A more advanced clinical stage is positively correlated with an increased prostate cancer detection rate

To determine whether an additional subclassification of the assessed clinical stage for prostate cancer before biopsy increases our ability to predict the biopsy outcome. A suspicious digital rectal examination (DRE) and/or a suspicious transrectal ultrasound (TRUS) investigation increases the likelihood of prostate cancer given a certain prostate-specific antigen level.

Biopsies done in 2199 men with suspicious DRE and/or TRUS findings were studied. The clinical stage was assessed according to the 1992 TNM classification. Univariate and multivariate statistical analyses were performed.

The assessed extent of disease classified as intracapsular or extracapsular (ie, clinical Stage T2 versus T3 and T4) was a significant independent predictor for the biopsy outcome. Men with suspected extracapsular disease on the basis of the DRE findings before the sextant biopsy had a twofold increased odds ratio of having prostate cancer detected compared with men with suspected intracapsular disease. A suspicion of extracapsular disease on the basis of TRUS findings, however, significantly decreased the risk of having prostate cancer detected in a biopsy.

We found a modified version of the clinical stage (ie, extracapsular, clinical T3 or T4 cancer versus intracapsular) to be significantly better in predicting the presence of prostate cancer at a given prostate-specific antigen level than a simple "yes or no abnormality found on DRE and/or TRUS" qualification. A suspicion of extracapsular disease raised on the basis of the DRE findings should be valued differently than a similar suspicion raised on the basis of the TRUS findings. Apparently, the extracapsular lesions seen by TRUS are primarily nonmalignant.