The role and efficacy of exercise in persons with cancer.

Improvements in cancer screening, diagnosis, and treatment have resulted in an increasing population of cancer survivors with impairments in physical function, cancer-related symptoms, and reduced quality of life. Exercise and physical activity have therapeutic value at multiple points along the cancer disease continuum, spanning disease prevention, treatment, survivorship, prognostic outcomes, and end-of-life issues. Molecular mechanisms for the influence of exercise in persons with cancer include altering tumor initiation pathways and affecting hormonal, inflammatory, immune, and insulin pathways. Physical activity has been found to play a role in the prevention of certain malignancies, including breast, colon, and other cancers. An increasing amount of evidence indicates that physical activity may affect prognostic outcomes in certain cancer diagnoses, especially breast cancer. Structured exercise and physical activity interventions can be helpful in addressing specific survivorship issues, including overall quality of life, cardiorespiratory impairment, cancer-related fatigue, and lymphedema. Exercise also may be helpful during the palliative care phase to alleviate symptoms and increase physical well-being. This article will familiarize physiatrists with the current state of evidence regarding the role and efficacy of exercise in persons with cancer.