Diagnostic ability of Japan Narrow-Band Imaging Expert Team classification for colorectal lesions by magnifying endoscopy with blue laser imaging versus narrow-band imaging

Renma Ito1, Hiroaki Ikematsu1, Tatsuro Murano1, Kensuke Shinmura1, Motohiro Kojima2, Kana Kumahara1, Yasuaki Furue1, Hironori Sunakawa1, Tatsunori Minamide 1, Daiki Sato1, Yoichi Yamamoto1, Kenji Takashima1, Yusuke Yoda1, Keisuke Hori 1, Tomonori Yano1

Endosc Int Open. 2021 Feb;9(2):E271-E277. doi: 10.1055/a-1324-3083. Epub 2021 Feb 3.

Background and study aims: The Japan Narrow-band imaging (NBI) Expert Team (JNET) classification was proposed for evaluating colorectal lesions. However, it remains unknown whether the JNET classification can be applied to magnifying endoscopy with image-enhanced endoscopies other than NBI. This study aimed to compare the diagnostic ability of JNET classification by magnifying endoscopy with blue laser imaging (ME-BLI) and with ME-NBI.

Patients and methods: We retrospectively assessed consecutive patients diagnosed per the JNET classification by ME-BLI (BLI group) or ME-NBI (NBI group) between March 2014 and June 2017. We compared the diagnostic value of JNET classification between the groups with one-to-one propensity score matching.

Results: Four hundred and seventy-one propensity score-matched pairs of lesions were analyzed. In the BLI and NBI groups, the overall diagnostic accuracies were 92.1 % and 91.7 %, respectively, and those for differentiating between neoplastic and non-neoplastic polyps were 96.6 % and 96.8 %, respectively. The positive predictive value by each JNET classification in BLI vs. NBI group was 90.6 % vs. 96.2 % in Type 1, 94.3 % vs. 94.6 % in Type 2A, 57.7 % vs. 42.3 % in Type 2B, and 100 % vs. 91.7 % in Type 3. The negative predictive value was 97.0 % vs. 96.9 % in Type 1, 88.1 % vs. 82.8 % in Type 2A, 98.0 % vs. 98.2 % in Type 2B, and 98.5 % vs. 98.7 % in Type 3. No statistical difference in the diagnostic results was found between the groups.

Conclusions: The diagnostic ability of the JNET classification by ME-BLI and ME-NBI was comparable, with the former also applicable for diagnosis of colorectal lesions.

1 Department of Gastroenterology and Endoscopy
2 Division of Pathology, National Cancer Center Hospital East