ERBB2 and breast cancer: However, this is also consistent with the findings from a recent study on unselected breast cancers from Chinese women who reported a lower prevalence of PAM50 luminal A subtype and a higher prevalence of luminal B subtype compared to Caucasian series.14 The frequency of HER2-overexpressing and basal-like breast cancers was similar between Chinese and Caucasian breast cancers.