Early-stage disease: likelihood (OR with 95% CI and P values from logistic regression) of receiving trastuzumab by deprivation and adjusted for age, ethnicity, rural/urban residence, government region, stage at diagnosis, whether received surgery, ER status, comorbidities, whether discussed at MDT meeting, and diagnosis year for women with stage I–III HER2+ breast cancer who were diagnosed between January 01, 2012 and December 31, 2017 (n = 34,616). Here, ERBB2 is linked to breast cancer.