By Marilynn Larkin
NEW YORK (Reuters Health) - 22/8/2019
In overweight breast cancer survivors, neither losing weight nor exercising at home improves lymphedema, a new study shows.
"Current guidelines from the National Cancer Institute, American Cancer Society, National Lymphedema Network and others tell overweight women with breast cancer lymphedema that weight loss will help their condition," Dr. Kathryn Schmitz of Pennsylvania State University of Medicine in Hershey told Reuters Health by email.
"Our trial is definitive: Weight loss does NOT help with symptoms or swelling or clinical outcomes for breast cancer related lymphedema," she said by email. "This should result in a change in clinical practice."
In an earlier study by her team, published 10 years ago in The New England Journal of Medicine, progressive resistance that induced substantive changes in strength and body composition resulted in fewer lymphedema symptoms and flares. (http://bit.ly/31TyQPB)
"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?' I thought that was a good question, so we revised the exercise intervention to be entirely home based," Dr. Schmitz said. "Unfortunately, that translated into less increase in strength and NO change in body composition."
Based on that earlier study and the new findings, patients may find resistance training in a gym or other facility more beneficial than home-based exercise and weight loss for improving lymphedema symptoms, her team says.
For the current study, Dr. Schmitz and colleagues randomized 351 overweight women with breast cancer-related lymphedema (mean age, 59; 62% white; 35% black) to one of four groups for a year:
The main outcome was the 12-month change in the percentage of inter-limb volume difference.
As reported online August 15 in JAMA Oncology, mean total upper extremity score changes from the objective clinical evaluation were: −1.40 in the control group; −2.54 in the exercise group; −3.54 in the weight loss group; and −3.84 in the combined group.
The mean overall upper extremity score changes from the self-report survey were −0.39 for controls; −0.12 for exercise alone; −0.57 for weight loss alone, and −0.62 for the combined program.
Weight loss from baseline was −0.55% for controls; −0.44% for exercise; −7.37% for weight loss; and −8.06% for the combined program.
"Study results indicate that weight loss, home-based exercise, and combined interventions did not improve breast cancer-related lymphedema outcomes," the authors conclude.
Dr. Kerri Winters-Stone, Elnora E. Thomson Distinguished Professor at Oregon Health and Science University, said the findings were not surprising. "If you review the extant literature on exercise for cancer survivors, supervised programs tend to provide superior results to home-based exercise," she told Reuters Health by email.
"This does not always mean that home-based exercise isn't helpful, but that sometimes it may not produce as large, or in the case of this paper, clinically meaningful benefits," she said. "Women in the home-based exercise program in this study did get stronger and more aerobically fit, but it wasn't enough to impact their lymphedema. The reasons could be that supervised training provides more support, motivation and guidance for people to achieve a greater effort during exercise."
The weight loss findings seem to "shed some new light on previous thinking about the contribution of excess weight to lymphedema," she said. "You'd expect weight loss to reduce lymphedema but it did not. However, as with the exercise findings, it could be possible that the degree of weight loss achieved in the study just wasn't enough to change lymphedema."
That said, she noted, "It may be difficult for some to achieve greater weight loss on their own without some other type of intervention (i.e., surgery)."
"Even in this case of null results for home-based exercise and a 10% weight loss for lymphedema, the other benefits of exercise - i.e., women got fitter - and weight loss should not be discounted," she said. However, in the current study, "rehabilitation professionals were involved in guiding women to learn how to do strengthening exercises and in the weight-loss portion; professionals also educated women on dietary changes."
"This type of professional support should be offered and covered for all breast cancer survivors," she said. However, supervised exercise programs specific to cancer survivors "meagerly exist in the US."
"Clinicians and patients should demand that more options for professionally-led supervised exercise programs for persons with cancer are available in hospitals, clinics and communities and that third-party payers cover them," Dr. Winters-Stone concludes. "The cost-benefit of these programs is undeniable."
JAMA Oncol 2019.
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