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 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.