Decluttering chemotherapy agents for HER2+early breast cancer: Do we still need carboplatin?

Over the past two decades, targeted anti-HER2 therapies have transformed management of HER2-positive early breast cancer (HER2 + eBC), enabling chemotherapy de-escalation without compromising efficacy. This review assesses the rationale for incorporating carboplatin into (neo)adjuvant regimens and critically examines its routine use in unselected patient populations with HER2-positive eBC. While initial translational and early clinical studies suggested that adding carboplatin to taxane-based chemotherapy combined with anti-HER2 therapy might be beneficial, more recent randomized trials have failed to demonstrate incremental advantage and have raised concerns about increased toxicity. Emerging prognostic and predictive biomarkers, most notably the HER2DX genomic assay, hold promise for identifying high-risk patient subgroups who may derive meaningful benefit from carboplatin. We conclude that carboplatin should not be routinely added in unselected HER2-positive early breast cancer, but rather, a biomarker-driven, personalized strategy is recommended to enhance patient selection, refine the treatment algorithm, and maximize the cost-to-benefit ratio.