Fig. 3: Chemotherapy benefit according to HER2DX pCR likelihood score.

A Kaplan–Meier curves for RFS by treatment arm (trastuzumab alone vs trastuzumab + chemotherapy) in HER2DX pCR-high tumors. B Kaplan–Meier curves for OS by treatment arm in HER2DX pCR-high tumors. C RFS by treatment arm in HER2DX pCR-medium/low tumors. D OS by treatment arm in HER2DX pCR-medium/low tumors. Hazard ratios, 95% CIs, and p-values were derived from univariable Cox models. Interaction p-values reflect formal tests for treatment–biomarker interaction.