Randomized crossover study that used methylene blue or random 4-quadrant biopsy for the diagnosis of dysplasia in Barrett's esophagus

Barrett's esophagus is generally accepted to be a premalignant condition. Previous studies have suggested the use of methylene blue (MB) chromoendoscopy to aid the identification of dysplasia in Barrett's esophagus surveillance programs, but a recent study has raised the concern that MB might induce oxidative damage of DNA. The aim of this study was to compare MB directed biopsies (MBDB) with our current standard, which is random 4 quadrant biopsies (RB). A randomized prospective crossover study. Single center. Patients with a diagnosis of dysplasia identified in Barrett's esophagus within a 2-year period before entering the study. Either 4 random quadrant biopsies taken every 2 cm through the length of the Barrett's esophagus or MBDB from unstained or heterogenously stained mucosa. The number of patients with a diagnosis of dysplasia by each intervention. Thirty-six percent of eligible patients declined the invitation to participate. Thirty patients completed the crossover study. The median length of Barrett's esophagus was 5 cm (interquartile range [IQR] 3-9 cm). At baseline histology, grades were as follows: 17 low-grade dysplasia (LGD), 3 high-grade dysplasia (HGD), and 10 no dysplasia. At completion, there were 10 LGD, 8 HGD, and 12 no dysplasia. Overall, dysplasia was identified in 17 of 18 patients by RB and in 9 of 18 by MBDB (McNemar test, p = 0.02). Our study showed MBDB to be significantly less sensitive in detecting dysplasia than RB in Barrett's esophagus. Hence, we discourage its use during routine surveillance of Barrett's esophagus.