LAUSR

Background To analyse the endoscopic characteristics and therapeutic methods of colorectal laterally spreading tumours. Methods Colorectal laterally spreading tumours were collected from digestive endoscopy centre of PLA army general hospital from Mar 2010 to May 2016. Their relationship between morphology? predilection site and histopathology were analysed retrospectively. Results A total of 615 colorectal laterally spreading tumours (551patients) were collected. The average diameter of lesion was 22.2? 14.7 mm, the size was from 10 to 20 mm in the most (66.5%), and LSTs were predominant in the proximal colon (55.4%). Granular-homogenous(LST-GH) was detected more frequently in the ileocecal region and ascending colon (75/140,53.7%); Granular-nodular mixed (LST-GM) was detected more frequently in the rectum and sigmoid colon (91/140,65.0%); Non-granular-flat-elevated (LST-NGF) and non-granular-pseudo-depressed (LST-NG-PD) were preferentially located in the proximal colon, especially more common in transverse colon, account for 25.9% and 32.1% respectively. Among lesions intramucosal carcinoma and submucosal carcinoma was 19.67% (121/615), submucosal carcinoma was 3.25% (20/615). LST-GM and LST-NGPD had a higher incidence of intramucosal carcinoma and submucosal carcinoma compared to the other subtypes, 43.28% and 34.52%, respectively. LST-NGPD was highest rates of submucosal invasion: 14.29%? LST-GM was predominant in the rectum; the mean tumour size was larger in the rectum than the colon (31.49?23.09 vs 20.82?9.86,p<0.05), higher incidence of high-grade dysplasia and submucosal carcinoma (36.43% vs 14.95%, p<0.001).Abstract IDDF2018-ABS-0159 Table 1 Clinicopathological characteristics of the lesions Colon, n=475 Rectum, n=140 p value All, n=615 Age, medium (range) 61 (17–92) 64 (31–88) <0.05 62 (17–92) Male gender 281 (59.16) 78 (55.71) 0.47 359 (58.37) Subtypes of LST <0.05 LST-GH 109 (22.95) 31 (22.14) 140 (22.76) LST-GM 78 (16.42) 62 (44.29) 140 (22.76) LST-NGF 216 (45.47) 35 (25.00) 251 (40.81) LST-NGD 72 (15.16) 12 (8.57) 84 (13.66) Size, mean±SD(mm) 20.82±9.86 31.49±23.09 <0.05 23.25±14.69 Histological classification <0.0001 Low-grade dysplasia 275 (57.68) 74 (53.57) 349 (56.75) High-grade dysplasia 58 (12.21) 44 (31.43) 102 (16.59) Submucosal cancer 13 (2.74) 7 (5.00) 20 (3.25) Conclusions LSTs were predominant in the proximal colon, but a greater proportion of LST-GM, greater mean-size, and greater presence of submucosal cancer found in rectal LST. LST-GM and LST-NGPD had a higher incidence of intramucosal carcinoma and submucosal carcinoma, in particular, LST-NGPD was highest rates of submucosal invasion, should be noticed by endoscopic physicians.