Abstract P1-01-01: The Role of Adjuvant Chemotherapy for Elderly Women with Triple-Negative Breast Cancer

Abstract

Purpose: There is little evidence determining whether elderly patients (from 70 to 90 years old) with triple-negative breast cancer (TNBC) could benefit from adjuvant chemotherapy (AC). The objective of this study was to explore the effect of AC in these population following surgery. Methods: A total of 4610 patients were identified in the Surveillance, Epidemiology, and End Results database (2010-2018). Inverse probability of treatment weighting (IPTW) was used to reduce the selection bias. IPTW-adjusted Kaplan-Meiers survival analysis and Cox proportional hazards models were performed to compare breast cancer specific survival (BCSS) and overall survival (OS) in the two different treatment groups. Results: All eligible patients were divided into two groups, the chemotherapy (n=1989) and the observation (n=2621) groups. The percentage of patients receiving AC versus observation increased significantly from 2010 to 2018 (estimated annual percentage change, 1.49%; 95%CI, 0.75-2.16%, p=0.002). The 5-year IPTW-adjusted rates of BCSS and OS in AC group were better than that in observation group (BCSS: 82.32% vs. 78.42%, p=0.010; OS: 75.54% vs. 64.65%, p< 0.001). In IPTW-adjusted Cox proportional hazards regression analysis, elderly patients could benefit from AC (BCSS: HR, 0.77, 95%CI, 0.62-0.94, p=0.012; OS: HR, 0.66, 95%CI, 0.57-0.78, p< 0.001). AC was associated with a significant outcome benefit across year at diagnosis, marital status, stage, lymph node, surgery and radiation subgroups (all p< 0.05). Patients with T1ab could not benefit from AC. Conclusions: We show a BCSS and OS benefit from AC in old patients with TNBC. AC may remain a reasonable treatment approach in these specific patients. For the patients with T1ab, de-escalated treatment should be administrated with caution. It requires further randomized controlled trial to ensure the AC effectiveness for elderly TNBC patients. Citation Format: Tian Lan, Qiusheng Guo, Yunyan Lu, Junwei Gu, Xiying Shao, Haibin Xu, Zujian Hu. The Role of Adjuvant Chemotherapy for Elderly Women with Triple-Negative Breast Cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P1-01-01.