Outcomes and Prognosis of Radiation Therapy in Locoregional Recurrent Breast Cancer after Mastectomy

Abstract

Purpose: To analyze the treatment outcomes of radiation therapy (RT) in breast cancer patients who developed locoregional recurrence (LRR) after initial treatment with mastectomy, and to investigate the prognostic factors influencing survival. Materials and Methods: We retrospectively reviewed medical records of breast cancer patients who received RT for post-mastectomy LRR in our hospital from 1989 to 2009. Patients who had previous RT and distant metastasis before LRR were excluded, but patients with synchronous distant metastasis were included in this study. Clinicopathologic parameters and outcomes were analyzed. Kaplan-Meier method was used to estimate local recurrence progression-free survival (LRPFS), distant metastasis -free survival (DMFS) and overall survival (OS). Cox proportional hazards models were utilized to assess the prognostic significance of these clinicopathologic parameters on survival. Results: One hundred and fifty-five patients were included in the study. Median followup time was 9.8 years. Thirty-one (20.0%) patients had synchronous metastasis at the diagnosis of LRR, while 124 (80%) patients had not. The median OS for patients with and without synchronous metastasis were 1.6 and 4.2 years, respectively (P= 0.001), but there was no difference on LRPFS between these two groups (P= 0.33). Among the 124 patients without synchronous metastasis, the 5-year LRPFS, DMFS and OS for were 58.9%, 35.4% and 46%, respectively. Eighty-three patients (67%) subsequently developed distant metastases. Patients with chest wall recurrence had a significantly better 5-year OS than patients with isolated LN or multiple sites recurrences (56.3% vs. 39.8% vs. 27.8%, P= 0.04). Multivariate analysis for patients without synchronous metastasis revealed that sites of LRR and initial stage were significant prognostic factors for LRPFS, while aggressive local therapy (including surgery and RT), initial stage and salvage systemic therapy were significant prognostic factors affecting OS. Conclusions: Locoregional recurrent breast cancer carries a high risk of distant metastasis. Use of aggressive local therapy and systemic therapy can achieve good survival outcomes in a substantial proportion of patients.