Head and neck cancer remains a common cause of mortality and morbidity in the United States and throughout the world. In spite of advances in the management of patients with advanced disease, overall survival in this group remains poor. Furthermore, although
cancer mortality is lower in patients with early-stage disease, treatment results in significant morbidity, and these patients also face the risk of developing a second primary
tumor.
Chemoprevention is an innovative approach to decrease overall
cancer morbidity and mortality using substances that are capable of preventing
cancer progression.
Head and neck cancer is an excellent model for
chemoprevention, as its biology is consistent with the two concepts important for the development of
chemoprevention strategies: field cancerization and multistep
carcinogenesis. Several classes of compounds have been evaluated in
chemoprevention trials. The most frequently studied agents, the
retinoids, were found frequently to induce remissions in patients with
oral leukoplakia. Furthermore,
retinoids prevented progression to
malignancy in one randomized maintenance study. Other agents, including
beta-carotene and
vitamin E, have been found also to have activity in the management of
oral leukoplakia. However, the clinical role of chemopreventive agents in reducing
cancer mortality remains to be defined. Two studies, one in
head and neck cancer and one in
lung cancer, have shown the ability of
retinoids to prevent the development of second primary
tumors. Current large randomized trials are defining the effectiveness of these agents in reducing the mortality of aerodigestive tract
tumors in individuals at high risk.