Moderate Weight Training Won't Worsen Lymphedema after Breast Cancer
Breast cancer, survivor, lymphedema, exercise. (Definitions of many terms related to cancer can be found in the Cancer.gov Dictionary.)
Breast cancer survivors whose armpit lymph nodes are removed or irradiated are at risk of lymphedema, a painful swelling of the arm. Current guidelines urge them to avoid upper-body exercise that may worsen the condition. In this trial, however, such women who followed a six-month weight-training regimen were no more likely than those who didn’t weight train to suffer from lymphedema.
The Journal of Clinical Oncology, published online May 15, 2006; in print June 20, 2006, (see the journal abstract)
(J Clin Oncol. 2006 Jun 20;24(18):2765-72. Epub 2006 May 15)
Lymph is a clear fluid that travels throughout the body to help fight infections and other diseases. Lymph nodes in the arm, shoulder, neck, and torso may be compromised or removed during breast cancer surgery and radiation. If the lymph fluid traveling from the upper arm cannot be properly drained into the bloodstream, irreversible and painful swelling (lymphedema) may occur. About one in four breast cancer survivors suffer from lymphedema to some degree, which in the United States could mean more than a half million women.
Current clinical guidelines urge breast cancer survivors to avoid upper-body exercise, even to the point of not lifting children and groceries, despite small pilot studies suggesting such exercise does nothing to worsen lymphedema. Exercise, in fact, has been shown to have many benefits, including recovery from cancer treatment and protection against chronic disease.
The randomized, controlled intervention trial described here is a substudy of the Weight Training for Breast Cancer Survivors Study (WTBS), whose main results concerning body composition and insulin levels were published in 2005 (see the journal abstract).
Eighty-five breast cancer survivors in the Minneapolis area were enrolled in the WTBS between October 2001 and June 2002. All had completed primary treatment for breast cancer at least four months prior to joining the trial. Many participants were taking tamoxifen or an aromatase inhibitor to help prevent a recurrence. None were more than moderately active in terms of exercise, and none had ever tried weight training before.
Their average age was 52, most were postmenopausal, and all except one were white.
Women in the trial were randomly assigned to one of two groups. The intervention group (42 women) followed a specific weight-training program for six months while the control group (43 women) did not. Otherwise, both groups were asked not to change their regular diets or exercise patterns during the course of the trial.
For the lymphedema substudy, the researchers focused on just those women who’d had some or all of their axillary (armpit) nodes removed 23 in the weight-training group and 23 in the control group. Lymphedema was assessed at the start of the trial and again at six months. Three sometimes overlapping measures were used: clinical diagnosis from a doctor; symptom reports from the participants themselves; and the circumference of the participants’ arms.
In the weight-training group, seven women entered the study with a clinical diagnosis of lymphedema versus six in the control group; 10 self-reported symptoms versus seven in the control group; and four women in each group had arm swellings of greater than 2 centimeters.
The weight-training regimen included upper and lower body exercises with free weights and machines. At each session the women in this group increased their upper body workouts by the smallest amount possible, if no lymphedema symptoms had appeared. For lower body exercises, they used as much weight as they could manage each session. Fitness professionals oversaw the women’s workouts.
The lead author of the lymphedema substudy is Kathryn H. Schmitz, Ph.D., M.P.H., now of the University of Pennsylvania’s Center for Clinical Epidemiology and Biostatistics in Philadelphia.
The researchers defined a worsening of lymphedema as an increase of at least two centimeters (just under an inch) in arm circumference. After six months of weight training, only one patient exceeded this measure, and she was in the control group. Overall, there was no statistical difference in arm circumference changes or in self-reports of symptoms between those who lifted weights and those who did not.
The WTBS trial is “the largest and longest randomized controlled trial to date to examine the effects of upper body exercise on lymphedema,” according to Schmitz and her co-authors. Their findings are consistent with prior studies and show that “twice-a-week progressive weight training does not increase the onset of, or exacerbate, lymphedema in recent survivors of breast cancer.”
“We need more good studies like this one looking at symptom management,” said Julia Rowland, Ph.D., director of the Office of Cancer Survivorship in the National Cancer Institute’s Division of Cancer Control and Population Sciences. Despite the small number of patients, she explained, the study was rigorously designed to prove the principle that moderate weight training does not harm breast cancer survivors, even when they have lost or compromised axillary lymph nodes.
“This is important because more evidence is beginning to mount about the benefits of physical activity, and survivors are asking what they can do to enhance their recovery and their health,” said Rowland. “And we are even beginning to think that physical exercise may have an important role in actually preventing breast cancer.”
Though this study shows no causal link between exercise and lymphedema, it is too early to recommend upper body weightlifting unequivocally, said Rowland. An acute injury from overexertion could cause some cases of lymphedema.
Though the study succeeded in demonstrating “no harm,” there were several ways these results might have been more generalizable, she said. Measuring the arm’s circumference is believed to be less reliable than measuring for volume. Symptoms might be better cataloged by actual clinical measures, rather than simply the patient’s self-reporting used here. Evaluating symptoms and circumference more frequently might also pick up trends that were not seen here, as would a follow-up period longer than six months.
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