Chemoprevention of head and neck cancer.

Squamous cell carcinoma of the head and neck is the most common epithelial neoplasm of the upper aerodigestive tract and represents a major health concern in the United States and worldwide. Invasive squamous cell carcinoma is the end result of a multiyear, multistep process of accumulation of genetic and phenotypic damage. Chemoprevention is defined as the use of pharmacologic or natural agents that inhibit the development of invasive cancer whether by blocking the DNA damage that initiates carcinogenesis or by arresting or reversing the progression of premalignant cells in which such damage has already occurred. Chemoprevention is widely recognized as an important area of research in head and neck cancer. This article reviews the field of chemoprevention and recent advances in molecular epidemiology and genetics. Current clinical trials are described.