Introduction/Background Inhibition of poly(ADP-ribose) polymerase (iPARP) proteins as a therapy for advanced ovarian cancer has improved patients’ prognosis, prolonging median progression-free survival (PFS) and time to first subsequent therapy (TFST), particularly in BRCA-associated cases.

The incidence of brain metastases (BM) from advanced ovarian cancer is low, ranging from 1–2.5%, and median survival from BM diagnosis ranges from 2.3–7.1 months.

Methodology 5 patients with advanced high-grade ovarian cancer managed at the Maria Skłodowska Curie Institute in Gliwice (MSCI) between 2018 and 2022 with olaparib-based therapy based on STUDY-19 clinical trial criteria developed brain metastases.

Results The mean age at initial diagnosis was 48.9±10.8 years. 3 patients underwent radical cytoreduction and 2 – suboptimal cytoreduction. The cancer stage at diagnosis in all cases was identified as IIIC according to FIGO (International Federation of Gynaecology and Obstetrics). All the patients received chemotherapy. 2 of the patients were treated with bevacizumab as their first line of therapy. Prior to receiving iPARP-based therapy, the patients were treated with 2 or 3 lines of platinum-based therapies.

Somatic versus germline BRCA1/2 mutations were identified in 3 versus 2 patients respectively. In 2 patients BM were identified prior to iPARP-based therapy, in 1 patient during treatment, and in 3 patients after its completion. 2 patients underwent surgery followed by stereotactic radiotherapy, while 2 patients were managed with stand-alone palliative brain radiation therapy. 3 patients were offered another line of treatment due to simultaneous metastases to parenchymal organs.

Conclusion Based on our experience, we regard BM an adverse prognostic factor. Despite surgical treatment, chemotherapy and maintenance iPARP-based therapies prolonging OS, the patients’ prognosis remains poor.

Disclosures The mean OS for our patients was 5.8±1.6 years, and survival from BM diagnosis was 8 months and 12 days. One of the patients is still alive and continuing iPARP therapy.