Serum tPSA, cPSA, related density parameters and chromogranin A as predictors of positive margins after radical prostatectomy.

摘要

Serum levels of total prostate specific antigen (t-PSA) and PSA complexed to antichymotrypsin (PSA-ACT), as well as their corresponding density parameters were measured in prostate cancer (PC) candidates for radical prostatectomy. In these patients blood Chromogranin A (CgA) values were also recorded. The PSA-ACT recordings in presurgically characterized organ-confined disease were assumed to predict post-surgical staging better than t-PSA. If this proved correct the novel approach might contribute to the positive predictive value of Partin nomograms. In this prospective study 50 patients with clinically localized PC underwent staging pelvic lymphadenectomy and radical prostatectomy. The numerical values of the tPSA and PSA-ACT parameters were presurgically measured. The PSA and PSA-ACT densities (PSAD and ACTD) of the whole prostate were calculated by using transurethral ultrasound (TRUS) data. These preoperative results together with the CgA values were correlated with post-surgical pathological staging data. The relationships between serum tPSA, PSA-ACT, PSAD, ACTD, CgA and the final stage of prostatectomy specimens derived from the pathological data were analyzed. This preliminary study was performed on a relatively small number of patients who were characterized by a serum PSA <20 and a Gleason score (GS) < or =7. Nevertheless, the application of the logistic regression model showed both t-PSA and PSA-ACT to be superior to their density derivatives in predicting postsurgical pathological stage in PC patients who initially seemed to have localized prostate cancer. An elevation in serum CgA level, although rather infrequent at the early stages of PC is principally found in patients with higher Gleason score PC and was mostly associated with extracapsular tumor spread. Our results do not justify the substitution of PSA-ACT for t-PSA data in the Partin nomogram approach.