Dec. 8, 2010 (San Antonio) -- Contrary to what’s been thought, a program of weight lifting may not increase the risk for arm swelling caused by lymphedema in breast cancer survivors. This is according to a new study performed by the same researchers who previously found that weight lifting may help breast cancer patients who already have lymphedema in their arms to gain strength.
Lymphedema is buildup of fluid that causes swelling. It can be a lasting side effect of removing lymph nodes during breast cancer surgery.
To avoid developing the condition or making it worse, the vast majority of the 2.4 million breast cancer survivors in the U.S. are typically advised against lifting children, heavy bags, or anything else weighing more than 5 pounds.
But the studies challenge such advice.
The findings "do not mean women can just go out, buy a set of weights and start their own rehabilitation program," says researcher Kathryn Schmitz, PhD, MPH, associate professor of epidemiology and biostatistics at the University of Pennsylvania School of Medicine.
What "breast cancer survivors should do is go to their physician and insist on getting a prescription for physical therapy. The physical therapist can evaluate them and develop a safe weight lifting program," Schmitz tells WebMD.
The new study was presented at the San Antonio Breast Cancer Symposium and published online in the Journal of the American Medical Association.
The study involved about 150 breast cancer survivors who had their cancer diagnosed one to five years previously. All had two or more lymph nodes removed, and none had signs of lymphedema when they entered the study.
Arm measurements were taken throughout the one-year study. A woman was considered to have lymphedema if her affected arm swelled by 5% or more.
Eleven percent of 72 women in the weight lifting group had their affected arm swell by 5% or more vs. 17% of 75 women who did not change their normal physical activities.
Among women who had five or more lymph nodes removed during breast cancer surgery, 7% of 45 women in this group had arm swelling of 5% or more, compared with 22% of 49 women who did not lift weights. This translates to a 70% reduction in risk, Schmitz says.
Women in the weight lifting group were given a one-year membership to a local fitness center. For 13 weeks, they attended small, twice-weekly, 90-minute classes led by certified fitness professionals who taught them safe techniques for weight lifting using both free weights and machines. Weight was increased slowly for each exercise if the women had no arm symptoms including swelling, pain, tingling, or numbness.
For the remainder of the study, the women exercised on their own while being monitored for any change in symptoms.
The rest of the women weren't asked to start weight training, and they got a one-year pass to a health club only when the study ended.
Any woman who developed lymphedema was given a custom-fitted compression garment for their affected arm and was required to wear it if performing weight lifting exercises.