Abstract
Recently, the lives of the Japanese people have been affected by the rapid increase in the incidence of colorectal cancer, and advances in the treatment and prevention of this disease are urgently needed. Many epidemiological studies have demonstrated that physical inactivity, a Western-style diet and subsequent obesity increase the risk of colorectal cancer. Furthermore, it is noteworthy that obesity, especially visceral fat accumulation, induces the abnormal secretion of adipocytokines, which are secreted from adipose tissue. Epidemiological and molecular biological studies have shown an association between adipocytokines, such as adiponectin and leptin, and the incidence/progression of colorectal cancer. Thus, the mechanisms underlying the promotion of colorectal carcinogenesis by obesity have gradually become clear. Recently, studies concerning the chemoprevention of colorectal cancer have made progress, and it is desirable that safe and effective chemopreventive drugs are identified.
