According to the World Health Organization, every year about 3.4 million adults die of consequences related to overweight or obesity. People with a Body Mass Index above 30 are more likely to express certain diseases, including some types of cancer. In this narrative review, we assess the role of adipose tissue as a modulator of the endocrine system and facilitator of chronic subclinical inflammation. We discuss how obesity can induce a suitable micro environment for the development of tumors, mainly by enhancing the levels of oxidative stress and the concentrations of hormones such as leptin, insulin and prolactin. We conclude that all together, these factors increase the probability of cancer development.