According to several recent studies, regular physical activity reduces the risk of death from all causes. However, studies are now emerging which demonstrate that increasing exercise after cancer diagnosis can reduce the risk of dying from cancer.
A recent study published in the journal Cancer Epidemiology, Biomarkers and Prevention assessed data from a cohort of 4,623 Swedish men derived from the National Prostate Cancer Register of Sweden who had been diagnosed with localised prostate cancer. The study investigated the effect of physical activity on mortality from all causes, as well as cancer-specific mortality. Inclusion criteria for the study included a serum PSA level of less than 20ng/mL, local tumor stage T1-T2, with no signs of metastasis and, being less than 70 years of age at the time of diagnosis.
A metabolic equivalent (MET) measurement was assigned to various forms of physical activity, to allow for a comparison between the men. The results of the study revealed a statistically significant difference in both overall and prostate cancer-specific mortality when comparing men for different amounts of physical activity. Higher mortality was observed in the men who were less active than those who had higher levels of physical activity. All forms of physical activity assessed (walking, bicycling, exercising, and household work) were associated with decreased mortality. However, only walking, bicycling, and exercising were associated with decreased prostate cancer-specific mortality. The rate of prostate cancer-specific mortality was up to 44% lower in men who had the highest level of physical activity.
Physical activity has also been assessed in regards to mortality following diagnosis with breast cancer. A review of 33 clinical studies also demonstrated that increased levels of physical activity had positive effects on breast cancer-specific mortality. The most common forms of physical activity assessed across the studies were aerobic exercise, resistance training, or a combination of the two. Again, physical activity was expressed in terms of metabolic equivalents (METs), and categorised as low, moderate, or vigorous activity. A significant association was found between increased physical activity and reduced mortality, which were also associated with increased physiological functions and alterations to metabolic markers. The greatest differences were visible when undertaking moderate to vigorous exercise, however there was no conclusive evidence to state that one type of exercise was better than another.
These studies demonstrate a benefit for those diagnosed with prostate or breast cancer to resume or initiate at least moderate forms of exercise to reduce their risk of cancer-specific mortality.
Bonn SE, Sjölander, A, Lagerros, YT,Wiklund, F, Stattin, P, Holmberg, E, Grönberg, H, Bälter, K. “Physical Activity and Survival among Men Diagnosed with Prostate Cancer”Cancer Epidemiology, Biomarkers and Prevention, Published Online First December 19, 2014; doi: 10.1158/1055-9965.EPI-14-0707
Image courtesy of Ambro at FreeDigitalPhotos.net
Written by Deborah Tallarigo, PhD