Adapting the Bellmunt Risk Score for Prognostic Stratification in Metastatic Castration-Sensitive Prostate Cancer.

Background: The management of mCSPC has improved with the addition of docetaxel and androgen receptor pathway inhibitors (ARPi) to androgen deprivation therapy. However, patient outcomes remain heterogeneous, highlighting the need for practical prognostic models. The Bellmunt risk score, based on ECOG status, hemoglobin, and liver metastases, was developed for urothelial carcinoma, but its role in mCSPC is unclear.

Methods: This retrospective study analyzed 182 mCSPC patients treated with first-line docetaxel or ARPi from 2010 to 2024. Patients were stratified into low- and high-risk groups by the Bellmunt score. Overall survival (OS) was assessed with Kaplan-Meier and Cox models. Subgroup and interaction analyses were performed to evaluate the consistency of the Bellmunt risk score's prognostic value across treatment modalities. The Bellmunt, CHAARTED, and LATITUDE criteria were compared using the concordance index (C-index).

Results: Patients with a low Bellmunt risk score had significantly longer OS than high-risk patients (median OS: 44.4 vs. 14.1 months; p < 0.001). This prognostic effect was consistent in both ARPi and docetaxel subgroups, with no significant interaction between treatment type and Bellmunt score (p-interaction = 0.185). In multivariate analysis, the Bellmunt score remained an independent predictor of OS (HR: 3.13; 95% CI: 1.16-8.43; p = 0.024). The Bellmunt score showed better discriminative ability for OS (C-index: 0.67) than CHAARTED (0.62) and LATITUDE (0.64) criteria. However, the absolute differences in C-index values were modest, and the analysis was restricted to patients with complete data, potentially introducing selection bias.

Conclusion: The Bellmunt risk score appears to offer a practical approach to risk stratification in mCSPC, with promising prognostic value across treatment types. However, its incremental clinical utility over existing criteria is limited, and its role in guiding therapy remains unestablished. These exploratory findings warrant prospective validation.