# Real‐World Treatment Patterns Before and After Metastatic Castration–Resistant Prostate Cancer in Japan: Retrospective Analysis Using a Hospital‐Based, Multicenter Database

## TL;DR

This study examines treatment patterns for metastatic castration-resistant prostate cancer in Japan using a large hospital database.

## Contribution

The study provides real-world insights into treatment sequences for mCRPC in Japan using a multicenter database.

## Key findings

- Classical hormone therapy was the most common pretreatment for mCRPC, followed by androgen receptor signaling inhibitors.
- Enzalutamide was the most common first-line treatment for mCRPC, followed by abiraterone and docetaxel.
- Use of vintage hormone therapy has decreased annually, with a trend toward replacing it with ARSIs.

## Abstract

Although treatment options for metastatic castration–resistant prostate cancer (mCRPC) have been increasing since 2014, the actual treatment sequences of each drug in clinical practice in Japan have only been reported in a limited number of patients and facilities. The primary objective of this database study was to investigate the general situation and the transition of prior and post‐mCRPC treatments.

Using Medical Data Vision’s medical record database across Japan, patients diagnosed with mCRPC from January 2015 to December 2022 based on defined criteria were extracted. Treatment sequences before and after mCRPC diagnosis were analyzed.

Analysis of 4967 patients revealed that the most common pretreatment for mCRPC was classical vintage hormone therapy (77.1%), followed by androgen receptor signaling inhibitors (ARSI), including enzalutamide (7.8%) and abiraterone (7.4%). The most common treatments for first‐line mCRPC were enzalutamide (43.1%), abiraterone (28.3%), and docetaxel (10.7%). When the treatment prior to mCRPC was ARSI, docetaxel was the most common first‐line treatment for mCRPC, but another ARSI that had not been used as treatment prior to mCRPC was also selected as first‐line mCRPC treatment at a similar rate to docetaxel. Regarding annual changes, the proportion of vintage hormone therapy for mCRPC has been decreasing annually, and there has been a trend to replace it with ARSIs.

In terms of the treatment sequence for mCRPC in Japan, vintage hormone therapy was the most common pretreatment for mCRPC, and ARSIs were the most common first‐line treatments for mCRPC.