Exercise May Cut Risk of Colon Cancer's Return

For the second time in as many days, new research suggests that lifestyle changes can fend off new tumors in people who survive cancer the first time around.

In the latest study, people treated for colon cancer were about half as likely to die or have their tumors return if they participated in regular, moderate-intensity physical activity as those who rarely exercised.

Yesterday, other researchers reported that postmenopausal breast cancer survivors who cut down on fats in their diet also cut the chance their cancer would come back.

"Finally, we have a hint that lifestyle changes can make a difference for people with cancer," says Douglas W. Blayney, MD, medical director of the University of Michigan Comprehensive Cancer Center in Ann Arbor.

After completing treatment, "almost every cancer patient asks if there is something they can do to prevent a recurrence," says Blayney, who was not involved with either study, "But up to now, we've had no evidence that diet or exercise help."

The study was presented at the annual meeting of the American Society of Clinical Oncology.

Physical Activity Benefits Colon Cancer Patients

The study included 832 people who were still alive one year after undergoing surgery followed by chemotherapy to treat colon cancer.

"Right after you have chemo and part of your colon taken out, physical activity is a little hard, so we looked at them a year later, when they're presumably more stable," says researcher Jeffrey A. Meyerhardt, MD, MPH, of the Dana-Farber Cancer Institute in Boston.

Participants were asked what type of exercise they did, how often they exercised, and how hard they exercised.

After nearly two years, those who exercised the equivalent of "moderate-paced" walking an hour a day, six days a week were 49% less likely to have a recurrence or die, compared with those who rarely exercised, he says.

A moderate pace is about 2-3 miles an hour, Meyerhardt tells WebMD.

Other types of physical activity count, too. "The same levels of health benefit can be attained by jogging three times a week or playing tennis three or four times a week, for example," he says.

Advice for Cancer Survivors

Previous studies have shown that physical activity can lower the risk of ever developing colon cancer, but the new research is the first to suggest a benefit for people who already have the disease, Meyerhardt says.

J. Len Lichtenfeld, MD, deputy chief medical officer of the American Cancer Society (ACS), agrees. He points out that the ACS already recommends that adults get 45 minutes of moderate exercise five days a week to prevent breast and colon cancer.

"This important finding, while needing confirmation, suggests that by maintaining this level of activity after a diagnosis of colon cancer, you can improve your outlook," he tells WebMD.

That said, most people with colon cancer are diagnosed in their late 60s, a time of life when they're "not that active," he says.

While that doesn't diminish the value of the recommendation, Lichtenfeld also tells people not to be scared off if it sounds like too much.

"The important thing is to get out and do something," he says.

The American Cancer Society estimates that nearly 105,000 Americans will develop colon cancer this year; over 56,000 will die of the disease.

By Charlene Laino, reviewed by Brunilda Nazario, MD

SOURCES: 41st Annual Meeting of the American Society of Clinical Oncology, Orlando, Fla., May 13-17, 2005. Jeffrey A. Meyerhardt, MD, MPH, associate physician, Dana-Farber Cancer Institute, Boston. Douglas W. Blayney, MD, medical director, University of Michigan Comprehensive Cancer Center, Ann Arbor. J. Len Lichtenfeld, MD, deputy chief medical officer, American Cancer Society, Atlanta.