Comparison Between Prognostic Classifications in De Novo Metastatic Hormone Sensitive Prostate Cancer

Background: The CHAARTED and LATITUDE trials demonstrated improved outcomes with docetaxel or abiraterone plus androgen deprivation therapy in metastatic hormone sensitive prostate cancer (mHSPC) using two different prognostic scores. Objective: The aim of our study was to assess the concordance between the two scores and if these retained their prognostic value exclusively in de novo mHSPC. Patients and Methods: De novo mHSPC patients referring to our institution were retrospectively stratified according to the CHAARTED and LATITUDE classifications: high volume/high risk (HV/HR), low-volume/low-risk (LV/LR), and HVorHR (HV/LR and LV/HR). The Kaplan-Meier method and Cox proportional-hazard models were used to estimate hazard ratios for overall survival. Results: The study population included 106 patients. Concordance between the CHAARTED and LATITUDE classifications was observed in 86.8% of cases (65.1% HV/HR, 21.7% LV/LR), while 13.2% of patients fulfill the criteria of only one of the two classifications (HVorHR). When analyzed independently, the CHAARTED and LATITUDE classifications maintained their prognostic value (mOS 28.2 months in HV versus 60.9 months in LV, p = 0.006; 28.2 months in HR versus 40.6 months in LR, p = 0.017). The LR/LV population showed significantly longer mOS compared to the HR/HV group (72.6 months versus 26.3 months; p = 0.005), and to HVorHR patients (35.1 months; p = 0.003). No difference in OS was observed between HV/HR and HVorHR patients. ECOG PS ≥ 1 and patient age improved the prognostic value of the two classifications with multivariate analysis. Conclusions: Our study showed a lack of complete concordance between the CHAARTED and LATITUDE classifications. The analysis confirmed the role of these prognostic scores to stratify de novo mHSPC patients in clinical practice.