Effects of locoregional radiotherapy in patients with metastatic breast cancer

Abstract

ObjectivesThis 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 methodsBetween 2005 and 2013, we retrospectively evaluated patients with MBC who received breast or chest wall RT with or without regional lymph node irradiation. Results2761 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). ConclusionRT 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.