Metronomic oral cyclophosphamide prednisolone chemotherapy is an effective treatment for metastatic hormone-refractory prostate cancer after docetaxel failure.

BACKGROUND There is currently no standard of treatment for patients with hormone refractory prostate cancer (HRPC) after failure of docetaxel-based chemotherapy. The purpose of this study was to assess the anticancer activity and tolerance of metronomic cyclophosphamide prednisolone combination in this setting. PATIENTS AND METHODS From 2005 to 2010, patients with HRPC who failed at least docetaxel-based chemotherapy were proposed metronomic cyclophosphamide-prednisolone regimen, and were prospectively registered. Twenty-three patients received 50 mg cyclophosphamide and 10 mg prednisolone per os daily until disease progression. Treatment tolerance and efficacy on PSA decrease and pain were studied. RESULTS Metronomic cyclophosphamide prednisolone was safe, well tolerated, and demonstrated interesting clinical activity, yielding a prostate specific antigen decrease by ≥50% in 26% of patients and decrease by ≥30% in 48% of patients, but also favorable palliative effects on pain in 43% of patients. The median progression-free survival was 6 months (95% CI: 4-8 months) and the median overall survival was 11 months (95% CI: 7-19 months). CONCLUSION For this patient population, low dose metronomic cyclophosphamide prednisolone might be a viable alternative. Its convenient oral administration, low cost, and lack of toxicity justify further studies alone, or in combination with other agents in HRPC patients.