Prognostic significance of changes in short-term prostate volume and serum prostate-specific antigen after androgen withdrawal in men with metastatic prostate cancer.

Objective: Endocrine therapy is the standard treatment for metastatic prostate cancer although progression to androgen independence is inevitable. To evaluate prognostic factors in metastatic prostate cancer, patients who had been treated with endocrine therapy were investigated especially for the change in prostate volume.

Methods: Fifty-nine patients with untreated metastatic prostate cancer who received endocrine therapy were included in the present study. Blood chemistry, histological grade, extent of bony metastasis, clinical response to hormone therapy including the short-term change in prostate volume and serum prostate-specific antigen (PSA), and prognosis of the patients were evaluated.

Results: With univariate analysis, hemoglobin concentration, serum alkaline phosphatase, lactate dehydrogenase (LDH), histological grade, extent of bony disease, the short-term change of prostate volume and response of PSA at 3 months were shown to be significant prognostic factors. Response of PSA, LDH and the change in prostate volume were significant for predicting prognosis with multivariate analyses. Five-year survival rate in patients whose prostate had regressed 20% or more at 1 month and whose PSA had been normalized at 3 months was 67%, whereas that in patients whose prostate had regressed less than 20% and whose PSA had not been normalized was 0%.

Conclusions: The patients in whom PSA had not been normalized at 3 months and the prostate volume had regressed less than 20% at 1 month were in the high-risk group. New or more aggressive treatment should be considered.