By Jeannine Stein, Los Angeles Times
December 8, 2010, 4:07 p.m.


Breast cancer survivors sometimes avoid strength training for fear it could increase their chances of lymphedema, blockage of the lymphatic system. But a study finds that a yearlong weightlifting program did not raise the risk of lymphedema among women who had had breast cancer.

The study, released Wednesday in the Journal of the American Medical Assn., followed 154 female breast cancer survivors who had at least two lymph nodes removed but were without symptoms of breast-cancer-related lymphedema when the study started. Removed or damaged lymph nodes can upset the normal lymphatic drainage process, often causing arm swelling and discomfort.

Half of the study participants were randomly assigned to a weight-lifting program, which included 13 weeks of instruction at a gym, a gym membership and nine months of working out on their own. The other participants did no exercise and served as a control.

In the weightlifting group, 11% of the women had an onset of lymphedema, versus 17% in the control group. When researchers looked at data on women who had had five or more lymph nodes removed, 7% in the weightlifting group and 22% in the control group had an onset of lymphedema.

Many breast cancer survivors avoid exercise or even lifting heavy objects, fearing they'll trigger lymphedema. That can lead to weakened muscles and injuries.

Those in the weightlifting group got stronger (no surprise there) and had a lower percentage of body fat that those in the control group. Food intake didn't differ between the groups.

In the study, the authors wrote, "The findings of our study remove concerns that slowly progressive weightlifting will increase risk of lymphedema onset in breast cancer survivors."