Endometrial cancer is the most common malignant tumor of the female genital tract in our means. The diagnosis is made by endometrial biopsy sampling with anatomopathological analysis which pinpoints the cell line and the level of cell differentiation. Its treatment is surgical with adjuvant treatment (chemotherapy or radiotherapy) besides, depending on the staging. Thus far, in the first diagnosis it is only request the tumor marker CA125 in serum, but there are studies that identify the HE4 protein in blood as a feasible marker for endometrial cancer. Furthermore, the staging changes the surgical and the adjuvant treatment: in its early stages, surgery is based on hysterectomy and double adnexectomy, however, in later stages it is necessary to add pelvic and paraaortic lymphadenectomy with the associated comorbidity. This makes extremely important that the preoperative diagnosis is accurate. The aim of this study is to identify and characterize the HE4, Ki67, p53 and other potential biomarkers in endometrial tissue in order to diagnose patients with disease only with a biopsy. Moreover, the investigators are searching for connections among these markers and prognostic factors such as grade of cell differentiation, cell line, lymphatic affectation, tumor stage or even features as survival or disease free survival.

List of abbreviations:

• HE4: Human Epididymis Protein 4
• CA125: Carbohydrate Antigen 125
• Ki67: antigen KI67
• EC: Endometrial Cancer
• CT: Computed Tomography
• NMR: Nuclear Magnetic Resonance
• FIGO: International Federation of Gynecology and Obstetrics

The purpose of this study is:

• The proportion of positive H-score of HE4, as quantified in endometrial tissue. It is significantly higher in patients with endometrial cancer than in non-EC patients.
• Percentage of HE4, CA125 and other markers positives in cases and controls.
• Concentration of HE4 in tissue, as measured by H-score, correlates linearly with HE4 concentration in serum, as measured in terms of ppmol/l.
• Differences in serum CA125 levels between cases and controls.
• Quantification of tissue tumor markers of EC patients, per disease stages.
• Relation of the immunohistochemistry intensity with survival and disease-free survival times.
• Analysis of other risk factors adjusting for known variables like age, menopausal status, hypertension, diabetes or obesity.
• Feasibility of the technique.

Steps in the study:

1. Patients enter the study when a diagnosis of endometrial cancer is done. As it is ordinary in the clinical practice the diagnosis is made with an endometrial tissue sample taken in the office which is afterwards studied by a pathologist, who makes the final diagnosis.
2. Patients undergo the regular preoperative study with pelvic ultrasound, CT and/or NMR for the extension study, blood tests and the preanaesthetic consultation. As it is registered in the protocol of Endometrial Cancer Treatment.
3. Then a matched control is selected from the group of patients that are going to be hysterectomized for other non-malignant reasons (abdominal way, vaginal, or laparoscopic way). Variables considered for matching are: age (variability of five years), pre or postmenopausal status, hypertension, obesity and diabetes.
4. Every patient then is asked for accept and sign the informed consent. The next step is to prepare the patient for the surgery. In this moment the serum sample is taken. Subsequently the surgery will be performed.
5. Then the anatomopathological study is conducted over the preoperative tissue sample. HE4 marker in endometrial tissue is defined by H-Score while Ki67 and p53 are defined as usual. Although Ki67 is matched in > or <25% of expression instead of 14% as it is made in breast cancer tissue samples.
6. After discharge, the patient will be follow-up for two years in order to register the evolution of the disease.

Inclusion Criteria:

• Female
• Of legal age (≥ 18 years)
• Wish to participate in the research study and sign consent forms voluntarily
• Patients diagnosed of endometrial cancer derived to hysterectomy

Exclusion Criteria:

• Patients that underwent surgery for other malignant pathologies, whether for ovarian carcinoma, cervical carcinoma or uterine sarcoma.

Every patient who is treated in Hospital de Leon of endometrial disease between August 2017 and the end of the recruitment