Clinical outcomes in metastatic prostate adenocarcinoma treated with abiraterone and enzalutamide

The management of metastatic prostate cancer has progressed immensely in the last decade. This study aims to investigate the real-world clinical outcomes of metastatic prostate adenocarcinoma treated with abiraterone and enzalutamide. The findings will assist healthcare providers in making more informed decisions when choosing between these two drugs for treating these patients.

A retrospective analysis of 80 patients at our tertiary care hospital was conducted from January 2015 to July 2022. Data were analysed using SPSS version 20.0. An independent sample T-test was used for continuous data and the chi-square test for categorical data. Medians and means were calculated for continuous or ordinal variables. Kaplan-Meier survival curves presented progression-free and overall survival (OS), with comparisons made using the log-rank test. Survival rates with 95% CIs were reported, with p < 0.05 considered significant.

In our final analysis of 80 patients, the median age was 65 years, with 88% having an eastern cooperative oncology group performance status between 0 and 2. Histopathology showed adenocarcinoma in 91% of cases. Grade Group III-IV disease was present in 51.3%, and 67.5% had a Gleason Score of >8. Bilateral orchidectomy was performed in 41 patients (51.25%), with a median Gonadotropin-releasing hormone analogue use of 32 months. Most patients (72.5%) were castration-sensitive. Among the 80 patients, 60 (75%) were treated with abiraterone and 20 (25%) with enzalutamide. The prostate-specific antigen (PSA) doubling time was >6 months in 80% of the abiraterone group and 75% of the enzalutamide group. PSA response rates were similar for both drugs, with comparable rates of progressive disease, partial response, stable disease and complete response (p = 0.036). There was no significant difference in median time to progression (19 months for abiraterone versus 18 months for enzalutamide) (95% CI 9.7-27.9; p = 0.004). The median OS for the entire cohort was 67 months (95% CI 39-94; p = 0.003).

The findings suggest that both abiraterone and enzalutamide are effective in prolonging progression-free and overall survival in this patient population, providing comparable safety. Further studies are recommended to validate these findings and inform clinical decision-making.