ERBB2 and neoplasm: We found no indication that proportional reductions in recurrence with anthracycline were any different in HER2-positive and HER2-negative disease, as previously suggested.38 However, too few trials included HER2-negative and HER2-positive tumours for meaningful subgroup investigation of differential efficacy of anthracycline or taxane according to HER2 amplification, and too few participants had data on Ki-67, TOP2A, or gene expression for subgroup analysis.