Cyclophosphamide, Methotrexate, and 5-Fluorouracil as Palliative Treatment for Heavily Pretreated Patients with Metastatic Breast Cancer: A Multicenter Retrospective Analysis

PURPOSE: This study aimed to evaluate the efficacy and safety of cyclophosphamide, methotrexate, and 5-fluorouracil (CMF) chemotherapy beyond standard treatment for anthracycline- and taxane-pretreated metastatic breast cancer (MBC). METHODS: We consecutively enrolled 158 MBC patients who underwent CMF chemotherapy in a palliative setting at two academic hospitals in Korea between 2002 and 2016. RESULTS: The median age of the 158 enrolled patients was 51 years (range, 30–77 years). The enrolled patients were treated with a median of 5 lines of systemic treatment (range, 2–11) before CMF therapy, and the median time from diagnosis of MBC to CMF administration was 36.0 months (range, 7.1–146.7 months). The median number of cycles of CMF treatment was 3 (range, 1–19), and the relative dose intensity was 90.4%. The toxicity profile was mild, with an observed 3.1% of grade 2 and 5.0% of grade 3/4 neutropenia. Among 147 patients (93.0%) whose response to CMF was evaluated, the response rate was 10.9% (16/147), with complete response (CR) in one and partial response (PR) in 15. In addition, the disease control rate (calculated as CR+PR+stable disease) was 44.2% (65/147). The median progression-free survival and overall survival were 3.1 months (95% confidence interval [CI], 2.7–3.6) and 9.4 months (95% CI, 7.1–11.6), respectively. CONCLUSION: CMF therapy is effective and tolerable as salvage treatment for heavily pretreated MBC.