SP12. Risk Factors for Lymphedema Development in the Setting Of Axillary Lymph Node Dissection

PURPOSE: Breast cancer-related lymphedema (BCRL)remains a burdensome sequela after multi-modal treatment. Patients undergoing axillary lymph node dissection (ALND) are at highest risk for developing BCRL; however, the impact of other risk factors in this setting is not as well-defined. The role of preventative measures such as immediate lymphatic reconstruction (ILR) in this high-risk population is of particular interest. METHODS: Retrospective chart review of patients who underwent ALND at a tertiary cancer center between 2018 and 2022 was performed. Patient demographics, medical histories, cancer treatments, operative details and post-operative complications were recorded. The primary outcome measure was the development of lymphedema after at least one year of follow up. Univariate and multivariate regression analysis was performed to determine risk factors for lymphedema after ALND. RESULTS: 200 patients were identified who met criteria. Patients were predominantly female (98.0%) with an average age of 52 (44-65) years and an average BMI of 27.7 (23.6 - 32.7). The majority of patients were white (57.5%) with 33% self-identifying as black and 9.1 % denoting Other or Mixed as their race. Most patients had chemotherapy (60%) and post operative radiation therapy (73%) as part of their treatment. 71 patients (35.5%) were diagnosed with lymphedema after ALND. Univariable regression identified BMI and race to be risk factors for developing lymphedema after ALND, particularly obesity class II (OR 2.70 [1.17 - 7.29]) and class III (OR 3.96 [1.17 - 14.6] p<0.004 compared to normal BMI category. Black patients were more likely to develop lymphedema (OR 2.44 [1.30 - 4.62] p=0.02). Additional risk factors included chemotherapy (OR 3.27 [1.69 - 6.65] p<0.001) and radiation (OR 2.4 [1.2 - 5.12] p=0.02). 48 patients in our study (24%) underwent ILR. Among those who developed lymphedema, 9 patients (12.7%) had undergone ILR while 62 did not (87.3%; p=0.005). Patients who underwent ILR were significantly less likely to have symptomatic lymphedema (OR 0.21 [0.15 - 0.27] p<0.001). CONCLUSION: Breast cancer related lymphedema has significant impact on survivorship after treatment. Our study identifies both patient and cancer-related risk factors that are associated with the development of lymphedema in a diverse patient population. We show race to be as important as chemotherapy and radiation in the development of lymphedema after ALND, while ILR could mitigate this risk. Further prospective and randomized studies are warranted to clearly define the role of ILR in high-risk patients.