New Cancer Guidelines Reverse Decades of Advice for Patients to Avoid Exercise
by Tony Isaacs
A new set of national guidelines for cancer patients presented at this year's meeting of the American Society of Clinical Oncology (ASCO) is reversing decades of common mainstream advice for such patients to avoid exercise. Instead, the new guidelines advise patients to "avoid inactivity" to boost quality of life, strength and fitness.
Kathryn Schmitz, PhD, MPH, an associate professor of Epidemiology and Biostatistics and a member of the Abramson Cancer Center at the University of Pennsylvania School of Medicine, presented the new guidelines at an educational session at the 2010 ASCO meeting on June 6th. The presentation was titled "Exercise Testing and Prescription for Cancer Survivors: Guidelines from the American College of Sports Medicine."
Schmitz, whose previous research reversed decades of cautionary exercise advice given to breast cancer patients with the painful arm-swelling condition lymphedema, led a 13-member American College of Sports Medicine expert panel that developed the new recommendations after reviewing and evaluating literature on the safety and efficacy of exercise training during and after cancer therapy.
"We have to get doctors past the ideas that exercise is harmful to their cancer patients. There is a still a prevailing attitude out there that patients shouldn't push themselves during treatment, but our message -- avoid inactivity - is essential," Schmitz says. "We now have a compelling body of high quality evidence that exercise during and after treatment is safe and beneficial for these patients, even those undergoing complex procedures such as stem cell transplants. If physicians want to avoid doing harm, they need to incorporate these guidelines into their clinical practice in a systematic way."
For decades, doctors have been telling cancer patients to take it easy and rest and avoid too much physical activity. Such advice was similar to the advice doctors still often give to cancer patients about avoiding supplements and other items that boosted cellular and overall health. In part, such advice may have been due to the longstanding practice of trying to use chemo drugs to beat cancer by lowering cellular activity and "starving out the cancer". Since chemo drugs also weaken major organs, it may have been felt that exercise was risky for hearts weakened by chemo.
However, it has since been established that regular exercise is extremely beneficial for heart attack victims because it strengthens the heart after a heart attack and lessens the risk of further problems. Now, heart attack victims are routinely told to exercise. If the new guidelines are any indication, a similar trend may develop for the advice given to cancer patients.
Exercise also improves the circulation of the blood and its immune cells which neutralize pathogens in the body. The better immune cells circulate, the more efficient the immune system is at locating and eliminating viruses and diseases such as cancer which are trying to attack your body. Regular exercise also reduces insulin levels, which creates a low sugar environment that discourages the growth and spread of cancer cells. Lowered sugar reduces the risk of developing cancer and having it return once you have beaten it.
Physical exercise has been shown to be particularly beneficial against colon cancer. Physically active adults experience about half the incidence of colon cancer as do sedentary adults. In addition to lowering insulin levels, exercise also lowers prostaglandins and bile acids which may encourage the growth and spread of cancer cells in the colon. Exercise also improves and speeds up bowel function resulting in waste having less time to be in contact with the colon's mucosal lining.
It's also believed that exercise triggers programmed death of cancer cells via the process of apoptosis.