ERBB2 and metastatic neoplasm: Similarly, in multivariable analysis including the known prognostic factors age (according to menopausal status), duration of disease-free survival and presence of visceral disease and metastatic sites at diagnosis of metastatic disease, we did not observe a statistically significant difference between patients with HER2-low and HER2-0 tumors both the HR+ (HR 0.89; 95% CI 0.74–1.05; P = 0.171; Table 2) and in the triple-negative subgroup (HR 0.92; 95% CI 0.68–1.25; P = 0.585; Table 3).