Chemoprevention strategies: the relevance of premalignant and malignant lesions of the upper aerodigestive tract.

Patients with premalignant and malignant lesions of the upper aerodigestive tract have historically been the focus of chemoprevention trials within the United States. Experience with this population has formed the basis for trials involving other environmentally induced cancers such as lung and bladder. Given that head and neck cancer patients are at risk for second primary malignancies, prevention strategies can be directed towards decreasing mortality from these metachronous neoplasias. Validity of these strategies, including risk determination, intermediate endpoints, and preventive efficacy of single and combination agents, can be determined. Current limitations in chemoprevention trials involving these patients relate to the sporadic nature of the disease. In fact, the prevalence of oral premalignancy within the United States has not been clearly defined. Individual physician experience with this disease process is limited. Organizational efforts should therefore be directed towards facilitating clinical trials involving dentists, oral surgeons, head and neck surgeons, and other primary health care providers in the community. Risk factors which identify clinically defined normal or premalignant tissue at risk for malignant progression need to be better defined.