ERBB2 and breast cancer: Here we present results from an observational cohort study of white women and black women with invasive breast cancer in which two quantitative measures of ER alone and an adaptation of Cuzick’s combined score, based on quantitative values of ER and PR, and HER2 status [11], were assessed to determine how they compare with each other and with ER status (positive versus negative) in predicting mortality risk.