Purpose: Overexpression of the human epidermal growth factor receptor 2 (HER2) protein negatively affects survival in breast cancer. This study aimed to assess real-world treatment patterns and costs associated with resected nonmetastatic HER2-positive breast cancer in the United States.
Patients and methods: Commercially insured patients with HER2-positive breast cancer were identified from oncology registry data linked to a large US commercial administrative claims database. Treatment patterns and health care use and costs in the initial phase of care were examined.
Results: Among the 915 patients who met the study criteria, 662 (72%) were hormone receptor (HR) positive, and 253 (28%) were HR negative. Overall, 72% (n = 662) of patients received HER2-targeted therapy (HR positive, 69% v HR negative, 80%; P < .01), specifically trastuzumab. The most common treatment regimens, regardless of HR status, were carboplatin, docetaxel, and trastuzumab (47% of patients) during neoadjuvant therapy and carboplatin, docetaxel, and trastuzumab ± hormone therapy (30% of patients) during adjuvant therapy. Overall unadjusted cost of treatment per patient per month (HR positive, $11,906 v HR negative, $14,367; P < .001) was mainly cancer related (HR positive, $10,513 v HR negative, $13,073; P < .001). Adjusted 12-month cost was $176,779 (HR positive, $167,088 v HR negative, $180,226; P > .05).
Conclusion: Although trastuzumab-based therapy is considered standard of care among patients with HER2-positive early-stage breast cancer, approximately 28% of these patients did not receive HER2-targeted therapy. Additional studies are warranted to examine whether patients who have not received targeted therapy are eligible for and would benefit from an HER2-targeted approach.
Copyright © 2015 by American Society of Clinical Oncology.