The Role of Obesity in the Regulation of Immunosuppressive Cell Infiltration and Immunosurveillance in Cancers.

Cancer is a leading cause of death worldwide, causing about 10 million deaths annually. Obesity contributes to cancer progression by inducing chronic inflammation, immunosuppressive microenvironment, metabolic dysfunction, and therapeutic resistance. Accumulating evidence shows that obesity can advance the infiltration of immunosuppressive cells and ameliorate the function and cytotoxicity of tumor-killing cells such as natural killer cells, natural killer T cells, macrophages, and CD8 T cells in cancer patients, resulting in cancer progression. Understanding the molecular signaling pathways involved in obesity-induced immunosuppression and cancer cell proliferation enables us to screen new biomarkers for cancer early diagnosis and improve anti-tumor therapeutic efficacy in obese patients with cancer. In this review, we first review the molecular mechanisms by which obesity induces the immunosuppressive landscape in the tumor microenvironment and some key obesity-associated factors causing immunotherapeutic suppression and metabolic dysfunction. Then, the application of natural products in the treatment of obesity and obesity-associated cancers is summarized. In addition, we discuss the contradictory functions of obesity in cancer risk and treatment outcome. The potent roles of precision medicine and artificial intelligence in the management of obesity-related cancers are highlighted.