It may be safe for breast cancer survivors to lift weights, including upper-body exercises, without increasing risk for lymphedema. These results were reported in the Journal of the American Medical Association.
Lymphedema refers to swelling of the arm due to an accumulation of lymph fluid. It commonly affects women who have had axillary (underarm) lymph nodes removed for the staging of early breast cancer. The extensive removal of lymph nodes (known as axillary lymph node dissection) is more apt to cause lymphedema than the removal of only a small number of nodes (known as a sentinel lymph node biopsy), but lymphedema can occur following either procedure.
Because of concern that upper-body exercise may increase the risk of developing lymphedema or worsen existing lymphedema, breast cancer survivors are sometimes advised to avoid heavy lifting and other upper-body exercises. These recommendations, however, are based on little evidence.
Determining whether weight lifting is safe for breast cancer survivors is important because this type of exercise can provide important benefits, including an increase in bone density.
To determine whether breast cancer survivors may perform upper-body weight-lifting exercises without increasing risk for lymphedema, researchers compared lymphedema incidence between women who lifted weights and women who did not. Participants had completed treatment one to five years prior to the study and had at least two lymph nodes removed. None had clinical signs of lymphedema when the study began.
Those in the weight-lifting group were given gym memberships and 13 weeks of weight-training instruction. Instruction was provided twice a week and involved very gradual increases in the amount of weight used. After 13 weeks, women in the weight-lifting group continued their exercise programs for nine months without instruction. The remainder of study participants performed no exercise. When the study was completed, women in the no-exercise group were offered a one-year gym membership with 13 weeks of instruction.
At one year the following results were available for 134 participants:
- 11% of participants in the weight-lifting group experienced incident breast cancer-related lymphedema (determined by an increase in arm swelling of 5% or greater during 12 months) compared with 17% in the no-exercise group.
- In the weight-lifting group, among women who had five or more lymph nodes removed, 7% experienced incident breast cancer-related lymphedema versus 22% in the no-exercise group.
The researchers concluded that slowly progressive weight lifting does not increase the incidence of lymphedema among women who have been treated for breast cancer. Weight lifting is known to have many health benefits, and it may be safe for many breast cancer survivors to perform this type of exercise. It remains important, however, that all exercise programs are first discussed with a doctor.
Reference: Schmitz KH, Ahmed RL, Troxel AB, et al. Weight lifting for women at risk for breast cancer-related lymphedema. JAMA [early online publication]. December 8, 2010.