The following is a summary of “External Validation of a Prognostic Model of Overall Survival in Men With Chemotherapy-Naïve Metastatic Castration-Resistant Prostate Cancer,” published in the May 20, 2023 issue of Oncology by Halabi, et al.

For a study, researchers sought to externally validate a prognostic model for overall survival (OS) in men with docetaxel-naïve metastatic, castration-resistant prostate cancer (mCRPC). The validation aimed to include a broader group of patients, including different racial and age subgroups and patients receiving specific treatments. Based on the validated model, the study also aimed to classify patients into two and three prognostic risk groups.

Data from seven phase III trials, comprising 8,083 docetaxel-naïve mCRPC men, were used to validate the prognostic model for OS. The model’s predictive performance was assessed by calculating the time-dependent area under the receiver operating characteristic curve (tAUC). The two-risk (low and high) and three-risk prognostic groups (low, intermediate, and high) were also validated.

The tAUC for the prognostic model was 0.74 (95% CI, 0.73 to 0.75). After adjusting for the trial status of the first-line androgen receptor (AR) inhibitor, the tAUC improved to 0.75 (95% CI, 0.74 to 0.76). Similar results were observed across different racial, age, and treatment subgroups. In patients enrolled in first-line AR inhibitor trials, the median OS in the low-, intermediate-, and high-risk groups were 43.3 months (95% CI, 40.7 to 45.8), 27.7 months (95% CI, 25.8 to 31.3), and 15.4 months (95% CI, 14.0 to 17.9), respectively. Compared to the low-risk group, the hazard ratios for the high- and intermediate-risk groups were 4.3 (95% CI, 3.6 to 5.1; P < .0001) and 1.9 (95% CI, 1.7 to 2.1; P < .0001), respectively.

The prognostic model for OS in docetaxel-naïve men with mCRPC was externally validated using data from seven trials. The model demonstrated consistent results across different racial, age, and treatment subgroups. The identified prognostic risk groups are robust and can be utilized for patient stratification in clinical trials and enrichment designs.

Source: ascopubs.org/doi/full/10.1200/JCO.22.02661