[Prognostic factors for PSA relapse of prostate cancer after endocrine therapy]

Advanced prostate cancer responds well to endocrine therapy initially, but soon becomes refractory and has a poor prognosis. We analyzed the prognostic factors of prostate cancer responding well initially to endocrine therapy with lowering of serum prostate specific antigen (PSA) level but later showing PSA relapse.

In prostate cancer patients newly diagnosed from January 1992 to December 2004 at our institution, there were 93 patients in that the PSA level of 10 ng/ml or more before therapy initially dropped below 10 ng/ml by endocrine therapy, but showed PSA relapse thereafter. We investigated the relationship between clinical stage, pathological differentiation, initial PSA, duration between initiation of therapy and PSA nadir, the value of PSA nadir, duration between initiation of therapy and PSA relapse, PSA doubling time (PSA-DT) at relapse, PSA response three months after initiation of second line therapy and prognosis after PSA relapse.

In Kaplan-Meier method, between all or some categories investigated showed significant difference in prognosis after PSA relapse. In multivariate analysis, the factors that significantly affected prognosis after PSA relapse were clinical stage, pathological differentiation, PSA nadir value, duration between initiation of therapy and PSA relapse and PSA response three months after initiation of second line therapy.

We investigated the prognostic factors refractory to endocrine therapy. These results are useful in planning the therapy, and in explaining the status or future prospective of the disease to patients and families.