[Chemoprevention in cancer of the head and neck].

The world-wide incidence of cancer of the head and neck of 500,000 cases/year has remained unchanged in recent years in spite of anti-smoking campaigns. Moreover, long-term survivors of cancer of the head and neck or of other respiratory and digestive tumors have a constant annual 5-7% risk of developing a second primary tumor in the same area. Lately, prevention programs have added synthetic and natural products to prevention programs for the purpose of reversing the progression of premalignant lesions to invasive cancer or reducing the probability of developing cancer in high-risk individuals. These products are known as chemoprevention agents. In the case of tumors of the head and neck, it is known that leukoplasia and erythroplasia are epithelial lesions on which invasive tumors may develop. Recent studies have demonstrated that the use of retinoids can produce regression rates over 60%, thus reducing the risk of secondary neoplasms of the respiratory and digestive tract by 35-55%. The current status of chemoprevention in head and neck cancer and the use of retinoids as chemoprevention agents in this type of neoplasm are reviewed.