Prospective observational study to assess value of prostate cancer diagnostic methods

Abstract

The purpose of this article is to evaluate the efficiency and effectiveness of analytical and imaging methods for diagnosing prostate cancer in northwest Spain. The authors investigated prospectively two groups of patients with a pathological digital rectal examination (DRE) or prostate-specific antigen (PSA). Sensitivity, specificity, positive predictive value, negative predictive value, receiver operating characteristics curves, and other analyses were performed to determine the relative contributions of PSA, DRE, gray-scale transrectal ultrasonography (TRUS), color Doppler ultrasound (CDUS), symptoms, and patient age to cancer prediction. The presence of prostatic disease symptoms did not distinguish between subjects with and without cancer. The most sensitive (98%) was total PSA (> 4 ng/Ml), and the most specific (78%) was DRE and TRUS (65%). The contribution of PSA, DRE, and TRUS to the diagnosis of prostate cancer was significant. In patients with a PSA between 4 and 10 ng/Ml, PSA specificity increased, using a free/total PSA ratio of 15%. The PSA continues to be the most sensitive method for prostate cancer diagnosis. DRE tends to be more negative at early stages of cancer detection. Comparing the conventional TRUS echography with the CDUS, the latter is a better detector in the diagnosis of cancer.