Endoscopic Characteristics And Treatments Of Laterally Spreading Colorectal Tumors: A Retrospective Analysis

Objective: Laterally spreading tumor(LST)refers to a superficial uplifted lesion that is greater than 10 mm in diameter and tends to grow large and laterally along the intestinal wall,which is significant to colorectal cancer progression.Precise endoscopic diagnosis,on the gross morphology to differ its malignancy and submucosal invasion risks,is crucial in the treatment of LST.In the past,Paris classification and pit pattern classification could not distinguish all the risk of LST.Up till now,the clinical value of LST subtype classification and JNET is yet to be identified.The aim of this study is to find out the endoscopic characteristics of LST,compare different diagnosis classifications and treatments,in order to offer optimum diagnostic and therapeutic methods.Methods: All involved patients were diagnosed with LST and underwent biopsies,either by endoscopy or surgery,at Renji hospital Shanghai Jiao Tong university school of medicine,between July 2012 and July 2017.Following contrastive analyses were based on endoscopic images reviewed by two experienced endoscopists and pathology as gold standard:(1)LST subtypes classification and Paris classification under white light endoscopy,(2)JNET classification and Pit Pattern classification under narrow band imagine endoscopy,(3)advantages and disadvantages between EMR,EPMR and ESD.Results: 1.In the first part,236 cases were included.No difference in distribution of pathological type existed in LST subtype classification and Paris classification(p=0.277 and p=0.677)The incidence rate of submucosa was 23.5% in LST-P,6.5% in LST-M,4.9% in LST-F,2.0% in LSTH.54.7% of further LST subclass did not correspond to any Paris subtype.2.In the second part,177 cases were included.The accuracy of Pit Pattern classification contrasted with JNET classification was 79.7% vs 85.9%,sensitivity was 70.3% vs 92.2%,specificity was 85.0% vs 82.3%,positive predictive value was 72.6% vs 74.7%,negative predictive value was 83.5% vs 94.9%.No significant differences in diagnostic accuracy between pit pattern and JNET(PLST = 0.159,PLST-G = 0.224,PLST-NG = 0.559).3.In the third part,236 cases included.32(13.6%)were EMR,10(4.2%)were EPMR,174(73.7%)were ESD,and 20(8.5%)were surgery.Compared with EMR,ESD has greater diameter(p<0.001),the ec Bloc rate was higher(p=0.001),the R0 rate has no significant difference(p=0.368).Postoperative complications were only found in ESD,and the incidence of complications was 4.7%.All patients were recovered with symptomatic treatment.Among EMR,EPMR and ESD,hospitalization rates were 25.0% vs 40.0% vs 100.0%,the rates of patients hospitalized <7 days were 87.5% vs 100.0% vs 64.9%,average cost was 7236 CNY,11,828 CNY and 21,980 CNY,respectively.Conclusion: Submucosal infiltration risks of LST can be preliminary predicted by different subtype of gross morphology under white light endoscopy.JNET classification using NBI gives a more accurate prediction of pathological characteristics of LST;it is also more practical compared to choromoendoscopy,among which JNET type 2b and 3 better predicts depth of submucosal infiltration.Treatments of LST based on gross morphology and JNET would be more cost effective.