Does ablative therapy for Barrett esophagus affect the depth of subsequent esophageal biopsy as compared with controls?

ABSTRACT

BACKGROUND: Photodynamic therapy (PDT) and radiofrequency ablation (RFA) are associated with high rates of complete eradication of Barrett esophagus (BE). However, if ablation were to induce fibrosis in the regenerated squamous epithelium, then postablation biopsies may not penetrate deeply enough to detect subsquamous intestinal metaplasia (SSIM) and, therefore, complete response rates could be over-estimated. GOALS To assess the depth of esophageal biopsies from the squamous epithelium of ablation-naive controls and from the neosquamous epithelium of post-PDT and post-RFA patients to determine if prior ablation results in a reduced proportion of biopsies containing lamina propria (LP) as compared with controls. STUDY Review of archived esophageal specimens from a prospective multicenter cohort study (post-RFA) and 2 retrospective consecutive case series (ablation-naive controls, post-PDT). SETTING: Eight US centers and 1 US gastrointestinal pathology laboratory. PATIENTS Ablation-naive controls with GERD, dyspepsia, and/or BE. Post-PDT and post-RFA BE patients with biopsies more than 6 months after achieving complete eradication of BE. INTERVENTIONS: Review of endoscopic biopsies from ablation-naive controls, post-PDT patients, and post-RFA patients. MAIN OUTCOME MEASUREMENTS One GI pathology lab processed all tissue and slides. One expert GI pathologist, blinded to cohort, graded the depth of each esophageal specimen as partial epithelium, full epithelium, LP, muscularis mucosae, or submucosa. Each specimen was also evaluated for SSIM. RESULTS: There were 82 patients [ablation-naive (12), post-PDT (10), post-RFA (60)] with 899 biopsy specimens. The proportion of specimens containing "LP or deeper" was similar between groups ablation-naive (88%), post-PDT (88%), post-RFA (91%) (P>0.05). No SSIM was detected in any group. CONCLUSIONS: There is no difference in esophageal biopsy depth between ablation-naive squamous epithelium and post-PDT/post-RFA neo-squamous epithelium, thus refuting the concern of ablation-induced mucosal resistance to procurement of adequate biopsy specimens. Most biopsies (88% to 91%) from both ablation cohorts were deep enough to detect SSIM, in that they included "LP or deeper."