What is laryngeal cancer and its causes?
Laryngeal cancer is more prevalent in men, and 97% of diagnosed patients were smokers. Early detection of the tumor is key to improving the quality of life and survival of the patient.
Laryngeal cancer as its name suggests is cancer that affects the larynx. It is much more common in men, especially among smokers, since 97% of people who have a tumor of this type are tobacco users.
Anatomical description of the larynx
To better understand what laryngeal cancer consists of, we begin by making a brief anatomical description of the area it affects.
Together with the nasal passages, the paranasal sinuses and the nasopharynx constitute the upper airways. The area includes the base of the tongue to the windpipe. Taking the vocal cords as a reference, we can divide it into three parts:
- The upper part (supraglottis) where the epiglottis is located.
- The part of the vocal cords themselves (glottis).
- The subglottis.
These areas have different lymphatic vascularization and, therefore, a different lymph node dissemination pattern (which is the most frequent situation, even in early tumors).
The hematogenous spread (through the blood vessels) is uncommon and occurs in advanced tumors or those who relapse after a first surgical maneuver. The most frequent locations are the lung followed, by far, by the skeleton and liver.
Causes of laryngeal cancer
The causes of laryngeal cancer, as is usual in this type of pathology, are always multiple, and among them, we can highlight:
- Viral infections such as herpes papillomavirus (HPV) and Ebstein Barr virus (DNA from the virus has been isolated in up to 50% of cases). These viruses appear to inhibit specific tumor suppressor genes such as p53 and pRb (from retinoblastoma).
- Use and abuse of alcoholic beverages (especially in supraglottic tumors) found that up to 88% of the patients had a history of significant alcoholic intake). Although it is not very well known how alcohol works, it seems that it exerts an irritant action to which tobacco exerts its carcinogenic action.
- A diet high in animal fats and low in fruit and vegetables (rich in vitamin A and beta carotenes). The high intake of smoked, red meat, fried is also considered to increase the risk.
- Some occupational and hormonal factors (it is more frequent in men) and immunological.
- The most important is cigarette smoking. Epidemiological studies show that up to 97% of patients diagnosed with a laryngeal tumor were smokers (this does not mean that 97% of smokers will have laryngeal cancer).
- We know that a consumption greater than 40 cigarettes/day increases the risk 13 times compared to non-smokers and if this habit has been started before the age of 15, this number doubles. As with lung cancer, this risk remains for up to ten years after smoking cessation; second-hand smokers are also at risk of developing laryngeal cancer. Tobacco produces an increase in the keratin layers’ thickness, with subsequent hyperplasia, metaplasia, edema, and chronic inflammation of the submucosa. Several promoter chemicals have been identified in tobacco smoke, which also induces mutations in these tumor suppressor genes that we have seen.
