Optimisation of second line antihormonal treatment for castration resistant metastatic prostate cancer

Background: The prognosis of castration resistant metastatic prostate cancer has been improved by several recently introduced therapeutic options, among others the second line antihormonal agents. Still, several questions related to the optimal use of these new drugs have remained open. The following ones were addressed in this paper. (1) Is the use of abiraterone + hydrocortisone inferior to abiraterone + prednisone in terms of overall survival? (2) Is the treatment up to prostate specific antigen (PSA) progression inferior to the treatment up to radiological progression in terms of overall survival? (3) Does the level of initial PSA decrease have a predictive value for the duration of response? Methods: As part of our self-assessment the dataset of 62 patients with castration resistant metastatic prostate cancer who started second line antihormonal therapy at our outpatient clinic before 31st of December 2019 was analysed. Results: 35 patients received abiraterone with prednisone substitution, 12 patients received abireterone with hydrocortisone substitution and 15 patients received enzalutamide. 39 patients were treated until clinical or radiological progression and 23 patients were treated until biological progression. (1) Median overall survival of patients substituted with hydrocortisone was not inferior as compared to patients substituted with prednisone (31 months vs. 17 months). (2) Median overall survival of patients treated until PSA progression was not inferior as compared to patients treated until radiological progression (32 months vs. 17 months). (3) Median overall survival of patients whose first control PSA level was below the normal value was 50% higher than median survival of patients whose first control PSA level was over the normal value (25 months vs. 17 months). Median overall survival of patients treated with abiraterone or enzalutamide was similar (21 months vs. 24 months). Conclusions: The combination of abiraterone + hydrocortisone is not inferior to the combination of abiraterone + prednisone and the treatment up to PSA progression is not inferior to the treatment up to radiological progression in terms of overall survival for patients with castration resistant metastatic prostate cancer.