1. Decentralized sites.
2. Lack of sites interest in the study.
3. Super estimate of potential patient numbers.
4. Transforming the protocol to a retrospective one could impact the study's publication timeline.

PROCeed is an observational study assessing real world clinical endpoints and demographic characteristics in patients with castration-resistant prostate cancer treated with Olaparib+Abiraterone.

PROCeed is an observational, longitudinal study with prospective data from Brazilian participating sites, so as to generate real-world data. 10 Brazilian oncology sites are estimated to participate in the study. Each site will have participating investigators in charge and a proper technical team who will be in charge of data from each service. For this study, a convenience sample will be adopted, with an expected 2-year recruitment of 80 patients. The protocol was created in Germany and other countries could use it, with the potential for data from other countries to be pooled for analysis.

Recruitment to each subgroup will be monitored every 3 months and feasibility for continued enrolment will be assessed after 1 year of recruitment (at months 3 and 6, recruitment will be evaluated for proper site selection); if <20 patients have only been enrolled in a particular subgroup after 1 year, the study team will assess feasibility of pooling data from other countries to allow for at least 40 patients in a pooled analysis for that subgroup.

The study plans to recruit patients for no more than 2 years and to follow patients from the start of olaparib to 1 year after last patient inclusion (LPI). Data will be collected from the medical record through an electronic case report form (eCRF). Participating physicians will be responsible for ensuring that all necessary data are collected and entered in the eCRF. Data compilation will be performed by the principal investigator and statistical analysis will be performed by the statistics team appointed by the Academic Research Organization (ARO).

The target sample size of 80 patients in Brazil is based in a 24-month recruitment period. In order to avoid unnecessary imprecision for the subgroup previously exposed to a new hormonal agent, a minimum enrolment of 50% (40 patients) of the total sample size will be imposed for this subgroup. Estimation is determined based on the primary objective of the TTD event-free rate; the main measure of interest is at 6 months for patients previously exposed to NHA and 12 months for patients naïve to NHA. Assuming a 6- month TTD event-free rate is of approximately 50% for patients previously exposed to new hormonal agent, with a sample size of 40 patients in this subgroup, the precision would be +/- 15,5%.

Inclusion Criteria:

1. Willing to provide written informed consent;
2. 18 years or older;
3. Documented histology or cytology of PCa, adenocarcinoma;
4. Documented as mCRPC;
5. Olaparib+abiraterone started after the activation of the research site.

Exclusion Criteria:

Patients participating in a clinical trial with investigational treatment for prostate cancer within 30 days before starting olaparib.

Mens with documented histology or cytology of PCa and adenocarcinoma and Documented as mCRPC. This population needs to be 18 years or older. The treatment with Olaparib+abiraterone needs to start after the activation of the research site.

Qualified researchers can request access to anonymized individual patient-level data from AstraZeneca group of companies sponsored clinical trials via the request portal

Vivli.org. All requests will be evaluated as per the AZ disclosure commitment:

https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure. "Yes", indicates that AZ are accepting requests for IPD, but this does not mean all requests will be approved.

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

When a request has been approved AstraZeneca will provide access to the anonymized individual patient-level data via secure research environment Vivli.org. A Signed Data Usage Agreement (non-negotiable contract for data accessors) must be in place before accessing requested information.