[Comparative value of molecular forms of prostate-specific antigen in diagnosis of prostatic cancer]

The aim of the study was to compare diagnostic significance of free PSA (fPSA)/total PSA (tPSA) versus PSA complex with alpha1-antichymotrypsin (cPSA) in tPSA level within 4-10 ng/ml in differential diagnosis of prostatic cancer (PC). A complete urological examination (digital rectal test, transrectal ultrasound investigation, serum assay for fPSA and tPSA, multifocal transperineal prostatic biopsy) was made in 108 patients with tPSA blood level 4-10 ng/ ml. Prostatic adenoma (PA) was histologically verified in 61 of 108 patients, fPSA/tPSA was normal. In the other 39 of 108 patients fPSA/tPSA was under 15% while cPSA was in the range 3.8-9.6 ng/ml. A course of etiotropic therapy of chronic prostatic inflammation produced no significant changes in fPSA/tPSA and cPSA in 28 out of 39 patients. Histologically, these 28 patients had PC. In the rest 11 of 39 patients chronic prostatitis treatment fPSA/tPSA significantly rose to 18.2%, on the average. CPSA decreased to 2.4 ng/ml. These 11 patients were found histologically to have PA and signs of chronic inflammation. In 8 of 108 patients fPSA/tPSA was not indicative of PC being 18,2% on the average while cPSA indicated the presence of PC and was 4.2 ng.ml, on the average. PC was verified histologically in these 8 patients. Thus, cPSA in PC suspects is more informative than fPSA/tPSA in PC diagnosis. CPSA in the serum depends on prostatic inflammation making difficult differential diagnosis of PC in interpretation of tPSA, fPSA/tPSA and cPSA. Therefore, estimation of PSA variants and molecular forms in PC suspects and prostatic inflammation should be made after etiotropic therapy.