Retrospective Analysis of Concurrent vs. Sequential Administration of Radiotherapy and Hormone Therapy Using Aromatase Inhibitor for Hormone Receptor-positive Postmenopausal Breast Cancer

Abstract

Background: The optimal sequence of adjuvant aromatase inhibitors and postoperative radiotherapy for postoperative patients with hormone receptor-positive breast cancer treated with breast-conserving surgery is unknown. Patients and Methods: Retrospective analyses of the association of the treatment sequence (concurrent or sequential) of postoperative radiotherapy and adjuvant hormone therapy using aromatase inhibitors with breast cancer outcomes such as ipsilateral breast tumor recurrence, relapse-free and overall survival, and treatment-related complications were performed. Patients were grouped as concurrent (aromatase inhibitors given during radiotherapy followed by continued aromatase inhibitors; 113 patients) and sequential (radiotherapy followed by aromatase inhibitors; 151 patients). Results: At a median follow-up of 2.9 years, there were no differences in the breast cancer outcomes and treatment-related complications between the two treatment groups. In addition, the frequencies of grade 3-5 treatment-related complications were very rare for both treatment groups. Conclusion: Both concurrent and sequential use of postoperative radiotherapy and adjuvant hormone therapy using aromatase inhibitors may be allowed in terms of the breast cancer outcomes and treatment-related complications.