Obesity and cancer.

Epidemiological studies have suggested that obesity is associated with increased risk of several cancer types including colon, esophagus, breast (in postmenopausal women), endometrium, kidney, liver, gallbladder and pancreas. Suggested mechanisms include increased intake of potentially carcinogenic food ingredients along with excessive amount of calories, loss of cancer protective effects due to reduced physical activity, carcinogenic factors released from increased adipose tissue mass and "secondary" associations via "precursor" condition such as gallstones. The increased cancer risk in patients with obesity is a neglected topic which deserves more scientific attention. Because of its extreme chronicity and co-association with numerous other conditions true causality and underlying mechanisms are difficult to study. Nevertheless, a large body of literature is already available which provides concepts for future research.