ERBB2 and breast cancer: One large retrospective case review of 965 patients with T1aN0 orT1bN0 breast cancers, (10% of which were HER2+) showed that the HER2+ patients had a significantly worse recurrence-free survival compared with HER2− cases (77.1% vs 93.7% at 5 years P<0.0001; Gonzalez-Angulo et al, 2009).