Analysis Of Clinical,Endoscopic And Pathological Features Of Colorectal Laterally Spreading Tumors

Background:Colorectal laterally spreading tumors(LSTs)are a special type of adenomas,and are defined as lesions greater than 10 mm in diameter that grow laterally along the superficial bowel wall rather than vertically infiltrating.It is regarded as precancerous lesions of the colorectum.The lesions are divided into granular type(LSTs-G)and non-granular(LSTs-NG)type according to whether there is granular hyperplasia in the lesion endoscopically.The granular type can be further divided into homogeneous type(LSTs-G-H)and nodular mixed type(LSTs-G-M),and the non-granular type can be further divided into flat-elevated type(LSTs-NG-F)and pseudo-depressed type(LSTs-NG-PD).Studies have shown that there are differences in growth patterns and pathological characteristics between different types.LSTs lesions tend to spread superficially and laterally along the colon wall and rarely invade the submucosa,so most lesions can be treated by endoscopic resection.Objective:Colorectal laterally spreading tumors(LSTs)are easy to be missed under endoscopy due to their superficial and lateral growth characteristics.This article aims to summarize and analyze the clinical,endoscopic and pathological features of LSTs,and to discuss the efficacy and safety of endoscopic treatments of LSTs,providing references for digestive endoscopists to identify LSTs lesions,judge the prognosis and select appropriate treatment methods.Methods:A retrospective search was performed for patients diagnosed with laterally spreading colorectal tumors(LSTs)and treated by complete electronic colonoscopy at the Gastrointestinal Endoscopy Center of the Second Xiangya Hospital of Central South University from January 2016 to January 2022.A total of 175 patients,180 lesions,of which 5 patients had 2 lesions at the same time,168 lesions were excised endoscopically.The hospitalization data of the patients were collected,and the clinical features,endoscopic features and pathological features of LSTs lesions were analyzed and summarized.The multivariate logistic regression was used to analyze the risk factors for the occurrence of high-grade histology in LSTs lesions,and the safety and efficacy of endoscopic treatment were analyzed.Results:(1)A total of 175 patients with colorectal LSTs were detected in this study,with a male to female ratio of 0.86:1,and there was no significant difference in the distribution of males and females(P>0.05).The average age of the patients was 58.5±9.9 years old,and the most common age group was 60-69 years old.There was no significant difference in the distribution of males and females in each age group(P>0.05).A total of180 lesions were included,with an average diameter of 3.3±3.0cm.The most common lesions were 20-29 mm in diameter,accounting for 33.3%.LSTs lesions involving the proximal colon were the most common,accounting for 42.2%,followed by the rectum,accounting for 39.5%.There were differences in lesion diameter,location distribution and histopathology among different types of LSTs(P<0.05).In terms of lesion size,LSTs-G-M lesions had the largest average diameter of 42.9±39.1mm.The lesions of LSTs-G-M type were mainly distributed in the rectum,and the LSTs-G-H,LSTs-NG-F,and LSTs-NG-PD types were mainly distributed in the proximal colon.In terms of histopathology,LSTs-G-M type had a higher incidence of high-grade histopathology(P<0.05).(2)Among the 180 lesions in this study,there were 77 lesions in the cancerous group,including 60 lesions of HGIN and 17 lesions of submucosal carcinoma.Multivariate logistic regression was used to analyze the risk factors related to carcinogenesis,and the results showed that the location of the rectum,the large diameter of the lesion,and the types of LSTs-G-M and LSTs-NG-F were closely related to carcinogenesis.(3)In this study,a total of 168 lesions underwent endoscopic treatment,of which 13 lesions underwent endoscopic mucosal resection(EMR)with an average diameter of 14.8±4.0 mm;12 lesions underwent endoscopic mucosal resection(EPMR),the mean diameter was21.8±6.6mm;143 lesions were treated with endoscopic submucosal dissection(ESD),and the mean diameter was 35.1±32.8mm.The diameter of the lesions in the ESD group was significantly larger than that in the EMR and EPMR groups,suggesting that ESD is more suitable for resection of larger diameter lesions.Among the 168 lesions that underwent endoscopic treatment,the en bloc resection rate was 88.1%,the complete resection rate was 94.0%,the endoscopic-related bleeding rate was 7.1%,and the gastrointestinal perforation rate was 1.8%.The patients improved after conservative medical treatment,no serious adverse events occurred,and the recurrence rate was 1.2%,suggesting that endoscopic treatment of colorectal LSTs is feasible,safe and effective.Conclusion:(1)There are differences in the size,location and distribution of colorectal lesions and histopathology of different types of LSTs.In terms of lesion diameter,the average diameter of LSTs-G-M type lesions is larger than the other three types.In terms of location distribution,LSTs-G-M type lesions Mainly distributed in the rectum,the other three types are mainly distributed in the proximal colon.In terms of histopathology,LSTs-G-M type has a higher incidence of high-grade histopathology.(2)The location of the lesion in the rectum,the diameter of the large lesion and the classification of LSTs-G-M and LSTs-NG-F are closely related to cancer.(3)Endoscopic treatments of LSTs lesions are safe and effective.