Use of Systematic Biopsy Results to Predict Pathologic Stage in Patients with Clinically Localized Prostate Cancer: A Preliminary Report

Background: The purpose of this study was to determine the ability of clinical tests to predict advanced pathologic stage (seminal vesicle invasion, pT3c, or pelvic lymph node metastases, pN+). Methods: T stage, PSA, PSA density, and pathologic features in systematic biopsy specimens were correlated with pathologic stage in 190 consecutive patients with clinically localized (T1-3) prostate cancer detected by systematic needle biopsies and treated with radical prostatectomies. Results: Thirty-three patients (17%) had an advanced pathologic stage cancer (pT3c or pN+). In logistic regression analysis, the total length of cancer in all biopsy cores (P < 0.0005), the percent of poorly-differentiated cancer in each specimen (P < 0.021), and serum PSA (P < 0.028) were the only significant predictors of advanced stage. A model was constructed to predict advanced stage: if the PSA was 6 ng/mL and 4 or more biopsy cores were positive and the total length of cancer in all cores was 20 mm and at least 10% of the cancer was poorly-differentiated, then 14 (93%) of 15 patients had an advanced pathologic stage cancer compared to 11% of the remaining 175 patients (P < 0.0005). Conclusion: The pathologic features of cancer in systematic needle biopsy specimens more accurately predicts which patients have advanced stage cancer than standard clinical tests alone.