The contemporary value of pretreatment prostatic acid phosphatase to predict pathological stage and recurrence in radical prostatectomy cases

Purpose: We examine the clinical prognostic value of the currently available simple and inexpensive immunoenzymatic prostatic acid phosphatase (PAP) assay for the staging and prognosis of radical prostatectomy cases. Materials and Methods: Between February 1, 1990 and May 3, 1996 pretreatment PAP was measured in 295 patients who underwent radical prostatectomy. From February 1, 1990 to May 17, 1992 the Hybritech Tandem-E dagger assay was used in 75 cases, from May 18, 1992 to February 28, 1993 the Abbott EIA double dagger assay was used in 49 and from March 1, 1993 to May 3, 1996 the Abbott IMx double dagger assay was used in 171. PAP assays were analyzed individually and the results were combined with pretreatment prostate specific antigen (PSA) values to assess the ability to predict organ confined prostate cancer and serological recurrence after radical prostatectomy. Results: PAP testing was not of value for predicting organ confined disease or positive margins. However, this test was useful for predicting the first serological PSA recurrence ih the 3 periods (77 to 85% correct) and overall (82% correct, p <0.001, odds ratio 6.06). The Kaplan-Meier disease-free survival rate at 4 years was 78.8% for men with PAP less than 3 ng./ml. and 38.8% for those with PAP 3 ng./ml. or greater, which was significant when pretreatment PSA was less than 10 ng./ml. (p = 0.047), 10 ng./ml. or greater (p = 0.012) and overall (p <0.001). PAP testing added prognostic information to pretreatment PSA values and it was an independent predictor of recurrence. Conclusions: The widely available and inexpensive PAP assays of the 1990s are predictors of recurrence after radical prostatectomy. They should be included in future studies of prostate cancer recurrence modeling. However, they do not predict pathological stage or margin status.