The efficacy of The Japan NBI Expert Team (JNET) classification for endoscopically resectable lesions of colorectal tumors

(Objectives)JNET classification was proposed in June, 2014. This study aimed to assess the efficacy of JNET classification for endoscopically resectable lesions of colorectal neoplasms.(Methods)We included a total of 468 colorectal lesions in 444 consecutive patients that were endoscopically or surgically resected from January 2010 to December 2014, with a final pathological diagnosis of adenoma with severe atypia, Tis, and T1a, and T1b carcinoma. The third person selected 50 (14, 13, 11, and 12) lesions with good quality images. Three experts (T.T, M.I, Y.H) assessed the invasion depth of these lesions, as predicted by the JNET classification from NBI magnification images. Re-evaluation of the same lesions was performed 60 days later by the same experts. Type 2A were classified into adenoma with severe atypia and Tis lesions (endoscopically resectable lesions). Inter- and intra-observer coefficients were assessed. (Results)The sensitivity, specificity, and accuracy of JNET classification were 74.1%, 100%, and 86%, respectively. Inter-observer kappa coefficient of the vascular pattern of 2A and surface pattern of 2A were 0.67, 0.66 and 0.64, 0.69. Intra-observer kappa coefficient of them were 0.71, 0.84 for T.T, 0.71, 0.68 for M.I, and 0.82, 0.83 for Y.H.(Conclusions)JNET classification may be useful and reliable modality to differentiate between endoscopically resectable lesions from T1a or more deeper lesions.