Effects of locoregional radiotherapy in patients with metastatic breast cancer

Abstract

Objectives: This study aims to assess the clinical outcomes of patients with metastatic breast cancer (MBC) who underwent local radiation therapy (RT) for the primary site. Material and methods: Between 2005 and 2013, we retrospectively evaluated patients with MBC who received breast or chest wall RT with or without regional lymph node irradiation. Results: 2761 patients with breast cancer were treated with RT. Of them, 125 women with stage IV breast carcinoma were included. The median follow-up was 15 months (ranging from 3.8 to 168 months), when 54.7% of the patients had died; local progression was observed in 22.8% of the patients. The mean overall survival (OS) and local progression free survival (LoPFS) were 23.4 +/- 2.4 months and 45.1 +/- 2.9 months, respectively. Three-and five-year overall survival rates were, respectively, 21.2% and 13.3%. Local progression free survival was the same, 67.3%, at three and five years, respectively. Karnofsky Performance Status (KPS) (p = 0.015), number of metastatic sites (p = 0.031), RT dose (p = 0.0001) and hormone therapy (p = 0.0001) were confirmed as independent significant variables correlated with OS. The variables that were independently correlated with LoPFS were the number of previous chemotherapy lines (p = 0.038) and RT dose (p = 0.0001). Conclusion: RT of the primary site in patients with MBC is well tolerated. The factors that presented positive impact on survival were good KPS, low disease burden (1-3 metastatic sites), and the use of hormone therapy.