A population-based comparison of treatment, resource utilization, and costs by cancer stage for Ontario patients with HER2-positive breast cancer.

Per-patient annual costs were substantially higher for women with metastatic HER2+ BC, despite less frequent exposure to surgery and radiation compared to those with early stage disease. Increasing NAT rates in early stage disease represent a critical opportunity to prevent recurrence and reduce the costs associated with treating metastatic HER2+ BC.