Progression after docetaxel-based chemotherapy in androgen-independent prostate cancer

To assess the clinical pattern of progression and prostate-specific antigen doubling time (PSA-DT) after exposure to docetaxel-based chemotherapy in patients with androgen-independent prostate cancer (AIPC).

Fifty-five patients received docetaxel-based chemotherapy; data were collected retrospectively from three different departments. Progression was known in 44 (79%) and the PSA-DT was available in 33 patients.

Of the 29 patients with soft-tissue and soft-tissue plus bone metastases, 22 (76%) developed soft-tissue progression. Among the 35 patients with bone and bone plus soft-tissue metastases, 27 (77%) had osseous progression. There was no difference between the PSA-DT at progression before and after docetaxel-based therapy (mean 3.1 vs 2.7 months, P = 0.592, Student's t-test.). However, the median (range) PSA-DT at progression after docetaxel-based therapy was 0.84 (0.3-4) months in patients with a PSA response, significantly shorter than the median of 3.1 (0.3-12) months of patients with no biochemical response (P = 0.002, Student's t-test). The PSA-DT dynamics at progression had no effect on survival (P = 0.63, log-rank test).

The pattern of progression after docetaxel-based chemotherapy is predominantly osseous in patient with bone metastases and mostly soft-tissue in those with soft-tissue disease. Progression after docetaxel-based chemotherapy in AIPC does not modify the PSA-DT before docetaxel. Evaluation of a larger population is needed to assess the clinical relevance of PSA dynamics after docetaxel therapy.