[Androgen deprivation as initial and backbone therapy for prostate carcinoma cancer : A retrospective data analysis from urological practices in Germany].

Abstract

Background: The aim of this study was to determine the proportion of patients with prostate cancer (PCa) who remained on primary androgen deprivation therapy (ADT) after starting treatment for castration-resistant prostate cancer (CRPC) and to describe their treatment patterns.

Materials and methods: The study comprises a retrospective analysis of 609,308 patients in urological practices in Germany from 2011 to 2020 based on anonymized secondary data from the UROscience webserver. PCa patients were eligible for inclusion if they received ADT after a 6-month prescription-free pre-index period.

Results: A total of 3,112 patients (mean age 75.5 [±8.0] years) were included. Most patients received gonadotropin-releasing hormone (GnRH) agonists (72.3%), followed by antiandrogens (24.9%). The median duration of ADT treatment was 25.9 months. The estimated probabilities of continuing ADT 3, 6, and 8 years after starting treatment were 40.7%, 20.1%, and 12.7%, respectively. Interruption across all ADTs occurred in 42.7% of patients, switching of primary ADT in 52.2% and discontinuation in 82.2% of patients. After starting ADT, 14.6% of patients received treatment for CRPC, of whom 76.4% continued primary ADT. The median duration of CRPC treatment was 11.0 months. The estimated probabilities of developing CRPC 3, 6, and 8 years after starting ADT were 11.1%, 20.1%, and 25.9%, respectively.

Conclusion: This study has shown that a relevant proportion of patients discontinued primary ADT after starting treatment for CRPC, although guidelines recommend continuing ADT if the disease progresses.