Cribriform intraductal carcinoma of the prostate may be more aggressive than cribriform conventional/acinar prostatic adenocarcinoma.

It remains to be determined if the prognostic value of cribriform morphology (Crib) associated with intraductal carcinoma of the prostate (IDC) is equivalent to that in conventional/acinar prostatic adenocarcinoma (CPA). We herein assessed radical prostatectomy findings and long-term oncologic outcomes in 732 men with Grade Group 2-4 CPA without any Gleason pattern 5. Our cases were divided into four cohorts according to the absence or presence of Crib within CPA and/or IDC: Cohort-1, no Crib (n=347; 47.4%); Cohort-2, Crib only in CPA (n=203; 27.7%); Cohort-3, Crib only in IDC (n=17; 2.3%); and Cohort-4, Crib in both CPA and IDC (n=165; 22.5%). Compared with that in CPA only (Cohort-2), Crib in both CPA and IDC (Cohort-4) was significantly associated with adverse histopathological features, including higher tumour grade/stage and larger tumour volume. Univariate analysis revealed significantly higher risks of postoperative recurrence in patients with Crib in IDC only [Cohort-3; hazard ratio (HR) 2.450, p=0.022] or both CPA and IDC (Cohort-4; HR 2.835, p<0.001) than in those with Crib in CPA only (Cohort-2), whereas the prognosis was analogous between Cohort-3 and Cohort-4 (p=0.913). In a multivariable analysis [Crib in CPA only (Cohort-2) as a reference], Crib in IDC only (Cohort-3; HR 3.821, p=0.002) or both CPA and IDC (Cohort-4; HR 1.905, p=0.004) showed significantly worse recurrence-free survival. Compared with Crib in CPA only, its presence in both CPA and IDC was thus found to be independently associated with a poorer prognosis, suggesting a potentially greater clinical impact of Crib in IDC than in CPA.