P33. A Multi-hospital Network Analysis of Long-term Outcomes and Predictors of Lymphedema Following Immediate Lymphatic Reconstruction and Axillary Lymph Node Dissection

Abstract

PURPOSE: Breast cancer-related lymphedema (BCRL) significantly affects quality-of-life after axillary lymph node dissection (ALND). Immediate lymphatic reconstruction (ILR) may reduce BCRL incidence, but long-term outcomes and predictors are unclear. This study sought to compare long-term BCRL prevalence in patients undergoing ILR with pooled estimates from ALND alone and to identify factors associated with BCRL after ILR. METHODS: We retrospectively studied consecutive patients who underwent ILR following ALND between January 2020 and March 2024 across six hospitals in the Indiana University network. Primary outcome was BCRL prevalence, defined as ≥2cm limb difference at two contiguous points. Secondary outcomes included BCRL predictors, postoperative complications, and compression garment use. RESULTS: Among 150 patients (mean age 51.2±10.6 years; BMI 29.6±7.1 kg/m²; follow-up 17.9±10.8 months) that underwent ILR, cumulative BCRL incidence was 10.7% (n=16). Compared to pooled estimates from 10,774 patients undergoing ALND alone, our ILR cohort had significantly lower BCRL rates: 2% vs. 16.5% (<12 months), 6.7% vs. 24.6% (12-24 months), and 10.7% vs. 23.6% (>24 months) (p < 0.001). Compression was used in 29% following ILR, with 64.6% (n=28) not meeting lymphedema diagnostic criteria. Breast-related complications occurred in 29.3% (n=44). Patients with obesity (56.3% vs. 38.3%, p=0.179) and postoperative radiotherapy (93.8% vs. 82.8%, p=0.260) had higher rates of lymphedema following ILR, although not statistically significant. Multivariable analysis did not identify any independent predictors of BCRL among ILR patients. CONCLUSION: ILR following ALND is associated with significantly lower rates of BCRL compared to ALND alone. The prevalence of lymphedema increases over time with longer term follow-up.