ERBB2 and neoplasm: These results were confirmed by multivariate analysis which identified ER expression (OR = 2.66; 95 CI: 1.12–6.29; P = 0.027) and time to recurrence (OR = 2.14; 95 CI: 1.15–4.01; P = 0.017) as two parameters independently associated with the risk of an increased HER2 expression in the recurrent tumour.