Introduction
Larynx (voice box) cancer is a type of throat cancer – it is not as well known by the general public as some other types of cancer, yet it is not a rare disease. Even for survivors, the consequences of laryngeal cancer can be severe with respect to voice, breathing, or swallowing. It is fundamentally a preventable disease since the primary risk factors for laryngeal cancer are associated with modifiable behaviours.
Larynx cancer risk factors
Development of laryngeal cancer is a process that involves many factors, but approximately 90% of head and neck cancers occur after exposure to known carcinogens (cancer causing substances). Chief among these factors is tobacco. Over 90% of laryngeal cancers are a type of cancer called squamous cell carcinoma (SCCA), and over 95% of patients with laryngeal SCCA are smokers. Smoking contributes to cancer development by causing mutations or changes in genes, impairing clearance of carcinogens from the respiratory tract, and decreasing the body’s immune response.
Tobacco
Tobacco use is measured in pack-years, where one pack per day for one year is considered one pack-year. Two pack-years is defined as either one pack per day for two years, or two packs per day for one year (longer terms of pack years are determined using a similar ratio). Depending upon the number of pack-years smoked, studies have reported that smokers are about 5 to 35 times more likely to develop laryngeal cancer than non-smokers. It does seem that the duration of tobacco exposure is probably more important overall to cancer causing effect, than the intensity of the exposure.
Alcohol
Alcohol is another important risk factor for laryngeal cancer, and acts as a promoter of the cancer causing process. The major clinical significance of alcohol is that it potentiates the effects of tobacco. The magnitude of this effect is between an additive and a multiplicative one. That is, people who smoke and drink alcohol have a combined risk that is greater than the sum of the individual risks. The American Cancer Society recommends that those who drink alcoholic beverages should limit the amount of alcohol they consume, with one drink per day considered a limited alcohol exposure.
Other risk factors
Human papilloma virus (HPV)
HPV is known to cause changes in the cells of the cervix, which can lead to cervical cancer. The virus has a similar effect on the cells of the pharynx and larynx.
Acid reflux
Untreated laryngopharyngeal reflux can lead to sore throat, chronic cough, swelling of the vocal folds, the formation of granulomas and worsening of asthma, emphysema and bronchitis. Untreated acid reflux also may play a role in the development of cancer of the voice box.
Factors which may may play a protective role against laryngeal cancer
- Vitamin A
- beta-carotene
Larynx / throat cancer symptoms
The signs and symptoms of larynx cancer include:
- progressive or persistent hoarseness
- difficulty eating and drinking
- persistent sore throat or pain with swallowing
- difficulty breathing
- pain in the ear
- a lump in the neck
Anyone with these signs or symptoms should be evaluated by an Otolaryngologist (Ear, Nose and Throat specialist). This is particularly important for people with risk factors for laryngeal cancer.
Larynx cancer treatment
The primary treatment options for laryngeal cancer include surgery, radiation therapy, chemotherapy, or a combination of these treatments. Remember that this is a preventable disease in the vast majority of cases, because the main risk factors are associated with modifiable behaviour. Do not smoke and do not abuse alcohol.