The presence of intraductal carcinoma of the prostate is closely associated with poor prognosis: a systematic review and meta-analysis

We aimed to confirm the predictive ability of the presence of intraductal carcinoma of the prostate (IDC-P) for prognosis and the associations between IDC-P and clinicopathological parameters. Studies were identified in PubMed, Cochrane Library, EMBASE, Web of Science, and SCOPUS up to December 1, 2019. Hazard ratios (HRs) for survival data and odds ratios for clinicopathological data with 95% confidence intervals (CIs) were extracted. Heterogeneity was evaluated by the I² value, and quality was assessed by the Newcastle–Ottawa Scale criteria. A total of 4179 patients from 13 studies were included. The results showed that IDC-P presence was significantly associated with poor progression-free survival (PFS; HR = 2.31; 95% CI: 1.96–2.73), cancer-specific survival (HR = 1.89; 95% CI: 1.28–2.77), and overall survival (HR = 2.14; 95% CI: 1.53–3.01). In the subgroup analysis, IDC-P presence was significantly associated with poor PFS in prostate cancer treated by radical prostatectomy (HR = 2.48; 95% CI: 2.05–3.00) and treated by radiotherapy (HR = 2.83; 95% CI: 1.65–4.85). Regarding clinicopathological characteristics, patients with IDC-P presence had significantly higher tumor clinical stages, Gleason scores, probabilities of lymph node invasion, positive surgical margins, and positive extraprostatic extension. Our meta-analysis indicates that the presence of IDC-P is closely associated with poor prognosis and adverse clinicopathological characteristics. Our data support the value and clinical utility of the routine detection of IDC-P by pathological examination. These conclusions need further validation, and prospective studies are needed to find better treatment modalities other than traditional first-line therapy for patients with IDC-P.