Can optical evaluation distinguish between t1a and t1b esophageal adenocarcinoma: an international expert inter-observer agreement study.

Abstract

While piecemeal endoscopic mucosal resection (EMR) for T1a oesophageal adenocarcinoma is acceptable, enbloc-R0 excision is advocated for T1b disease as it may offer a potential cure and mitigate recurrence. Thus, distinguishing between T1a and T1b disease is imperative under current treatment paradigms. We sought to ascertain whether expert Barrett's endoscopists were able to make this distinction based on optical evaluation. Sixty sets of endoscopic images of histologically confirmed high grade dysplasia (HGD), T1a and T1b disease (n=20 for each) were compiled from consecutive patients at a single institution. Each set contained four images, and were standardized to include an overview, a close-up in high-definition white light, a near-focus magnification image, and a narrow-band image. Experts were invited to predict histology for each set. 19 experts from 8 countries (Australia, USA, Italy, Netherlands, Germany, Canada, Belgium, and Portugal) participated. The majority had been practicing for >20 years, with a median annual case volume for Barrett's EMR of 50 (IQR 18-75), and Barrett's ESD of 25 (IQR 10-45). Oesophageal adenocarcinoma (T1a/b) could be distinguished from HGD, with a pooled sensitivity of 89.1% (95% CI:84.7-93.4. When predicting T-stage for T1b adenocarcinoma cases, pooled sensitivity was 43.8% (95% CI:29.9-57.7). Fleiss' kappa was 0.421 (95% CI:0.399-0.442, P<0.001), indicating fair-to-moderate agreement. Expert Barrett's endoscopists can reliably differentiate T1a/T1b oesophageal adenocarcinoma from HGD. Although there is fair-to-moderate agreement for T-staging, T1b disease cannot be reliably distinguished from T1a disease. This may have implications on clinical decision making and selection of endoscopic treatment methods.