Which Factors Predict Overall Survival in Patients With Metastatic Castration-Resistant Prostate Cancer Treated With Abiraterone Acetate Post-Docetaxel?

• Published in: Clinical genitourinary cancer Vol. 15; no. 4; pp. 502 - 508
• Main Authors: Van Praet, Charles, Rottey, Sylvie, Van Hende, Fransien, Pelgrims, Gino, Demey, Wim, Van Aelst, Filip, Wynendaele, Wim, Gil, Thierry, Schatteman, Peter, Filleul, Bertrand, Schallier, Denis, Machiels, Jean-Pascal, Schrijvers, Dirk, Everaert, Els, D'Hondt, Lionel, Werbrouck, Patrick, Vermeij, Joanna, Mebis, Jeroen, Clausse, Marylene, Rasschaert, Marika, Van Erps, Joanna, Verheezen, Jolanda, Van Haverbeke, Jan, Goeminne, Jean-Charles, Lumen, Nicolaas
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-08-2017
• Subjects: Abiraterone Acetate - therapeutic use; Aged; Chemotherapy; Humans; Male; Prednisone - therapeutic use; Prognosis; Proportional Hazards Models; Prostatic neoplasms; Prostatic Neoplasms, Castration-Resistant - drug therapy; Retrospective Studies; ROC Curve; Steroids; Survival; Survival Analysis; Taxoids - therapeutic use; Treatment Outcome; Chemotherapy; Prognosis; Prostatic neoplasms; Survival; Steroids
• ISSN: 1558-7673; 1938-0682
• DOI: 10.1016/j.clgc.2017.01.019

Individual patients' survival varies greatly in metastatic castration-resistant prostate cancer. Retrospective analysis of 368 patients treated with docetaxel and starting abiraterone acetate revealed 5 adverse prognostic factors: hemoglobin < 12 g/dL, > 10 metastases, ECOG performance status ≥ 2, radiographic progression, and time since diagnosis < 90 months. A prognostic model stratifies patients into 3 groups with different estimated survival, which can aid in patient counseling.
Abiraterone acetate (AA) increases overall survival (OS) in patients with metastatic castration-resistant prostate cancer (mCRPC) previously treated with docetaxel. However, survival time varies substantially between individuals. Our goal was to identify prognostic factors that better estimate OS.
This is a retrospective multicentric analysis of 368 patients with mCRPC starting AA with prednisone after docetaxel. Cox proportional hazards statistics were applied. A multivariate model was constructed based on significant univariate predictors by using a manual stepwise forward and backward selection strategy. Model performance was determined by using receiver operating characteristic (ROC) curves.
Univariate analysis identified 20 significant OS predictors. A multivariate model was constructed, based on 220 patients, incorporating 5 independent risk factors for decreased OS at the time of AA initiation: hemoglobin < 12 g/dL (hazard ratio [HR] 2.02), > 10 metastases (HR 1.80), ECOG performance status ≥ 2 (HR 1.88), radiographic progression (HR 1.50), and time since diagnosis < 90 months (HR 1.66, all P < .05). Patients were stratified into 3 groups: good (0-2 risk factors, median OS 22.6 months), intermediate (3 risk factors, median OS 13.9 months), and poor prognosis (4-5 risk factors, median OS 6.2 months). The area under the ROC curve based on the event “death by the time of median OS (13.3 months)” was 0.736 (95% confidence interval 0.670-0.803).
We identified 5 readily available risk factors independently associated with decreased OS. The resulting model may be used for patient counseling in daily clinical practice, as well as patient stratification in clinical trials.