BIOCHEMICAL ANALYSES OF FREE, COMPLEXED, AND TOTAL PROSTATE SPECIFIC ANTIGEN IN BENIGN PROSTATIC HYPERPLASIA AND PROSTATE CANCER IN THE UNIVERSITY OF CALABAR TEACHING HOSPITAL, CALABAR

Abstract

Background The study exploited adjunct tests of molecular components of prostate specific antigen (i.e. free and complexed) to establish their clinical usefulness in the diagnosis of Benign Prostatic Hyperplasia (BPH) and Prostate Cancer (PCa). Method It was a cross sectional descriptive study involving 120 male participants between the ages of 40 and 80 years. They were consecutively recruited from the Urology Clinic of the University of Calabar Teaching Hospital. The study lasted for a period of twelve months. Participants were stratified into two groups of 60 each with histologically confirmed diagnosis of PCa and BPH respectively. Their sera were analysed for free, complexed, and total PSA using ELISA kits and read off with AWARENESS stat fax 2100 model microplate reader. Results Total Prostate Specific Antigen (tPSA) values were significantly lower in BPH than in PCa with median values of 8.4 ng/ml and 19.3 ng/ml respectively. Levels of fPSA were significantly higher in BPH with median value of 6.0 ng/ml compared to PCa with median value of 2.6 ng/ml. cPSA on the other hand had significantly higher values in PCa than BPH, with median values of 15.8 ng/ml in PCa and 0.85 ng/ml in BPH. The ROCs of fPSA/tPSA ratio compared to cPSA/tPSA ratio was statistically not different having AUC of 0.667 for fPSA/tPSA and 0.678 for cPSA/tPSA ratios. The sensitivity and specificity were 80.3% and 52.5% respectively for fPSA/tPSA ratio and 57.6% and 71.2% respectively for cPSA/tPSA ratio. P = .001. Conclusion The molecular forms of PSA i.e. fPSA and cPSA individually have a statistically significant ability to differentiate between BPH and PCa compared to tPSA. While fPSA/tPSA ratio showed high specificity for differentiating BPH, cPSA/tPSA ratio outperformed fPSA/tPSA ratio by showing a higher specificity to discriminate PCa from BPH.