ERBB2 and breast neoplasm: In univariable analysis, higher histological grade (histological grade 3 versus 1, HR 2.4 CI 95% 1–5.76, p = 0.049 and histological grade 2 versus 1, HR 1.52 CI 95% 0.65-3.53, p = 0.33), subtype (luminal B vs luminal A; HR 2.12, CI 95% 1.18–3.84, p = 0.013; HER2-positive vs luminal A, HR 4.51 CI 95% 1.7–11.99, p = 0.003), and increased tumor size (HR 1.03, 95% CI: 1.01–1.05 per mm, p = 0.003) were associated with a higher risk of ipsilateral breast tumor recurrence (IBTR).