Imaging Prostate Cancer
Posted: Nov 01, 2018
POSTED: December 18, 2017
Professor Rob Newton is the Associate Dean of Medical and Exercise Sciences and the Co-Director of the Exercise Medicine Research Institute, School of Medical and Health Sciences at Edith Cowan University in Perth, Australia.
Prostatepedia spoke to Dr. Newton about his exercise for men with metastatic prostate cancer.
Dr. Rob Newton: Traditionally, the recommendation for patients with metastatic disease was to rest. The patient should avoid physical activity, and weight/resistance training in particular, due to concerns that bones might fracture at a point of weakness.
We’ve run two studies that challenge this idea. One has been published; the other is ongoing. We’ve been exercising men with metastatic prostate cancer and women with metastatic breast cancer and we’ve seen no adverse events—no increase in pain medication. We’ve seen good physiological responses and improved fitness, strength, and muscle size. It appears that in a well-controlled environment, with appropriately qualified personnel, the risk of a fracture at the site of metastasis is very low.
We use accredited exercise physiologists, but in the United States, men should find a clinical exercise physiologist in a good, monitored facility. Patients respond very well.
It’s counterproductive to recommend to patients with metastatic disease that they rest because they’ll only decline faster and die quicker. Physical inactivity is not an option; they have to exercise. The challenge is to implement this safely and effectively.
Clearly, a home-based program is inadvisable. These patients most likely will have cardiovascular issues, so they’re at risk of having a heart attack or stroke. Their program needs to be monitored by the right personnel using the correct equipment with sound emergency procedures. Our recommendation—and what we have implemented—is a clinic-based program, supervised by exercise physiologists.
In those particular clinical trials, we designed a program so that the exercises avoided the side of the metastasis. For example, if they had a lesion in their left femur, then we wouldn’t exercise that limb to avoid overloading it and causing a fracture.
Some preclinical work in an animal model showed that controlled exercising on the metastatic site compressed tumor progression. When you load bone, bone cells send chemical and electrical signals to other cells that they should respond, generally by laying down more bone to make the bone stronger. Those same electrical and chemical signals also suppress tumor cells.
We have two trials running currently —one in breast cancer and one in prostate cancer—looking at exercise for patients with metastatic spinal lesions. We’re doing controlled isometric contractions to produce compressive load on the side of the lesion. Then we’re using sophisticated MRI techniques to monitor the volume of the metastatic tumors.
Those two studies are ongoing but, again, we’ve had no adverse effects. We have no exacerbation of bone pain. We’re just waiting now for the complete studies to see if, relative to usual care, we’ve observed a slower rate of growth of the bony metastases.
Dr. Newton: If he has metastatic disease within the skeleton, then he has to avoid any risk of falling. Obviously, contact sports are out, as well as waterskiing, skiing, and snowboarding. It’s critical he exercises. It’s critical he does both aerobic and resistance exercise.
Currently, we recommend he avoid loading the specific site of the metastases, but in the near future, we may see a prescribed exercise program that targets and controls loading. An oncologist or physician would not be able to prescribe an exercise program because they have no background or training in exercise physiology. You have to have the right medical professional give the right exercise prescription.
In Australia, we’re strongly encouraging people to seek the consultation of an accredited exercise physiologist. In the United States, you would look for a clinical exercise physiologist. The American College of Sports Medicine (http://www.acsm.org/) now has specific certifications for exercise oncology, but as this is a relatively new field, there are not many of these health professionals out there at the moment. But the field is growing and specialists can be found.
Dr. Newton: Visit Movember, which has some support programs in the United States. In Australia, which is as big a country geographically as the United States, we now manage around 2,000 men with prostate cancer entirely via telephone and online.
Dr. Newton: Absolutely. Seventy-five to 150 minutes per week of moderate to vigorous aerobic exercise and two or more resistance training sessions per week is sufficient to maintain normal health. That means that if you do vigorous exercise, 75 minutes is sufficient. That is for healthy people. If you’ve got cancer, you’re going to have to be more specific about the exercise you do. You’re going to have to do exercise medicine that will give you the best cancer survival.
It’s highly problematic to recommend to patients that they be more physically active. For example, if a patient likes walking and decides to do more walking, that might benefit some aspects of their health. But walking will not benefit a man on ADT who has rapidly developing osteoporosis and sarcopenia (muscle loss). Walking will benefit his cardiorespiratory system, but that probably won’t be what kills him.
Most likely, he’ll become dysfunctional due to low muscle mass and he’ll have an osteoporotic fracture. If it’s in the hip, he probably won’t survive it.
These generic recommendations are helpful generically, but if you have cancer you really need to be assessed by a specialist. That specialist can determine your life-limiting factor and then prescribe medicine tailored to reduce that factor.
Dr. Newton: Exactly. We’re working a lot with men with advanced disease, and the American Cancer Society guidelines are difficult for them, particularly if they’ve got cachexia, or muscle wastage. Most likely, 150 minutes per week of moderate intensity exercise is counterproductive. That makes for a greater energy imbalance; they will lose more muscle.
You’ve got to be a little bit careful, particularly with patients who are having a difficult time due to treatment or the stage of their disease. Exercise must be targeted.
That said, any exercise is better than none. The overwhelming clinical evidence and research show that men with prostate cancer—or anyone with any cancer—regardless of the stage of disease, even while undergoing difficult treatments, must be physically active on most, if not, every day of the week. If they adopt a rest strategy, then they will only deteriorate faster. We totally reject the rest strategy; it doesn’t work.
Any amount of physical activity is beneficial and will likely increase survival, but a targeted exercise prescription will be far more effective and safer. We must move to the next stage where highly tailored exercise medicine is standard.