tissue tumours and mucosal melanomas are best treated with primary surgery, post-operative (rarely pre-operative) radiotherapy may be indicated depending on the individual situation.

The anatomical sites of the oral cavity are: floor of mouth, lower alveolus, buccal mucosa, upper alveolus, hard palate, and anterior two thirds of the tongue. careful clinical and radiological assessment is essential to determine the extent of these tumours. When assessing tumours of the upper alveolus, gingiva and hard palate, it is important to rule out the possibility that they represent downward extension of a primary tumour of the nose or paranasal sinuses.

The following general principles hold for all oral tumours, important points relating to specific anatomic subsites are described thereafter.

Clinically "early tumours" (less than 4 cm)

T1 T2 NO N1 MO

Treatment of the primary tumour may be either excision or radiotherapy. Surgery is usually recommended when the tumour can be removed with a good functional result, radiotherapy is used in preference to more major resections and reconstruction. The radiotherapeutic options include both radioactive implants and external beam radiotherapy. Implants treat only the primary tumour whereas external beam treatment may include both the primary tumour and adjacent lymph nodes.

  1. Gold seed implant
    Suitable for very superficial lesions confined to the floor of the mouth or tongue. Tumours that lie very close to the mandible are not usually suitable for a radioactive implant.

    The small radioactive gold "seeds" or "pellets" are implanted under local or general anesthesia and remain in the tissues permanently. The patient is admitted to a shielded hospital room for one or two days until most of the radioactivity has decayed. Within 2 months the seeds have lost their remaining radioactivity and are effectively inert.

  2. Radioactive Iridium Implant
    Used alone to treat more invasive but localised tumours without evidence of nodal metastasis. In some cases an implant is used in combination with external beam treatment to boost the dose to the site of bulky disease.

    Under general anesthesia, thin plastic catheters are placed in and around the cancer. The patient is placed alone in a shielded room and then Iridium-192 is loaded into the catheters either manually or by remote control.

    Treatment duration is usually 3 to 7 days, following which the plastic catheters are removed under mild sedation.

  3. External Beam Irradiation

    This is used for lesions which are not felt to be suitable for an implant such as floor of mouth cancers that have extended marginally onto the alveolar ridge or when it is desirable to treat the regional lymph nodes. The standard course of treatment for early cancers usually lasts for 5 weeks and is given on an outpatient basis.

Locally Advanced Lesions (more than 4 cm or with bone invasion)

T3 T4 N0 N1 N2 N3 M0

For these advanced lesions the primary curative treatment is usually a combination of surgery and radiation. The decision for each individual patient depends on the specific clinical situation, the patient's overall general condition and the extent of the disease. Bone involvement and/or the presence of regional lymph node metastases may indicate primary surgical treatment. Patients who are unfit for surgery or deemed unresectable are usually treated by radiotherapy. If the patient is still suitable for radical treatment, accelerated radiotherapy with twice daily treatment or radiation may be used with concurrent chemotherapy.

Major resections of advanced oral cavity tumours require the specialized skills of individuals with experience in head and neck surgical oncology including primary reconstructive techniques. The surgical emphasis is to cure the cancer and obtain the best functional and cosmetic results

6.7 Oropharynx

Updated: May 2003

Anatomical Sites of the Oropharynx are:

  1. Base of the tongue (posterior third of the tongue), vallecula, and anterior surface of the epiglottis
  2. Posterior wall of the oropharynx
  3. Soft palate and uvula
  4. Tonsils and faucial pillars.

1. Base of the tongue (posterior third of the tongue), Vallecula and Anterior surface of the epiglottis and Posterior wall of the oropharynx

Early tumours T1 T2 N0 are treated by external beam irradiation including the adjacent lymph node bearing areas bilaterally. Localized accessible tumours of the lateral base of tongue may be suitable for a radioactive implant boost.

Advanced tumours T3 T4 N0 N1 N2 N3 should be considered for a twice daily radiotherapy schedule or concurrent chemotherapy with radiotherapy if the patient is fit.

Surgical resection with appropriate reconstruction followed by postoperative irradiation may be indicated for advanced disease. Resection of an extensive base of tongue carcinoma may require a total glossectomy and a total laryngectomy to prevent tracheal aspiration. Radiotherapy alone is used if the patient is in poor condition.

2. Soft Palate and Uvula

Radiotherapy is the treatment of choice for most cancers. Some localized superficial lesions of the soft palate and uvula may be suitable for a gold seed or iridium implant, or local excision. The remainder and those with lymph node metastases are treated by external beam irradiation.

3. Tonsils and Facial Pillars

Early tumours are treated by external beam irradiation. Well lateralized lesions are usually treated with a unilateral technique to spare the contralateral salivary glands. Larger tumours may be suitable for a twice daily radiation schedule or radiation with concurrent chemotherapy.

More advanced tumours should be considered for combined treatment with surgery and radiotherapy. If the patient is not fit for surgery or is unresectable but still suitable for radical treatment, accelerated radiotherapy with concomitant boost or concurrent chemotherapy with radiotherapy can be employed. Radiotherapy alone is used if the patient is in poor condition.

6.8 Nasopharynx

Updated: May 2003

General Information

The majority of tumours are carcinomas. Classical Nasopharyngeal carcinoma has been classified into three types by the WHO:

Type 1: Keratinizing squamous cell carcinoma

Type 2 Nonkeratinizing /poorly differentiated carcinoma

Type 3 Undifferentiated/anaplastic carcinoma.

Type 1 may have an association with cigarette and alcohol consumption and accounts for up to 30% of cases in non-endemic areas and < 5% in endemic areas.

Other less common tumour types include minor salivary gland tumours, sarcomas, lymphomas, plasmocytomas and angiofibromas. The management of these tumours is individualized.

Common presenting symptoms include unilateral hearing loss, a mass in the neck, nasal stuffiness/bleeding, headache and cranial nerve palsies.

Nasopharyngeal carcinoma may spread by direct extension into neighbouring structures. Superior spread into the foramen lacerum or foramen ovale often results damage to cranial nerves VI, V and occasionally III. Posterolateral spread into the parapharyngeal space is common and may lead to lower cranial nerve palsies.

The nasopharynx has a rich supply of lymphatics and lymph node metastases are common at presentation. Nodes that are commonly involved include the jugulodigastric, the posterior cervical and retropharyngeal lymph nodes.

Systemic dissemination (15 – 20%) is more common at presentation than other head and neck cancers. It is more common when there is extensive nodal disease and consideration should be given to a metastatic workup at presentation if there is a high index of suspicion of distant disease.

The staging system employed is the UICC 1997 System.

Nasopharynx (T)

T1 Tumour confined to the nasopharynx

T2 Extension to the oropharynx or nasal cavity

T2a without parapharyngeal extension

T2b with parapharyngeal extension

T3 Bone invasion and/or paranasal sinuses

T4 Cranial nerve palsies, extension to the infratemporal fossa , intracranial extension etc

Lymph nodes (N)

N1 Unilateral lymph node (s)< 6 cm above supraclavicular fossa

N2 Bilateral lymph nodes < 6 cm above supraclavicular fossa

N3 Unilateral or bilateral node(s) > 6 cm or nodes in the supraclavicular fossa

Distant Metastasis

M0 No evidence of distant metastasis

M1 Distant metastasis

Patient Assessment

The assessment of the tumour and regional lymph nodes is based on physical examination, endoscopy and appropriate radiological investigation.

Imaging of the nasopharynx and its environs is best carried out with either CT scan and/or an MRI. In both cases axial and coronal images are required for optimal evaluation. CT is better for determining the presence or absence of bone invasion. MRI is particularly helpful in differentiating between inflammatory change and tumour and for evaluating intracranial extension.

Other radiological investigations include a chest X-ray, liver ultrasound if liver function tests are abnormal or there is advanced nodal disease and, a bone scan if there is bone pain, elevation of alkaline phosphatase or advanced nodal disease. Other imaging modalities such as PET may be cost effective in detecting systemic metastatic disease for those at high risk.

Treatment

Radiotherapy

Radiotherapy is the primary treatment modality for carcinoma of the nasopharynx. The precise volume to be irradiated will be defined for each patient. In general it will consist of the tumour with a margin, involved lymph nodes and lymph nodes at risk of disease. The nasopharynx is a midline structure and there is a high incidence of bilateral nodal involvement hence both sides of the neck are usually irradiated. Because of the juxtaposition of the tumour volume to a number of critical number structures (optic nerve, chiasm, temporal lobe, brain stem, spinal cord etc), meticulous treatment planning is essential. The tumour and nodal chains are irradiated en-bloc usually through opposed lateral fields although the precise field arrangement will depend on the configuration of disease. A shrinking field is used and shielding is introduced so that the dose to critical structures dose not exceed organ tolerance.

Reference:

  1. Lee et al Nasopharyngeal carcinoma: Local control by megavoltage irradiation. The British Journal of Radiology 1993;66:528-536.

There is no evidence to support the use of altered fractionation schemes (accelerated/hyperfractionated radiotherapy) outside a randomized trial.

Escalation in dose with the use of either stereotactic radiotherapy or brachytherapy is not recommended routinely but may be considered in selected instances.

Chemotherapy

Nasopharyngeal cancer is much more sensitive to chemotherapy than other cancers arising in the upper aerodigestive tract. It has been used in a number of settings. These will be discussed individually below.

Neoadjuvant (prior to definitive treatment)

There have been several Phase 2/3 studies evaluating chemotherapy given prior to and/or following radiotherapy The majority of the regimes were cisplatin based. Other active agents include 5-flurouracil,bleomycin, cyclophosphamide and adriamycin. In general these have shown increased toxicity, encouraging response rates but no increase in overall survival. this is not a recommended standard treatment at this time.

Concurrent/Adjuvant

A randomized trial comparing radiotherapy alone versus radiotherapy and concurrent cisplatin followed by adjuvant cisplatin/5-FU demonstrated in increase in 3 year relapse-free survival (24% versus 69%) and overall survival at 3 years (47% versus78%). The radiotherapy (70 Gy in 35 fractions) was identical in both arms. These differences are significant. Concerns expressed about this study include the poor results in the radiotherapy alone arm and the high proportion of patients with type 1 (well differentiated squamous cell carcinoma) who are not well represented in populations where this disease is endemic. In addition the treatment delivery was limited /problematic in the patients in the combined arm. In the light of these concerns this treatment strategy has not as yet been adopted as a standard at BCCA. The BCCA is currently participating in a multicenter international trial in an effort to evaluate this treatment strategy further.

Reference:

  1. Al-Sarraf M et al. Chemo-radiotherapy versus radiotherapy in patients with advanced nasopharyngeal cancer: phase III randomized intergroup study 0099 .Journal of Clinical Oncology 1998;16:1310-1317

Adjuvant (following definitive treatment).

This has not been widely studied. One randomized trial using non-cisplatin based therapy did not show any benefit.

Reference:

  1. Rossi et al Adjuvant chemotherapy with vincristine, cyclophosphamide, and doxorubicin after radiotherapy in local-regional nasopharyngeal cancer:results of a 4-year multicenter randomized study. Journal of Clinical Oncology 1988;61401-1410.

Chemotherapy for metastatic disease

There have been several phase 2 studies employing a variety of active agents (cisplatin, bleomycin,methotrexate, 5-flurouracil, gemcitabine) encouraging response rates are encountered. Median survival is between 10 = 16 months. Occasional long-term survivors are encountered.

References:

  1. Siu et al Phase I/II study of the CAPABLE regimen for patients with poorly differentiated carcinoma of the nasopharynx. Journal of Clinical Oncology 1998;16:2514-2522.

  2. Boussen et al chemotherapy of Metastatic and/or recurrent Undifferentiated nasopharyngeal Carcinoma with Cisplatin, bleomycin and Fluorouracil. Journal of Clinical oncology 1991;9:1675-1681.

Treatment of recurrence

Patients with local recurrence should be considered for salvage radiotherapy which may be curative. This may take the form of a gold seed implant or repeat external beam radiotherapy. Patients with a regional nodal recurrence should be considered for a neck dissection.

Reference:

  1. A Lee et al Retrospective analysis of patients with nasopharyngeal carcinoma treated during 1976-1985:survival after local recurrence. IJORP;1993:773-782.

6.9 Other Tumours

​Updated: May 2003

  1. Lymphoma:
    Full lymphoma work-up and appropriate treatment.

  2. Juvenile Fibroma:
    The treatment of choice of early lesions is surgical. Patients with unresectable disease should be considered for radiation therapy which offers an excellent chance of life long control of the disease.

  3. Plasmacytoma:
    The patients are seen in conjunction with the Lymphoma Clinic: solitary plasmacytoma should be treated by beam-directed megavoltage therapy

    Multiple myeloma involving the nasopharynx will require palliative beam-directed treatment with standard chemotherapy for multiple myeloma.

  4. Malignant Melanoma:
    These patients are seen in conjunction with the Melanoma Clinic: postoperative beam-directed megavoltage therapy is usually recommended.

  5. Soft Tissue Sarcoma:
    Radical surgical excision, where possible, followed by beam-directed radiotherapy to tissue tolerance levels.

  6. Adenocarcinoma:
    The radiotherapy treatment volume usually includes only the primary site and adjacent normal tissues.

6.10 Hypopharynx

​ Updated: May 2003

The anatomical sites of the hypopharynx are the pyriform fossae, postcricoid region and posterior pharyngeal wall. Most are squamous cell carcinomas.

T1-2 NO Lesions.

These will normally be treated by radiation with surgery for salvage of radiation failure.

T3-4 NO-N3 Lesions

These patients require a multidisciplinary assessment. Options include:

  1. Radiation using either a twice daily or concurrent chemotherapy-radiation regimen.
  2. Combined treatment with:
    1. preoperative radiation
    2. primary surgery with postoperative radiation

6.11 Larynx

​ Updated: May 2003

The majority of laryngeal tumours are squamous cell carcinomas. Rare tumours include minor salivary gland tumours, sarcoma and plasmacytoma.

Hyperkeratosis of the Vocal Cords

Hyperkeratosis of the vocal cords should be viewed with caution and all of these patients should have repeat microlaryngoscopy and excision if any abnormality persists.

Biopsy reports may be misleading because of sampling error. Many dysplastic lesions progress to malignancy.

Carcinoma in-Situ

All involved physicians must be aware of the high incidence of multicentric lesions and of co-existing invasive carcinoma in the larynx of these patients. Surgery usually involves stripping the cord or CO2 laser excision.

Radiotherapy is indicated for bilateral in situ disease or disease that recurs after adequate surgical treatment.

Squamous Cell Carcinoma of the Larynx

Early lesions T1 T2

Primary treatment is by radiation therapy. Partial or total laryngectomy is reserved for persistent or recurrent disease, although it may be an option in selected cases as a primary treatment.

Locally advanced T3 T4

These patients often require a combination of a planned course of radiation and surgery. Many patients may be curable by radiation or surgery alone and selection of the treatment modality in each patient will require a multidisciplinary assessment.

Nodal metastases

Nodal metastatic disease is common in all but cancers confined to the true vocal cords. A small single node located within the radiation field may be cured by radiation alone, but larger or multiple nodes will require a neck dissection.

Surgery for persistent or recurrent disease will require radical resection of the primary and neck dissection.

6.12 Nasal Cavity & Paranasal Sinuses

Updated: May 2003

Cancers of the maxillary sinus are the most common of the paranasal sinus cancers. Tumours of the ethmoid sinuses, nasal vestibule, and nasal cavity are less common, and tumours of the sphenoid and frontal sinuses are rare. The majority of tumours of the paranasal sinuses present with advanced disease. The cancers grow within the bony confines of the sinuses and often are asymptomatic until they erode and invade adjacent structures. Nodal involvement is infrequent. Metastases from both nasal cavity and paranasal sinus may occur, but most deaths are due to direct extension into vital areas of the skull or loco-regional recurrences.

Squamous cell carcinoma is the most frequent type of malignant tumour in the nose and paranasal sinuses (70%-80%). Inverted papillomas are distinct entities that may undergo malignant degeneration.

The importance of adequate pretreatment evaluation and staging, as well as the need for multidisciplinary pretreatment assessment must be stressed.

1. Patient Assessment

The assessment of the tumour is based on inspection, palpation, and direct endoscopy when necessary. The tumour must be confirmed histologically, and any other pathological data obtained on biopsy may be included. The appropriate nodal drainage areas are examined by careful palpation.

Many of these tumours obstruct the drainage of the superior sinuses, MRI is usually able to distinguish between tumour and retained secretions and is the scan of choice in the evaluation of these patients. CT is less effective in making this distinction and is often misleading. If a patient relapses, complete restaging must be done in order to select the appropriate additional therapy.

Staging of nasal cavity and paranasal sinus carcinomas is not as well established as for other head and neck tumours. Only the maxillary sinus and ethmoid sinus have a staging system (TNM) agreed on by the International Union Against Cancer (UICC).American Joint Committee on Cancer (AJCC).

2. Treatment Principles

Treatment of tumours of the paranasal sinuses and of the nasal cavity should be planned on an individual basis because of the complexity involved.

Except for T1 mucosal or early carcinomas of the maxillary infrastructure, the accepted method of treatment is a combination of radiation therapy and surgery. Routine radical neck dissection or elective neck irradiation is recommended only for patients presenting with positive nodes.

Radical craniofacial surgical resection may be possible in selected advanced clinical situations if there is the potential for cure. This radical surgical procedure requires, however, the involvement of individuals with specialized expertise and should be performed in hospitals which have adequate support facilities.

3. Recurrent Paranasal Sinus and Nasal Cavity Cancer

Recurrent disease after surgery may be managed with radiation therapy or craniofacial resection with postoperative radiation therapy. Those recurring after radiation therapy may be considered for craniofacial or salvage resection, if indicated. Otherwise, chemotherapy should be considered. Chemotherapy for recurrent squamous cell cancer of the head and neck has been shown to be efficacious as palliation and may improve quality of life and length of survival.

6.13 Salivary Gland

Update: May 2003

Tumours of the salivary glands, both major (parotid, submandibular and sublingual) and minor, comprise only a small minority (3%) of head and neck cancers (1). Of these, approximately 80% are classified as benign and 20% as malignant.

Pathology

Benign lesions include pleomorphic adenoma (mixed tumour), papillary cystadenoma lymphomatosum (Warthin's tumour), benign lymphoepithelial tumour (Godwin's tumour), oncocytoma, papilloma, and monomorphic tumours.

Malignant lesions include mucoepidermoid carcinoma (low and high grade), malignant mixed tumour, adenoid cystic carcinoma, acinic cell carcinoma, adenocarcinoma, SCC, oncocytic cell carcinoma, clear cell carcinoma, lymphoma, melanoma and metastatic lesions.

Presentation

Benign lesions are often present for many years with little change. A malignant lesion often presents as a rapidly growing mass. Facial weakness, skin involvement, pain, adenopathy and speed of growth suggest malignant disease (2).

Workup

This should include history and physical, basic lab work (CBC, electrolytes, BUN, creatinine, LFT's), and imaging (CT of head and neck, Panorex, CXR). FNA is indicated in some circumstances, especially when one suspects malignant disease, or the patient is not a good surgical risk (3).

Staging

AJCC staging using TNM system.

Prognostic Factors

  • Stage
  • Grade: all malignant tumours are divided into low or high risk, depending on grade.

    "low risk" = low grade = low grade mucoepidermoid, acinic and oncocytic cell
    "high risk"= high grade = high grade mucoepidermoid and all the rest.

  • Adenoid cystic is subdivided histologically:
    • Tubular pattern: best prognosis
    • Cribriform pattern: intermediate prognosis
    • Solid pattern: worst prognosis

Management

Surgery: type of surgery depends on location, grade and adenopathy. For both benign and malignant lesions, en bloc surgery with margin and without spillage.

  • Low grade: superficial parotidectomy, sparing 7th nerve.
  • High grade, deeply invasive or nerve involvement: sacrifice nerve to get good resection and use sural nerve for grafting.

Radiotherapy: indications (4):

  • Primary treatment: only when patient medically unfit or refusing surgery.
  • Adjuvant treatment for both benign and malignant lesions:
    • Benign: recurrent disease, tumour spillage, narrow margin or enucleation.
    • Malignant: depends on risk:
      • Low grade, no radiation unless tumour spillage, positive margin, gross residual disease, recurrence.
      • High grade, all require treatment.

Outcomes

Benign:

  • after narrow excision or enucleation, recurrence rate is 20% at 10-15 years without radiation, and 3% with radiation (5).

Malignant:

  • for low grade, 10 % recurrence if well resected and 20% if partial resection or biopsy only.
  • For high grade, 30-50% recurrence without radiotherapy, decreases to 10-15% with radiotherapy, but this is dependent on stage at diagnosis.

References:

  1. DeVita, V.T., et al, Cancer, Principles & Practice of Oncology, 5th Edition, Vol. 1, 29(4), p 830.

  2. Million, R.M, and Cassisi, N.J., Management of Head and Neck Cancer, A Multidisciplinary Approach, 2nd Edition, p 716.

  3. DeVita, V.T., et al, Cancer, Principles & Practice of Oncology, 5th Edition, Vol. 1, 29(4), p 836.

  4. DeVita, V.T., et al, Cancer, Principles & Practice of Oncology, 5th Edition, Vol. 1, 29(4), p 836.

  5. Million, R.M., and Cassisi, N.J.,Management of Head and Neck Cancer, A Multidisciplinary Approach, 2nd Edition, p730.

6.14 External Auditory Canal & Middle Ear

Updated: May 2003

These tumours require an adequate radiological investigation to determine the real extent of the disease prior to any definite treatment as often they are more extensive than clinically apparent.

1. External Auditory Canal

Surgery

A sleeve resection and a skin graft are occasionally possible for "in situ" and early lesions but have limitations related to the ill-defined boundaries of the tumour, and surgery may be incomplete.

A lateral temporal bone resection or subtotal temporal bone resection may be necessary in order to remove the tumour completely.

Radiation Therapy

External beam treatment may be considered as an alternative to surgery or used postoperatively when resection margins are close or uncertain. Treatment volume is designed to cover the potential areas of involvement while minimizing unnecessary irradiation to the adjacent vital organs (eye and brain). Treatment is usually prescribed post-operatively.

2. Primary Carcinoma Involving the Petrous Temporal Bone

Surgery

Subtotal or partial temporal bone resection followed by postoperative radiotherapy is the curative treatment standard whenever possible.

Radiation Therapy

External beam radiation is used when surgery is not possible and is usually not curative.

Glomus Tumours (Chemodectoma)

The primary treatment of these benign tumours when small and accessible (glomus tympanicum) should be surgical. Most conditions, however, require radical surgical approaches with significant morbidity in view of the tumour location in the temporal bone and proximity to the jugular vein and carotid artery.

Radiotherapy may be recommended larger glomus tumours (glomus jugularis) where surgery will be incomplete or where surgical morbidity is significant.

Lymph Node Metastases to the Neck Secondary to an Unknown Primary

Cervical lymphadenopathy is a common clinical problem that is usually associated with infection or inflammation. When this fails to respond to apparently appropriate treatment, malignancy should be suspected. Although many patients with head and neck cancer present with enlarged nodes in the upper two thirds of the neck, approximately five per cent will still have an occult primary after full clinical and radiological investigation. Excluded from this discussion are patients presenting with metastases in the supraclavicular fossa (who are likely to harbour a primary in the thyroid or below the clavicles) and those with known metastatic disease elsewhere.

Evaluation of the patient with enlargement of the neck node(s) should include:

  1. Full history, general clinical examination and a thorough examination of the head and neck
  2. If the clinical examination is negative, a fine needle aspiration biopsy should be performed
  3. Chest X-rays
  4. EB virus antibody titres (IgA ECA) in patients at high risk of nasopharyngeal cancer
  5. CT scan of the head and neck
  6. Examination under anesthetic and panendoscopy of the upper airways with esophagoscopy and bronchoscopy if clinically indicated or for patients with lymph nodes in the lower neck. Biopsies should be taken from sites likely to harbour the primary such as the nasopharynx, tonsils, base of tongue, lateral pharyngeal walls and pyriform sinuses.
  7. MRI may be considered in individual cases and PET has been reported to be helpful in some cases.
  8. If the above is negative or unsatisfactory, an excisional biopsy of the node metastases may be performed to obtain an adequate histopathological diagnosis prior to definite treatment.

Having established the diagnosis and completed the recommended work-up, subsequent treatment will depend on individual circumstances. Clinical experience and several publications have shown that this condition is potentially curable with survival rates similar to other head and neck malignancies. Radiation therapy is most commonly used for squamous cell carcinoma, but in the absence of randomised trials, optimal management continues to be debated.

Squamous Cell Carcinoma

In general, when the primary is thought to be in the adjacent upper airway, a course of radical radiotherapy will usually be recommended to include the likely primary sites and at least the ipsilateral neck. When there is a high probability of a primary in the nasopharynx - such as in Asian patients with poorly differentiated carcinoma in an upper neck node- bilateral neck irradiation is indicated. Subsequent CT scanning and surgical management of the neck will follow according to the usual guidelines for neck dissection.

Adenocarcinoma

It is usually assumed that these metastases have come from a primary salivary gland carcinoma and surgical treatment is recommended.

Follow-up

This should be along the same lines as for other head and neck cancers with particular attention to the early detection of potential emerging primaries.

6.15 Thyroid Malignancies

Updated: 15 September 2004

Any disease of the thyroid gland can manifest as an apparent solitary nodule and as such become a clinical problem for the physician. While carcinomas of the thyroid are uncommon and account for only 1% of all malignancies, an adequate initial pathological diagnosis is essential for the successful eradication of the disease.

Although surgery is the basic treatment for cancer of the thyroid, the initial assessment, treatment planning and subsequent follow-up requires the active involvement of pathologists, internists and oncologists.

Prognostic Factors

The size of the primary tumour and the lymph node involvement (staging) are important prognostic factors but less significant than the age at diagnosis, sex, pathological differentiation of the tumour, and the completeness of the surgical excision. Most cancers are derived from the epithelial cells of the thyroid follicles and are well-differentiated papillary, follicular or mixed adenocarcinomas (75%). Cancer of the thyroid in the young (under 40 years of age) is usually well-differentiated and the overall prognosis is excellent. On the other hand, anaplastic carcinomas (l5%), particularly in older patients, have a significantly poorer prognosis and are rarely cured.

The pathological assessment of the thyroid tumours is of paramount importance as it will not only give the degree of differentiation of the tumour but will assess multicentricity, the extent and site of nodal involvement and the completeness of the surgical resection.

1. Surgery

Appropriate thyroidectomy and surgical removal of lymph nodes containing metastatic cancer remains the basic treatment for patients with thyroid malignancy. The surgeon undertaking surgical treatment in such patients should be prepared to perform total or near total thyroidectomy when indicated and be competent to deal appropriately with lymph node involvement. The first surgical procedure is unquestionably the key to cure and when incomplete removal necessitates further procedures, the morbidity increases significantly.

In the majority of patients, the diagnosis of malignancy should have been made or been strongly suspected prior to the surgical procedure. The methods of diagnosis have been outlined. Open biopsy for diagnosis is rarely indicated. It is probably to the patient's benefit if the surgeon has immediate rush diagnosis by a pathologist available at the time of thyroid surgery but it is not essential.

Types of Thyroidectomy

The minimal procedure for a solitary lesion confined to one lobe is a total lobectomy which includes the isthmus and anterior aspect of the contralateral lobe. This necessitates early identification of the recurrent laryngeal nerve with careful preservation. The superior pole vessels should be ligated well above the upper pole margin to ensure complete removal of thyroid tissue. If significant removal of the contralateral lobe will also be necessary, the parathyroid glands should be identified and protected. Careful evaluation by palpation of the thyroid is mandatory. Careful search for lymph nodes in the area must be made and all obvious nodes removed, (see paragraph on lymph nodes). In most cases more extensive thyroidectomy is needed. The type of thyroidectomy will depend upon the histological type of the malignancy, the size of the primary, and lymph node involvement. If strap muscles are adherent to the thyroid gland, they should be widely removed and left attached to the tumour. If the surgeon, on dissecting the malignant thyroid gland from the trachea, suspects there may be further tumour which is non-removable, a biopsy of the paratracheal tissue beyond the resection line should be taken and appropriately labelled. This can assist any decision for adjuvant therapy.

Conventional Radical Neck Dissection

Patients are still seen with metastatic lymph node involvement invading the jugular vein, sternomastoid muscle, etc. These patients require a classical radical neck dissection with the sacrifice of muscle and vein. Morbidity, however, is low. If the surgeon encounters areas where he suspects incomplete removal deeply, appropriate marking of the area will assist the radiation oncologist in postoperative therapy. Patients with lymph node involvement in medullary carcinoma should have a radical neck dissection.

Well Differentiated Papillary and Mixed Papillary-follicular Carcinoma

In patients with a solitary nodule, confined to one lobe and with no lymph node metastases evident, surgical treatment as described above will be sufficient. If there is evidence of multifocal disease, even in one lobe, a near total thyroid lobectomy should be performed on the contralateral side, leaving only a small rim of tissue posteriorly for added protection of the parathyroids. If at the time of diagnosis there is clinical and pathological involvement of lymph nodes, even from an apparent solitary nodule in one lobe, the more extended surgery with near total thyroidectomy is indicated. This will facilitate and reduce the morbidity of subsequent radioactive iodine therapy which is indicated in this situation. Both recurrent laryngeal nerves must be carefully dissected and every effort made to preserve some parathyroid tissue.

Pure Follicular Carcinoma

As these lesions are the most likely to benefit from radioactive iodine treatment of metastases, a near total thyroidectomy is indicated in all patients with planned radioactive iodine ablation of any residual thyroid tissue post-operatively. The patient with a well-differentiated lesion in which the pathologist has difficulty in differentiating between benign and malignant, can be treated by total lobectomy alone.

Poorly Differentiated Carcinoma

These frequently occur in older patients. If, on clinical assessment, the surgeon believes that thyroidectomy is possible, exploration should be carried out and thyroidectomy performed, but in the majority of patients resection is not possible. There is an occasional patient with papillary carcinoma and associated thyroiditis which masquerades as a poorly differentiated carcinoma. When possible, these patients should be identified and appropriate surgery performed.

Medullary Carcinoma

Total or near total thyroidectomy is the operation recommended for such patients.

Carcinoma Developing in Multinodular Goiter

The surgeon must remember that patients with large multinodular goiters may develop malignancy as well. Usually, palpation at the time of surgery will lead the surgeon to suspect a malignancy in certain areas of the goiter. Rush diagnosis can confirm this. A near total thyroidectomy is indicated.

Cervical Lymph Node Metastases in Thyroid Cancer

A significant number of patients with thyroid cancer present with metastatic lymph nodes in the neck and no palpable thyroid lesion. These patients have a so-called occult cancer. In many patients, preoperative ultrasound can confirm the presence of the primary lesion. All such patients require a near total thyroidectomy and appropriate node dissection.

Whenever patients have a thyroidectomy for malignancy, the surgeon should carefully search for potentially involved lymph nodes in the perithyroid area, even when no nodes have been clinically detected preoperatively. In such cases the most common sites for lymph node involvement are along the recurrent nerves and in the paratracheal space below the isthmus. It is worthwhile exploring the lower jugular area as well. All obvious nodes and especially enlarged ones should be removed and appropriately labelled as to site.

Lymph Node Involvement Other Than Perithyroid

The jugular lymph nodes are the next most likely site of lymph node involvement in the neck, followed by involvement of supraclavicular and posterior triangle nodes. The submandibular triangle is not frequently involved but if there is upper jugular involvement, submandibular triangle involvement is quite possible. Clinical evaluation of lymph nodes in the neck containing metastatic thyroid cancer is not accurate and the experienced surgeon is often amazed at the degree of involvement found at the time of node dissections. The type of node dissection will depend on the site involved and the character of the nodal involvement.

Picking Procedure

This localized removal of involved lymph nodes is justified if only perithyroid and lower jugular nodes are involved. It is not commonly indicated.

Functional and Radical Lymph Node Dissection

If nodal involvement clinically extends to the mid jugular level, a more complete lymph node dissection of the neck is indicated. In patients who have mobile nodes not adherent to or involving the jugular vein, and not invading adjacent muscle, a functional type of neck dissection is indicated. In this, the sternomastoid muscle is skeletonized but preserved and the jugular vein and accessory nerve left intact. With experience, extensive removal of lymph nodes is possible. In patients who have lymph node metastases at the time of initial diagnosis, the lymph node dissection should be done in association and in continuity with the thyroidectomy. Some patients, of course, develop their lymph node metastases at varying times following initial surgical treatment of the primary.

2. Radioactive Iodine

Radioactive iodine is recommended in the post-surgical treatment of well-differentiated thyroid carcinomas in the following circumstances:

  1. To ablate the remaining normal thyroid gland after sub-total thyroidectomy.
  2. To treat patients with metastatic or recurrent cancer which take up 131 I.
  3. To scan for and determine radioiodine uptake characteristics of metastases.

The indication for radioactive iodine ablation after subtotal thyroidectomy is related to the fact that the potential for recurrent disease is increased if: 1) the initial mass is greater than 2.5 cm; 2) the disease is multifocal; 3) the tumour is follicular; 4) the tumour has penetrated the thyroid capsule; 5) there is metastatic node disease; 6) the patient is older than 40 years of age.

Patients having any of these high-risk parameters should be recommended to have radioactive iodine ablation. The recommended dose of radioactive iodine should be enough to reduce the uptake to 1%. This can be usually accomplished with 50 millicuries which could be repeated if required.

Another indication for radioactive iodine is to treat metastatic, well-differentiated carcinoma of the thyroid. In these patients, radioactive iodine initially is prescribed to destroy the normal thyroid tissue. This will induce hypothyroidism. It is hoped that a high TSH will promote uptake in the tumour tissue and allow use of the radioactive iodine as therapy. When metastatic disease is present, larger doses of radioactive iodine are employed (100 to 200 millicuries). After the initial dose a body scan is done to determine if the metastatic tumour concentrates the 131 I. Thyroid replacement therapy is prescribed for three months and a repeat body scan is done using 5 millicuries 131Iodine with uptake measurements at 48 and 72 hours. If there is uptake in the tumour, a further l50 millicuries is given. If uptake does occur then the dose is repeated every three to four months until there is no further uptake in the tumour. Thyroid therapy is prescribed after each therapy dose of radioactive iodine.

When T4 is to be discontinued for scanning, T3 (liothyronine 50 mcg per day) should be prescribed for one month. It will then be discontinued for two weeks prior to the scan to achieve high endogenous TSH levels.

Recombinant TSH (Thyrogen) is an effective, though costly, alternative to thyroxine withdrawal for iodine scanning. It can be funded for appropriate patients via an Undesignated Drug Application to the Systemic Therapy Program.

3. Hormonal Treatment

Treatment with thyroxine is an important part of the management of patients with thyroid carcinomas. The aim of such treatment is to suppress TSH stimulation of the thyroid. This can be achieved by maintaining the serum T4 at the upper limit of normal. The starting dose of thyroxine is 1 mcg/lb/day. The level will equilibrate in one month and then the T4 and TSH can be checked. The dosage can then be altered to achieve the desired level.

4. External Irradiation

While surgical resection is the main treatment for cancer of the thyroid gland, external irradiation has a definite role as an adjuvant to surgery or as treatment in the following circumstances:

  1. As an adjuvant treatment following surgery and radioactive iodine ablation when the surgical resection has been incomplete and residual microscopic or macroscopic disease is left behind which does not take up the radioisotope.
  2. As a palliative treatment for inoperable unresected tumours or anaplastic carcinomas.
  3. As a palliative treatment of symptomatic metastases.

5. Chemotherapy

Metastatic thyroid carcinoma may be an indolent disease, especially if the primary tumour was well differentiated. Treatment is palliative and cytotoxic chemotherapy should be reserved for patients whose symptomatic disease cannot be controlled by localized irradiation. Anaplastic thyroid carcinoma is often locally or systemically aggressive and may require chemotherapy early to manage disease which cannot be managed with irradiation because of local recurrence or extensive metastases. Medullary carcinoma, when metastatic, may pursue either an indolent or aggressive course.

When cytotoxic chemotherapy is used for thyroid carcinoma, the intent is palliative and potential benefits must be weighed against known toxicity. Combinations containing doxorubicin and cisplatin are the most active with 30-60% response rate. A reasonable starting regimen of doxorubicin 50-60 mg per m² and cisplatin 40-50 mg per m² intravenously every 3-4 weeks may be tried then adjusted appropriately based on patient tolerance and tumour response. Second line chemotherapy is of no proven value.

6.16 Thyroid Cancer in Children

​Updated: May 2003

The general guidelines for adults are also applicable for younger patients. In general, younger patients have a more favorable prognosis. The concern that should exist is the use of radioactive isotope treatment or external irradiation in view of the long-term hazards related to radiation. The standard procedure should be a near total thyroidectomy to remove the disease completely and possibly avoid the need for adjuvant treatment. It follows that an experienced head and neck surgeon be involved in the initial surgical management of children with thyroid carcinoma.

7. Follow-up

Updated: May 2003

Squamous Cell Carcinoma

Curative treatment is still possible for many patients who develop recurrent disease either at the primary site or in the neck nodes. Therefore it is essential that patients with head and neck cancer are followed carefully after initial treatment. A large majority of recurrences will be detected in the first two years after treatment and therefore patients should be seen more frequently during this time, very few recurrences are found after three years. After five years the chance of recurrence of most squamous cell carcinomas is negligible, but the patients have a significant risk of developing a second primary in the upper aerodigestive tract. This risk is between 2 and 4% per year, and exceeds the risk of recurrence if patients are disease free more than three years after their initial treatment. It is important that patients are informed about possible symptoms – such as persistent hoarseness, pain, dysphagia or bleeding and or enlarged lymph nodes - and told to report them in a timely fashion rather than wait until their next appointment.

Patients should be followed by someone with the equipment and skills to examine the areas in question. This usually means that patients will be seen either in the head and neck clinic at a cancer centre, or by their otolaryngologist, or, preferably, alternate between the two.

Follow-up Schedules for Squamous Cell Carcinoma

Patients should be seen at monthly intervals until the acute radiation reaction has subsided and the epithelium has healed. If there is any residual mucosal abnormality or undue delay in resolution of the radiation reaction, biopsy should be considered.

Patients with nodal disease prior to treatment should have a CT scan approximately 6 weeks after the completion of radiotherapy.

When the mucosa has healed and, where appropriate, a follow-up CT scan is negative, patients should be seen at 2 monthly intervals until 2 years after treatment. Thereafter they should be seen at 3 monthly intervals for the next year. There is no evidence that routine follow-up beyond three years improves prognosis, but it is most important that patients are told of the risk of a second primary tumour and encouraged to report any new symptoms. The risk of a second primary carcinoma is highest in those who continue to smoke.

Nasopharyngeal Carcinoma

Similar schedules to those for squamous carcinoma apply with the exception that late recurrence is more common in patients with nasopharyngeal cancer so follow-up is recommended for the first seven years after treatment.

Tumours of Major and Minor Salivary Glands

Once the radiation reaction has healed, patients should be seen 3 monthly for 2 years then 6 monthly to five years. Clinical examination is sufficient for most patients, but for patients with tumours that are not accessible for palpation – such as those in the deep lobe of the parotid and some minor salivary gland tumours – should have CT scans periodically. Some of these tumours – such adenoid cystic carcinomas – may recur many years after their initial treatment and symptoms should be investigated as appropriate for the individual circumstances.

Thyroid Carcinoma

Initial follow-up is usually undertaken by an endocrinologist or surgeon or at a cancer centre or on an alternating basis. Thereafter most patients are referred back to the care of their family doctor. The recommended schedule is a visit every three - four months for the first two years. If there is no evidence of recurrence, six monthly for the next two years, with annual visits thereafter. Iodine scanning is usually continued until there is no evidence of uptake in the neck or elsewhere and then only repeated if the thyroglobulin starts to rise or recurrence or metastasis is detected clinically. Examination should include the thyroid bed and the neck nodes and any other symptomatic areas.

Investigations should include Thyroglobulin and TSH. T4 should also be measured periodically to ensure that serum thyroxine levels are not significantly elevated as this is associated with excessive loss of mineral from the bones.

Serum Thyroglobulin

This is a useful marker in many patients with papillary or follicular carcinoma. After total thyroidectomy and 131Iodine ablation of any residual thyroid tissue, the thyroglobulin should be at or below the lower limit of the detectable range. The thyroglobulin assay may be affected by the presence of antithyroglobulin antibodies. If present, the level of these antibodies should fall slowly after thyroidectomy and ablation, a rising titre of antibodies should raise the suspicion of tumour recurrence.

Thyroglobulin is most sensitive when the TSH is very high (such as after thyroxine withdrawal prior to an iodine scan) and values above 10 suggest recurrent or metastatic disease. Thyroglobulin levels when the patient has a low TSH are not directly comparable to those taken when the TSH is significantly elevated, but rising values in specimens taken under the same conditions suggest recurrence and are an indication for an iodine scan.

Anaplastic Carcinoma

The disease is known to progress rapidly and most patients are treated palliatively. In those who have been treated for cure, it is unlikely that recurrence will be curable. Follow-up schedules will depend on the individual circumstances.

Medullary Carcinoma

The follow-up schedule will be the same as for those with differentiated carcinomas. Laboratory investigations should include serum calcitonin and the patient's relatives should be screened for multiple endocrine neoplasia. In some patients radionuclide scanning may be of benefit follow-up.

SOURCE: Head & Neck ( )
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