Andrea Barrio, MD
New data from researchers at Memorial Sloan Kettering Cancer Center (MSK) featured in the 2021 San Antonio Breast Cancer Symposium (SABCS) press program highlights the important impact that race and ethnicity have on the incidence and severity of breast cancer–related lymphedema after axillary lymph node dissection (ALND). Epidemiological and self-reported data has previously suggested that Black women may be at an increased risk of developing lymphedema after ALND; however, prospective clinical data is lacking and lymphedema risk for other racial minorities has not been well studied. MSK breast surgeon Andrea V. Barrio, MD, and her colleagues sought to assess the incidence of lymphedema after ALND, identify risk factors associated with lymphedema development, and evaluate the impact of race and ethnicity on lymphedema incidence and severity. The findings were presented at the 2021 SABCS.
“To our knowledge, this is the first time that race has been looked at as a factor associated with lymphedema in a prospective study,” explained Dr. Barrio. “After adjusting for other factors, we found that Black race is the strongest predictor of lymphedema development. We now need to understand more about why this is happening. Identifying the links between race, cancer treatment, and the effects of treatment could ultimately help improve quality of life for breast cancer patients and survivors. As we continue our research into the biological mechanisms behind these racial disparities, we aim to identify higher risk patient populations and uncover possible preventive strategies.”
Lymphedema is a frequent and feared side effect of breast cancer treatment, particularly for women who undergo axillary lymph node dissection. Caused by damage to the lymph system, lymphedema typically leads to pain and swelling of the arms or legs.
The study cohort was composed of 276 individuals. Patients undergoing ALND were enrolled in the prospective lymphedema screening study with arm volume measurements and body mass index evaluated at baseline, postoperatively, and at six-month intervals. Lymphedema was defined as a relative increase in arm volume of at least 10% from baseline. At trial enrollment, the median age was 48 years and median BMI was 26.4 kg/m2. Sixty percent of the trial participants were white, 20% Black, 11% Asian, and 6% Hispanic. At a median follow-up of 22.6 months, 56 of the trial participants had developed lymphedema. The two-year lymphedema rate was 39.4% in Black women, 27.7% in Hispanic women, 23.4% in Asian women, and 20.5% in white women.
On multivariable analysis, the researchers found that Black race was the strongest predictor of lymphedema development with a 3.5-fold increased incidence of lymphedema in Black women compared with white women. They also identified an increased incidence of lymphedema in those who had neoadjuvant chemotherapy versus upfront surgery, with lymphedema rates at 30.9% and 11.1%, respectively. Other factors, including older age and increasing time from surgery, were associated with a modest increased risk of lymphedema. Researchers found that Hispanic women in the study had a threefold increased risk of lymphedema compared with white women; however, the Hispanic study population was small, and further research will be necessary to confirm these findings.
