Contrary to expectations from clinical experience, a new study found that a weight loss program, alone or in conjunction with a home-based exercise intervention, was not effective in reducing lymphedema symptoms in breast cancer survivors.
These results contradict recommendations in current clinical guidelines, note the authors.
In addition, the findings are contrary to their own clinical experience, they add, inasmuch as they have seen patients with breast cancer–related lymphedema (BCRL) whose lymphedema symptoms improved after they lost weight.
"Current guidelines from the National Cancer Institute, the American Cancer Institute, National Lymphedema Network, and others tell overweight women with breast cancer lymphedema that weight loss will help their condition," commented lead author Kathryn H. Schmitz, PhD, MPH, professor, Department of Public Health Sciences, Penn State College of Medicine, in Hershey.
"Our trial is definitive — weight loss does not help with symptoms or swelling or clinical outcomes for breast cancer–related lymphedema," she emphasized.
"This should result in a change in clinical practice," she told Medscape Medical News. "One could say that we should avoid 'fat shaming' overweight women with lymphedema — giving them the impression that it is their fault that they have this condition when, in fact, it is not their fault."
The study was published August 15 in JAMA Oncology.
Lymphadema is a common complication of breast cancer treatment, especially among those who undergo axillary lymph node dissection. Excess body weight has been linked to a higher likelihood of developing BCRL and a poorer outcome, and thus breast cancer organizations have recommended that overweight patients with BCRL achieve and maintain a healthy weight.
Schmitz and colleagues previously reported results from the Physical Activity and Lymphedema (PAL) trial, which showed that a slowly progressive weight training and resistance exercise program reduced lymphedema exacerbations by 50% and improved lymphedema symptoms.
However, the PAL trial was facility-based, and the intervention was supervised. Challenges to implementing this type of intervention include cost, difficulties in developing and sustaining the workforce needed to conduct such a program, and the fact that the women may prefer to exercise at home.
"Our prior work has shown that slowly progressive resistance exercise that really progresses enough to cause substantive strength and body composition changes results in a decrease in lymphedema symptoms as well as 'flare-ups' of the condition," said Schmitz. "When we published that work, some asked, 'But will women go to the gym to do this? Shouldn't we give them a home-based version of this program to make it more accessible?' "
Schmitz said this was a good question, and so her team revised the exercise intervention so as to make it entirely home based. This led to the current study. "Unfortunately," she said, the home-based exercise regimen "translated into less increase in strength and no change in body composition.... Clearly, the dose of exercise was smaller in this trial, despite also being a 1-year trial."
Her advice to breast cancer survivors who want to exercise to reduce lymphedema symptoms is "to either head to the gym or figure out how to truly progress with weights in a home program."
No Differences Between Groups
The latest study, dubbed Women in Steady Exercise Research (WISER), involved 351 overweight breast cancer survivors with BCRL. They were randomly assigned to either the control group (facility-based lymphedema care with no home-based exercise or weight loss intervention); to the exercise intervention group; to the weight loss intervention group; or to the combined exercise and weight loss intervention group.
The exercise program was a 52-week, home-based intervention of strength/resistance training, which involved two training sessions per week, and 180 minutes of walking per week. The weight loss program consisted of 20 weeks of meal replacements and 52 weeks of lifestyle modification counseling.
The main outcome was 12-month change in the percentage of interlimb volume difference.
As compared with control patients, the percentage in change from baseline in perometry-based lymphedema outcomes (the study's primary outcome) was 0.66% in the combined group, 0.53% in the weight loss group, and 0.04% in the exercise group.
During the 12-month study period, there were greater decreases in individual limbs for both affected and unaffected limbs in the weight loss and combined intervention groups vs the control group.
When comparing clinical evaluation and self-reported lymphedema outcomes by intervention group, there were no differences between groups at baseline or in 12-month changes in clinical lymphedema assessment values or self-reported symptoms.
The mean total upper-extremity score changes from the objective clinical evaluation were −1.40 (11.10) in the control group, −2.54 (13.20) in the exercise group, −3.54 (12.88) in the weight loss group, and −3.84 (10.09) in the combined group.
Similarly, the mean self-reported overall upper-extremity score changes were −0.39 (2.33) in the control group, −0.12 (2.14) in the exercise group, −0.57 (2.47) in the weight loss group, and −0.62 (2.38) in the combined group.
As expected, weight loss was significant for the combination and weight loss groups (P < .001 for both groups vs the control group), compared to the control group. Control group participants lost 0.55% of their baseline weight vs −8.06% in the combined group, −7.37% in the weight loss group, and −0.44% in the exercise group.
The research was supported by grants from the National Institutes of Health, the National Center for Advancing Translational Sciences of the National Institutes of Health, and the Comprehensive Cancer Center Support Grants of the National Cancer Institute. Schmitz received 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 course titled Strength After Breast Cancer. Several coauthors have received funding from government agencies and have relationships with industry, as detailed in the original article.
JAMA Oncol. Published online August 15, 2019.
Medscape Medical News © 2019
Cite this: Practice Change? Weight Loss Advice for Breast Cancer Lymphedema - Medscape - Aug 15, 2019.