External Validation of a Prognostic Model Predicting Metastatic Castration-Resistant Prostate Cancer Survival in...

Area of Science:

• Oncology
• Clinical Research
• Prostate Cancer

Background:

• The Halabi model is used to predict overall survival (OS) in patients with metastatic castration-resistant prostate cancer (mCRPC) undergoing second-line therapy post-docetaxel.
• External validation of prognostic models is crucial for establishing their generalizability and clinical applicability.

Purpose of the Study:

• To externally validate the Halabi model's predictive accuracy for OS in an independent cohort of mCRPC patients treated with cabazitaxel after docetaxel.
• To assess the performance of both the two- and three-risk group stratifications of the Halabi nomogram.

Main Methods:

• A multi-institutional study included 66 mCRPC patients treated with cabazitaxel post-docetaxel.
• Patients were stratified using the Halabi nomogram's two- and three-risk groups.
• Kaplan-Meier analysis, Cox proportional hazard models, and receiver operating characteristic (ROC) curves with area under the curve (AUC) were used to evaluate survival prediction.

Main Results:

• The two-risk Halabi stratification showed significant OS differences (median OS: 12.9 months low-risk vs. 5.06 months high-risk, p<0.001) with an AUC of 0.72.
• The three-risk stratification did not show significant differences between risk groups (p=0.84) and had lower predictive accuracy.
• High-risk patients in the two-risk model had a hazard ratio (HR) of 9.50 (95% CI 4.12-21.6, p<0.001) compared to low-risk patients.

Conclusions:

• The two-risk stratification of the Halabi model effectively predicts survival in mCRPC patients receiving second-line therapy after docetaxel.
• The three-risk stratification was less effective in this independent cohort.
• The findings support the clinical utility of the two-risk Halabi nomogram for prognostic assessment in this patient population.