The Heterogeneity of Intraductal Carcinoma of the Prostate Is Associated With Different Efficacy of Standard First-Line Therapy for Patients With Metastatic Castration-Resistant Prostate Cancer

Background: To explore whether patients with distinct intraductal carcinoma of the prostate (IDC-P) subtypes respond differently to standard first-line therapy among patients with metastatic castration resistant prostate cancer (mCRPC).MethodsWe retrospectively analyzed data of 170 mCRPC patients receiving abiraterone (ABI) or docetaxel (DOC) as first-line therapy between 2014 and 2019. PSA response, PSA progression-free survival (PSA-PFS), radiographic progression-free survival (rPFS), and overall survival (OS) were analyzed and compared based on the presence of IDC-P and its sub-patterns.ResultsTotally, IDC-P was confirmed in 91/170 (53.5%) patients. Among them, 36/91 (39.6%) and 55/91 (60.4%) harbored IDC-P pattern 1 and pattern 2, respectively. The presence of IDC-P was confirmed to be associated with poor prognosis in the whole cohort. Patients with IDC-P pattern 1 shared similar clinical outcomes to those without IDC-P in both ABI and DOC treatment. However, compared to patients with IDC-P pattern 1 and without IDC-P, IDC-P pattern 2 had markedly poorer prognosis in either ABI (PSA-PFS: P <0.001; rPFS: P <0.001) or DOC (PSA-PFS: P <0.001; rPFS: P <0.001) treatment. For patients without IDC-P, DOC had comparable therapeutic efficacy with ABI. In contrast, the therapeutic efficacy of DOC in patients with either IDCP pattern 1 (PSA-PFS: P =0.021; rPFS: P =0.027) or pattern 2 (PSA-PFS: P =0.003; rPFS: P =0.007) was significantly inferior to ABI.ConclusionCompared to DOC, ABI exhibited better efficacy in patients with IDC-P of either pattern. However, IDC-P pattern 2 still responded unsatisfactorily to either ABI or DOC therapy. Novel therapeutic strategies appropriate for IDC-P pattern 2 need to be further investigated in the future.