Obesity and Cancer: What’s the Interconnection?

Abstract

Obesity is one of the most prevalent nutritional diseases, associated with chronic morbidity and mortality. Persuasive evidence indicates a striking association between obesity and incidence of common neoplasms, such as those of the esophagus, endometrium, kidney and breast in post menopause women, prostate in men, in addition to colon, rectum and bladder. Such an association has been supported by clinical and laboratory experiments on humans and animals, respectively. The findings have revealed that obesity and increased body fatness, in general and visceral adiposity, in particular, increase the vulnerability to develop different cancers. Although the impact of obesity in cancer progression differs according to the type of cancer, all the obesity-related cancers are centered around body adiposity. This review highlights the different hormonal, biochemical and molecular changes that might be involved in obesity-related cancers. Increased serum insulin, insulin-like growth factor, steroids "sex hormones" and the disturbances in adiponectin and leptin hormones are included. Biochemical and metabolic changes that mediate obesity-related carcinogenesis involving elevated oxidative stress and inflammation levels in the body and the concomitant increment in circulatory proinflammatory cytokines are discussed.

Enriched environment inhibits breast cancer progression in obese models with intact leptin signaling

“…Overweight and obesity have become a global epidemic affecting one third of the world's population (GBD 2015Obesity Collaborators et al 2017. Obesity is among the most common etiological factors for chronic diseases (Faris & Attlee 2015). Obesity further increases the risk and morbidity of many cancer types including breast cancer and has contributed to over 120,000 cancer-related deaths worldwide, increasing the risk of dying from cancer by 40-80% (Zheng et al 2011, Ogden et al 2014, Gallagher & Leroith 2015.…”