PSA decline is an independent prognostic marker in hormonally treated prostate cancer.
The aim of this study was to estimate the prevalence of primary hormone-refractory prostate cancer and to evaluate the prognostic value of decline of prostate-specific antigen (PSA) after primary hormonal therapy. The material consisted of 236 consecutive, hormonally treated prostate cancer patients, whose clinicopathological findings, as well as serum PSA values, were retrieved from patient files. Multivariate analysis was performed based on the PSA decline at 12 months from the commencement of therapy and patients were thereafter categorised into four groups: complete response (CR), partial response (PR), stable disease (SD), and no response (NR) according to the biochemical response. Only 14 (5.9%) of the patients were included in the NR group, i.e. PSA declined less than 50%, suggesting that primary androgen-independent prostate cancer is uncommon. The PSA decline was significantly (p < 0.001) associated with cancer-specific survival. Patients with CR had a median survival of more than 6 years, whereas those with NR had a median survival of only 14 months. In multivariate analysis, PSA decline showed independent prognostic value together with M-stage and histological grade. Primary prostate cancer is probably even more sensitive to hormonal treatment than previously assumed, and PSA decline seems to be useful in predicting disease outcome after hormonal therapy.