According to clinical practice and relevant retrospective research data, both modified cap-assisted endoscopic mucosal resection (mEMR-C) and endoscopic mucosal resection with a ligation device(ESMR-L) were reported to be effective for the treatment of small rectal neuroendocrine tumors (NETs) . However, there is a lack of multicenter prospective studies to evaluate the advantages and disadvantages of mEMR-C and mEMR-L. mEMR-C is the modified ESMR-L without submucosal injection.

We aimed to conduct a muticenter randomized controlled trial to compare mEMR-C with mEMR-L for the treatment of small rectal neuroendocrine tumors (NETs) in ten tertiary hospitals in China.

Inclusion Criteria:

1. Age from 18 to 80 years;
2. With a high suspicion or evidence of rectal NET assessed using EUS or colonoscopy;
3. With tumor size ≤10 mm assessed by colonoscopy;
4. Plan to receive mEMR-C or mEMR-L treatment and provide written informed consent;

Exclusion Criteria:

1. Unable to tolerate mEMR-L or mEMR-C as assessed by the research team of each center;
2. Complicated with serious diseases such as malignant tumor, which may lead to shorter life expectancy, the research team considers that it is not suitable for inclusion in the study after comprehensive evaluation;
3. Rectal NET with lymph node metastasis or distant metastasis;
4. Received resection of rectal neuroendocrine tumor by other surgical procedures;
5. Multiple rectal neuroendocrine tumors;
6. Vulnerable groups such as pregnant women or patients with mental disorders;
7. Poor compliance, unable to cooperate with treatment.