Intraductal carcinoma of the prostate in prostate biopsy samples: Correlation with pathological features after radical prostatectomy and prognostic value in high-risk prostate cancer patients.

123 Background: Intraductal carcinoma of the prostate (IDC-P) is a biologically aggressive form of prostate cancer. We investigated the correlation between IDC-P in prostate biopsy samples (Pbx) and several pathological features after radical prostatectomy (RP), also its prognostic value in high-risk prostate cancer patients. Methods: Totally, 455 patients diagnosed with PCa during 2010 to 2017 in West China Hospital were included in this study. Chi-squared test and binary logistic regression were used in discovering the correlation between IDC-P and post-RP pathological features. Kaplan Meier curve, log-rank test, Cox’s proportional hazards model and C-index were applied in the investigation of the prognostic value of IDC-P on 418 high-risk patients. Results: The detection rate of IDC-P in Pbx is 7.91%. IDC-P was an independent predictor of SVI ( p= 0.014), EPE ( p< 0.001), cT stage ( p= 0.001), PSM of urethra end ( p= 0.042). Patients with IDC-P in PBx specimens manifested poorer BFS than those without IDC-P ( p< 0.001), and IDC-P pattern 2 (HR: 4.429, p= 0.020) was associated with worse prognosis than IDC-P pattern 1 (HR: 3.225, p= 0.047). Further analyses also demonstrated that the addition of IDC-P in several nomograms could improve their C-index. Conclusions: IDC-P is associated with several post-RP pathological features after radical prostatectomy. Also, IDC-P can effectively predict the patients’ BFS, and the addition of it can increase the C-index of several nomograms.