Physical activity for prostate cancer patients and its effect on tumors
Prostate cancer affects 15% to 20% of North American men. Living with a cancer diagnosis can be frightening and anxiety-inducing, but at the same time there exists a hopeful phenomenon called the “teachable moment.” The teachable moment describes cancer patients’ increased likelihood of accepting and acting on their health care provider’s lifestyle change recommendations because of their diagnosis. Vancouver Coastal Health Research Institute scientist Dr Ryan Flannigan is currently studying whether the teachable moment offers an opportunity to get prostate cancer patients into a regular exercise routine that may change the genetic expression and molecular makeup of their tumor and improve their diagnosis.
Dr Flannigan is a urologist focused on men’s health at Vancouver General Hospital and senior research scientist at the Vancouver Prostate Centre. He is also clinical lead of the Prostate Cancer Supportive Care Sexual Medicine Program, British Columbia, director of the Male Infertility & Sexual Medicine Research Program, and assistant professor in the Department of Urologic Sciences at UBC.
There have been a number of research studies on a population level that have identified the association between exercise and reduced risk for acquiring prostate cancer, prostate cancer-specific mortality, and delayed disease progression. Studies have also shown a connection between regular exercise and improved quality of life for patients in terms of alleviating treatment-associated side effects such as fatigue and decreased muscle strength and physical function.
Dr Flannigan’s study participants were 20 men diagnosed with immediate-risk prostate cancer, meaning eventual surgery to remove the prostate gland. Ten participants were randomly assigned to an 8- to 12-week exercise intervention completed prior to surgery. The intervention comprised two 1-hour sessions of supervised resistance and aerobic training per week, as well as home aerobic training at least twice weekly. The other 10 participants received standard prostate cancer care that included education about healthy exercise and diet.
The study found that introducing exercise during the teachable moment (after diagnosis and before surgery) led to increased physical activity among participants 6 months postsurgery and well after the exercise intervention period. The study also found that prostate cancer–specific quality of life and depressive symptoms were similar 6 months after surgery as before surgery.
Studies using animal models have demonstrated decreased tumor activity following exercise treatments. For example, research suggests that exercise may interfere with oxygen delivery in prostate cancer tumor microcirculation and tumor proliferation, decreasing chances of the cancer spreading to other parts of the body and delaying tumor growth.
As part of their study, Dr Flannigan and his team are testing participants’ tumor specimens to see if there are any changes resulting from the exercise intervention. They hope to have preliminary molecular and genetic study results by summer 2020.
