Abstract
BACKGROUND: Both hormonal therapy (HT) and maintenance capecitabine monotherapy (MCT) have been shown to extend time to progression (TTP) in patients with metastatic breast cancer (MBC) after failure of taxanes and anthracycline-containing regimens. However, no clinical trials have directly compared the efficacy of MCT and HT after response to first-line capecitabine-based combination chemotherapy (FCCT) in patients with hormone receptor (HR)-positive and human epidermal growth factor receptor 2 (HER2)-negative breast cancer. METHODS: We retrospectively analyzed the charts of 138 HR-positive and HER2-negative MBC patients who were in non-progression status after FCCT and who were treated between 2003 and 2012 at the Cancer Institute and Hospital, Chinese Academy of Medical Sciences, in Beijing, China. The median number of first-line chemotherapy cycles was 6 (range, 4-8); combined agents included taxanes, vinorelbine, or gemcitabine. Of these 138 patients, 79 received MCT, and 59 received HT. Single-agent capecitabine was administered at a dose of 1250 mg/m(2) twice daily for 14 days, followed by a 7-day rest period, repeated every 3 weeks. Of the 59 patients who received HT, 37 received aromatase inhibitors (AIs), 8 received selective estrogen receptor modulators (SERMs), and 14 received goserelin plus either AIs or SERMs. We then compared the MCT group and HT group in terms of treatment efficacy. RESULTS: With a median follow-up of 43 months, patients in the HT group had a much longer TTP than patients in the MCT group (13 vs. 8 months, P = 0.011). When TTP was adjusted for age, menopausal status, Karnofsky performance status score, disease-free survival, site of metastasis, number of metastatic sites, and response status after FCCT, extended TTP was still observed for patients in the HT group (hazard ratio: 0.63; 95% confidence interval: 0.44-0.93; P = 0.020). We also observed a trend of overall survival advantage for patients in the HT group vs. patients in the MCT group, but the difference was not significant (43 vs. 37 months, P = 0.400). In addition, patients in the HT group generally tolerated the treatment well, whereas patients in the MCT group experienced grades 3-4 adverse events, the most frequent of which were hand-foot syndrome (15.8%) and hematologic abnormalities (7.6%). CONCLUSION: For HR-positive and HER2-negative MBC patients, HT might be considered a treatment after response to FCCT but prior to MCT as a long-term administration.