When comparing NACT with ACT across clinical characteristics, a stronger association with breast cancer-specific mortality, independent of demographic factors, tumor characteristics and treatment modes, was observed for patients in NACT-disfavored subgroups including lobular/mixed histology, well/moderated differentiated tumor, stage I, HR+/HER2- molecular type (HR 1.63-1.93; P for interaction < .001; Figure 2). Here, ERBB2 is linked to breast cancer.