title: Prostate specific antigen and prostatic acid phosphatase for monitoring therapy of carcinoma of the prostate.
abstract: Serial serum prostatic acid phosphatase (PAP) and prostate specific antigen (PSA) measurements were performed in 871 patients treated with hormonal combination therapy for stage C (95 patients) or stage D2 (776) prostate cancer for an average followup of 26 months. The relative efficacy of serum PAP and PSA for predicting recurrence of the disease was evaluated by 2 statistical methods at the time of progression as well as 6 and 12 months before clinical relapse of disease using optimized cut-off values of 2.0 and 4.0 micrograms/l. for serum PAP and PSA, respectively. At the time of progression the sensitivity (plus or minus standard deviation) of the 2 tests was estimated at 61.1 +/- 3.2% and 86.7 +/- 3.1% for PAP and PSA, respectively, while the specificity (plus or minus standard deviation) was calculated at respective values of 79.6 +/- 1.3% and 92.4 +/- 4.1%. Receiver operating characteristic analysis disclosed a greater accuracy for PSA at 89.2 +/- 1.7% versus 78.7 +/- 1.6% (plus or minus standard deviation) for PAP. The somewhat lower positive predictive value of the PSA test (81.4% versus 89.6%) is more than compensated by its superior negative predictive value (92.4% versus 79.6%). The present data also show that serum PSA measurements are superior to those of serum PAP for predicting disease recurrence in stages C and D prostate cancer patients treated by combination endocrine therapy and they indicate that measurement of serum PAP does not add significantly to single measurement of serum PSA alone.
authors.affiliation: Clinical Research Unit in Endocrinology-Oncology, CHUL Research Center, Quebec, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Dupont
authors.forename: L
authors.initials: L
authors.lastname: Cusan
authors.forename: J L
authors.initials: JL
authors.lastname: Gomez
authors.forename: M M
authors.initials: MM
authors.lastname: Thibeault
authors.forename: M
authors.initials: M
authors.lastname: Tremblay
authors.forename: F
authors.initials: F
authors.lastname: Labrie
mesh_terms: D000135:Acid Phosphatase / Q000032:analysis*; D000368:Aged; D000951:Antigens, Neoplasm / Q000032:analysis*; D014408:Biomarkers, Tumor / Q000032:analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011467:Prostate / Q000201:enzymology; D017430:Prostate-Specific Antigen; D011471:Prostatic Neoplasms / Q000175:diagnosis / Q000628:therapy*; D012372:ROC Curve; D012680:Sensitivity and Specificity
chemical_list: D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D000135:Acid Phosphatase; D017430:Prostate-Specific Antigen