The Diagnostic Value of Predictive Factors for Clinically Insignificant Prostate Cancer / 대한비뇨기과학회지

ABSTRACT

PURPOSE: In the present study, we identified the pre-operative predictive factors of insignificant prostate cancer and we analyzed their diagnostic accuracy. MATERIAL AND METHODS: Of a total 343 patients who had undergone radical prostatectomy, 33 patients(9.6%) were diagnosed with insignificant cancer that was characterized by a total cancer volume < or=0.5cc, a Gleason score (GS)< or=6, a T stage< or=2c and no positive surgical margin. We found the statistically significant factors after comparing of preoperative clinico- pathological findings between two groups and determined the diagnostic accuracy of the identified predictors. RESULTS: Of several factors, prostate-specific antigen(PSA) level(p=0.04, odds ratio(OR)=4.3 3.589< or=95%confidence interval(CI)< or=5.692), PSA density(PSAD)(p=0.01, OR=6.6, 2.115< or=95%CI< or=278.826), biopsy GS(p=0.03, OR=4.6, 1.114< or=95%CI< or=12.568) and volume of the largest cancer(p=0.02, OR=5.6, 2.471< or=95%CI< or=9.725) were analyzed as independent predictors of insignificant cancer. The volume of the largest cancer was the most precise predictor(AUC=0.791), followed by the PSAD (AUC=0.748) and the PSA level(AUC=0.677) in the ROC (receiver operating characteristic) curve analysis. The sensitivity, specificity and positive predictive value for predicting insignificant cancer were 10.3%, 63.7% and 12.8% at a PSA level of 10ng/ml, and 44.8%, 16.8% and 26.3% at a PSAD of 0.15ng/ml/ml, and 13.8%, 53.8% and 14.2% at a volume of the largest cancer of 50%, respectively. Even with using a combination of these three factors as well as a biopsy GS< or=6, only 53% of insignificant prostate cancer could be predicted preoperatively. CONCLUSIONS: In our study, PSA level, PSAD, biopsy GS and volume of the largest cancer were identified as predictors of insignificant cancer in spite of their unsatisfactory diagnostic accuracy.