Weight lifting does not increase breast cancer-related lymphedema
MedWire News: A program of slowly progressive weight lifting does not increase the incidence of lymphedema among breast cancer survivors, US study findings indicate.
"The findings from our trial should help clarify clinical advice to patients who have completed breast cancer treatment regarding the safety of resuming or beginning a weight lifting program," remark Kathryn Schmitz (University of Pennsylvania School of Medicine, Philadelphia) and colleagues.
The researchers note that current clinical guidelines for breast cancer survivors without lymphedema advise against upper body exercise.
"Such guidance is often interpreted in a manner that deconditions the arm, increasing the potential for injury, overuse, and, ironically, lymphedema onset," they add in JAMA.
To evaluate lymphedema onset after a 1-year weight lifting intervention compared with no exercise, Schmitz and team performed a long-term study among 154 women who were treated for unilateral breast cancer 1 to 5 years previously. Participants had at least two lymph nodes removed and had no clinical signs of breast cancer-related lymphedema (BCRL).
The women were randomly assigned to a "no exercise" control group or to receive 13 weeks of supervised instruction performing upper and lower body weight lifting exercises, followed by 9 months of unsupervised exercise.
The women in the exercise group started training at a low weight (1-2 lb) and increased resistance according to symptom response.
The proportion of women who experienced incident BCRL onset - defined as at least a 5% increase in interlimb difference, as measured by water volumetry - during the study period was significantly lower in the weight lifting group compared with the control group, at 11% versus 17%.
Among women with five or more lymph nodes removed, the proportion who experienced incident BCRL onset was also significantly lower in the in the weight lifting group than in the control group, at 7% versus 22%.
Schmitz and co-authors note that the primary goal of their study was to test the safety of weight lifting, not superiority compared with no exercise, "therefore, additional research is needed before concluding that weight lifting prevents lymphedema."
"However, even with the finding of no harm, our results combined with previously published results for women with breast cancer-related lymphedema suggest that the many health benefits of weight lifting should now become available to all breast cancer survivors," they conclude.
MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2010
By Laura Dean