Weekly docetaxel rechallenge in patients with hormone-resistant prostate cancer refractory to conventionally three weekly docetaxel.

e15004 Background: The common standard treatment for hormone resistant prostate cancer is a 3-weekly (q3w) schedule with prednisone 10 mg qd and docetaxel 75 mg/m2 q3w. In case of progression almost 2/3 of patients profit from a docetaxel rechallenge. If the PSA rises again therapy is usually discontinued. Methods: We identified 31 out of 106 patients retrospectively (Jun 2004-Oct 2009) who were reportedly refractory to the q3w schedule and were continued on a weekly (q1w) schedule of prednisone 10 mg qd and docetaxel 30 mg/m2 q1w. 5 patients never responded to q3w, 25 patients responded initially to q3w but then became progressive, 1 patient showed a PSA decline to q3w but was regarded as clinically progressive. Median time to PSA nadir under q3w schedule was 12 weeks. Average age was 71 years and median q3w treatment of docetaxel was 16 weeks. Median baseline PSA was 96 ng/ml. Under the q3w schedule median PSA decline was about 43%. Results: Surprisingly 80% (25/31) of the q3w pretreated patients showed...