Are proton pump inhibitors alone able to induce regression in the length of Barrett's esophagus?
R.E. Sampliner (Tucson)
Proton pump inhibition therapy has become the mainstay of the treatment of Barrett's esophagus (BE). The response to therapy has often been judged by measuring the length of Barrett's mucosa at endoscopy the distance from the incisors to the proximal margin of continuous Barrett's epithelium is subtracted from the distance from the incisors to the end of the esophagus . The latter is judged by the end of the tubular organ, the endoscopic lower esophageal sphincter "pinch" and/or the proximal margin of the hiatal hernia folds. There are three published series reporting 74 patients treated for one year and 58 patients treated for at least two years using omeprazole 20 and 40 mg and lansoprazole 60 mg daily [2-4]. Although the majority of patients develop squamous islands in Barrett's esophagus, only one patient had apparent complete regression of BE. An additional 101 patients treated with omeprazole 20 mg, 40 mg or 80 mg daily for 2 to 4 years have been reported in abstract form (Table I) [5-9].
The mean change in the length of Barrett's mucosa in all but one of these trials was less than 1 cm. Length is clearly an inadequate assessment of the surface area of BE given the frequency of an irregular squamo-columnar junction and the development of squamous islands. One group assessed the area of Barrett's and reported a significant decrease . An ideal technique for a more accurate assessment of the impact of therapy on the area of BE would be "quantitative endoscopy"  (and page 999). This technique utilizes computer software to create two-dimensional maps to calculate the area of Barrett's.
These trials have not titrated the dose of proton pump inhibitor to ensure normalization of 24-hour esophageal acid exposure. Patients with BE may require more than conventional doses to achieve normalization of esophageal acid exposure. In eight patients treated with 60 mg lansoprazole daily an average of 5.7 years with documented normalization of esophageal acid exposure (mean time pH ¾ 4: 0.8%, range 0-3.5%), there was a mean decrease in the length of Barrett's esophagus of only 0.5 cm - not a significantly greater decrease than in patients lacking esophageal acid control . The interim conclusion based on the proton pump inhibitor trials to date is that total regression of BE rarely occurs and clinically significant regression in the length is uncommon with pharmacologic therapy alone.
10. Kim R, Baggott BB, Rose S, Shar AO, Mallory DL, et al. Quantitative endoscopy: precise computerized measurement of metaplastic epithelial surface area in Barrett's esophagus. Gastroenterology 1995;108:360-366.