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

The costs associated with metastatic HR+/HER2- BC reflect a significant disease burden. Low endocrine treatment rates captured by the publicly funded system suggest guideline non-adherence or that a fair portion of Ontarian patients may be incurring out-of-pocket drug costs.