Laryngeal cancer
Also called carcinoma larynx or throat cancer — when laryngeal tissue gives rise to malignant cells forming a tumour, most often squamous cell carcinoma.
What is cancer of the larynx?
Also called carcinoma larynx or throat cancer, it is the disease where the laryngeal tissue gives rise to cancer-causing (malignant) cells forming a tumour. The tumour commonly originates from the thin flat cells (squamous cells) in the inner lining of the larynx, therefore it is referred to as squamous cell carcinoma. Other types, such as adenocarcinoma, can also affect the larynx.
The larynx is a hollow organ made of cartilage and muscles, situated behind the tongue in the throat. It connects to the windpipe (trachea) below, humidifies inspired air, and contains the vocal cords that produce speech — hence its name, the voice box. Laryngeal cancer often obliterates the cavity of the larynx and affects vocal cord function.
What are the types of laryngeal cancer?
Based on the position of the vocal cords, the larynx is divided into three parts:
- Supraglottis — above the vocal cords
- Glottis — containing the vocal cords
- Subglottis — below the vocal cords
Laryngeal cancer is divided into the same three categories. Cancer of the glottis is the most frequent, followed by supraglottic tumours. Subglottic cancers are the least common.
Who is likely to get laryngeal cancer?
Risk factors include both extrinsic and intrinsic factors:
- Smoking and other forms of tobacco use (typically more than 8–10 years)
- Long-term heavy alcohol consumption
- HPV (human papillomavirus) infection
- Long-term acid reflux (laryngopharyngeal reflux)
- Exposure to heavy metal paints, asbestos or radiation
- Older age (over 55 years), male sex, and family history
Typically, a 60-year-old man who is a habitual smoker and/or tobacco user is most likely to have throat cancer.
What are the symptoms?
Symptoms vary with the part of the larynx involved. Glottic cancers being most common, the voice is affected in about 60–70% of cases. Patients usually present with two or more of the following:
- Voice change or hoarseness (or inability to speak) lasting more than 2 weeks
- A swelling or lump in the neck felt from outside
- Difficulty or pain while chewing or swallowing
- Constant ear pain that does not go away
- Slight difficulty in breathing
- Coughing up blood on more than one occasion
- Weight loss with or without loss of appetite
On examination the doctor may find a palpable neck lump, enlarged lymph nodes, or generalised paleness. Indirect laryngoscopy may or may not show a tumour; further diagnostic tests are then advised.
How is throat cancer diagnosed?
Depending on symptoms, signs and risk factors, a referral to an ENT specialist is often recommended. Common procedures include:
- Imaging — chest X-ray, CT scan and MRI
- Endoscopy — a thin flexible scope passed through the nose or into the larynx in the outpatient clinic
- Biopsy — a small piece of tissue taken under endoscopic guidance and studied under the microscope
- Fine needle aspiration — sampling an external lump with a needle in the outpatient setting
The “stage” of cancer describes extent and spread; the “grade” relates to severity or prognosis. Clinicians use the TNM system; for patients, stages are often simplified with a number system.
What are the treatment options?
Treatment aims to remove the tumour and prevent recurrence while keeping laryngeal function as intact as possible. Choice depends on tumour location, stage and grade, and the patient’s general health.
Major modalities are surgery and radiotherapy. Radiotherapy or chemotherapy may be given before surgery to shrink the tumour. In more advanced cases where surgery is not possible, chemoradiation may slow growth.
Supportive measures after medical advice can include dietary support, speech therapy, lifestyle modification, exercise, a balanced diet, and — critically — quitting smoking. These are palliative aids, not replacements for medical treatment.
What is the outlook?
Success rates for stage I and II disease are quite good, approaching 90% five-year survival; outlook for more advanced cases is more guarded. Where the larynx is removed entirely, newer aids such as a voice prosthetic valve can help restore near-normal speech.
Throat cancer is largely preventable and highly treatable if diagnosed early. Quitting smoking drastically reduces risk; avoiding risk factors and adopting a healthier lifestyle go a long way toward prevention.