Applied cancer prevention in practice.

In 1982, more than 125,000 cancer cases in the United States should be preventable. Every physician should advise all patients to eliminate all tobacco use, moderate alcohol use, avoid the use of drugs which are carcinogenic, minimize sun and x-ray exposure, maintain an ideal weight, and follow a "prudent" diet. Secondary prevention efforts would include the American Cancer Society recommendations for the early detection of cancer in asymptomatic persons. Worldwide epidemiologic studies suggest that over 80% of human cancer is due to factors in the environment such as diet, life style, and synthetic chemical contaminants, and perhaps a complex interaction of factors including genetic susceptibility. Current research into the mechanisms of carcinogenesis and in the role of diet in cancer cause, are underway. Chemoprevention of cancer may someday be possible using retinoids, vaccines, and diet alteration.