Outcomes of postoperative radiation therapy for breast cancer in older women according to age and comorbidity status: An observational retrospective study in 752 patients.

Abstract

The aim of this study was to assess efficacy, tolerability, and the impact of comorbidities on outcomes in older women treated by radiation therapy (RT) for non-metastatic breast cancer. Women aged ≥70 years at diagnosis who received postoperative RT for primary non-metastatic BC between 2003 and 2009 were retrieved from the Institut Curie registry. We calculated the Charlson Comorbidity Index (CCI) for each patient. We analyzed overall survival (OS), progression free survival (PFS), and acute and late toxicities according to the Common Terminology Criteria for Adverse Events (CTCAE) v3.0. A total of 752 patients were included in this study. Median age at diagnosis was 75 years [70-93.3]. With a median follow-up of 7.3 years [0.4-12.9], OS and PFS at 5 years were 87.2% CI95%[84.8-89.8] and 85.7% CI95%[83.1-88.3], respectively. OS at 5 years was statistically different according to the CCI: 90.7% CI95%[87.6-93.9] for a CCI of 0, 85.8% CI95%[81.8-90.1] for a CCI of 1, and 79.1% CI95%[71.1-87.9] for a CCI ≥ 2 (p < 0.01, log-rank test), respectively. Similar results were found for PFS (p < 0.05, log-rank test). Most (23.3%) of the patients had no toxicities; of those who experienced side-effects, the majority were grade I or II (96.9%). Postoperative RT for non-metastatic BC in older women is effective and well-tolerated. Outcome is impacted by age and comorbidities, which are clear independent prognostic factors.