Value of the serum prostate-specific antigen-alpha 1-antichymotrypsin complex and its density as a predictor for the extent of prostate cancer

Objective To determine whether serum levels of the prostate-specific antige n-alpha1-antichymotrypsin complex (PSA-ACT) and its density (ACTD) in patie nts scheduled to undergo radical prostatectomy for clinically localized pro state cancer can predict organ-confined vs extraprostatic disease. Patients and methods Serum samples were obtained from 62 patients with clin ically localized prostate cancer before they underwent radical prostatectom y. PSA and PSA-ACT were measured using immunofluorometric techniques with d ifferent monoclonal antibodies against PSA and ACT, respectively, Furthermo re, the PSA and PSA-ACT densities of the whole prostate (PSAD and ACTD, res pectively) were calculated. The relationships of serum PSA, PSA-ACT, PSAD, ACTD and the pathological stage of the prostatectomy specimens were analyse d. Results The disease was organ-confined or extraprostatic in 30 and 32 men, respectively, In men with organ-confined cancer, the mean PSA and PSA-ACT l evels were significantly lower than in those with extraprostatic disease, F urthermore, there were significantly higher mean PSAD and ACTD levels in me n with extraprostatic than with organ-confined disease. There were also sig nificant differences in PSA, PSA-ACT, PSAD and ACTD levels at each patholog ical stage, whereas there was no significant association between these vari ables and the Gleason score. Receiver-operating characteristic curve analys is for detecting organ-confined disease showed that PSA-ACT and ACTD had a larger area under the curve than PSA and PSAD, respectively, but these diff erences were not significant. Furthermore, PSA-ACT and ACTD provided signif icantly better sensitivity for detecting organ-confined disease than PSA an d PSAD, respectively. Conclusions Measuring PSA-ACT and ACTD may improve the preoperative evaluat ion of patients scheduled to undergo radical prostatectomy, because these f actors better differentiate extraprostatic from organ-confined disease than PSA and PSAD.