Evolving Profile of Acute Spinal Cord Injury Demographics, Outcomes, and Surgical Treatment in North America: Analysis of a Prospective Multi-Center Dataset of 989 Patients

Tumor size, tumor grade, invasion depth, and lymphovascular invahave been reported as risk factors for rectal neuroendocrine tumetastasizing to the lymph nodes. However, there are discrepancies among guidelines regarding the treatment, and the decision should be in consideration of risk factors and quality of life. Large prospective studies are needed. Introduction incidence of neuroendocrine neoplasms (NENs) arising from gastro-entero-pancreatic tract (GEP-NENs), across all sites, stages, grades, is steadily increasing, with a 6.4-fold increase from 1.09 per 100,000 in 1973 to 6.98 per 100,000 in 2012.[1,21 The incidence of by site differs according to the country and region of the world. United States, the rectum is the third most common site after the and small intestine.[11Meanwhile, in Japan, South Korea, China, Taiwan, the rectum is the most common site of occurrence.[3-61 The increase in the number of colonoscopies for colorectal cancer screening and the improvement of endoscopic equipment and technology have contributed to the increase in rectal NENs, especially ever, it has been reported that NETs and positive resection margins are often found on histopathological examination after the tumors are misidentified as colorectal polyps and managed with normal polypectomy.[91 Localized, well-differentiated rectal NETs are mainly treated with local excision and radical rectal resection with lymphadenectomy. Compared with rectal cancer, rectal NET G1/G2 has different characteristics such as easy lymph node metastasis despite its small size and slow progression, and thus, there are many controversial aspects in its treatment strategy. In addition, most NETs occur in the lower rectum, and surgery has a significant adverse impact on quality of life (QOL), including on bowel function, urinary function, and sexual function, making treatment difficult. In this review, we focus on the treatment of localized well-differentiated rectal NET G1/G2, introduce the latest evidence, and organize current knowledge. 3. Methods We conducted an electronic literature search using the PubMed database to identify studies conducted on rectal NETs that were published between January 1990 and October 2022. The following key words were