Black race strongest predictor of lymphedema development after treatment for breast cancer
Further research needed to determine cause of the racial disparity
Black women were three-and-a-half times more likely to develop lymphedema than white women following treatment for breast cancer, according to results of a prospective study presented at the San Antonio Breast Cancer Symposium on December 10.
Lymphedema occurs when fluid builds up in the lymph nodes. It can cause swelling and sometimes pain, often in the arms or legs. People who receive treatment for breast cancer can develop lymphedema in their arms up to 18 to 24 months after surgery. It can worsen over time.
Lymphedema is more common among people who have a procedure called axillary lymph node dissection (ALND) to remove lymph nodes near the tumor. ALND is usually done at the same time as surgery to remove a breast tumor. Chemotherapy can also lead to lymphedema. It can be given before or after surgery to treat breast cancer. Chemotherapy given before is neo-adjuvant therapy.
Lymphedema was diagnosed using arm measurements taken before and after surgery, and every six months for two years. At 22 months, 56 women had lymphedema. The researchers reported data at 24 months then conducted a multivariate analysis to see which factors are the greatest predictors of lymphedema. They found:
- After 24 months, 39 percent of Black women had lymphedema, compared to 21 percent of white women, 28 percent of Hispanic women, and 23 percent of Asian women. Based on multivariate analysis, Black race was the strongest predictor of lymphedema. Black women were three-and-a-half times more likely to develop lymphedema than white women.
- Hispanic women, also, were three times as likely as white women to develop lymphedema. The sample size of Hispanic women was small, so these results are less reliable.
- Neoadjuvant chemotherapy was also associated with lymphedema. Thirty-one percent of women in the study group who had chemotherapy prior to surgery developed lymphedema, compared to 11 percent of women who had surgery up front. Final analysis showed that women who had neoadjuvant chemotherapy were more than two times as likely to get lymphedema as those who went straight to surgery.
- Older women and women who had surgery more than six months after chemotherapy were just slightly more likely to get lymphedema. Notably, factors that did not affect the likelihood of lymphedema include body mass index, number of positive lymph nodes, and number of lymph nodes removed.
What this means for Black women
This study provides important findings to inform practice and guide research. First, Black women are more likely to develop lymphedema than white or Asian women. Second, and even more significant, being Black was the strongest predictor in the study of whether someone would get lymphedema.
One possible reason for this disparity is that research has shown that Black women are often diagnosed with later-stage breast cancer, thus more likely to undergo the axillary surgery that can lead to lymphedema. The study team recommends future research on biological mechanisms that may come into play, such as inflammatory response or tissue fibrosis. This research also did not address possible inequities in care, another area for further study. For example, physical therapy can help prevent lymphedema. Yet, in this study, only patients who requested physical therapy were sent for physical therapy.
The data on Hispanic women in this study also suggest a much higher risk of lymphedema; however, the small sample size calls for further study.
Doctors also do not know why having chemotherapy before surgery might lead to lymphedema. This too is an area for future study.
Based on this research, it is especially important for doctors and nurses to talk with their Black and Hispanic patients about lymphedema and how it might be prevented.