A non-endoscopic approach to Barrett’s esophagus (BE) surveillance after radiofrequency ablation (RFA) would offer a less invasive method for monitoring. We assessed the test characteristics and cost-effectiveness of the Cytosponge® in post-RFA patients.
We performed a multicenter study of dysplastic BE patients after at least one round of RFA. A positive Cytosponge® before endoscopy was defined as intestinal metaplasia (IM) on cytological assessment and/or TFF3 immunohistochemistry. Sensitivity, specificity, and receiver operator characteristic (ROC) curves were calculated. Multivariable regression was used to estimate the odds of a positive Cytosponge® in BE. A microsimulation cost-effectiveness model was performed to assess outcomes of various surveillance strategies: endoscopy-only, Cytosponge®-only, and alternating endoscopy/Cytosponge®.
Of 234 patients, Cytosponge® adequately sampled the distal esophagus in 175 (75%). Of the 142 with both endoscopic and histologic data, 19 (13%) had residual/recurrent BE. For detecting any residual Barrett’s, Cytosponge® had a sensitivity of 74%, specificity of 85%, accuracy of 84%, and ROC curve showed an area under the curve of 0.74. The adjusted odds of a positive Cytosponge® in BE were 17.1 (95% CI: 5.2-55.9). Cytosponge®-only surveillance dominated all the surveillance strategies, being both less costly and more effective. Cytosponge®-only surveillance required <1/4 the endoscopies, resulting in only 0.69 additional EAC cases/1,000 patients, and no increase in EAC deaths when compared to currently-practiced endoscopy-only surveillance.
A positive Cytosponge® test was strongly associated with residual BE after ablation. While the assay needs further refinement in this context, it could serve as a cost-effective surveillance examination.