Outcome of patients with hormone-refractory prostate cancer: Prognostic significance of prostate-specific antigen-doubling time and nadir prostate-specific antigen

Objective: Most patients with advanced prostate cancer after prostate-specific antigen (PSA) relapse following maximum androgen blockade rapidly progress to death. The present study was aimed to predict the survival of these serious patients after PSA relapse. Methods: Sixty-eight patients with M1b and 20 patients with T3b, who relapsed and died of cancer within a short period, were studied. PSA-doubling time (PSA-DT) at PSA relapse influenced the outcome after PSA relapse [hazard ratio (CI): 2.000 (1.283-3.226)]; thus, on the basis of the median values of PSA-DT (> 2 months) and additionally nadir PSA in previous treatment (<= 2 ng/ml), patients were stratified into four groups. Outcome in the respective groups was examined. Results: The patients with PSA-DT of > 2 months and nadir PSA of <= 2 ng/ml showed the longest survival. The other patients in various classifications proceeded with the similarly worse outcomes, in which PSA-DT still influenced survival [hazard ratio (CI): 0.422 (0.203-0.878)]. In several treatments, estramustine phosphate and dexamethasone were relatively effective. A similar rate of response to these drugs was obtained in all four groups, irrespective of stratifying with PSA-DT and nadir PSA, and this may be possibly due to the intervals between relapse and treatments, in which tumor volume was increased and tumor property was altered. Patients responding to treatment showed prolonged survival. Conclusion: Both PSA-DT and nadir PSA were predictive factors for subsequent survival at PSA relapse, and the patients with long PSA-DT and low nadir PSA may show long outcome.