ERBB2 and breast cancer: Analysis corrected for other prognostic factors found that HER2 2+ status was an unfavorable prognostic factor for DFS (HR=1.217, 95% CI: 1.052-1.408, p=0.008), but there was no significant difference between HER2 2+ and the other groups in HR-negative HER2-negative breast cancer patients with respect to DFS (24).