Inaccuracies in assignment of clinical stage for localized prostate cancer.

BACKGROUND: Recent data have suggested that clinical T stage is not independently associated with biochemical recurrence of localized prostate cancer after radical prostatectomy. One explanation for this lack of predictive power may be the inaccurate application of staging criteria.
METHODS: Data from men in the Cancer of the Prostate Strategic Urologic Research Endeavor (CaPSURE) database with localized prostate cancer (clinical T1-T2) were analyzed. Correct stage was determined by digital rectal examination (DRE) and transrectal ultrasound (TRUS) findings and was compared with the clinical stage reported directly by the practitioner. DRE/TRUS findings and biopsy results were evaluated to determine factors influencing staging errors. The ability of corrected stage to predict biochemical disease recurrence after prostatectomy was assessed using multivariable analysis.
RESULTS: Clinical stage was assigned incorrectly in 1370 of 3875 men (35.4%). Errors more commonly resulted in patient downstaging than upstaging (55.1% vs 44.9%; P < .001). Patients with TRUS lesions were more likely to be staged incorrectly than those with abnormal DRE findings (65.8% vs 38.2%; P < .001). Biopsy laterality was found to strongly influence stage assignment. Even after correction of staging errors, there was no association noted between clinical stage and biochemical disease recurrence after radical prostatectomy.
CONCLUSIONS: Errors in applying clinical staging criteria for localized prostate cancer are common. TRUS findings are frequently disregarded, and practitioners incorrectly incorporate biopsy results when assigning stage. However, staging errors do not appear to account for the inconsistent reliability of clinical stage in predicting prostate cancer outcomes. These findings further challenge the utility of a DRE-based and/or TRUS-based staging system for risk assessment of localized prostate cancer.