Immune response modifiers and cutaneous neoplasia.

The incidence of skin cancer exceeds that of all other cancers combined, and the trend is increasing. Around 1.2 million new cases of skin cancer are seen annually in the United States alone. The 3 major types of skin cancer commonly seen, in frequency of occurrence, include basal cell carcinoma, squamous cell carcinoma, and melanoma. All are thought to arise from cells in the epidermis, and all are most often induced by exposure to ultraviolet radiation. There is a relatively low mortality rate from cutaneous neoplasia--approximately 10,000 per year--with the majority of deaths due to malignant melanoma. However, there is a significant morbidity from these tumors, making skin cancer a major public health problem.