Clinical outcomes of intraductal carcinoma or cribriform in radical prostatectomy specimens of men opting for active surveillance: data from the PRIAS-JAPAN study.

Background: Among early stage prostate cancer patients, intraductal carcinoma of the prostate (IDC-P) and invasive cribriform are key prognostic factors; however, their presence and clinical significance following active surveillance (AS) are unknown. In men who opted for AS, we aimed to examine the presence and impact of IDC-P or cribriform, utilizing radical prostatectomy (RP) specimens.

Methods: We re-reviewed 137 RP specimens available in the PRIAS-JAPAN prospective cohort between January 2010 and September 2020. We assessed the presence of IDC-P or cribriform, and compared the patients' characteristics and prostate-specific antigen (PSA) recurrence-free survival after RP between groups with and without IDC-P or cribriform. In addition, we examined the predictive factors associated with IDC-P or cribriform.

Results: The percentage of patients with IDC-P or cribriform presence was 34.3% (47 patients). IDC-P or cribriform pattern was more abundant in the higher Gleason grade group in RP specimens (P < 0.001). The rates of PSA recurrence-free survival were significantly lower in the IDC-P or cribriform groups than in those without them (log rank P = 0.0211). There was no association between IDC-P or cribriform on RP with the Prostate Imaging-Reporting and Data System (PI-RADS) 4,5 score on magnetic resonance imaging (MRI) before RP even with adjustments for other covariates (OR, 1.43; 95% confidence interval [CI] 0.511-3.980, P = 0.497).

Conclusions: IDC-P or cribriform comprised approximately one-third of all RP specimens in men who underwent RP following AS, confirming their prognostic significance.