Exercise and Cancer

Abstract

There are an estimated 13.7 million cancer survivors in the United States. Persistent and late effects of cancer therapy have contributed to an increased risk for co-morbid illness and higher all-cause mortality. Physical exercise is a targeted rehabilitative intervention following cancer therapy and a health promotion risk reduction intervention for patients as they transition into survivorship. This chapter provides a brief overview of the research on exercise and cancer survivor outcomes with a specific focus on randomized controlled trials (RCT) on the effects of exercise on body composition and bone health. There were 17 RCT trials that were identified with body composition outcomes. There was no change in weight in 16/17 trials, 4 reported decreases in percent fat mass and 2 reported increases in lean mass. Eight exercise trials were identified with bone outcomes, two of which had pharmacologic comparison arms. These trials demonstrated preservation of bone in the intervention group compared with loss in the usual care or placebo control group. The majority of trials were with breast cancer survivors, the largest survivor group. Many are overweight or obese at diagnosis; weight gain continues to increase after therapy; and treatment is associated with bone loss. The findings of the 25 trials reviewed suggest that exercise maintains weight and bone mass in a high risk population. However, differences in design, measurement of body composition and bone mass and lack of targeted exercise to the specific outcomes warrants additional research to improve the quality of life for survivors.

Systematic review and meta‐analysis of experimental studies: In‐hospital mobilization for patients admitted for medical treatment

“…This study showed a modest magnitude of the effect of exercise in eight studies, suggesting that longer interventions may have lasting effects. Another systematic review by Knobf and Winters‐Stone () included 17 RCT aimed at determining the impact of moderate exercise (walking) in patients with cancer. The trials demonstrated preservation of bone and maintenance of weight in the intervention group compared with the control group.…”

“…The trials demonstrated preservation of bone and maintenance of weight in the intervention group compared with the control group. This review may be unique, considering that many patients with cancer are prescribed bed rest (Knobf & Winters‐Stone, ). Knobf and Winters‐Stone () found that older patients who walked were discharged earlier compared with those who did not exercise, similar to our results.…”

Practical clinical interventions for diet, physical activity, and weight control in cancer survivors

“…Although the vast number of studies in healthy populations indicate that, whereas caloric restriction is key to promoting weight loss, exercise and behavioral counseling to promote and support behavior change also are required to maintain weight loss long term; however, data are limited in cancer populations. Studies by Goodwin et al and others support the role that exercise plays in predicting weight loss at 1‐year follow up in cancer populations, and increased physical activity is recommended as an essential part of weight management in cancer survivors as it is for the general population. The need for exercise, however, may be particularly important for individuals with cancer, because there is sparse but concerning evidence that weight loss independent of exercise (especially resistance training) may promote sarcopenia or the loss of lean mass in an already compromised patient population.…”

Angiogenesis: focusing on the effects of exercise in aging and cancer

“…Despite the importance of angiogenesis, there has been little research on the relationship between cancer and exercise in terms of angiogenesis. While the effects can vary according to the type of cancer, exercise is effective in alleviating cancer 45 , 46 . A consideration of the mechanisms of cancer and exercise in terms of angiogenic factors indicates that both may induce angiogenesis, which contradicts the view that the effects of cancer are lessened by exercise 47 , 48 .…”