Distinct Prognostic Roles of Grade Group and Intraductal Carcinoma of the Prostate in Metastatic Hormone-Sensitive Prostate Cancer Treated With Androgen Receptor Signaling Inhibitors.

OBJECTIVES: The study aimed to evaluate the impact of grade group (GG) and intraductal carcinoma of the prostate (IDC-P), as established prognostic factors, on clinical endpoints in metastatic hormone-sensitive prostate cancer (mHSPC) patients treated with androgen receptor signaling inhibitors (ARSIs).

METHODS: We retrospectively analyzed 147 patients with mHSPC treated with androgen deprivation therapy and ARSIs (abiraterone acetate, enzalutamide, or apalutamide). Associations between clinicopathological factors, including GG 5 and IDC-P, and prostate-specific antigen progression-free survival (PSA-PFS), cancer-specific survival (CSS), and overall survival (OS) were evaluated by Kaplan-Meier analysis and Cox proportional hazards models.

RESULTS: GG 5 was identified in 66% of patients, and IDC-P was present in 51% of patients. GG 5 was an independent predictor of PSA-PFS, whereas IDC-P was not. In contrast, IDC-P was independently associated with poorer CSS, while GG was not. Neither IDC-P nor GG was significantly associated with OS. The combined evaluation of GG 5 and IDC-P showed the best prognostic predictive ability for PSA-PFS, CSS, and OS.

CONCLUSIONS: In patients with ARSI-treated mHSPC, both GG 5 and IDC-P are important prognostic factors, although they play distinct roles in predicting clinical outcomes.