Exercise makes the body much less hospitable to cancer. Or, if you think of prostate cancer as the machine it is, mastering countless physiological mechanisms of the body so it can grow and spread: Exercise throws a monkey wrench into the works!
UCLA urologist William Aronson, MD, was recently asked, “What do your prostate cancer patients ask you about exercise?” His answer: “None of my patients ask about exercise.” It is a pity.
Unfortunately, exercise is not on the radar for many men with prostate cancer and it should be, why the prolongs life, improves quality of life and slows the progression of prostate cancer. Aronson, who also sees patients at the Greater Los Angeles VA Hospital, was asked this question at a discussion hosted by the Prostate Cancer Foundation (PCF) about the effects of diet and exercise on advanced prostate cancer and survival. I covered this discussion for the PCF website. Notably, the focus here was not prevention prostate cancer or delayed treatment time – although studies show that exercise can contribute to each of these. Instead, it was for men already living with cancer that has gotten away from the prostate – and the overwhelming consensus among the participants is that exercise and diet can make a big difference. Hear these words: If you have prostate cancer, no matter the stage, you can help fight it with exercise!
The results of several large studies show that Exercise reduces the risk of dying from prostate cancer by 30 percent and the risk of dying from other causes by 40 percent, says UCSF epidemiologist June Chan, Sc.D., who was also part of the panel discussion. Chan is a pioneer in studying the benefits of exercise in prostate cancer. In 2011, Chan and colleagues found a lower risk of developing cancer in men who exercised vigorously. But in later studies, “we saw benefits with brisk walking.”
What exactly makes exercise beneficial? What is he doing? It may help to think of prostate cancer as a weed. Exercise may not directly affect prostate cancer, but if that disturbs the environment – affects the plant’s access to sun, soil, air or water – then the plant is not going to grow as well. In other words, exercise makes the body much less hospitable to cancer. Or, if you think of prostate cancer as the machine that it is, hijacking countless physiological processes and mechanisms of the body so that it can grow and spread: the exercise throws a monkey wrench into the works.
Exercise lowers insulin and insulin-like growth factor, says Harvard scientist Edward Giovannucci, MD, Sc.D., professor of epidemiology and nutrition and also part of the panel discussion. “Physical activity improves insulin sensitivity, which is important for diabetes.” Insulin, a hormone that regulates carbohydrate and fat metabolism, may also play a role in cancer. So can a closely related hormone called insulin-like growth factor. Both of these hormones also affect cell growth and division, Giovannucci adds. “If you have higher levels because you’re physically inactive or maybe a little overweight or maybe you don’t have the best diet, those high levels will sometimes lead to diabetes, sometimes to heart disease, and sometimes to cancers. “Prostate cancer is one of those cancers that is probably sensitive to these key hormones.”
The crux of the matter
Chan presented a very interesting study in the discussion: the ERASE trial, published in JAMA Oncology in 2021. Canadian researchers examined the effects of 12 weeks of high-intensity interval training in patients in premature end of the prostate cancer spectrum: men on active surveillance who had very low to favorable intermediate risk prostate cancer. At first glance, you might not think this study applies to men with advanced prostate cancer. Not only did the participants have localized prostate cancer, but that was it aerobics exercise: supervised treadmill sessions in which the men achieved 85 to 95 percent of maximal oxygen consumption, compared to a control group of men who continued their normal exercise routine. But wait: in just three months, the exercise proved lower men’s PSA levels, slow their PSA rate, and slow the growth of prostate cancer cells. Obviously, more studies are needed to examine the effects of exercise in men each stage of prostate cancer; In fact, the investigators noted that “to date, only one exercise study has been conducted in this clinical setting.” Still, these are exciting results!
Even more exciting: ERASE trial participants showed improvement in cardiorespiratory fitness. For men with prostate cancer, Cardiovascular health should be a concern and improving it should be a goal. “Cardiovascular disease is a leading cause of illness and death for patients with prostate cancer,” says Harvard epidemiologist Lorelei Mucci, Sc.D., who moderated the discussion. These are also words to consider: If you have advanced prostate cancer and are on ADT, you should be aware that ADT can have cardiovascular side effects. But exercise helps protect the heart.
In related research, UCSF epidemiologist Stacy Kenfield, Sc.D., a colleague of Chan’s in the Department of Urology, recently led a small study specifically looking at high-intensity interval training in men with advanced prostate cancerand a larger study is planned, “designed to examine overall survival and progression-free survival benefits and biomarkers,” says Chan.
The bottom line: In addition to what exercise does specifically to discourage prostate cancer growth—something that’s not yet fully understood—exercise accomplishes what many forms of treatment don’t: prolongs life. It reduces the risk of death from prostate cancer and heart disease. Exercise is good medicine, and the good news is that you don’t have to sprint on a treadmill or cycle at Tour de France-level speed to reap a benefit: even moderate exercise can make a big difference! More on exercise and advanced prostate cancer in a future post. Note: I know the monkey in this picture is smoking a cigar and smoking is bad for prostate cancer. But his gritty attitude conveys what I hope you have: a spirit of contentment in the fight against prostate cancer!
Additionally with Book, I have written much more about prostate cancer on the Prostate Cancer Foundation website, pcf.org. The stories I have written are in the “Understanding Prostate Cancer” and “For Patients” categories. As Patrick Walsh and I have said for years in ours books, Knowledge is power: Saving your life can start with going to the doctor and knowing the right questions to ask. I hope all men put prostate cancer on their radar. Get a baseline PSA blood test in your early 40s and if you are of African descent or have a family history of cancer and/or prostate cancer, you should be screened regularly for the disease. Many doctors don’t do this, so it’s up to you to ask.
©Janet Farrar Worthington
