The role of epidemiology in cancer prevention

Cancer is a major cause of morbidity and mortality throughout the world. As the population lives to an older age, cancer incidence and mortality are expected to increase because of the strong relationship between cancer and advancing age. Epidemiology plays a key role in cancer prevention and control by describing the distribution of cancer and discovering risk factors for cancer. Epidemiologic study designs include descriptive, ecologic, cross-sectional, and analytic (cohort, case-control, and intervention) studies. In the past 50 years, epidemiologic research has helped to elucidate many risk factors for cancer. Lifestyle factors such as smoking, diet, alcohol consumption, reproduction (pregnancy, lactation, age at menarche, and menopause), obesity, and inactivity have been suggested as the major contributors to the development 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 research is crucial to public health and cancer prevention. Individuals or communities at increased risk of cancer can be targeted for risk factor modification, as well as for secondary prevention and chemoprevention strategies.