This is a prospective observational multi-country, multi-center study of a large real-world cohort of first line (1L) epithelial ovarian cancer patients, exposed to standard of care (SOC) treatment stratified according to BRCA1/2 and HRD status.

The overall objective of the study is to demonstrate the distribution of ovarian cancer (refers collectively to ovarian, tubal, and peritoneal cancer) by homologous recombination deficiency (HRD) and breast cancer susceptibility gene 1 and 2 (BRCA1/2) mutational status (both germline/gBRCA and somatic/tBRCA is recommended), and further characterize sub-cohorts of long- and short-term responders by identifying clinical and/or molecular markers. Additionally, the translational objective is to collect representative clinical samples for further translational analyses to identify prognostic and/or predictive biomarkers of treatment response/resistance.

The overall objective is separate for each of two distinct observational periods defined as Observational Period 1 (OP1) and Observational Period 2 (OP2):

• OP1: From date of diagnosis to date of first response assessment visit following first line (1L) chemotherapy, to progression or to death, whichever occurs first.
• OP2: From date of first response assessment visit following 1L chemotherapy to 60 months after first response assessment visit following 1L chemotherapy, to death or to withdrawal of consent, whichever occurs first.

Objective for Observational Period 1 (OP1) is to demonstrate the distribution of ovarian cancer patients with FIGO (International Federation of Gynecology and Obstetrics) stage I-II Breast Cancer Susceptibility Gene 1 and 2 mutations (BRCA1/2mut) ovarian cancer, or stage IIIIV ovarian cancer in cohorts of BRCA1/2, HRD (either BRCA1/2 mutation and/or genomic instability), homologous recombination proficient (HRP) and homologous recombination (HR)- unknown patients.

Objective for Observational Period 2 (OP2) is to further characterize sub-cohorts of short-term responders (progressing < 6 months following maintenance treatment) and long-term responders (progressing ≥ 36 months following maintenance treatment) in real-world cohorts of ovarian cancer patients. For FIGO stage I-II BRCA1/2mut or FIGO stage III-IV defined by HRD status determined by Myriad myChoice® CDx HRD test or non-Myriad local HRD test, and BRCA1/2 status.

A total of 1000 patients will be enrolled from hospitals in Denmark, Finland, Norway, and Sweden. Competitive enrollment will be applied.

Eligible patients must have newly diagnosed histologically confirmed epithelial ovarian cancer:

• FIGO stage I-II with a known BRCA1/2 mutation (germline/gBRCA or somatic /tBRCA)
• FIGO stage III-IV of any histology of any histology.

Patients are eligible to be included in the study, if all the following inclusion criteria are met:

• Patients with newly diagnosed histologically confirmed epithelial ovarian cancer:

  • FIGO stage I-II with a known BRCA1/2 mutation (germline/gBRCA or somatic/tBRCA)
  • FIGO stage III-IV of any histology

• Women aged ≥18 years of age at the time of diagnosis

• Patients intended for platinum-based chemotherapy treatment

• Patients capable of giving signed informed consent, which includes compliance with the requirements and restrictions listed in the informed consent form (ICF) and in this protocol

• Patients consent to provide archival tumor tissue sample

Patients are ineligible to be included in the study, if any of the exclusion criteria are met:

• Non-epithelial ovarian cancer, borderline tumors, or mucinous histology
• Patients with FIGO stage I-II, BRCAwt ovarian cancer

Newly diagnosed epithelial ovarian cancer patients (FIGO stage I-II with known BRCA1/2 mutation and FIGO stage III-IV of any histology), who are intended for 1L chemotherapy, will be recruited from specialist care centers across Denmark, Finland, Norway, and Sweden. In total 1000 patients will be enrolled applying competitive enrollment. Each patient must meet all the inclusion criteria and none of the exclusion criteria to be included in the study. Under no circumstances can there be exceptions to this rule. Patients who do not meet the entry requirements are screen failures.