Quantitative endoscopy in the chemoprevention of Barrett's Esophagus Trial

Abstract

SUMMARYThe Chemoprevention for Barrett's Esophagus Trial (CBET) was a phase IIb, multicenter, randomized, placebo-controlled trial of celecoxib in patients with Barrett's esophagus. The overall outcome of the study was that there were no significant differences in primary, secondary, or tertiary outcomes. The purpose of the current study is to focus on results related to the method of measuring lesion size called quantitative endoscopy (QE). The design includes a review of a total number of studies and then restricts analyses to the four clinics that enrolled more than four patients each for whom a baseline and 1-year QE study was performed, comparing intra-and inter-patient and clinic differences in Barrett's esophagus. Measurements include the number of total QEs and adverse events, changes in areas from baseline to 1 year and other intervals, classification of Barrett's lesion type with respect to patients, clinics, and treatment. A total of 309 QE studies were completed with no adverse events. Differences in surface area measurements over time for a particular patient are smaller than the differences for randomly selected patients. The complexity mix (as defined by the mix of circumferential, tongues, and islands) of the Barrett's lesions varied with different clinics. In conclusion, QE is an efficient, safe, and accurate way to measure the area of Barrett's lesions variation between different clinical sites may be attributable to a subtle type of selection bias at the individual clinics rather than to regional differences.

Barrett′s esophagus: Where do we stand?

“…[ 45 46 ] Another method for measuring the surface area of BE lesion size, designated as quantitative endoscopy (QE), was shown to be a safe and accurate way of following up BE lesions. [ 47 ] However, the recently developed and validated Prague C and M criteria for endoscopic diagnosis of BE has excellent landmark recognition of the squamocolumnar junction, gastroesophageal junction, the extent of circumferential columnar lining, and the most proximal extension of the columnar mucosa not accounting for islands of BE[ 48 ] and should be used as a standard method for describing BE. Although using methylene blue (MB) can selectively stain intestinal metaplasia, and the intensity of staining does correlate with the histological degree of dysplasia, it was not proven to be superior in the detection of dysplasia compared with the conventional four-quadrant biopsies (4QB).…”

Modeling using baseline characteristics in a small multicenter clinical trial for Barrett's esophagus

“…The system (US Patent #7,011,625) transforms photographs of Barrett’s esophagus into two-dimensional maps, and the surface area of Barrett’s esophagus is calculated from the reconstructed images. The key steps in capturing the images are relatively simple and are described in [14]. The images in Fig.…”

“…In [14], it is shown that there was a statistically significant difference in the patient complexity mix at the four primary CBET clinics (CPMC, HVA, JHH, and UCLA).…”

“…Based on this classification of forms, in [14] the authors introduced the concept of Barrett’s esophagus complexity using the following scheme. Note that the term “complexity”, in this context, is not intended to imply a ranking, but simply a characterization.…”

“…A model for Total F04 should take into account the initial baseline QE measurement, Total BL. Also, given our findings in [14], clinic should be included as a covariate. Complexity class measures another baseline characteristic that may impact Total F04.…”