ERBB2 and neoplasm: Analysis of the various receptor subclasses by women’s demographics showed that those diagnosed before 45 years of age had the highest proportions of tumours with poor prognostic features (HR+/HER2+ and HR− tumours at 16% and 20%, respectively), compared to women diagnosed at or above 45 years of age (who had 9% of HR+/HER2+ and 12% HR− tumours) (Table 10).