Exercise is emerging as a new therapeutic weapon to tackle cancer

Jun 7 2006

When individuals with breast or prostate cancer followed a moderate, home-based exercise program using resistance bands and walking, the patients had less fatigue during radiation treatments, greater strength and could walk farther and faster in only four weeks, researchers discovered in a pilot study.

"At the end of the study, the patients in the exercise program were averaging more than 12,000 steps a day - which is above the American College of Sports Medicine and Centers for Disease Control recommendations of 10,000 steps a day for healthy people without cancer," said principal investigator Karen Mustian, Ph.D., of the University of Rochester James P. Wilmot Cancer Center.

"The results of this study are extremely promising and I am hopeful this that this type of research is creating a body of knowledge that is focused on treating the whole patient and all of the complexities of cancer," Mustian said.

Mustian presented the results of her randomized, controlled study at the American Society of Clinical Oncology (ASCO) 2006 annual meeting in Atlanta on June 5. ASCO awarded her an ASCO Junior Investigator Research Merit Award, given to outstanding early-career researchers to recognize their cancer prevention and control research.

Exercise is emerging as a new therapeutic weapon to help cancer patients manage and reduce side effects and improve quality of life. Studies are beginning to show that exercise is safe and feasible for many patients. In her clinical trial, Mustian found that the participants were enthusiastic and adhered well to the exercise program, even though they were older (average age was 60), half of them had received chemotherapy, and 84 percent had already endured a surgery. Still, 95 percent completed the prescribed exercise routine.

The National Cancer Institute funded the study. It included 38 people, 27 of whom were women diagnosed with breast cancer and 11 were men with prostate cancer. All of the patients were prescribed at least 30 radiation treatments, scheduled for five days a week during six weeks. Eligibility required patient consent and the completion of baseline tests to measure fatigue, strength and cardiovascular health before undergoing radiation.

Half of the group was randomly assigned to receive radiation therapy plus the home-based exercise prescription, and the other half received standard radiation therapy alone with no exercise.

The exercise program required the patients to take daily walks and to try and increase the total number of steps walked each day. They wore pedometers and kept a diary. Also, they were asked to complete 11 resistance band exercises daily, performing one set of eight to 15 repetitions daily and gradually increasing to three or four sets. Results showed an 82-percent increase in the number of steps walked daily. The patients used the resistance bands an average of 3 = days a week for 20 minutes, at moderate intensity level.

This amount of moderate physical activity resulted in the exercisers being able to maintain their strength during radiation (when compared to their baseline strength scores), and to improve aerobic capacity, Mustian said. They also reported significantly less cancer-related fatigue than the non-exercise group. Those who were not exercising showed a great decline in muscle strength, as measured by a handgrip dynamometer.

Mustian is doing additional research to measure why fatigue occurs during radiation and the mechanisms of action that cause exercise to alleviate the fatigue. She is also studying for whom home-based exercise programs work best, and whether a subset of patients might need more tailored programs.

"One of our goals is to make exercise for people with cancer even more streamlined and efficient," said Mustian, an assistant professor of Radiation Oncology at the University Medical Center, Rochester, N.Y. "These are busy people who are working, caring for families, and coming in for treatment at least two hours a day. So we need to make sure that exercise is not viewed as an additional burden, but rather a pleasant integrative therapy to make their cancer treatments as tolerable and effective as possible."

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