The aim of the project is to corroborate them on a large retrospective cohort of HGS-EOC and confirm the possibility of identify TP53 mutations in high grade endometrioid tumors.

This will consequently allow to confirm the previous results and define with a greater precision the temporal windows in which it will be possible to detect, through the TP53 analysis, tumor material by vaginal swab sampling. The results of the study will be the first step of a multiphase prospective validation program for the development of a novel approach for early diagnosis of EOC.

All participating women will be identified through the ovarian cancer audit implemented by the "Oncological Network of Piedmont and Valle d'Aosta" and the Clinical Epidemiology Unit of CPO Piemonte between 2015 and 2020. Women with EOC, and the center where they have been treated for the tumor, will be identified by linking the databases of the "Oncological Network of Piedmont and Valle d'Aosta" with those of the "Prevenzione Serena" project.

A few clinical information from EOC patients will be collected by clinical investigators at each center using an electronic case report form (e-CRF) developed at the Mario Negri Institute. These information will include age, date of diagnosis, histological subtype and grading, tumor stage according to FIGO 2014 classification2,3, previous gynecologic conditions and surgical operations, date of Pap Test collection, and Pap Test cytological reports. Participants' data will be identified by a unique patient code.

Inclusion Criteria:

age ≥18 years;

• confirmed histologic diagnosis of HGS-EOC or high grade endometrioid tumor;
• presence of one FFPE primary tumor biopsy with at least 40% of tumor cells based on Hematoxylin and Eosin staining, in the archive of the Pathology Departments of the hospital centers where they have been treated;
• presence of one or more Pap Tests sampled up to eight years before EOC diagnosis during routine cervical cancer screening;
• negative history for other gynecologic malignancies;

Exclusion Criteria:

• pap test not available in patients with ovarian cancer

The study population will be composed of about 190 women with a diagnosis of EOC, identified through the ovarian cancer audit conducted by the "Rete Oncologica Piemonte e Valle d'Aosta" between 2015 and 2020. In order to be eligible for the study, patients should respect the following inclusion criteria:

• age ≥18 years;
• confirmed histologic diagnosis of HGS-EOC or high grade endometroid tumor;
• presence of one FFPE primary tumor biopsy with at least 40% of tumor cells based on Hematoxylin and Eosin staining, in the archive of the Pathology Departments of the hospital centers where they have been treated;
• presence of one or more Pap Tests sampled up to eight years before EOC diagnosis during routine cervical cancer screening;
• negative history for other gynecologic malignancies;

This study is part of a more complex and long-lasting project aimed to develop an innovative strategy for early diagnosis of EOC. It aims to detect TP53 variants in the DNA purified from PAP tests, as an early genetic biomarker of EOC tumorigenesis.

12-18 months

Age ≥18 years;

• confirmed histologic diagnosis of HGS-EOC or high grade endometrioid tumor;
• presence of one FFPE primary tumor biopsy with at least 40% of tumor cells based on Hematoxylin and Eosin staining, in the archive of the Pathology Departments of the hospital centers where they have been treated;
• presence of one or more Pap Tests sampled up to eight years before EOC diagnosis during routine cervical cancer screening;
• negative history for other gynecologic malignancies;
• written informed consent for the participation to the study and the molecular analysis of biological samples.