Clinical Significance of Intraductal Carcinoma of the Prostate After High-Dose Brachytherapy With External Beam Radiation Therapy: A Single Institution Series and an Updated Meta-Analysis

We compared oncological outcomes between prostate cancer (PCa) patients with and without intraductal carcinoma of the prostate (IDC-P) after high-dose-rate brachytherapy (HDR-BT) with external beam radiation therapy (EBRT). We performed a retrospective analysis of 138 patients with clinically high-risk, very high-risk, or locally advanced PCa who received HDR-BT with EBRT. Of these, 70 (50.7 %) patients were diagnosed with IDC-P; 68 (49.3 %) patients with acinar adenocarcinoma of prostate. The oncological outcomes, including biochemical recurrence-free survival (BCRFS) and clinical progression-free survival (CPFS), were assessed using Kaplan–Meier curves. Additionally, Cox proportional hazards models were used to identify significant prognostic indicators or biochemical recurrence (BCR). Meta-analysis of existing literatures was performed to evaluate the risk of BCR in patients with IDC-P after radiation therapy, compared to those without IDC-P. Kaplan–Meier curves demonstrated significantly inferior BCRFS and CPFS in patients with IDC-P. Multivariate analysis revealed that IDC-P and Grade Group 5 status were associated with increased BCR risk. in our meta-analysis, IDC-P was associated with BCR (HR = 2.13, P = .003). Amongst the patients who received HDR-BT, patients with IDC-P displayed significantly more rapid disease progression, compared with patients who did not have IDC-P. Intraductal carcinoma of the prostate (IDC-P) has been recognized as an adverse pathological feature of prostate cancer (PCa). We performed a retrospective analysis of 138 patients with clinically high-risk, very high-risk, or locally advanced PCa who received high-dose-rate brachytherapy with external beam radiation therapy, elucidating a significant association between the presence of IDC-P and a higher incidence of disease progression.