ReCAP: Treatment Patterns and Cost of Care Associated With Initial Therapy Among Patients Diagnosed With Operable Early-Stage Human Epidermal Growth Factor Receptor 2-Overexpressed Breast Cancer in the United States: A Real-World Retrospective Study

QUESTION ASKED: This study assessed real-world treatment patterns, health care use, and costs associated with initial treatment of resected nonmetastatic human epidermal growth factor receptor 2–overexpressing (HER2+) breast cancer in the United States. SUMMARY ANSWER: Although trastuzumab-based therapy is considered standard of care among patients with HER2+ early-stage breast cancer, approximately 28% of these patients did not receive HER2-targeted therapy; in addition, receipt of HER2-targeted therapy differed by hormone receptor status. METHODS: Oncology registry data linked to a large US commercial administrative claims database were used to identify and examine treatment patterns, health care use, and costs of commercially insured patients with operable HER2+ breast cancer during the initial phase of care. BIAS, CONFOUNDING FACTOR(S), DRAWBACKS: Claims data are appropriate for evaluating treatment patterns and health care costs; however, they typically lack important clinical information (eg, history of cardiac disease) that may influence treatment decisions and, ultimately, study outcomes. The follow-up period for many patients was censored, which limited the ability to determine when the initial phase of care should be considered completed. Also, newer therapies may not have been adequately captured. For example, pertuzumab was approved for neoadjuvant use after the end of the study period. Finally, the results of this study are limited to the patient sample examined and may not be generalizable to other populations such as patients older than 65 years, those with no or different types of insurance coverage, or patients outside the United States. REAL-LIFE IMPLICATIONS: Although HER2-targeted therapy is the standard of care for patients with HER2+ breast cancer, HER2-based therapy may be underused among patients with nonmetastatic HER2+ breast cancer in the United States. [Table: see text]