A Study of Barrett's Esophagus Patients to Investigate Quality of Life and Fear of Cancer, and Optimize a Risk Model Based on Biomarkers and New Technologies to Better Predict the Development of Cancer

This study serves, in part, to prepare for a future large cohort study. The goal of the study is:

1. The collection of various tissue samples (blood, biopsies and "esophageal brushes") and their analysis.
2. To set up standardized methods for different genetic analyses (DNA-FISH and so-called single cell sequencing) on the esophageal tissue samples.
3. Evaluating the quality of life of Barrett's Esophagus patients and the degree of fear of getting cancer.

Patients with a Barrett's Esophagus can participate in the study if they are minimally 18 years old, are capable of giving informed consent (fully understanding what the study entails before giving consent to participate), have Barrett Esophagus and are referred to one of the participating centers due to suspicion of high-grade dysplasia or early esophageal cancer, for which the participant will be evaluated by endoscopic imaging and biopsy.

Study procedures:

* An intake consultation will be planned, wherein the eligibility criteria will be assessed, and participant characteristics will be collected.
* A routine gastroscopy will be planned during which several minimally-invasive interventions will be performed: drawing a blood sample, brush cytology during the endoscopy (a brush is used to obtain cells from the surface of the esophagus) and obtaining biopsy samples (small pieces of tissue). Each participant will need to undergo all the interventions.

More specifically, you will have a standard endoscopy during which tissue samples will be taken from the esophagus to check for the severity of the disease. This is part of standard care. If you participate in the study, additional samples will be taken from the esophagus and also from the stomach (a total maximum of 10 samples of 1-2 mm). As a result, the endoscopic examination will take about 10-15 minutes longer than standard. Furthermore, in addition to the tissue samples, cells of the esophageal mucosa will be sampled (through 4 "esophageal brushes") and blood (4 tubes) will also be collected.

For this study, you will be contacted a total of two times. Once for a screening visit and once for the sample collection described above. The screening and sample collection will take place during the already scheduled treatments and consultations. Afterwards, patient outcomes will be documented for the study until a maximum of 5 years after inclusion. This documentation will take place during the routine follow up so does not require any additional visits for the patients.

Eligibility Criteria:
Inclusion Criteria:

* Patients with known BE undergoing endoscopy for possible treatment by EMR or ESD due to suspicion of early esophageal Barrett cancer
* Capable of receiving informed consent and of giving permission
* Age 18 and upward

Exclusion Criteria:

* Patients with current known malignancy of the gastrointestinal tract other than the esophageal lesion
* Patients with severe co-morbidity that prohibits endoscopic therapy under sedation or conscious sedation (such as severe cardiac or pulmonary disease)
* Esophageal varices
* Uncontrollable coagulation disorders
* Undergoing chemotherapy or immunotherapy or received chemotherapy \< 6 weeks prior to endoscopy
* Undergoing radiotherapy within the esophageal region or received chemotherapy \< 6 months prior to endoscopy
* WHO score \> 3