Melatonin Associated to Acid Inhibition for Chemoprevention in Barret Esophagus: a Pilot Study

Barrett's esophagus (BE) is a chronic disease secondary to the presence of stomach acid into the esophagus. This atypical situation produces an inflammation and ulceration of the distal esophagus mucosa. It is the main factor predisposing to the development of esophageal adenocarcinoma, which has a very poor prognosis. At present, therapy of Barrett's esophagus is based on acid secretion inhibition with proton pump inhibitors, which is a very effective therapy to reduce gastroesophageal reflux. However, this therapy does not completely eliminate this risk. Therefore, the better way to follow this disorder is to perform periodic upper gastrointestinal endoscopy and biopsies. Therefore, it is necessary to find new chemo-preventive agents that avoid more efficiently the neoplastic progression of BE. New advances in knowledge about BE suggest that antioxidants could be used to reduce the disorder development. These drugs are being used for long time ago in different pathologies in a lot of countries. One of these drugs is melatonin, which combines several characteristics that suggest it could be the most suitable antioxidant. It has no adverse effects reported.

Patients that meet the following characteristics will be included in this clinical study: Patients (males and females) with Barrett's esophagus (>18 years and <80) without macroscopic esophagitis at endoscopy and a length of the metaplasic mucosa of 2 cm or longer. By the same way, patients will be excluded of the study if present carcinoma or high grade dysplasia at basal endoscopy, previous gastric or esophageal surgery, patients on NSAID or aspirin treatment, neoplastic malignancies, hematological serious diseases (coagulation disorders and anemia with Hb < 9.5 gr/dL), serious/moderate cardiac, liver or renal diseases, need of corticosteroid therapy (a minimum of 5 days per month is allowed, as well as topical or inhaled treatment), patients on misoprostol or anticoagulants, patients with inflammatory bowel disease and allergy to investigational drugs.

Patients, who agree to participate in the study and meet criteria, will be randomized to one of the two following therapies: omeprazole alone or omeprazole + Circadin (melatonin.).

This intervention hardly produces any adverse effects, the most frequent adverse effects of proton pump inhibitors are headache and stomach ache. For melatonin has not reported any adverse effect.

This study will be done in the Hospital Clinico Lozano Blesa (Zaragoza, Spain), promoted by the Health Science Aragon Institute and its principal investigator is Angel Lanas Arbeloa (Digestive Disease Service). It will start in March-april 2012 and will finish 12 months later approximately. The study sponsor is I+CS (Aragon Institute of Health Sciences) that carries the cost of the trial.