[High-risk factors in the development of head and neck cancers]

It is considered that the great majority of head and neck squamous cell cancers are self-inflicted cancers. The main high-risk factor for squamous cell cancers of the oro-airway region is heavy smoking. Well-known habits of smoking include reverse smoking and betel nut chewing in South Asia. Tobacco smoking has distinct carcinogenecity as both an initiator and promoter. Also the risks associated with smoking and alcohol consumption are synergistic. There are many adjuvant carcinogens which act as promoting factors and which are also causes of cancer in the head and neck area. Distinct promotion factors are poor dental hygiene for mouth cancer, vocal abuse in laryngeal cancer, Plummer-Vinson's syndrome in post-cricoid cancer and chronic sinusitis in maxillary cancer. High-risk factors for carcinogenesis in the larynx are smoking (Brinkman index, over 600), heavy drinking, being over 50 years of age in males and anyone with a husky voice and abnormal sensation in the throat. In the piriform sinus, main risk factors of carcinogenesis are heavy smoking and drinking in males and in the post-cricoid area, those most at risk are female patients with Plummer-Vinson's syndrome. The prevention of head and neck cancers involves discouragement from smoking, and earlier detection of these cancers is very important. If early detection can be achieved, the highest cure rate among human cancers will be achieved.