Background: Multiple experimental approaches are meanwhile available for progressive metastatic castration resistant prostate cancer (mCRPC) patients after failure of guideline recommended therapy (i. e., chemotherapy and/or hormonal treatment). We evaluated the outcome of metronomic chemotherapy with cyclophosphamide (CY) in combination with low-dose prednisolone.
Materials and methods: A total of 14 mCRPC-patients were treated with CY 50 mg/day (plus prednisolone 10 mg/day) between November 2012 and September 2017 after being resistant or unfit for chemotherapy and/or further hormonal treatment. Time to progression and overall survival (OS) were retrospectively determined by using Kaplan-Meier curves.
Results: Eight of 14 (57.1%) patients had undergone radical prostatectomy and 2 (14.3%) external beam radiation. All patients had at least three therapy lines and 50% had ≥5 mCRPC therapies. The median time from first diagnosis to mCRPC was 88 months; the median age was 78 years with a median baseline serum prostate-specific antigen (PSA) level of 341 ng/ml. With a median follow-up of 16.4 months, progression-free survival (PFS) was 71, 64, and 43% after 2, 4, and 6 months, respectively. Median OS was 8.1 months. No relevant adverse events occurred.
Conclusion: Since CY is a well-tolerated medication with partially good clinical tumor control, it seems to be a convenient, individual treatment option in progressive mCRPC patients after failure of guideline recommended therapy.
Keywords: Cyclophosphamide; Metronomic chemotherapy; Prostate cancer.