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Biopsy Proven Malignant Melanoma

Revised September 2016​

Link to Skin Cancer Atlas

All patients are alerted that further surgery may be recommended, counseled about the possible appearance of a subsequent second primary and advised to avoid excess sun exposure and employ sun screen agents.

6.2.1 Management of the Primary Tumour

Documentation of the planned excision margin should be documented in the operative report. If SNLB is being considered, it would be advisable to perform the wide excision after the SLNB so as not to affect the accuracy of the SLNB.

1. Minimal Risk Non-Invasive Disease (Severe Atypical Nevi and Melanoma in-situ)

Lesions in this category include severe atypical nevi (with features suggesting possible in-situ melanoma), and in-situ melanoma. Such lesions are best excised with a 0.5 to 1 cm margin. In selected cases of lentigo maligna of the face, where the cosmetic results of surgery would likely be disfiguring, radical superficial irradiation is an alternative treatment.

2. Depth of invasion ≤ 1 mm 

For primary invasive melanoma 1.0 mm or less in thickness, wide excision with 1 cm margin is recommended.

3. Depth of invasion ≥ 1 – 2 mm

Based on consensus opinion, an excision margin of 1-2 cm is recommended with considerations given to tumour location, function and cosmesis.

4. Depth of invasion >2 mm

An excision margin of 2 cm is recommended. This can usually be accommodated with primary closure and an excellent cosmetic result. Primary closure is encouraged where possible. Flap repairs may assist in obtaining a good cosmetic repair. When a split thickness skin graft is used, the donor site should not be on the same extremity as the primary site. The excision should extend down to, and may include, the underlying fascia. Sometimes the recommended margin is not practical, particularly on the face, and narrower margins may be appropriate (consult BCCA oncologist). 

For tumours of the digits, amputation at the proximal joint is often indicated. Adequate excisions may require general or regional anesthesia. Consultation with the Melanoma Clinic may be especially helpful for problem cases. Where clinical or pathological features (eg neurotropic pattern) suggest local control may be problematic, wider margins may be recommended.

6.2.2 Management of Regional Lymph Node Basins

1. Prophylactic regional lymph node dissection (PRLND) is NOT recommended

In randomized phase III clinical trials PRLND has not been shown to be of therapeutic benefit (Balch, Ann. Surg 224:255; 1996). Routine PRLND is not recommended. Exceptions can be made if the primary tumour overlies the regional nodes, making future follow-up technically difficult.

2. Sentinel Lymph Node Biopsy (SLNB) and Completion Lymphadenectomy

While the status of sentinel lymph node has been found to be the best prognosticator, SLNB followed by completion lymphadenectomy, if the node is positive, has not been shown to improve overall survival. Thus, SLNB is considered a staging procedure which is optional. Whether early detection of occult nodal disease and completion lymphadenectomy provides greater regional control has not been definitively shown. 

SLNB is not recommended for patients with melanoma in situ or Stage 1A melanoma.

In patients with Stage 1B melanoma according to the 2009 AJCC Classification (i.e. T1b: melanoma ≤ 1 mm with presence of increased mitotic rate or ulceration), the benefit of SLNB for prognostication is untested. 

SLNB should be discussed with patients with Stage 2 or higher melanoma (melanoma >1 mm). Patients should be informed that it is an optional procedure which provides prognostic information but has not been shown to affect overall survival so that they can participate in the informed decision process.

SLNB should be performed in strict accordance with published standard technique. SLNB for head & neck melanomas is technically more challenging and requires special considerations and expertise. The BCCA melanoma group is available for consultations if necessary.

Patients with documented distant or regional metastasis should not undergo SLNB..

3. Therapeutic/Selective Regional Lymph Node Dissection

Patients with documented regional lymph node involvement (palpable or found with SLNB) should be considered for regional lymphadenectomy. The therapeutic benefit of completion lymphadenectomy for micrometastasis <0.2 mm (defined as metastatic focus found in SLNB) is controversial. Discussion of the management of these cases at BCCA Melanoma Conference is encouraged.  

Prior to surgical intervention, a CT scan of the abdomen/pelvis, chest +/- brain should be done to rule out metastatic disease. PET imaging may also be helpful in selected cases. In the setting of suspected distant metastatic disease, a regional lymphadenectomy is only recommended in selected cases, and consultation with a member of the BCCA Skin Tumour Group would be advised.

A full Level I-III dissection is recommended for axillary involvement. Groin involvement should be treated with an inguinal +/- iliac lymph node dissection (an iliac dissection is suggested if there is radiographic disease evident on CT or PET, and can be considered if there are greater than 3 inguinal lymph nodes involved). Head and neck melanomas should be treated with a level II-V dissection +/- level I / superficial parotidectomy depending on the location of the primary lesion.

4. Adjuvant Systemic Therapy

Interferon 

The role of adjuvant high dose interferon (SMAJIFN) has been studied extensively. A meta-analysis of individual patient data in 13 trials of interferon in different doses and schedules showed an improvement in overall survival by an absolute value of 3% (95% confidence intervals 1-6%) at 5 years. The benefit was unrelated to dose or schedule of interferon, or disease stage, primary site, age or gender (Wheatley et al, Proc ASCO 2007). SMAJIFN was introduced in BC after the first ECOG trial (E1684) showed a survival benefit (Kirkwood JM, et al. J Clin Oncol 1996; 14: 7-17). A subsequent analysis of this trial, presented in abstract form, demonstrated that with longer follow-up, the overall survival difference was no longer significant (p = 0.09). Individual trials of low dose interferon have not generally shown an overall survival benefit.

A more recent trial evaluated whether 1 month induction of high dose interferon was equally efficacious but less toxic than 1 month induction followed by 48 weeks of subcutaneous interferon (Pectasides et al, 2009 ). The event-free and overall survival was similar in the treatment groups, however, the induction dose of interferon used was only 15 million units (versus 20 million units), confounding interpretation of the study results. In addition, the results of the ECOG/NCIC study ME10 were recently reported (ASCO 2011) in which intermediate risk melanoma (T3/T4 and/or SNL positive) patients were randomized to the standard dose interferon or observation and the study was stopped prematurely due to a futility analysis. These results question the efficacy of interferon, however, if used, the one year course should be planned if tolerated. 

High dose interferon should only be offered after complete regional lymph node dissection and to patients with no residual disease.  Currently, the BCCA will fund interferon in patients with macroscopic nodal involvement that has been resected but other high risk cases can be considered on a case by case basis.  If radiation is planned, use of interferon should be avoided during radiation therapy and initiated after full recovery (4-6 weeks). Notable side effects for interferon include, severe flu-like symptoms, hepatic toxicity and neutropenia particularly in the induction phase. Depression and autoimmune phenomena have also been reported. Caution in elderly patients as this group has not been well studied. 

5. Radiation Therapy of Clinically Positive Lymph Nodes

Following lymph node dissection, high dose post-operative irradiation should be considered for any of the following: 

  • Microscopic identification of extranodal extension
  • Microscopic evidence of residual disease
  • Extensive nodal disease (where complete resection is unlikely)
    • One or more involved parotid nodes
    • Two or more cervical or axillary nodes
    • Three or more inguinal nodes
  • Resected, but bulky nodal disease with the largest mass >3cm diameter

Where regional lymph node disease is considered unresectable or inoperable for the patient, palliative radiation therapy may be considered to achieve local control.

Reference:

Burmeister BH, Henderson MA, Ainslie J, Fisher R, Di Iulio J, Smithers BM, Hong A, Shannon K, Scolyer RA, Carruthers S, Coventry BJ, Babington S, Duprat J, Hoekstra HJ, Thompson JF: Adjuvant radiotherapy versus observation alone for patients at risk of lymph-node field relapse after therapeutic lymphadenectomy for melanoma: a randomized trial. Lancet Oncol 2012; 13:589-97.

SOURCE: Biopsy Proven Malignant Melanoma ( )
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