Serum acid phosphatase level and biochemical recurrence following radical prostatectomy for men with clinically localized prostate cancer

Objectives. Serum acid phosphatase (ACP) was once used as the marker for ad vanced prostate cancer. However, with the development of assays for prostat e-specific antigen (PSA), a more sensitive and specific tumor marker, the u se of ACP has diminished. We investigated the prognostic value of preoperat ive serum ACP in predicting prognosis for men with localized prostate cance r following radical retropubic prostatectomy (RRP). Methods. Of 2295 men treated from 1982 to 1998, 1681 men had a preoperative ACP measurement using an enzymatic assay. We analyzed the actuarial freedo m from biochemical (PSA) progression following RRP according to ACP levels. We used multivariate logistic regression and proportional hazards models t o determine the independent prognostic value of ACP level with respect of p athologic stage and biochemical recurrence. Results. ACP was not an independent predictor of organ confinement or lymph node involvement in the multivariate logistic regression models using preo perative variables. However, in the proportional hazards model, ACP was an independent predictor of tumor recurrence following RRP, and there was a st atistically significant improvement in biochemical recurrence-free survival for men with lower levels of ACP (P < 0.001). Furthermore, the normalized hazard ratios of ACP and PSA for predicting biochemical recurrence were sim ilar. Conclusions. Stratification of men according to their preoperative ACP leve ls was predictive of patient outcome after RRP. Proportional hazards modeli ng using preoperative variables demonstrated that the serum ACP level is an independent predictor of tumor recurrence following RRP. UROLOGY 57: 707-7 11, 2001. (C) 2001, Elsevier Science Inc.