The purpose of this study is to investigate the prevalence of tissue homologous recombination repair (HRR)-related gene mutations (positive/negative/Variant of uncertain significance (VUS)), clinical outcome such as prostate-specific antigen-progression free survival (PSA-PFS), overall survivals (OS) and treatment pattern in mCRPC patients.

<Methods> Study design: multi-center, prospective cohort study

Data Source(s):

In this study, 155 patients (expected recruitment patients: maximum 205 patients) will be enrolled from approximately 20~30 sites in Japan. Study Population: mCRPC patients who diagnosed between 2014 and 2018. Exposure(s): N.A Outcome(s): Prevalence of tissue HRR-related gene mutations, clinical outcomes such as Over survival and PSA-PFS, Treatment pattern

Sample Size Estimations:

The target population is 155 patients based on the prevalence of HRR-related genes (BRCA1, BRCA2 and ATM) which is reported in previous global study (PROfound study).

Statistical Analysis:

This study is not intended to verify specific hypotheses, and the results are evaluated descriptively. There is no plan of interim analyses before the final analysis.

Inclusion Criteria:

• Age > 20, Japanese men at the time of informed consent.
• Patients who provided informed consent. If the patient has died, opt-out will be applicable.
• Patients who are diagnosed as mCRPC between January 1st in 2014 and December 31st in 2018.
• Patients who have a FFPE tumor sample (primary or metastatic) with Formalin Neutral Buffer Solution.
• Patients which the investigator judges to secure the enough amount of tumor samples for future laboratory test.

Exclusion Criteria:

• Patients who have failed HRR-related gene mutation testing with the myChoice HRD plus in screening period.
• Patients who have an only FFPE primary tumor sample (primary or metastatic) with unbuffered formalin including acidic formalin.
• Patients who have taken an investigational medical product for prostate cancer from Jan 1st , 2014 to Dec 31st 2020.

The target population is mCRPC patients who diagnosed between 2014 and 2018 and be confirmed to be succeeded HRR-related gene mutation analysis with archived primary or metastatic tumor sample. As median of expected overall survival of mCRPC is 2.5 to 3 years from diagnosis, follow up period is enough to measure outcomes including survival. The baseline period is set to calculate overall survival and to detect clinical outcome at least half. The patients will be enrolled consecutively to this study.

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AstraZeneca will meet or exceed data availability as per the commitments made to the EFPIA Pharma Data Sharing Principles. For details of our timelines, please rerefer to our disclosure commitment at https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure.

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