Endoscopic submucosal dissection for colorectal laterally spreading tumors: Clinicopathological features and treatment outcomes

Abstract Background and aim Colorectal laterally spreading tumor (LST) is a type of precancious lesions of colorectal cancer with high malignant potential. To investigate the endoscopic morphology and pathological traits of colorectal LSTs, evaluate clinical outcomes of endoscopic treatment, and identify risk factors associated with high-grade dysplasia (HGD) / carcinoma, submucosal invasion and complications. Methods This single-center retrospective study, from a prospectively collected database, was conducted between January 2016 and December 2023. We performed a retrospective analysis of the endoscopic and histological results of consecutive patients who underwent endoscopic resection for colorectal LSTs in our hospital. The pathological classification and outcomes were analyzed. Risk factors for high-grade dysplasia/carcinoma, submucosal invasion and complications were determined using logistic regression. Results A total of 375 colorectal LSTs were enrolled. The incidences of low-grade dysplasia, high-grade dysplasia and adenocarcinoma for LSTs were 60.3%, 25.3% and 14.4%, respectively. The size ≥30 mm, LST granular nodular mixed type (LST-G-M) and LST non-granular pseudo depressed type (LST-NG-PD) were independently associated with higher odds in HGD/carcinoma. The prevalence of submucosal invasion cancer was 10.1%. LST-NG-PD and tumor budding were associated with higher odds for submucosal invasion, and the tumor budding was an independent risk factor for deep submucosal invasion. The frequency of delayed bleeding and perforation were 2.1% and 4.8%, respectively. LST-G-M and size ≥30 mm were associated with higher odds for complications. Conclusions This study demonstrated that larger LST increased risk for HGD/carcinoma and complication during endoscopic treatment. LST-NG-PD lesions were more likely prone to submucosal invasion. Tumor budding was an independent risk factor for deep submucosal invasion.