Type 2 Diabetes and Cancer: What Is the Connection?

Abstract

Epidemiological studies have demonstrated an association between type 2 diabetes and cancer. Type 2 diabetes is characterized by insulin resistance and hyperinsulinemia. Hyperinsulinemia may lead to cancer through insulin's effect on its cognate receptor and the insulin-like growth factor system. The effects of insulin and insulin-like growth factor I on cancer development and progression have been demonstrated in animal and human studies. Type 2 diabetes has been positively associated with cancers of the breast, colon, and pancreas. An inverse relationship has been observed between type 2 diabetes and prostate cancer, and this may be due to lower testosterone levels in men with type 2 diabetes. Medications used to treat type 2 diabetes may affect cancer cells directly or indirectly by affecting serum insulin levels. Hyperinsulinemia may be an important risk factor for cancer as well as a target for cancer therapy.

Body Mass Index and Risk of Gastric Cancer: A Meta-analysis of a Population with More Than Ten Million from 24 Prospective Studies

“…Obesity promotes GER and its transition to Barrett esophagus and thus esophageal adenocarcinoma and GCCs (47,48). In addition, accumulation of adipose tissue may upregulate the production of endogenous hormones, including sex steroids, insulin, and insulin growth factor-1, which may increase cell proliferation and impair apoptosis, and consequently favor preneoplastic and neoplastic cell growth (49). Obesity is a recognized proinflammatory state which leads to elevated levels of the proinflammatory cytokine, such as TNF and interleukin (IL)-6, which favor the development of cancer (50,51).…”

The balance between rRNA and ribosomal protein synthesis up- and downregulates the tumour suppressor p53 in mammalian cells

“…As we found a close relationship between rRNA synthesis upregulation and the reduction of p53 function, we believe that a reduced tumour suppressor activity of p53 might contribute to increasing the risk of cancer development in the above mentioned tissue lesions, in which a stimulation of rRNA synthesis occurred as a consequence of the increased cell proliferation rate (Montanaro et al, 2008). Furthermore, a reduced p53 activity consequent to rRNA synthesis upregulation might explain the increased risk of cancer onset in people with obesity, insulin resistance and type II diabetes, all conditions that are characterised by a hyperinsulinemic status with activation of the insulin and IGF-1 pathways (Renehan et al, 2006(Renehan et al, , 2008Frasca et al, 2008;Cannata et al, 2010), and also might be responsible for the worse evolution of cancer in patients with the above mentioned metabolic features, by reducing the efficacy of the anti-tumour therapies that activate p53 (Renehan et al, 2006(Renehan et al, , 2008Frasca et al, 2008;Cannata et al, 2010).…”

Family History Attributes and Risk Factors for Breast Cancer in Turkey

“…Genetic tendencies, family history, previous incidence of breast cancer, increased Body Mass Index (BMI), diabetes, heavy alcohol consumption (exceeding 45g per day), smoking, thyroid illnesses, radiation effects, socioeconomic factors, education levels, metabolic syndrome, sex hormones are some of the risk factors of breast cancer (Hunter, 2000;Hamajima et al, 2002;Lee, 2003;McTiernan, 2003;Korde et al, 2004;Cannata et al, 2010;Muller et al, 2011;Wong et al, 2011;Gadeyne et al, 2012;Domchek et al, 2013;Esposito et al, 2013;Hartz and He, 2013;Kutanzi and Kovalchuk, 2013;Ogrondik et al, 2013;Pfeiffer et al, 2013;Szychta et al, 2013;Warner et al, 2013).…”