A real-world study of oral low-dose metronomic vinorelbine in elderly patients with metastatic triple-negative breast cancer

This exploratory study aimed to describe the clinical activity and tolerability profile of oral low-dose metronomic vinorelbine in a real-world cohort of elderly patients with pretreated metastatic triple-negative breast cancer (TNBC). Elderly metastatic TNBC patients received oral vinorelbine 20 mg thrice a week until disease progression, unacceptable toxicity, or consent withdrawal. The primary endpoints were objective response rate (ORR), clinical benefit rate (CBR; CR + PR + SD for ≥ 6 months). The secondary endpoints were tolerability, progression-free survival (PFS), overall survival (OS), and prognostic factors. 37 patients with elderly metastatic TNBC were enrolled, with a median of 2 prior chemotherapy regimens for MBC. Median age was 69 years (95% Confdence Interval (CI) 48.6–63.1). Number of metastases ≥ 2 in 26 patients (70.3%). The ORR was 29.7%, the DCR was 70.3%, the CBR was 45.9%, the median PFS was 8 months and the median OS was 29 months. The most common adverse events (AEs) included neutropenia (45.9%), anaemia(43.2%), nausea/vomiting(40.5%), and diarrhea (10%), the grade 3/4 AEs were less.The COX multivariate analysis results showed that efficacy of metronomic chemotherapy were independent prognostic factors affecting the survival of patients (P < 0.05). Oral metronomic vinorelbine may represent a potential therapeutic option for elderly metastatic TNBC patients, demonstrating promising efficacy and a manageable safety profile in this study.