Endoscopic diagnosis of lateral spreading tumours (LST) with submucosal invasion is important in guiding the treatment strategy. The use of advanced imaging is not standard clinical practice in China. A clinical trial is now under way comparing the accuracy of narrow band imaging (NBI), endoscopic ultrasonography (EUS) and magnifying chromoendoscopy (MCE) for the diagnosis of LST with submucosal invasion.

Endoscopic diagnosis of lateral spreading tumours (LST) with submucosal invasion is important in guiding the treatment strategy. The use of advanced imaging is not standard clinical practice in China. A clinical trial is now under way comparing the accuracy of narrow band imaging (NBI), endoscopic ultrasonography (EUS) and magnifying chromoendoscopy (MCE) for the diagnosis of LST with submucosal invasion.The final histologic diagnosis was used as the true diagnosis in the present study. By comparing the consistency of histologic diagnosis and preoperative evaluation,the diagnostic accuracies of various endoscopic examination techniques(narrow band imaging , endoscopic ultrasonography , and magnifying chromoendoscopy) was calculated respectively.

Inclusion Criteria:

- patients older than 18 years and Less than 65 years patients with endoscopic diagnosis of lateral spreading tumours signed informed consent

Exclusion Criteria:

- patients with serious heart, brain, lung, kidney complications patients with intestinal obstruction previous therapy for colorectal cancer women in gestational and lactational period taking anticoagulants or antiplatelet medications. based on the evaluations of physicians, the patient's condition is not suitable for the clinical trial

patients with endoscopic diagnosis of lateral spreading tumours