ERBB2 and breast cancer: The stage (stage 2: HR = 2.16; 95%CI = 1.23–3.78; stage 3: 4.35; 95%CI = 2.19–8.63) and HER2 metagene score classification (HR = 1.76; 95%CI= 1.09–2.86) remained significant in multivariate analysis (Table 2), and Figure 5 shows the 20-year breast cancer-specific survival estimates based on the metagene score classification.