Role of free to total prostate specific antigen ratio in serum in the diagnosis of prostatic enlargement.

ABSTRACT

This study was aimed to demonstrate the significance of free/total Prostate Specific Antigen (PSA) ratio in the diagnosis of prostatic enlargement. The study was carried out in a total number of 100 subjects, of which 58 had benign prostatic hyperplasia (BPH), 42 had carcinoma prostate and 50 were age matched control. The subjects were collected from Dhaka Medical College Hospital (DMCH) and Bangabandhu Sheikh Mujib Medical University (BSMMU). Venous blood (5ml) was drawn from each subject before digital rectal examination or pre-urethral manipulation for estimation of PSA. Final diagnosis was made by histopathological examination, specimen being obtained by transurethral resection of prostate (TURP), open prostatectomy and per rectal tru-cut biopsy with biopsy gun. The study showed a highly significant difference of serum PSA and free/total PSA ratio in differentiating BPH from carcinoma prostate. Free/total PSA ratio was highly significant in differentiating between BPH and carcinoma prostate (p<0.001) and carcinoma prostate and control (p<0.001). In the marginally elevated PSA, free/total PSA ratio reduced biopsy by 81-85% in BPH and carcinoma prostate respectively. The overall specificity, positive predictive value and efficiency of free/total PSA was much higher than that of total PSA in differentiating BPH from carcinoma prostate.