Toxicity and Efficacy of Intermittent Docetaxel Chemotherapy for Hormone Refractory Prostate Cancer

Background: Until today, docetaxel is the only EMEA and FDA approved active agent in hormone refractory prostate cancer (HRPC). In the absence of other effective and approved drugs we evaluated the toxicity and efficacy of intermittent docetaxel-chemotherapy in patients whose cancers progressed after successful first-line docetaxel therapy. Methods: 46, 18, and 5 patients with HRPC received 1, 2, or 3 cycles of docetaxel based chemotherapy. Toxicity, PSA response and general condition were evaluated systematically. SPSS 15.0 was applied for statistic analysis. Results: 26(56%) patients achieved a PSA response of >50%, another 10(22%) patients of up to 50%; 10(22%) patients were progressive under docetaxel. The median overall survival of the whole cohort calculated from the first docetaxel application was 16 (3-60+) months. Tolerance, toxicity and general condition were crucial for the administration of a second cycle (n=18); in contrast, age or the degree of the PSA decline in cycle I did not seem to be of importance. The median overall survival of all patients who received at least two blocks was 35 months; moreover, 13 / 18 patients achieved a biochemical response in cycle2. Toxicity did not rise significantly. Five patients were given a third docetaxel cycle, three of whom responded. Higher frequencies of grade 3/4 stomatitis, skin toxicity and leukocytopaenia were observed. Conclusion: Intermittent docetaxel therapy is well tolerated and shows high response rates in the second and third sequences of treatment in selected HRPC patients who presented with low docetaxel toxicity, good clinical condition and responded to prior docetaxel-based treatment.