Sandra Yin

November 08, 2011

November 7, 2011 (Washington, DC) — Doctors traditionally advised their cancer patients to rest and avoid activity. However, preliminary findings from a recently completed trial suggest that exercise during preoperative chemotherapy helps breast cancer patients avoid a decline in fitness.

Researcher Lee W. Jones, PhD, associate professor in the Department of Radiation Oncology and scientific director of Cancer Survivorship at Duke University Medical Center in Chapel Hill, North Carolina, presented the findings here at the American Institute for Cancer Research 2011 Research Conference on Food, Nutrition, Physical Activity and Cancer.

In the randomized controlled trial, 20 patients with breast cancer were treated with either neoadjuvant chemotherapy (control group) or neoadjuvant chemotherapy plus exercise for 12 weeks.

Patients' tumors were all larger than 1.5 cm. Those in the exercise group participated in interval training on a bike 3 times a week at 60% to 100% of baseline peak oxygen consumption.

In the control group there was a 10% reduction in fitness over 12 weeks of treatment. Typically, fitness declines about 10% every decade, Dr. Jones noted.

If you don't exercise during chemotherapy, you're going to get a hit, said Dr. Jones. "Just avoiding that decline in fitness is important."

He noted that this finding is similar to that from a much larger randomized trial in 2007 involving 242 breast cancer patients, which found a similar decline in fitness in a control group but not in the group randomized to supervised aerobic training 3 times a week.

According to the "multiple hit" theory, Dr. Jones explained that the effects of cancer therapy and deconditioning decrease the cardiovascular reserve — the ability to deliver oxygen from the environment to muscle mitochondria. Less exercise tolerance can lead to cardiovascular disease and to premature death in survivors.

"The good news is that if you exercise during that time, not only can you completely mitigate that effect...we show that you can improve fitness by about 12%," he said.

No changes in cardiac function were noted, but researchers did see significant improvements in endothelial function and vascular function in the exercise group.

After hearing Dr. Jones discuss studies of cancer and exercise, one of the meeting attendees, Dana Simpler, MD, who has a private practice in Baltimore, Maryland, proposed a way to get cancer patients to exercise.

"Why not have exercise be part of the chemo or radiation visit?" she said. She explained that when patients arrive, they have not received intravenous treatment are not yet sick. They might only be waiting on blood test results. "What if there was a treadmill where patients could walk 20 to 30 minutes, or whatever they could tolerate, before they get their chemo."

Dr. Jones explained that exercise reduces adverse effects, improves energy level, helps with mood, and can ameliorate some of the cardiac effects that patients experience with some chemotherapy agents.

Audience member Kathleen Wesa, MD, assistant attending physician in the integrative medicine service at Memorial Sloan-Kettering Cancer Center in New York City, wanted more details on exercise dose and duration. She said patients are always asking her whether it should be 10 minutes 3 times a day, or 30 minutes a day, or 1 hour 3 times a week, or 3 hours once a week. "What do I tell them?" she asked. "Are they all the same?"

Just doing once a week for 3 hours is not going to be enough, Dr. Jones said. "I think it needs to be repeated chronic exercise," he explained. He advised that at least 30 minutes of moderate-intensity exercise on 5 or more days a week is needed to produce a training response.

Exercise oncology is a relatively young field. Physical activity guidelines for cancer survivors, stating that cancer patients can be physically active, were only published last year, as previously reported by Medscape Medical News. "That's a huge step from where we were 10 years ago," Dr. Jones said.

Fifty years ago, patients faced 6 weeks of bed rest after myocardial infarction. Now, we get them up and moving the day of the event, said Dr. Jones. "Oncology is not there yet," he said, "but I think that's where we need to go."

If patients are feeling fatigued and weak during chemo, said Dr. Jones, the oncologist's advice is to rest and take it easy. "I think what we're finding in our studies is that that's probably the worst advice you could give," he said.

Dr. Jones, Dr. Simpler, and Dr. Wesa have disclosed no relevant financial relationships.

American Institute for Cancer Research (AICR) 2011 Research Conference on Food, Nutrition, Physical Activity and Cancer: Presented November 4, 2011.


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