NEW APPROACHES TO PRECLINICAL DIAGNOSIS OF PROSTATE CANCER

Abstract

THE AIM : to evaluate the clinical significance of the use of prostate-specific antigen (PSA) and its fractions and indexes for early detection of prostate cancer (PCA) in men with total PSA (tPSA) 2-10 ng/ml with a negative digital rectal examination (DRE). MATERIALS AND METHODS . It were examined 904 men aged 45-80 years with tPSA 2-10 ng/ml (Hybritech calibration) and a negative result DRE. Morphologic study of 628 people were identified benign prostatic hyperplasia (BPH) and 276 – PCA. All patients underwent ultrasound examination of the prostate, with determined total PSA (tPSA) concentration, its fractions and indexes. RESULTS. In PCA, the relative concentrations in the serum free PSA was 19% lower and the absolute content [-2]proPSA at 42% higher, and the prostate health idex (PHI) – at 49% higher. At low values of tPSA for prostate cancer would not be diagnosed in 9%, and at normal values of – 28% of patients. The sensitivity of the method at tPSA of 4.0 to 10.0 ng/ml is 0,630 and specificity of 0,519. tPSA, %fPSA were negative, but [-2]proPSA, %[-2] proPSA and PHI is positively correlated with the Gleason sum. All indicators in stage 2 for PCA are significantly different from the values characteristic of stage 1 of the disease. Though, for commonly used metrics – tPSA, fPSA and %fPSA – differences did not exceed 22-27%. However, [-2] proPSA, %[-2]proPSA and PHY at stage 2a increased by 20-53%, and at stage 2b – by 55-77%. CONCLUSION . The most informative indicators for early diagnosis of PCA was PHY, [-2]propsa. Determinatioms of PHY in the dynamics within the screening can substantially improve early diagnosis of PCA.