Lymphedema is swelling of the arm, hand, trunk, underarm, back, or breast caused by a build-up of lymph fluid in those tissues after breast cancer surgery or radiation therapy. Lymph is a thick, clear fluid that circulates through your body to remove waste, bacteria, and other substances from tissues. Edema is the medical term for swelling. Lymphedema can develop soon after treatment, or months or even years later.
Individual studies have reported that as few as 10% and up to as many as 90% of women develop lymphedema after breast cancer surgery and radiation therapy. Such a wide range of results may be due to:
- researchers have used different ways of defining and then measuring lymphedema
- many of these studies have involved small numbers of patients
- many studies were done with women who had a large number of underarm lymph nodes removed, which used to be standard practice
Today, many experts estimate that the range is probably close to 20-30%.
A University of California study suggests that certain genes may be linked to developing lymphedema. If women have altered versions of these genes, they may be more likely to develop lymphedema.
The research was published online on April 16, 2013 by PLoS ONE. Read “Lymphatic and Angiogenic Candidate Genes Predict the Development of Secondary Lymphedema following Breast Cancer Surgery.”
Because not all women develop lymphedema after breast cancer surgery or radiation therapy, the researchers wondered if genetics might play a role.
The study looked at 542 women who had been diagnosed with breast cancer in one breast who had mastectomy at least 6 months before the study started:
- 155 women had been diagnosed with lymphedema
- 387 women didn’t have lymphedema
Besides drawing a blood sample for genetic testing, the researchers also measured the women’s height and weight and used bioimpedance spectroscopy to measure lymphedema. Bioimpedance spectroscopy is non-invasive and measures body composition, including increases in fluid in the arm or leg. The women were followed for about 5 years.
The researchers found that several genes that were altered in women who had lymphedema compared to women who didn’t have lymphedema.
The risk of lymphedema was also higher in women who:
- had more advanced-stage breast cancer at diagnosis
- had more lymph nodes removed
- had a higher body mass index
According to the researchers, the genes that seem to be associated with lymphedema are turned on later in the development of the lymph system and blood vessels. The genes appear to play a role in the lymph system’s ability to function regularly. It might be that in people who have changes in these genes are more likely to develop lymphedema after breast cancer surgery because the genes aren’t functioning properly.
While the results of this study are very interesting, more research needs to be done before doctors know exactly how and why certain genes may increase the risk of lymphedema after breast cancer surgery, as well as how these tests would be used by doctors.
Until then, if you’re scheduled to have breast cancer surgery, be sure to ask your doctor about your risk of lymphedema and any steps you can take to lower that risk. If you’ve already had surgery and have been diagnosed with lymphedema, it’s a good idea to talk to a lymphedema therapist about a treatment plan that treats all the symptoms you’re having. Together, you can develop a plan that is effective and makes the most sense for your unique situation.
You can learn much more about how lymphedema happens, the risk factors for lymphedema, steps you can take to minimize that risk, and lymphedema treatments in the Breastcancer.org Lymphedema section.