General Information / Anatomy / Function / Statistics

• The larynx, or voice box, is a complex anatomic structure located below the oropharynx and above the trachea. Most of it lies just behind the Adam's apple. The hypopharynx lies on each side of the larynx and behind it
• It is divided into three distinct and important sub-sites:

Glottis

• consists of the two "true" vocal cords, these narrow fibrous bands vibrate to produce sounds which are turned into speech by the muscles of the tongue, mouth and lips

Supraglottic larynx

• a larger area above the vocal cords which extends up to the base of the tongue. Structures within the supraglottic larynx include the false cords, ventricles, aryepiglottic folds, the arytenoids and the epiglottis (a flap that helps prevent food from going into the lungs when swallowing). The structures at the top of the supraglottis separate the air and food passages

Subglottis

• the area between the vocal cords and the top of the windpipe or trachea

• Nearly all cancers arise from the lining of the larynx and are squamous cell carcinomas, but they differ widely in their behavior depending on their site of origin
• Cancers of the glottis or true vocal cords tend to be low grade tumours which grow slowly and spread late
• Cancers of the supraglottic larynx region tend to be higher grade tumours which are often more aggressive with more rapid growth and a tendency to early spread to the lymph nodes
• Cancers of the subglottic region are rare, but they also have a tendency for early spread
• Early cancer of all sites within the larynx is highly curable
• For statistics, please click here
  • Note: Female larynx cancer statistics not published annually due to low rates

Symptoms / Signs

• The most common symptom of cancers of the glottis or subglottis is persistent hoarseness. This is a common symptom of non cancerous conditions, but persistent hoarseness lasting for more than a few weeks must be evaluated by a physician
• Change in voice quality
• Supraglottic tumours may present with a sensation of something sticking in the throat or with pain on swallowing or earache
• Cough is usually a late symptom
• Difficulty in breathing is also a late symptom
• The first sign of a supraglottic larynx cancer may be a lump in the neck

 

Etiology / Carcinogens / Risks

• Tobacco and alcohol use
• In the rare case of laryngeal cancer in non smokers, acid reflux (heartburn) appears to be a cause

Prevention

• Avoidance of tobacco products and excess alcohol
• Treatment of acid reflux

Diagnosis / Staging / Grading / Types

• Diagnosed in the office by examination with a mirror (indirect laryngoscopy) or a fiberoptic telescope (endoscope)
• Confirmed by biopsy
• The physician will assess the extent of the primary tumour and the mobility of the involved portion of the larynx
• Appropriate scans and X-rays depending on site and extent

Treatment

Glottis

• Early cancer of the vocal cords is highly curable
• Over 90% of early tumours can be cured by radiation therapy alone
• Surgery is used later if the tumour recurs
• Certain selected early tumours can be treated by limited surgical procedures including partial removal of the larynx or destruction of the tumour using laser surgery
• Laser surgery is becoming increasingly common and uses intense light beams to vaporize cancerous lesions. This preserves the voice to a great extent
• More advanced tumours may be best treated by total removal of the larynx, called laryngectomy
• Total laryngectomy is often curative but results in loss of normal voice
• One method of restoring speech is called tracheo-esophageal fistula where a air-opening is created from the upper end of the trachea into the esophagus
• Modern speech aids (prostheses) such as electrolarynx can also give very good "artificial speech"

Supraglottic larynx and subglottis

• Early cancer of the supra- and subglottic regions is managed with radiation therapy with generally satisfactory results. Because of their higher tendency to spread the cure rates aren't quite as high as for glottic tumours
• More advanced cancers are usually treated by laryngectomy or by combined radiotherapy and surgery
• These cancers have a tendency to spread to neck lymph nodes and so both radiation and surgery may be used on these nodes even if not enlarged
• Clinical trials are being undertaken with new radiotherapy regimens as well as with chemotherapy
• Following laryngectomy (total or partial) intensive training is required to enable the patient to speak and be understood. They are taught by skilled speech therapists and a variety of electronic and vibrating aids are available to suit individual patients
• Regular follow-up examinations are required

Revised April 1998