BOVARY-CE is a monocentric, pilot, longitudinal, real-life study with a total duration of 36 months. The purpose of this study is to assess the feasibility of using liquid biopsy as a substitute for tissue multisampling, in order to describe clonal heterogeneity and tumor evolution in patients with ovarian cancer. The method involves the inclusion of 20 patients with high-grade ovarian adenocarcinoma, fallopian tubes or primary peritoneal origin, not pretreated, newly diagnosed, and eligible for treatment who will participate in the research. These patients will have several samples throughout their treatment for a period of 2 years: blood samples which will be taken at each therapeutic moment of interest.

Tissue samples which will be taken at the time of the diagnostic laparoscopy and at the time of surgery.

The concentration of cfDNA and tumor heterogeneity will be used to predict disease-related events defined as relapse, progression or death.

Inclusion Criteria:

• Age ≥ 18 years
• Patient with non-treated high grade serous and endometrioid carcinoma of ovarian, fallopian tube, or primary peritoneal origin proven cytologically or histologically at inclusion and eligible for treatment
• Patient eligible for an upfront surgery or pretherapeutic coelioscopy
• Adequate haemoglobin rate ≥ 9 g/dL
• Patient affiliated to a social security scheme
• Ability to provide written informed consent

Exclusion Criteria:

• Age < 18 years
• Any concurrent severe and/or uncontrolled medical conditions which could compromise participation in the study
• Contraindication to blood samples of 20 mL
• Pregnant or breast-feeding women
• Ongoing treatment for the newly diagnosed cancer or the recurrence
• Other cancers treated within the last 5 years
• Patient under guardianship or curatorship or deprived of liberty