Autofluorescence imaging endoscopy for screening of esophageal squamous mucosal high-grade neoplasia: A phase II study

Background and Aim: Few prospective studies examining the efficacy of autofluorescence imaging (AFI) screening for esophageal cancer have been reported. This study aimed to investigate the diagnostic value of AFI endoscopy for the screening of squamous mucosal high-grade neoplasia of the esophagus, performed by experienced and less-experienced endoscopists. Methods: Patients with a history of esophageal neoplasia or head and neck cancer underwent AFI endoscopic screening, followed by chromoendoscopy using iodine staining as the reference standard. The primary outcome was the sensitivity of AFI for detecting new squamous mucosal high-grade neoplasias. The secondary outcome was the positive predictive value (PPV) of AFI. Results: Of a total 364 patients who underwent endoscopic examination, 43 new mucosal high-grade neoplasias were detected. The sensitivities of AFI in the experienced and less-experienced endoscopist groups were 71% (95% confidence interval [CI]: 55-87%) and 50% (95% CI: 32-68%), respectively. The PPV of AFI in the experienced and the less-experienced endoscopist groups were 25% (95% CI: 16-34%) and 26% (95% CI: 15-37%), respectively. The sensitivity of AFI in lesions ≤10mm (31%, 5/16 lesions) was significantly lower than that in lesions >10mm (78%, 21/27 lesions) (P=0.003). Conclusions: The sensitivity of AFI for the detection of new squamous mucosal high-grade neoplasias, and its PPV, were both low. Based on these results, a randomized study to compare AFI with standard techniques is not justified.