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Is Exercise an Effective Treatment for Prostate Cancer?

— A deep dive with Rob Newton, a pioneer in the field of exercise oncology

MedpageToday
A photo of Professor Rob Newton, PhD, DSc.

The saying, "Let food be thy medicine, and medicine be thy food," has been attributed to the Greek physician Hippocrates, who is considered the father of Western medicine.

Rob Newton, PhD, DSc, a pioneering Australian exercise physiologist, has a different take: "Let exercise be thy medicine, and medicine be thy exercise." Newton has been a pioneer in the emerging field of exercise oncology, which uses physical fitness to enhance the lives of people with cancer.

In 2004, Newton founded the Exercise Medicine Research Institute at Edith Cowan University in Perth, Australia. And earlier this year, at the meeting of the American College of Sports Medicine in Boston, Newton and other leading researchers and clinicians in the field launched the International Society of Exercise Oncology, which is aimed at advancing the science and practice of exercise medicine as a treatment for people with cancer and for cancer survivors.

Newton's Pioneering Research and Influence

and others has shown that more than 20 physiological mechanisms within the body that may slow or stop the progression of prostate cancer. He has also conducted that muscle mass (which can only be improved through exercise) is more important for the survival of men with prostate cancer than fat mass (which is most effectively controlled by diet therapy).

Other that physical activity is associated with lower overall mortality and lower prostate cancer mortality. More broadly, Newton and his team have conducted research in cancer of the breast, lung, brain, pancreas, ovaries, bladder, melanoma, and colon, as well as in mesothelioma.

But Newton's specialty is prostate cancer. Some of his research on prostate cancer -- which showed for the first time that targeted exercise in men with prostate cancer who were on androgen deprivation therapy -- is starting to make its way into clinical recommendations. In fact, Newton is co-author of the on exercise medicine in cancer management. "Certainly, there is a strong association between being physically active and greatly reduced risk of prostate cancer-specific death," Newton said.

Beyond his own work, Newton has had an influence on how other researchers approach the field of exercise oncology.

Kinesiologist Kerry Courneya, PhD, who directs exercise oncology research at the Behavioral Medicine Laboratory and Fitness Center at the University of Alberta in Edmonton, Canada, said Newton has inspired research in the emerging field. His group's showed that a 12-week aerobic high-intensity interval training program improved several cardiometabolic biomarkers in patients with prostate cancer on active surveillance; this may contribute to cardiovascular health benefits and could potentially influence signaling pathways in the progression of prostate cancer.

Meanwhile, epidemiologist Stacey Kenfield, MS, ScD, director of the Urologic Clinical and Translational Science program at the University of California San Francisco, and her colleagues found that a moderate-to-vigorous aerobic program with brisk walking improves among men on active surveillance for prostate cancer.

Kenfield has worked with Newton since 2015. She now serves as director of the Study Coordination Center for the INTERVAL-GAP4 study -- the first and largest trial to determine if targeted exercise medicine actually extends the life of men with metastatic castrate-resistant prostate cancer. Newton and Fred Saad, MD, founder of the Oncology Urology Clinic at the University Hospital of Montreal, serve as co-principal investors of GAP4, the results of which are being analyzed now.

Speaking about Newton, Kenfield told me: "Rob's exercise research is expansive and cuts across age, gender, body composition, size (overweight and obesity), and a range of chronic diseases. Through his leadership in cancer, Rob has played a pivotal role in expanding cancer survivorship care to advanced cancer patients. He has made substantial contributions to understanding the mechanisms through which exercise impacts body systems to help reduce declines in strength, improve functional ability, and reduce cancer-related fatigue. His work as a whole truly contributes to and supports the concept that exercise is medicine."

A Career Shift

Before devoting his research to exercise and cancer, Newton had a completely different career trajectory -- helping elite athletes reach their performance goals.

In 1994-1995, he was a performance consultant on the strength and conditioning program for the Chicago Bulls -- one of the National Basketball Association's greatest dynasties -- around the time when they won six NBA championships. He worked with all of the Bulls' legendary players, including Scottie Pippen, Toni Kukoc, Steve Kerr, and Luc Longley -- save one, Michael Jordan, who had his own trainer and training facility.

"I only saw Michael during games and team training," Newton told me. His job was to help players develop maximal muscle power, such as jumping higher and boosting speed on the court.

"Elite athletes are almost a different species from 'normal' humans. They are genetically gifted with specific anatomical and physiological and mental advantages, which they hopefully can build through physical training and practice to be outstanding in their sport," Newton said. But his career took a turn as he watched his father's decline following prostatectomy and adjuvant radiation therapy.

"On the urologist's advice to rest, my dad sat in the front yard in the sun, and exercised as little as possible, because that's what he was told to do," recalled Newton. "And he became weaker and less functional, and then 2 years later he died of a stroke. I can't say for sure, but I wonder if they had not operated, if they just sort of left him alone, if he may have survived longer. He certainly would have had a better quality of life. The last 2 years of his life were absolutely dreadful. Everything in my fiber told me this was wrong. I watched him and I said, 'This advice is wrong.'"

For the past 27 years, Newton has focused on the role of exercise in cancer management, predominantly in patients with prostate cancer. "I find it more rewarding and feel I am making a difference," he said.

Newton told me that one of the most important findings of his research is that maintaining or increasing muscle mass through resistance training is absolutely critical for people with or at risk of prostate cancer. He said muscle tissue is a "drug store" within the body and keeping it large and dispensing regularly through exercise actually increases the capacity of the body to identify and destroy prostate cancer cells.

Newton is author of the forthcoming book aimed at cancer patients, .

Howard Wolinsky is a Chicago-based medical writer and patient with low-risk prostate cancer. On average, he walks 4-5 miles a day.