External validation of a model determining risk of neoplastic progression of Barrett's esophagus in a cohort of U.S. veterans

Abstract

Background and aims: Risk of esophageal adenocarcinoma (EAC) in those with Barrett's esophagus (BE) is 11-fold greater than the general population. It remains unclear which BE patients are at highest risk of progression to EAC. We aimed to validate a predictive model risk-stratifying BE patients.

Methods: We conducted a retrospective cohort study at the Houston Veteran Affairs Medical Center of consecutive patients with a new diagnosis of BE from November 1990 to January 2019. Study follow-up was through February 2020. Patients were excluded if they had no follow-up EGD with esophageal biopsy sampling after the initial BE-diagnosing EGD or evidence of high-grade dysplasia (HGD) or EAC on initial EGD. We performed an external validation study of a risk model containing sex, smoking, BE length, and low-grade dysplasia (LGD) status and assessed discriminatory ability using the area under the receiver operating characteristic curve (AUROC).

Results: Among 608 BE patients, 24 progressed to HGD/EAC. The points-based model discriminated well with an AUROC of .72 (95% confidence interval [CI], .63-.82). When categorized into low-, intermediate-, and high-risk groups according to published cutoffs, the AUROC was poor at .57. Restructured into low-risk versus high-risk groups, the AUROC was .72 (95% CI, .64-.80). Excluding baseline LGD did not reduce discriminatory ability (AUROC, .73; 95% CI, .64-.82).

Conclusions: This external validation provides further evidence that the model including sex, LGD status, smoking status, and BE length may help to risk stratify BE patients. A simplified version excluding LGD status and/or reducing the number of risk groups has increased utility in clinical practice without loss of discriminatory ability.

Figure 1.

Flow diagram of the 723 patients diagnosed with Barrett’s esophagus (BE) at the Michael E. DeBakey Veteran Affairs Medical Center from 1990 to 2019.

Figure 2.

Cumulative incidence of progression to high-grade dysplasia or esophageal adenocarcinoma by the 3 risk groups proposed by Parasa et al. (green=low risk, blue=intermediate risk, red=high risk) were not different (p-value by competing-risks regression 0.326).

Figure 3.

Cumulative incidence of progression to high grade dysplasia or esophageal adenocarcinoma by the points-based risk model proposed by Parasa et al. re-categorized into low risk with ≤15 points (blue) and high risk with >15 points (red) in a competing-risks regression (p-value<0.001).