Capecitabine and oxaliplatin in combination as first- or second-line therapy for metastatic breast cancer: a Wisconsin Oncology Network trial

Abstract

Several cytotoxic chemotherapy regimens are active against metastatic breast cancer; however, benefits are modest and overall prognosis remains limited. For anthracycline and taxane-pretreated metastatic breast cancer, there remains a relative paucity of therapies with significant activity. This Phase II study evaluated the combination of capecitabine and oxaliplatin (XELOX) among patients with metastatic breast cancer being treated in the first- or second-line setting. Patients received oxaliplatin 85 mg/m(2) on days 1 and 15, and capecitabine 1,500 mg/m(2) twice daily on days 1-7 and 15-21 of a 28-day cycle. Patients were treated until progression or intolerable toxicity. The primary objective was to estimate the objective response rate by the Response Evaluation Criteria in Solid Tumors (RECIST) criteria with tumor assessments every 8 weeks. Ten patients were treated of which 3 had received prior neurotoxic therapy in the metastatic setting. There were no confirmed complete responses, 5 patients had partial response, 4 patients had stable disease for at least 24 weeks, and one patient was unevaluable. Median time to progression (TTP) was 10.4 months (95% lower confidence bound [LCB]: 5.75 months), median progression-free survival (PFS) was 14.2 months (95% LCB: 6.14 months), and median overall survival (OS) was 19 months (95% LCB: 12.8 months). Multiple patients experienced pain syndromes and unusual neuropathies. Other common toxicities included fatigue, diarrhea, and nausea. XELOX is a promising regimen for anthracycline-pretreated metastatic breast cancer although careful patient selection is indicated and alternate dosing schedules should be explored to minimize neurologic morbidity.