This research study hopes to identify new molecular markers in the tissue of Barrett's esophagus that will help physicians better understand and manage this condition. Patients undergoing an upper endoscopy will be asked to complete a gastroesophageal reflux disease (GERD) questionnaire, provide a blood sample and allow additional biopsies to be taken during the procedure.

This research study hopes to identify new molecular markers in the tissue of Barrett's esophagus that will help physicians better understand and manage this condition. Currently there is very little understanding as to how Barrett's esophagus develops and why some people with Barrett's esophagus go on to develop esophageal cancer. The purpose of this study is to develop a better understanding of how these processes occur. The investigators also hope to use the information from this study to identify new molecular markers that the investigators can use to better determine who will or will not go on to develop esophageal cancer. Patients who have been diagnosed in the past with Barrett's esophagus will be asked to participate. Patients without Barrett's esophagus will be asked to take part so that the investigators can compare tissue from patients without the conditions to those with the conditions.

Inclusion Criteria:

For BE patients:

• History of histologically confirmed BE, defined as endoscopically-suspected BE with intestinal metaplasia with globlet cells on esophageal biopsies,
• BE length C1M1 or C0M2
• Age 18 years

Exclusion Criteria:

• History of gastric or esophageal surgery
• Inability to give informed consent
• Erosive esophagitis seen on upper endoscopy
• History of prior endoscopic therapy for BE 5 (for controls) History of intestinal metaplasia on previous esophageal, GE junction or cardia biopsies.

Patients with Barretts Esophagus with and without associated dysplasia or cancer and controls with and without gastro-esophageal reflux.