Obesity and breast cancer: Adipose tissue, adipocytokines, chronic inflammation, and hypoxia

Abstract

Obesity that has represented defense and warfare in the stone age and beauty, success, authority, and welfare in the middle ages, has now turned into a chronic and undesirable low-grade inflammatory disease that adversely affects the lifespan and quality of life. It results in serious complications such as Type 2 diabetes, cardiovascular disease, and cancer and is considered a pandemic all over the world. Chronic inflammation in obesity is attributed to an increase in the release of pro-inflammatory factors. This makes it a risk factor for many types of cancers, such as colon, gastric, breast, and prostate carcinomas, suggesting a cause and effect relationship between obesity and cancer. These proinflammatory factors act as signal transducers for tumor growth and progression. In recent years, animal studies have shown that adipocyte hypoxia can result in tumor growth in adipocytes and stromal vascular tissue. However, the mechanisms associated with obesity and cancer are still not completely understood. In the present study, we discussed the relationship between inflamed adipose tissue and cancer in obese patients, together with the contribution of interaction between hormones, cytokines, growth factors, and angiogenesis.