Table S2 shows the predicted breast cancer deaths with the assumption that patients who underwent chemotherapy were treated with anthracycline-based regimen (second-generation regimen). Table S3 shows the predicted breast cancer deaths with the assumptions that all patients with HER2-positive tumours were treated with trastuzumab, and patients who underwent chemotherapy and were diagnosed before 2010 were treated with anthracycline-based regimen and for those diagnosed after this time were treated with a taxane-based regimen. Here, ERBB2 is linked to neoplasm.