As Dr. Montgomery described in her post, ‘buried Barrett’s esophagus’ occurs when there is Barrett’s tissue underneath the normal squamous lining of the esophagus. It is also referred to as ‘subsquamous Barrett’s’ or ‘squamous overgrowth of Barrett’s’.
The study Dr. Montgomery mentioned followed the patients in the big photodynamic therapy study (mentioned in the blog post on PDT) for 5 years. This new paper includes 5-year results for 138 patients who were treated with photodynamic therapy plus omeprazole and 70 patients treated with only omeprazole for 5 years. Patients in the study were followed with upper endoscopy after treatment to look for residual BE, subsquamous BE, and dysplasia.
Here are some details of what the study showed:
- The researchers looked at 33,658 biopsies from patients in both study groups (PDT vs omeprazole)
- About 5% of patients had subsquamous BE prior to treatment
- About 1/3 of patients in each group had some subsquamous BE after treatment
- The number of biopsies for each patient that showed subsquamous BE was very low, with only about ½ of one biopsy showing subsquamous BE for each patient (the exact numbers are 0.48 biopsies with subsquamous BE in patients treated with BE and 0.66 biopsies per patient in patients treated with omeprazole)
- The risk of buried BE was very low for patients in the study
- For study patients who later went on to develop dysplasia or cancer, the dysplasia/cancer was found in multiple biopsies on the surface. No dysplasia or cancer was only found in the subsquamous BE.
Another study, presented at Digestive Disease Week 2008, an international GI meeting (but not yet published as a full article), looked at subsquamous BE before treatment with RFA (Barrx) and after treatment with RFA.
Here are details of what the study showed:
- 127 patients participated in the study and 2,151 biopsies were examined prior to any treatment
- Before treatment, 32 of 127 patients had some buried BE – about 25% of the patients
- Of all 2,151 biopsies, only 67 (3%) showed buried BE, so the number of buried BE biopsies per patient is low
- 35 patients had RFA and had completed all their follow-up biopsies. After treatment with RFA, only 1 biopsy showed subsquamous BE out of 1,223 biopsies
- For 16 patients who received sham treatment (they didn’t get RFA), and have had follow up biopsies: 20 of 290 biopsies showed subsquamous BE (about 4% of the biopsies)
- The final results of this study analyzing all the patients in the study haven’t been published yet, but probably will be soon
To summarize this information about subsquamous BE:
- Subsquamous BE can be found in many patients with Barrett’s esophagus whether they are treated with ablation or not
- The rate of buried BE/subsquamous BE is low after treatment with ablation therapy
- For patients who have been treated with ablation therapy, surveillance endoscopy with 4 quadrant biopsies should still be performed. Biopsies of the normal-looking squamous tissue (where the BE used to be) should be taken. This is the best way to detect subsquamous BE.
Bronner MP, Overhot BF, Taylor SL, et al. Squamous Overgrowth is not a Safety Concern for Photodynamic Therapy for Barrett’s Esophagus with High-Grade Dysplasia. Gastroenterology 2009, volume 136, issue , p. 56-64.
Shaheen NJ, Bronner MP, Fleischer DE, et al. Subsquamous Intestinal Metaplasia Is a Common Finding in Ablation-Naive Patients with Dysplastic Barrett’s Esophagus, and Significantly Decreases in Prevalence After Radiofrequency Ablation. Gastrointestinal Endoscopy, Volume 67, Issue 5, April 2008, Page AB176.
– posted by Kerry Dunbar, MD