The use of tobacco and/or alcohol is the most important contributing factor. Smokers and drinkers who fail to stop after treatment for a primary head and neck cancer are at significantly higher risk of developing another cancer. In fact, anyone with a head and neck cancer is somewhat more likely to develop another, although giving a drug called 13-cisretinoic acid to such patients has decreased the chance of their developing a second primary tumor .
• Poor oral hygiene, poorly fitting dentures or broken teeth cause chronic irritation of oral membranes.
• Wood dust inhalation (furniture workers) is related to nasal cavity cancer.
• Betel nut chewing (India) is related to cancer of the lining of the cheek.
• Increased carcinoma of nasopharynx among southern Chinese (environmental, not genetic).
• Epstein-Barr virus (EBV) infection is associated with nasopharyngeal cancer.
• Chronic iron deficiency in women is associated with tongue and postcricoid carcinoma.
• Nickel exposure is associated with paranasal sinus cancer.
