Characterization of Epithelial Ovarian Cancer Patients in Terms of Homologous Recombination Phenotype

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.