Neither weight-loss nor home-based exercise programs improved outcomes for women with breast cancer–related lymphedema, investigators found.
Among 351 overweight breast cancer survivors with breast cancer–related lymphedema (BCRL), there were no significant differences at 1 year of follow-up in the percentage difference between limb volumes from baseline, regardless of whether patients had been randomly assigned to a home-based exercise program, weight-loss program, combined interventions, or to a facility-based lymphedema care–only program, reported Kathryn H. Schmitz, PhD, MPH, from Penn State University, Hershey, and colleagues.
“Our findings are contradictory to our own clinical experience, as we have received reports from patients with BCRL who have noted improvements in their lymphedema symptoms after weight loss. Possible explanations for this mismatch of clinical experience and empirical evidence include alterations in aspects of lymphedema, such as tissue composition, that remain challenging to measure with high reliability and validity,” they wrote in JAMA Oncology.
The findings suggest that breast cancer survivors with lymphedema may benefit more from facility-based exercise than home-based lymphedema care, the investigators wrote.
In the randomized Women in Steady Exercise Research (WISER) Survivor trial, the investigators enrolled 351 overweight breast cancer survivors with lymphedema and randomly assigned them to a 52-week home-based exercise program consisting of strength and resistance training twice per week and 180 minutes per week of walking (87 patients), a weight-loss program consisting of 20 weeks of meal replacement and 1 year of lifestyle-modification counseling (87 patients), a combination of the two programs (87 patients), or a facility-based lymphedema care program only (90 patients, control group).
The primary endpoint was originally intended to be lymphedema clinical events such as incident flare-ups or cellulitis, but was changed to the percentage of interlimb difference (that is, between the affected and unaffected limb) because of a reduction in funding that led to a reduction in the sample size.
There were no significant between-group differences at either baseline or 12 months in either the percentage of interlimb differences or in absolute differences, the investigators found.
Women assigned to the diet and exercise intervention lost significantly more weight than controls (P less than .001), but saw significant improvements in fitness only in the maximum amount of weight they could lift (P = .01).
“Multiple national organizations currently advise overweight women to achieve and maintain a healthy weight to improve the outcomes of previously diagnosed BCRL. The empirical evidence base, including data from the present study, does not support the assertion that weight loss as an intervention improves the hallmark measure of BCRL severity, percentage of interlimb difference,” Dr. Schmitz and colleagues wrote.
They acknowledged that BCRL is a long-term condition and that the 1-year follow-up period may have been too short to observe lymphedema exacerbation or related clinical events; therefore, the results may not apply to women with severe lymphedema, such as those with interlimb differences of greater than 30%.
The study was supported by various National Institutes of Health grants. Compression garments were supplied by BSN Medical. Dr. Schmitz reported receiving grants from the National Cancer Institute and nonfinancial support from BSN Medical during the conduct of the study, personal fees from Klose Training outside the submitted work, and a licensed patent for a Strength After Breast Cancer course.
SOURCE: Schmitz KH et al. JAMA Oncol. 2019 Aug 15. doi: 10.1001/jamaoncol.2019.2109..