Incidence and clinicopathological characteristics of intraductal carcinoma detected in prostate biopsies: A prospective cohort study

Aims: Intraductal carcinoma of the prostate (IDC-P) is a distinct clinicopathological entity and is associated with aggressive, high-grade and high-volume prostate carcinoma (PCa). The incidence, clinicopathological characteristics and prognostic significance of IDC-P have not been reported in prostate biopsies (PBx) that surgical pathologists encounter in their daily practice. Methods and results: In 1176 prospectively collected PBx, 33 IDC-P cases were identified (2.8%). The mean age of patients with IDC-P was 65 (range 46-79) years and mean serum prostate-specific antigen was 16.2 (range 0.4-105.6) ng/ml. Three (0.26%) IDC-P cases did not have a concomitant invasive PCa. Of 30 cases with concomitant invasive PCa, Gleason score was 7 in 16 (53.3%), 8 in four (13.3%) and 9 in 10 (33.3%) cases. The mean number of biopsy cores involved by PCa was 7.2 (range 1-14). Nine patients were treated with radical prostatectomy. Seminal vesicle invasion was found in four of nine (44%) cases, significantly higher than the risk of 12% predicted by Partin Tables (P = 0.016). Conclusions: This is the first prospective study that has investigated the incidence and prognostic significance of IDC-P diagnosed in PBx encountered in daily practice. It is critical for surgical pathologists to diagnose and report IDC-P in PBx.