Treatment persistence evaluation of tamoxifen and aromatase inhibitors in breast cancer patients in early and late stage disease

Background: The aim of our study was to analyze the persistence with tamoxifen (TAM) and aromatase inhibitors (AIs) in postmenopausal women with hormone-receptor-positive breast cancer (BC) in early and late stage disease. Methods: This study based on data from The IMS Oncology Analyzer (OA) including retrospective longitudinal patient treatment histories from diagnosis for all cancer types. 4,626 patients with a diagnosis of breast cancer with current or terminated treatment with TAM or AIs between January 2003 and March 2012 in Germany were included. Results: Our results indicate a significantly increased risk for treatment discontinuation for patients in the age groups of 41 - 50 and 51 - 60 years compared to older patients as well as in patients with a stage IV tumor compared to patients with lower stage tumors. If treatment was initiated by a gynecologist, patients are less likely to discontinue their therapy compared to treatment initiated by an oncologist. Furthermore, the risk of therapy break up was significantly lower in patients treated in an office-based setting compared to the reference group of patients treated in general hospitals. Conclusion: In conclusion, persistence with endocrine treatment in woman with hormone-receptor-positive breast cancer is low, especially in later stage disease, and needs to be significantly increased to improve outcome in clinical practice. Further research is required to understand this complex, but important aspect.