Colorectal cancer survivorship: movement matters

Abstract

Colorectal cancer survivorship begins at diagnosis and continues throughout life. After diagnosis, survivors face the possibility of second cancers, long-term effects of cancer treatment, and comorbid conditions. Interventions that can provide primary, secondary, and tertiary prevention in this population are important. Physical activity has been shown to decrease colon cancer incidence and recurrence risk as well as improve quality of life and noncancer health outcomes including cardiovascular fitness in colon cancer survivors. The data are less robust for rectal cancer incidence and recurrence, although improvements in quality of life and health outcomes in rectal cancer survivors are also seen. Potential mechanisms for this benefit may occur through inflammatory or insulin-like growth factor pathways. The issues of colorectal cancer survivorship and the impact of physical activity on these issues are reviewed, with discussion of possible biologic mechanisms, barriers to physical activity intervention studies, and future research directions for physical activity in this burgeoning survivor population.

Fig. 1

Hypothesized mechanisms of physical activity in colon cancer. Physical activity may block inflammatory pathways, resulting in downregulating nuclear factor kappa B (NF-κB)/AKT signaling, decreased development of oxidative species, and less DNA damage. Physical activity may also affect the insulin-like growth factor (IGF) pathway and AMP kinase signaling, resulting in lower levels of cell proliferation and increased apoptosis. The effect of physical activity on cycloxygenase-2 (COX-2) and prostaglandin E2 (PGE2) levels is unclear (–50, 54). IGFBP, IGF binding protein; iNOS, inducible nitric oxide synthase; APC, adenomatous polyposis coli.