ERBB2 and breast cancer: Among 12 765 Medicare beneficiaries diagnosed with ERBB2-positive breast cancer between 2010 and 2019 (median [IQR] age at diagnosis, 74 [69-80] years; 99.2% female and 0.8% male), 8.1% were of Black, 6.9% Hispanic, and 85.0% White race and ethnicity (Table 1).