Among patients with stage III HER2+/HR- and TNBC, median TTBM was 23.3 and 18.0 months, respectively.<h4>Conclusion</h4>Up to 13% of patients with stage III HER2+ or TNBC received treatment for brain metastases within 5 years of diagnosis with early-stage breast cancer. Here, ERBB2 is linked to breast cancer.