Efficacy of immunotherapy in older adults with triple-negative breast cancer: A systematic review.

Abstract

Immune checkpoint inhibitors (ICI) have transformed the treatment landscape for triple-negative breast cancer (TNBC), but their efficacy in older adults remains unclear. The objective of this systematic review is to evaluate the efficacy of ICI in patients with TNBC aged ≥65 years. We conducted a systematic review of randomized controlled trials (RCTs) between January 2013 and September 2023 using searches of Medline, Embase, the Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, and the WHO International Clinical Trials Registry Platform. Eighteen full-text articles representing 11 unique RCTs were identified. Only four RCTs reported efficacy outcomes for patients ≥65 years: KEYNOTE 355, KEYNOTE 522, IMpassion130, and IMpassion131. Across these trials, 602 of 3215 patients (18.7%) were 65 and older. The overall risk of bias was low to intermediate, but heterogeneity in trial design and endpoints precluded meta-analysis. Pembrolizumab, the only FDA-approved ICI in TNBC, showed a nonsignificant trend toward improved pathological complete response and event-free survival among older adults with early-stage TNBC (KEYNOTE-522). In the metastatic setting, pembrolizumab may improve overall survival in older patients with PD-L1 combined positive score ≥ 10 (KEYNOTE-355). All studies enrolled few older patients, and none prespecified age-stratified analyses. These findings highlight a major evidence gap and underscore the need for further research evaluating ICI outcomes in older adults with TNBC.