What Is High-risk Breast Cancer With Pathologically Negative Lymph Nodes for Regional Recurrence?

Purpose: This study aimed to identify high-risk factors for regional recurrence in patients with breast cancer with pathologically negative lymph nodes. Methods and Materials: We retrospectively analyzed 3800 patients with stage pT1-pT3 breast cancer and pathologically negative lymph nodes between 2004 and 2012. All patients underwent upfront surgery with curative intent. Adjuvant systemic treatments were administered to most patients (96.7%) based on contemporary guidelines. Results: After a median follow-up of 83 months (range, 7-175 months), the estimated 10-year cumulative incidence rate of regional recurrence was 2.0%. Multivariate competing risk analysis revealed that high histologic grade, positive lymphovascular invasion, and stage pT2-3 were significant risk factors for any regional recurrence. Patients with >= 2 risk factors showed a significantly higher 10-year cumulative incidence rate of any regional recurrence than those with 1 or no risk factors (5.5% vs 1.2%; P < .001). When the number of retrieved lymph nodes was less than 10, the difference in the incidence rate of regional recurrence between patients with >= 2 risk factors and those with 1 or no risk factors was greater (6.6% vs 1.3%, respectively; P < .001). The 10-year disease-free survival was worse in patients with >= 2 risk factors than in those with 1 or no risk factors (84.7% vs 90.0%, respectively; P < .001). Patients with >= 2 risk factors also showed worse 10-year overall survival than did those with 1 or no risk factors (91.3% vs 97.0%, respectively; P < .001). Conclusions: Overall, the cumulative incidence rate of any regional recurrence was low at 10 years. However, patients with >= 2 risk factors showed an increased risk of any regional recurrence and worse disease-free survival, particularly when the number of retrieved lymph nodes was less than 10. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

This study identified high histologic grade, positive lymphovascular invasion, and stage pT2-3 as significant risk factors for regional recurrence in breast cancer patients. Patients with multiple risk factors had higher rates of recurrence and worse survival outcomes, especially when the number of retrieved lymph nodes was less than 10.