Impact of obesity on the development of malignant tumors - metabolic syndrome

Obesity is a major and modifiable risk factor influencing both the incidence and prognosis of malignant tumors.

This review aims to summarize current evidence on the relationship between obesity, metabolic syndrome, and cancer risk, with a focus on underlying pathophysiological mechanisms, epidemiological data, and potential interventions. According to the International Agency for Research on Cancer, obesity is causally linked to at least 13 types of cancer, with risk increasing in proportion to body fat. Key mechanisms include chronic inflammation, hormonal activity of adipose tissue, hyperinsulinemia and insulin resistance, and alterations in adipokine profiles, all of which contribute to a tumor-promoting microenvironment. We discuss diagnostic criteria for metabolic syndrome and highlight the concept of metabolically healthy obesity, which carries a lower - but not negligible - risk of malignancy and represents a dynamic state that can progress to metabolically unhealthy obesity. Evidence also indicates that obesity negatively affects cancer recurrence and long-term outcomes, particularly in breast, endometrial, and colorectal cancers. Achieving sustainable, long-term weight reduction is challenging and requires a multidisciplinary strategy, incorporating pharmacotherapy, structured physical activity, behavioral interventions, and individualized nutritional counseling. Successful weight loss not only reduces the risk of developing cancer but may also improve prognosis and decrease the likelihood of recurrence. Therefore, integrating obesity management strategies into both primary and secondary cancer prevention, as well as survivorship care, should be considered a critical component of comprehensive oncology care.