Endocrinology & Metabolic Syndrome
Open Access

Abstract

The Association between Obesity and Cancer

Melissa Kazan and Iskender Karalti

The prevalence of overweight and obesity has ascended from 15% in 1980 to 35% in 2005 and it will continue to increase in the future. Almost 22% of the whole cancer cases resulted from obesity and overweight according to the research done by Wolin et al. From multiple adequate evidences, it has been recorded about that obesity importantly causes a lot of types of cancer such as adenocarcinoma of esophagus, colorectal cancer, endometrial cancer (the lining of the uterus), post-menopausal breast cancer and renal cell cancer. Furthermore, obesity can lead to elevate other cancer risk the kind of gallbladder cancer, pancreatic cancer, hepatocellular cancer (subtype of liver cancer), thyroid cancer, cervical cancer (adenocarcinoma of the cervix), Non-Hodgkin Lymphoma (NHL), leukemia, multiple myeloma and malignant melanoma (a type of skin cancer). The attributable risks are 46% for endometrial cancer, 41% for gallbladder cancer between females, 40% for adenocarcinoma of esophagus between males, 37% for adenocarcinoma of esophagus between females, 27% for kidney cancer between females, 22% for kidney cancer between males, 22% for colon cancer between males, and 16% for breast cancer respectively in the 2008 metaanalysis. In addition, current investigations asserted that the attributable risks for all cancers are approximately 5% between males and 6% between females by associating with obesity and overweight in the UK. However, the mechanisms between cancer risk and obesity are uncertain and can be different according to the cancer types and also associated with the fat distribution in organism. Therefore, between some cancer types, waist hip ratio and waist circumference have been found to be more relevant than BMI because abdominal obesity can be diagnosed better with waist hip ratio and waist circumference. Generally, increased plasma insulin levels, elevated IGF-1 synthesis, reduced IGFBP-1 synthesis, and low plasma SHBG levels can be shown for mechanism of many of cancer types. In addition, adipokines can also be added in these mechanisms.