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Black women experienced higher rates of breast cancer-related lymphedema compared with White women, according to results of a study presented at the 2021 San Antonio Breast Cancer Symposium (SABCS) by Andrea V. Barrio, MD, an associate attending physician in the Breast Service, Department of Surgery, at Memorial Sloan Kettering Cancer Center.
In addition to the higher incidence, the study showed that Black race was the strongest predictor of lymphedema development.
Breast-cancer related lymphedema is a frequent and feared complication following axillary surgery for breast cancer, explained Dr. Barrio. Axillary lymph node dissection remains the main risk factor for lymphedema, but other risk factors are inconsistent in studies. In addition, epidemiologic studies have reported an increased susceptibility to lymphedema among Black women, but prospective clinical data are lacking.
This prospective study included 304 patients with breast cancer who underwent axillary lymph node dissection between November 2016 and March 2020. Of these, 276 had at least 1 longitudinal measurement after baseline. Sixty percent of patients were White; 20% were Black, 11% were Asian, and 6% were Hispanic.
To measure lymphedema, the researchers measured arm volume at baseline, postoperatively, and at 6-month intervals for a total of 2 years. Lymphedema was defined as a relative volume change of 10% or greater.
White and Black women in the study were older and Black and Hispanic women had higher baseline body mass index. Black women more likely to present with clinical N1 disease and Hispanic women more likely to present with clinical N2/3 disease.
Black and Hispanic women also are more likely to undergo breast-conserving surgery and more likely to receive nodal radiotherapy; Hispanic women had a higher total number of lymph nodes removed.
At 24 months follow-up, approximately one-quarter (24.7%) of patients had developed lymphedema.
“The incidence of lymphedema varied significantly by race and ethnicity with the highest incidence of lymphedema reported in Black women,” Dr. Barrio said.
The 24-month lymphedema rate was 39.4% for Black women, 27.7% for Hispanic women, 23.4% for Asian women, and 20.5% for White women. Women who received neoadjuvant chemotherapy were also significantly more likely to develop lymphedema compared with those who had surgery upfront (30.9% vs 11.1%; P =.0066).
Multivariable analysis showed that Black race was the strongest predictor of lymphedema development. Black women were 3.5 times more likely to develop lymphedema compared with White women. Hispanic women in the study had a threefold increased risk of lymphedema compared with White women, but the researchers noted that the population of Hispanic patients was small.
Other factors associated with risk were receipt of neoadjuvant chemotherapy (odds ratio [OR], 2.08), older age (OR, 1.04 per 1-year increase), and increasing time from surgery (OR, 1.70 per 6-month increase).
“In patient subsets unlikely to achieve nodal pathologic complete response to neoadjuvant chemotherapy, alternatives to avoid axillary lymph node dissection are needed,” Dr. Barrio said.
Future studies should address the biologic mechanisms behind racial disparities in lymphedema development.