Association of Adipokines and Insulin, Which Have a Role in Obesity, with Colorectal Cancer

Obesity-related diseases are an important part of public health; and obesity is related with colorectal cancer. Adipocyte hypertrophy and visceral adipose tissue accumulation can cause adipocitis-related diseases and pathogenic adipocyte formation. Adipose tissue has a very important and active role in immune response formation. Cytokines/adipokines, which are secreted from adipose tissue, have an active role in communication between adipocytes and macrophages. Thus, visceral adipocyte is related with low-grade chronic systemic inflammation. Adipocytes have an important role in colorectal cancer pathogenesis because of proinflammatory cytokines, growth factors, and hormones secretion. Most highlighted cytokines are adiponectin, resistin, and ghrelin. Also, insulin resistance, glucose intolerance, increased plasma insulin levels, body mass index, insulin-like growth factor (IGF-1), glucose, and serum free fatty acids levels are considered to be related with colorectal cancer pathogenesis. Thus, in this review, we focus on the role of adipokines and insulin in colorectal cancer.