(Voice Box or Laryngeal Cancer)
Laryngeal cancer is not as well known by the general public as some other types of cancer, yet it is not a rare disease. The American Cancer Society estimates that in 2012 there will be about 12,360 new cases of laryngeal cancer (9,840 men and 2,520 women) and about 3,650 deaths (2,880 men and 770 women). Even for survivors, the consequences of laryngeal cancer can be severe with respect to voice, breathing, or swallowing. It is fundamentally a preventable disease though, since the primary risk factors for laryngeal cancer are associated with modifiable behaviors.
Risk Factors Associated With Laryngeal Cancer
Development of laryngeal cancer is a process that involves many factors, but approximately 90 percent of head and neck cancers occur after exposure to known carcinogens (cancer causing substances). Chief among these factors is tobacco. Over 90 percent of laryngeal cancers are a type of cancer called squamous cell carcinoma (SCCA), and over 95 percent 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 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 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. 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 for laryngeal cancer include certain viruses, such as human papilloma virus (HPV), and likely acid reflux. Vitamin A and beta-carotene may play a protective role.
Signs and Symptoms of Laryngeal Cancer
Signs and symptoms of laryngeal cancer include: progressive or persistent hoarseness, difficulty swallowing, persistent sore throat or pain with swallowing, difficulty breathing, pain in the ear, or a lump in the neck. In addition, diminished appetite and weight is a worrisome accompanying symptom to the above.
Anyone with these signs or symptoms should be evaluated by an Otolaryngologist (Ear, Nose and Throat or ENT specialist). This is particularly important for people with risk factors for laryngeal cancer.
In the office, the ENT specialist will use a special camera called an endoscope to view the inside of the throat and the voice box (also called the larynx).
Treatment of Laryngeal Cancer
The two conventional treatments for vocal cord cancer are surgery, radiation therapy or combined chemotherapy and radiation therapy. In most circumstances, small and mid-sized vocal cord cancer can be treated through the mouth (trans-oral, or endoscopic) using a laser. Laser surgery has promising results and good voice outcomes.
While cure rates using radiation therapy can be as effective as for surgery, radiation treats the healthy parts of the larynx as well as those involved with cancer. For example, if a cancer involves only one vocal cord, laser surgery can preserve the other vocal cord completely, whereas the normal vocal cord tissue cannot be completely shielded from the effect of radiation therapy. In addition, radiation therapy can usually only be used once in the same part of the body, and it can be difficult to monitor for recurrence after a patient has received radiation. Finally, there can be substantial side effects (dry throat, difficulty swallowing, airway restriction, voice changes) from radiotherapy, which can be debilitating and progress with time.
As necessary, larger vocal cord cancers may require radiation therapy with chemotherapy and/or need to be removed by open surgery through the neck
Remember that this is a preventable disease in the vast majority of cases, because the main risk factors are associated with modifiable behaviors. Do not smoke and do not abuse alcohol!