Study: Research suggests exercise is safe for breast cancer patients at risk for lymphedema

IN DEPTH REVIEW OF RESEARCH

Study background:

Lymphedema, a swelling of the arm or hand due to lymph node damage, is an adverse side effect that often occurs after breast cancer treatment. Currently there is no cure for lymphedema. Patients who develop this condition can ultimately experience symptoms such as changes in sensation in the arms, a greater feeling of fatigue, and decreased quality of life. Other side effects of breast cancer treatment include decreased bone health and increased fat mass. Strength or resistance exercises can help patients to improve their bone health and weight gain that may occur.  However, some research suggests that resistance exercise may cause patients to develop lymphedema or make it worse.

Emily Simonavice and colleagues from the School of Health and Human Performance in George College and State University and other institutions studied the effect of resistance exercise in women who were treated for breast cancer; their results were published in the journal Supportive Cancer Care. This is one of several recent studies that suggests that strength exercise is safe for breast cancer survivors and does not cause lymphedema or make existing lymphedema worse.

Researchers of this study wanted to know:

How does exercise affect lymphedema in women who have been treated for breast cancer?

Population(s) looked at in the study:

• Study participants included 25 women who:
  • had breast cancer between stages 0-III
  • completed all primary treatments (surgery, radiation, and/or chemotherapy) at least 6 months before the study started
• Initially, 27 women began the study, but two dropped out due to clinical complications unrelated to lymphedema. However, data from these women while they were in the study were collected and included in the results.
• Three of the women already had lymphedema when the study began.
• Each woman had 2-hour, moderate resistance exercise training sessions per week, which included an aerobic warm-up and exercises targeting all major muscle groups (such as chest presses, leg presses, biceps curls).
• The presence and/or extent of lymphedema was determined by measuring each woman’s arm circumference every two weeks.

Study findings: 

1. After 6 months of resistance exercise training the extent of lymphedema did not change significantly.

Limitations:

These findings are preliminary because this study did not include a control group. Although all of the women included in the study performed the moderate resistance training, the researchers could not compare lymphedema between women who did and did not exercise (no information was available regarding the arm circumference changes of breast cancer survivors who did not exercise over the same period). It was also a relatively small study: just 27 women. Additionally, the study included only 3 women who already had lymphedema; too small to generalize the findings to all women with lymphedema. Another reason that this study cannot be generalized is because participants had different combinations of surgery, radiation, chemotherapy, and lymph node dissection (not all women had all four treatments). Finally, the study also looked only at breast cancer survivors. The effects of exercise on previvors after risk-reducing mastectomy due to a mutation in BRCA or other gene that affects cancer risk is not addressed by this study.

Conclusions:

This study suggests that women who have been treated for breast cancer can exercise without developing lymphedema or making their lymphedema worse. Because of the study’s limitations, however, more work needs to be done to fully understand the relationship between exercise and lymphedema. Other researchers have explored this area—a 2009 paper in the New England Journal of Medicine by Dr. Kathryn Schmitz from the University of Pennsylvania School of Medicine showed that breast cancer patients with existing lymphedema who did resistance exercise had greater improvements in the severity of their self-reported lymphedema symptoms compared to patients who did not exercise. Another recent report of preliminary findings presented at the Cancer Survivorship Symposium Advancing Care and Research in 2017 found no difference in the rates of lymphedema between breast cancer patients who exercised and those who did not.

All women who undergo breast surgery and/or radiation to treat breast cancer or reduce the risk of breast cancer are at risk for lymphedema; having axillary lymph node dissection increases that risk.

Current breast cancer survivorship care guidelines from the American Cancer Society and the American Society of Clinical Oncology recommend that health care providers refer patients with arm swelling or other symptoms of lymphedema to a lymphedema specialist who can recommend appropriate treatment. These guidelines also note that more research is required to develop clear evidence-based recommendations to prevent lymphedema after breast surgery and/or radiation.   Patients concerned about lymphedema should discuss symptoms with their health care providers to determine what treatment or prevention measures are best for them.

Posted 2/22/17

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