Long-term outcomes among breast cancer patients with extensive regional lymph node involvement: implications for...

Extensive lymph node (LN) involvement portends significant risk for distant metastasis (DM) among breast cancer patients. As a result, local management may be of secondary import to systemic control in this population. We analyzed patients with ≥10 involved LNs (N3) to evaluate the feasibility of breast conserving therapy (BCT) vs modified radical mastectomy (MRM) in this high-risk cohort. Among 98 women with N3 disease 46 (46.9%) underwent BCT and 52 (53.1%) received MRM. Nearly all patients (92%) received comprehensive radiotherapy (RT) including axillary and supraclavicular fields. The Kaplan-Meier method and Cox regression analyses were used to analyze time-to-event outcomes. Median follow-up was 76 months, with a 5-year DFS of 64.9% and OS of 71.9% among the cohort. Poorly differentiated (p = 0.007), ER-negative tumors (p = 0.015) had adverse DFS outcomes. Treatment groups did not differ with regard to 10-year DFS (45.4% for MRM vs. 57.6% for BCT; p = 0.31), or OS (61.4 vs. 63.7%; p = 0.79). DM-free survival was 48.9% following MRM and 60.6% following BCT (p = 0.19). Patients with ≥10 involved LNs have similar outcomes following BCT or MRM, suggesting that RT may obviate the need for more-extensive surgery. While local control is comparably favorable regardless of surgical approach, systemic control remains a challenge in this population.