Prostate Cancer Detection in Clinical Urologic Practice : Comparison of Digital Rectal Examination, Serum PSA Level, and Transrectal Ultrasonography

Seo, Weon Kyo; Kim, Geo Hwan; Park, Choal Hee; Lee, Sung Choon

Abstract

We examined 990 self-referred men with one of urologic diseases over age 50 years to compare clinical usefulness of digital rectal examination(DRE), serum PSA level, and transrectal ultrasonography of the prostate(TRUS) in a screening program for prostatic cancer. Biopsy was performed in 201(20%) cases, of which 20 percent was diagnosed as prostate cancer. Sensitivity of DRE was 68%, specificity was 91%, and positive predictive value was 53%, respectively. Positive predictive values are 26% in cases with serum PSA level above 4ng/ml, 36% in cases with serum PSA above 10ng/ml and 40% for TRUS, respectively. When serum PSA below 4ng/ml and negative DRE, the positive predictive value was merely 6%. But when serum PSA above 10ng/ml and positive DRE, the positive predictive value increased to 72%. When serum PSA below 4ng/ml, negative DRE and negative TRUS, the positivepredictive value was merely 7%. However when serum PSA above 10ng/ml, positive DRE and positive TRUS, the positive predictive value was 80%. We conclude that DRE has greater diagnostic effect than the serum PSA level greater than 10ng/ml or hypoechoic area on TRUS and DRE with a serum PSA concentration is considered as an effective screening method of prostatic cancer in all urologic patients over 50 years of age. If DRE and serum PSA level are normal, there is no reason to proceed with TRUS and/or biopsy of the prostate.