THE ROLE OF EPIDEMIOLOGY IN CANCER PREVENTION

Cancer is a major cause of morbidity and mortality throughout the worl d. As the population lives to an older age, cancer incidence and morta lity are expected to increase because of the strong relationship betwe en cancer and advancing age. Epidemiology plays a key role in cancer p revention and control by describing the distribution of cancer and dis covering risk factors for cancer. Epidemiologic study designs include descriptive, ecologic, cross-sectional, and analytic (cohort, case-con trol, and intervention) studies. In the past 50 years, epidemiologic r esearch has helped to elucidate many risk factors for cancer. Lifestyl e factors such as smoking, diet, alcohol consumption, reproduction (pr egnancy, lactation, age at menarche, and menopause), obesity, and inac tivity have been suggested as the major contributors to the developmen t of cancer. Epidemiologists have demonstrated that cancer is largely an avoidable disease and estimated that more than two-thirds of cancer might be prevented through lifestyle modification. Epidemiologic rese arch is crucial to public health and cancer prevention. Individuals or communities at increased risk of cancer can be targeted for risk fact or modification, as well as for secondary prevention and chemopreventi on strategies.