The 5-Year Disease-Free Survival of Third Generation Aromatase Inhibitor for Postmenopausal Women with HR-positive HER2-negative Non-Metastatic Breast Cancer

Background: Several studies showed the superiority of aromatase inhibitor (AI) as first-line therapy for patients with hormone-receptor (HR)-positive breast cancer (BC). For the clinician, studies in the real world are warranted to determine treatment based on the efficacy of each drug. We conducted a comparison of 5-y disease-free survival (DFS) of each AI in terms of survival benefit. Materials and Methods: We evaluated 450 medical records of postmenopausal women at Dr. Sardjito General Hospital who were diagnosed with HR-positive HER2-negative BC (stage I – III) from January to December 2019 and had undergone surgery, received chemotherapy or radiation therapy, and at least one year of anastrozole, letrozole, or exemestane administration. Kaplan Meier estimation survival curve was used to analyse of survival rate. Result: Of 79 patients meeting inclusion criteria, there were 21.52 distant metastases documented. Time to disease progression of anastrozole, letrozole and exemestane was 49 months, 58 months, and 53 months, respectively. Letrozole was found better than anastrozole (hazard ratio (HR)=4.342, 95 CI 0.95-19.95; p=0.038). Letrozole versus exemestane (HR=2.757, 95 CI 0.53-14.33; p=0,206) and anastrozole versus exemestane (HR=1.652, 95 CI 0.56-4.84; p=0.351) were found not significantly different. 5-y DFS rate of letrozole was better found (87.5) than exemestane (73.7) and anastrozole (61,4). Conclusion: 5-year letrozole administration could be proposed as first-line therapy for postmenopausal women with HR-positive HER2-negative BC. A considerable subject and long-term follow-up are needed for validation. © 2022 Tehran University of Medical Sciences.