Value of prostatic specific antigen in prostatic cancer detection

ABSTRACT

A prospective evaluation of 110 men above the age of 50 years, were performed, including three groups, first group [45 patients] with abnormal palpatory prostate, second group [45 patients] with symptoms of benign prostatic hyperplasia [BPH] confirmed by digital rectal examination [DRE] and third group [20 men] with no prostatic symptoms and normal DRE taken as a control group. We found that 37.8% of the first group, patients proved to have prostatic cancer, while only 8.9% of the second group and none of the third group had prostatic malignancy. The positive predictive value of prostatic specific antigen [PSA] was 26%, the sensitivity of the test was 95.2%, the specificity 18. 8%, while the negative predictive value was 92.3%. The other tumor marker prostatic acid phosphatase [PAP] was found to be less valuable than PSA in detecting prostatic cancer, having a sensitivity of 61.9% and a positive predictive value 24%. The results of this study favours the conclusion that DRE, PSA and transrectaI ultrasound [TRUS] are complementary tests which should be used together for early detection of prostatic cancer