Diagnosis of carcinoma prostate: the yield of serum PSA, DRE and TRUS

ABSTRACT

This randomised study was conducted on 100 patients with bladder outlet obstructive symptoms, their age ranged from 55 to 84 years, at a teaching hospital. The cancer detection rate with three tumour markers, the prostate specific antigen [PSA] and Transrectal Ultrasonography [TRUS] was 6%. Serum PSA level determination was followed by digital rectal examination [DRE] and TRUS. The mean value of serum PSA levels for this study was 15.57 ng/mL [Normal value upto 5 ng/mL] serum PSA level were > 10 ng/mL in 36 patients. DRE of prostate was positive [Hard, nodular] in 8 [8%] patients. On TRUS of prostate, the mean volume of prostate was 35.54 cm[3] + 11.98 cm[3]. More than 7 mm hypoechoic or hyperechoic focal defects were found in 17 individuals, they were 14 [82.3%] in peripheral and 3 [17.6%] in central zone of prostate gland. TUR prostat biopsies were performed in all patients. Histopathological reports revealed adenocarcinoma in 6%, chronic prostatitis in 2% and BPH in 92% cases. The sensitivity of three tumour markers [PSA, DRE, TRUS] was 83%. The specificity of DRE [96%] was higher as compared to that of PSA and TRUS. Positive predictive value [PPV] of TRUS was 50% and was higher than of PSA but less than of DRE. However, PPV significantly rose to 83% when results of abnormal TRUS were corroborated with abnormal results of DRE and PSA. The average cost of detection of carcinoma prostate by DRE, PSA and TRUS was Rs. 2100 per patient excluding hospital and equipment charges. Since use of these tumour markers in symptomatic individuals provide very high PPV, their routine use may be recommended in patients with bladder outlet obstructive symptoms