External Validation of a Prognostic Model Predicting Overall Survival in Metastatic Castrate-resistant Prostate Cancer Patients Treated with Abiraterone
Menée sur une cohorte de 158 patients atteints d'un cancer métastatique de la prostate résistant à la castration et traités par docétaxel puis abiratérone, cette étude évalue la performance d'un modèle mathématique, récemment développé à partir des données d'un essai de phase III et incorporant 6 paramètres pour prédire la survie des patients
A prognostic model was derived from the population of the COU-AA-301 phase 3 trial for metastatic castrate-resistant prostate cancer patients treated with abiraterone after docetaxel, and it stratifies patients into three risk groups based on clinical parameters. We validated this model in an independent cohort of patients treated with abiraterone after docetaxel outside a clinical trial (group A; n=94) and explored its utility in patients treated with abiraterone in the prechemotherapy setting (group B; n=64). For group A, median overall survival (mOS) was significantly different across the three prognostic groups (good: n=39, mOS: 21.8 mo; intermediate: n=44, mOS: 10.6 mo; poor: n=7, mOS: 6.8 mo; p<0.001; area under the curve [AUC]: 0.71). Analysis of group B confirmed the ability of the model to prognosticate for survival in the prechemotherapy setting: (good: n=44, mOS: 45.6 mo; intermediate or poor: n=20, mOS: 34.5 mo; p=0.042; AUC: 0.61). These results serve to validate the prognostic model in an independent population treated with abiraterone after docetaxel and support clinical implementation of the score. Calibration of the model was poorer in patients receiving abiraterone prechemotherapy. Prospective evaluation of this model in clinical trials is needed.
Take Home Message : This analysis externally validates a recently developed prognostic model in metastatic castrate-resistant prostate cancer patients receiving abiraterone after docetaxel, and it supports routine clinical implementation of the model. Prospective evaluation of the model within clinical trials is required.
European Urology , résumé, 2013