The subgroup analysis of the prognostic value of the intraductal carcinoma of the prostate in patients with metastatic prostate cancer

Abstract

Objective: To determine the prognostic value of the intraductal carcinoma of the prostate IDC-P in metastatic prostate cancer (mPCa) patients of different subgroups. Methods: Data of 582 de novo mPCa patients between January 2011 and December 2017 diagnosed at Departments of Urology, West China Hospital, Sichuan University were retrospectively analyzed. The age was (70±8) years (range: 45 to 89 years). IDC-P was identified from 12-core prostate biopsy. The prognostic role of IDC-P was assessed by Kaplan-Meier curves and Cox regression. Subgroup analysis was conducted by the forest plot. The endpoints were castration-resistant prostate cancer free survival (CFS) and overall survival (OS). Results: In total, 177/582 (30.4%) patients harbored IDC-P. Patients with IDC-P had poorer CFS and OS than those without IDC-P (mCFS: 12.1 months vs. 16.9 months, P=0.000; mOS: 39.7 months vs. not reached, P=0.000). Multivariate Cox regression analysis indicated that, the existence of IDC-P was an independent prognosticator of both CFS (HR=1.40, 95% CI: 1.10 to 1.79, P=0.006) and OS (HR=1.51, 95% CI: 1.02 to 2.25, P=0.041). Subanalysis indicated that, in most subgroups, IDC-P was an adverse prognosticator of both CFS and OS. Even in subgroups with adverse clinicopathological features, e.g. Gleason score 9 to 10 (CFS: HR=1.467, P=0.007; OS: HR=1.807, P=0.013), baseline prostate specific antigen≥50 μg/L (CFS: HR=1.616, P=0.000; OS: HR=1.749, P=0.006), anemia (CFS: HR=1.653, P=0.036; OS: HR=2.100, P=0.038), alkaline phosphatase≥160 U/L (CFS: HR=1.326, P=0.038; OS: HR=1.725, P=0.010) or abnormal lactate dehydrogenase level (CFS: HR=1.614, P=0.001; OS: HR=1.900, P=0.003), IDC-P was still closely associated with shorter CFS and OS. Conclusions: The presence of IDC-P was closely related to poor survival outcomes for patients with mPCa. IDC-P was an adverse prognosticator in most subgroup patients. The description of IDC-P in the pathological report of prostate biopsy would help clinicians to evaluate the prognosis of mPCa patients more accurately and make better treatment choices.