Does smoking cause lung cancer? Do high-fat diets increase the risk of breast cancer? Is arsenic in water linked to cancer? These are the kinds of questions that epidemiologists try to answer. In this month's Benchmarks, we talked to one of NCI's leading epidemiologists, Dr. Robert N. Hoover, about epidemiology in general, and about the research in NCI's Division of Cancer Epidemiology and Genetics (DCEG).

Epidemiology studies attempt to uncover the patterns and causes of disease in groups of people.

Epidemiologists gather data from a wide variety of sources in order to develop a comprehensive picture of health problems around the world.