ERBB2 and neoplasm: Eligible patients were considered HER2-positive if tumours were identified by HER2 immunohistochemical (IHC) staining of 3+ (defined as moderate to strong complete or basolateral membrane reactivity in >10% of tumour cells), or if HER2 gene amplification by fluorescence in-situ hybridisation (ISH) (defined as HER2/centromeric probe for chromosome 17 (CEP17) ratio of >2) was deemed HER2-positive.