Epidemiology of Cancer

Abstract Background Cancers are a large and heterogeneous group of malignant tumors that collectively accounted for approximately 600 000 US deaths in 2020; only heart disease claimed more lives. A large amount of knowledge has accumulated regarding the epidemiology of most cancer types, including their causes. Content The cancer types most frequently diagnosed among adults in most high-income countries are lung, colorectal, female breast, cutaneous melanoma, and prostate. In general cancer incidence and mortality is very low in children and adolescents, rising exponentially with increasing age during adulthood. There is marked international variation in the incidence of most cancers. The most important causes of cancer are tobacco use (primarily cigarette use), excess alcohol consumption, obesity, lack of physical activity, diets low in fruits and vegetables, infectious agents, and sun exposure. Early detection can reduce the chances that a person will die of cancers of the female breast, uterine cervix, colon and rectum, lung, and prostate. Summary Although the most common cancers in the United States continue to have a substantial impact on public health, they are caused in whole or part by factors over which people and governments have control through choices they make. Among these are tobacco and alcohol use, obesity, diets low in fruits and vegetables and lack of physical activity, and sun exposure. Thus, a very large proportion of cancer’s impact could be ameliorated if more people avoided these exposures.