Prospective randomized trials have demonstrated that postmastectomy radiotherapy (PMRT) improves not only locoregional recurrence-free survival, but also overall survival for node-positive breast cancer patients. Subset analyses in previous trials have shown that improvement of overall survival with PMRT is not always demonstrated for patients with 1-3 positive nodes. Indications for PMRT are still marginal for patients with pathological invasion 5 cm in diameter and 1-3 positive nodes. The aim of this study was to clarify poor prognostic factors for breast cancer patients with pathological invasion size 5 cm and 1-3 positive nodes. Participants comprised 428 breast cancer patients with T1-2 tumor and 1-3 positive axillary nodes (pT1-2 N1) treated using total mastectomy without radiotherapy. Correlations between clinicopathological characteristics and 10-year Kaplan-Meier estimates of locoregional recurrence-free survival, disease-free survival, and overall survival were retrospectively analyzed. Median follow-up was 98 months. Locoregional recurrence was observed in 20 patients (4.7%), and distant recurrence was observed in 70 patients (16.4%). Disease-free survival rate was 80.8%, and overall survival rate within the study period was 90%. Multivariate analysis demonstrated that favorable prognostic factors for locoregional recurrence-free survival were the presence of chemotherapy and positive hormone receptor status, and for disease-free survival were presence of chemotherapy, pT1 tumor, and single positive node. Physicians may consider these favorable prognostic factors in decision to eliminate PMRT from patients with the borderline indications.
Keywords: breast cancer; pT1-2N1; postmastectomy radiotherapy; prognostic factor.
© 2018 Wiley Periodicals, Inc.