Factors associated with prolonged overall survival in patients with postmenopausal estrogen receptor-positive advanced breast cancer using real-world data: a follow-up analysis of the JBCRG-C06 Safari study

摘要

Background Assessing survival risk is important for discussing treatment options with estrogen receptor-positive (ER+) advanced breast cancer (ABC) patients. However, there are few reports from large-scale databases on the survival risk factors in ER+ ABC. The Safari study (UMIN000015168) was a retrospective, multicenter cohort study involving 1072 Japanese patients receiving fulvestrant 500?mg mostly as a second- or later-line endocrine therapy for ER+ ABC. The follow-up data after the Safari study were examined, focusing on any relationship between clinicopathological factors and overall survival (OS) in ER+ ABC patients. Methods OS in patients with ER+ ABC was analyzed by univariate and multivariate analyses with a Cox proportional hazards model in this study. Results A total of 1031 cases were evaluable for OS analysis. Multivariate analysis showed that younger age (