ERBB2 and breast cancer: This finding was consistent with a prior study in localized HER2-positive breast cancer that showed survival outcomes were better in those with HER2 IHC 3+ than in those with 2+ and positive FISH; additionally, among those with HER2 IHC 2+ and positive FISH, patients with a HER2 copy number of ≥8 had better survival outcomes than those with low HER2 copy numbers [18].