Mechanistic Insight into Physical Activity Pleiotropy in Cancer Prevention

ABSTRACT Although improvements in prevention and screening have curbed the incidence of some cancers, the global burden of cancer is substantial and continues to grow. The sustained high prevalence of many cancers reveals the need for additional strategies to reduce occurrence. Observational studies have linked physical inactivity to the risk of 13 different cancers. Indeed, physical activity can reduce the occurrence of several cancers by more than 20%, whereas sedentary behavior can increase cancer risk. Thus, physical activity presents a viable lifestyle intervention to reduce the global burden of cancer, and current research efforts are focused on establishing the effective physical activity mode and intensity for cancer prevention. Preclinical cancer studies have provided insight into the mechanisms mediating these effects. There is growing evidence that physical activity can 1) reduce the risk of obesity and, by extension, metabolic dysregulation; 2) improve immune surveillance and reduce inflammation; 3) enrich the colonic environment by favoring beneficial microbes and reducing transit time; and 4) regulate sex hormones. This graphical review describes the current state of knowledge on the benefits of physical activity for cancer prevention and associated plausible mechanisms.