Barrett Esophagus With Dysplasia:Flow Cytometric DNA Analysis of Routine, Paraffin-Embedded Mucosal Biopsies

Abstract

Flow cytometric DNA ploidy analysis has been reported to be more objective and sensitive than morphologic evaluation as a surveillance method in patients with Barrett esophagus (BE) for the development and progression of precancerous lesions. Such analyses are typically performed using fresh samples that require a separate or "jumbo" biopsy, are prone to false DNA aneuploidy if not promptly processed, and do not allow for retrospective studies. The feasibility of performing flow cytometric DNA analysis on paraffin-embedded biopsies was studied to circumvent some of these problems using 12 squamous esophageal mucosa with inflammation and 58 BE cases showing varying degrees of dysplasia. Among the BE cases, 12 had no dysplasia, 20 were indefinite for dysplasia, 14 had low grade dysplasia, and 12 had high grade dysplasia. Satisfactory histograms were obtained in 86% of the analyzed An increased risk ofdeveloping carcinoma has been well established among patients with ulcerative colitis (UC) and Barrett esophagus (BE). It has become standard medical practice to perform periodic surveillance endoscopy with biopsy for the detection of dysplasia, a presumed precancerous lesion. Because consistent and objective detection of precancerous changes by histology may not be always possible, other adjunctive methods that are more objective and/or sensitive have been explored, including flow cytometric DNA ploidy analysis. The latter has been performed using fresh mucosal samples in the vast majority of reported studies.1 " 4 We recently reported the technical feasibility and advantages of using formalin-fixed and paraffin-embedded mucosal biopsy samples in patients with UC.5 Herein, we have analyzed DNA ploidy by flow cytometry using archival paraffin-embedded mucosal biopsies from patients with BE and dysplasia. MATERIALS AND METHODS Case SelectionA total of 58 BE cases with varying degree of dysplasia accessioned between 1990 and 1995 were retrieved from the files of the Armed Forces Institute of Pathology and Georgetown University. All hematoxylin-and-eosinstained slides were reviewed by two of the authors (EAM, NJC) using established criteria for dysplasia in BE. 6 The diagnosis of "indefinite" for dysplasia was assigned when moderate nuclear atypia was associated with active inflammation or only minimal nuclear abnormalities were present. A group of control cases (12 cases) showing inflamed esophageal squamous epithelium were selected from files of Georgetown University. In all cases, formalin-fixed and paraffin-embedded tissue blocks were available. DNA AnalysisParaffin blocks from these cases were processed for flow cytometry using the modified Hedley technique, 78 2 9 8

Diagnosis and risk stratification of Barrett’s dysplasia by flow cytometric DNA analysis of paraffin-embedded tissue

“…Montgomery et al reported that DNA aneuploidy was present in 77% of HGD,29 whereas only 32% of HGD showed DNA content abnormality in another study 22. In our cohort, abnormal flow cytometric results were identified in 95% of HGD, 21.1% of LGD, 9.5% of IND and no sample without dysplasia.…”

Selectively Advantageous Mutations and Hitchhikers in Neoplasms

“…The evolution of clones that we report here is also consistent with neoplasia, and recognition of BE as a benign neoplasm may improve our understanding of the basis for its precancerous potential. The study of evolution requires measurement of changes in allele frequencies, and we did not assess the relationship between genotypes and dysplastic phenotypes because the two were generated on different samples that could not be directly compared quantitatively, although the relationships among p16, p53, and cytometric abnormalities and dysplasia have been published previously by us and others (2,17,18,25,69,(82)(83)(84)(85)(86).…”

Molecular Biology of Barrett’s Adenocarcinoma

“…[35][36][37] Moreover, abnormal DNA content shows a correlation with the histologic diagnosis of dysplasia and carcinoma. 38,39 Flow cytometry also detects a subset of patients whose biopsy samples are histologically indefinite or negative for dysplasia and carcinoma but who have DNA content abnormalities similar to those otherwise seen only in dysplasia and carcinoma. 37,40 Therefore, this technique (in combination with histology) may be useful in screening patients with BE for early signs of malignant change.…”