In patients with HER2 IHC discordance‐driven treatment changes, there was a trend towards increased risk of recurrence (7.4% vs. 16.7%, p = 0.38) but not towards increased risk of metastatic disease (21.0% vs. 0%, p > 0.99) or death (6.9% vs. 0%, p > 0.99) compared to patients with no treatment changes. This evidence concerns the gene ERBB2 and metastatic neoplasm.