Shaping endometrial cancer diagnosis via the identification of protein biomarkers in gynecological fluids

Eva Coll de la Rubia

Colas Ortega, Eva Comella Carnicé, Joan Xavier Gil Moreno, Antonio Cabrera Diaz, Silvia

HUVH VHIR VHIR

Endometrial cancer (EC) is the sixth most common tumor in women worldwide, with 417,367 new cases and 97,370 deaths in 2020 (GLOBOCAN), and a 46% increase in its incidence is expected by 2040 (IARC, WHO). Although early diagnosis of EC is key, there is currently no screening test for its early detection. Only women who present with classic symptoms of EC, mainly abnormal uterine bleeding (AUB), initiate the long process of EC diagnosis based on invasive endometrial biopsy. This represents a great burden on women's health, as AUB is a very nonspecific symptom. Therefore, the development and implementation of a non-invasive test to distinguish benign conditions from EC is urgent. Additionally, endometrial biopsies should provide information on histology and tumor grade to guide surgery. Unfortunately, this determination fails in 11% and 27%, respectively. Therefore, objective measurement of prognostic factors using prognostic biomarkers would be a step forward in providing optimal surgical treatment of EC. The aim of this thesis is to provide a non-invasive, objective and accurate diagnosis in early stages of the disease by using gynecological fluids as a source of protein biomarkers of EC, as well as to position these fluids as new liquid biopsies for EC. In this thesis, we aimed to identify highly sensitive, specific and reproducible biomarkers that improve the diagnosis and preoperative risk assessment of endometrial tumors in gynecological fluids. First, the fluid from pipelle biopsies, i.e., uterine fluids, was studied as a source of biomarkers of histological type and grade, as well as prediction of recurrence. In order to identify prognostic biomarkers of EC, a literature review and in-silico validation were carried out, as well as a retrospective clinical study in uterine fluids from 149 patients quantified by mass spectrometry (MS). The study allowed defining panels of 2 proteins that diagnose the histological type, grade and predict recurrence with sensitivities ranging between 90.9-100%, 85.3%, and 85.7-100%, respectively. Second, cervical fluids were used as a source of protein biomarkers for the accurate and non-invasive diagnosis of EC. Three retrospective clinical studies were performed including cervical fluids from 625 patients using MS. As a result, a 3-protein panel was developed capable of diagnosing EC with a sensitivity of 95.4%. Additionally, panels were developed to determine the histological type and grade with AUC of 0.91 and 0.97, respectively. The results of this thesis are expected to generate a paradigm shift in the management of women suffering from SUA and improve the early detection of EC. We have developed biomarker panels that allow an objective and more accurate preoperative risk assessment for patients with EC in uterine fluids, as well as a non-invasive diagnosis of EC based on cervical fluids.

The application of the results obtained in this thesis would have different beneficiaries. First, women, who would be allowed a faster, simpler and non-invasive diagnostic sequence with the suppression, in the first instance, of pain and complications, as well as a saving of time and stress that entails waiting for a diagnostic result. In addition, for those women diagnosed with EC, a personalized treatment would be ensured with fewer complications and post-operative comorbidities and a better life expectancy. Second, these results would be a benefit for the specialist, since it allows him to send 100% of women home with an accurate and objective diagnosis, at the same time as reliable. In addition, the determination of prognostic factors will help the gynecologist to classify the patient in the relevant risk and carry out a personalized and optimal surgery. Finally, the implementation of the tools developed in this thesis would have a benefit for the payer, which, in the case of Catalonia, would be the public healthcare system in addition to private insurers. In this case, the benefit would come from cost-effective and efficient patient management that would reduce the costs associated with the diagnosis and treatment of EC.

Endometrial Cancer (EC); Global Tumor; Incidence Increase; Early Diagnosis; Screening Test; Classic Symptoms; Abnormal Uterine Bleeding (AUB); Invasive Endometrial Biopsy; Women's Health Burden; Benign Conditions; Non-Invasive Test; Histology; Tumor Grade; Surgical Guidance; Prognostic Factors; Prognostic Biomarkers; Optimal Surgical Treatment; Gynecological Fluids; Protein Biomarkers; Liquid Biopsies; Highly Sensitive Biomarkers; Specific Biomarkers; Reproducible Biomarkers; Improve Diagnosis; Preoperative Risk Assessment; Endometrial Tumors; Pipelle Biopsies; Uterine Fluids; Histological Type; Grade; Recurrence Prediction; Literature Review; In-silico Validation; Retrospective Clinical Study; Mass Spectrometry (MS); Protein Panels; Cervical Fluids; Non-Invasive Diagnosis; 3-protein Panel; AUC; Paradigm Shift; SUA Management; Early Detection Improvement; Objective Risk Assessment; Accurate Risk Assessment.