Safety and efficacy of low-dose metronomic chemotherapy with capecitabine in heavily pretreated patients with metastatic breast.

Abstract

1060 Background: Metronomic chemotherapy regimens have shown efficacy in patients with metastatic breast cancer by antiangiogenic mechanisms. Due to its pharmacokinetic characteristics and low toxicity profile capecitabine is the ideal drug to be administred in a metronomic fashion. Methods: Since October 2006 to December 2009 we tested objective responses, clinical benefit, and safety of capecitabine administered with a metronomic schedule of 500 mg thrice daily in heavily pretreated metastatic breast cancer patients. Among 55 enrolled patients at the moment, 44 were evaluable. ECOG performance status (PS) was 0-3, median age 60 years (range 36-82), HER-2/neu overexpression in 23%; bone plus visceral disease in 41% of cases. All the patients were pretreated with at least 2 endocrine therapy lines (range 1-3) and a median of 3 chemotherapy regimens (range 1-6). Metronomic capecitabine was administered for a median duration of 28 weeks (range 12-144). Results: We observed 10 partial responses (PR: 23 %), 26 (59%) stable disease (SD), and 8 patients with progressive disease (PR+SD=36; 82%). Additional long term disease stabilization (SD>or > 24 weeks) occurred in 19 patients for an overall clinical benefit (CR+PR+ SD >or > 24 weeks) of 59%. Median time to progression was 28 weeks (95% CI, 12 to 144 weeks). Safety of metronomic capecitabine was excellent. Neither grade 2-4 haematological or clinical side effects were recorded and only 4 patients experienced grade I (WHO) hand-foot syndrome. Conclusions: Treatment with metronomic capecitabine was effective and minimally toxic in heavily pretreated breast cancer patients. No significant financial relationships to disclose.