Patterns of care and patient characteristics in postmenopausal women with HER2+ and hormone receptor-positive (HR+) metastatic breast cancer (MBC).

Abstract

e11107 Background: Treatment of women who are HER2+/ HR+ is challenging due to the complexity of regimens including chemotherapy (CT), hormonal therapy (HT), and targeted therapy (TT). This study evaluated patient characteristics and treatment patterns in women with HER2+/HR+ MBC initiating 1st line therapy in community oncology setting. Methods: We conducted a retrospective observational study utilizing data from US Oncology’s iKnowMed electronic medical record system. Post-menopausal female patients with HER2+/ HR+ MBC from January 2007 to June 2010 were identified and followed through September 2010 to observe treatment patterns. Patients were stratified by presence or absence of visceral crisis (VC), which was identified by chart reviews. For patients without VC, subgroup analyses were conducted by ECOG performance status (PS), year of diagnosis and location of metastasis. Results: The study population consisted of 347 patients; 258 without VC and 89 with VC. Patients with VC were more likely to have multiple sites of metastasis and lower PS than patients without VC. Irrespective of VC status, the most frequently used treatment regimen was CT+ TT followed by HT (without VC: 32%; VC: 37%). In patients without VC, the next most frequently used regimen was HT+TT (20%), compared to CT+TT in women with VC (21%). Trastuzumab, paclitaxel and letrozole were the most frequently used TT, CT and HT, respectively. In patients without VC, better ECOG PS was a predictor of TT and HT; bone only metastasis was a predictor of HT; whereas non-bone metastasis, a predictor of receipt of CT. Approximately 25% of patients without VC did not receive TT, and 35% did not receive HT. Treatment patterns were relatively stable over observation period. Conclusions: When medically appropriate, there may be opportunities to improve patient outcomes (with minimal toxicity) through increased use of TT +/- HT.