Preoperative parameters to predict incidental (T1a and T1b) prostate cancer

Introduction: Prostate cancer has been found incidentally in transurethral resection of the prostate (TURP) specimens without prior diagnosis in 5% to 13% of the patients. We evaluated whether incidental prostate cancer (stages T1a and T1b) could be predicted preoperatively. Methods: TURP was performed in 307 patients between 2006 and 2011. Patient age, prostate-specific antigen (PSA) level, total prostate volume, transitional zone volume, PSA density, history of needle biopsy, and pathological diagnosis on TURP specimen were assessed. We analyzed the association between these parameters and prostate cancer detection. Results: Incidental prostate cancer was found in 31 patients (10.1%), and 13 cases (4.2%) had cancer with T1b and/or Gleason ≥7. Multivariate analysis demonstrated that age ≥75 years (odds ratio [OR] 2.58, p = 0.022), prostate volume ≤50 cc (OR 4.11, p < 0.001), and the absence of preoperative needle biopsy despite PSA ≥4 ng/mL (OR 2.65, p = 0.046) were independent risk factors. In patients who had 2 or 3 of these risk factors, incidental prostate cancer and cancer with T1b and/or Gleason ≥7 were observed in 25% to 50% and 16% to 25% cases, respectively. Conclusions: Older patient age, small prostate volume, and the absence of previous needle biopsy (despite a high PSA level) might be independent risk factors for detecting incidental prostate cancer, although external validation is warranted to confirm our results.