Clinical Significance of Serum Prostate Specific Antigen in Orchiectomized Patients with Metastatic Prostate Cancer

Kim, Duk Kyo; Chang, Sung Goo

Abstract

To identify clinical significance of prostate specific antigen (PSA) in orchiectomized patients with metastatic prostate cancer, we longitudinally investigated significant factors in the progression of the advanced prostate cancer in 28 patients who were comparatively well followed after subcapsular orchiectomy. Following results were obtained. 1) The mean followup interval was 25.9 months (1 to 68 months). Mean patient age was 67.6 years (50 to 82 years). 2) Eleven of 28 patients were expired during follow-up. Death rate was 39.3 percent. 3) Patients whose post-treatment nadir PSA level decreased below 2.8 ng/ml had a significantly longer remission duration rate than those whose nadir PSA remained elevated (mean survival times 53.9 versus 25.4 months, survival rate 85.0 versus 0%, p <0.01). 4) Patients whose interval to nadir PSA was less than 6 months had a significantly longer remission and a larger survival rate than those whose interval to nadir PSA was more than 6 months (mean survival times 58.3 versus 36.4 months, survival rate 93.3 versus 33.3%, p <0.05). 5) After orchiectomy, patients whose duration from nadir PSA level decreased below 2.8 ng/ml to the above 2.8 ng/ml was more than 9 months had a significantly longer remission duration and a larger survival rate than those whose duration was less than 9 months (mean survival times 62.7 versus 24.9 months, survival rate 88.9 versus 27.3%, p <0.001). 6) Patients whose serum PSA was changed earlier than bone scan had a significantly shorter survival duration and a smaller survival rate than those whose bone scan was changed earlier than PSA (mean survival times 24.4 versus 50.3 months, survival rate 30.0 versus 75.0%, p <0.05). 7) Patients whose Gleason grade was below 3 had a better prognosis than those whose Gleason grade was above 4 (mean survival times 50.4 versus 29.9 months, survival rate 78.6 versus 42.9%, p<0.05). 8) Patients` age over 70 years at the time of diagnosis was a Significantly better prognostic factor (p<0.05). pre-treatment PSA levels and PSA half-times were not significant in advanced prostate cancer patients (p>0.05). As the result of the above, we conclude that serial serum PSA levels in advanced prostate cancer patients after endocrinal therapy can aid in distinguishing favorable from nonfavorable responders early in the course of therapy and greatly assist in monitoring for progression.