Trastuzumab produced similar proportional reductions in recurrence of ER-positive and ER-negative disease, as did chemotherapy alone in previous meta-analyses.12, 17 Similar to HER2-negative disease, the risk of early (years 0–4) recurrence was higher for HER2-positive, ER-negative tumours than for HER2-positive, ER-positive tumours. This evidence concerns the gene ERBB2 and neoplasm.