title: Long-Term Clinical Outcomes of Rectal Neuroendocrine Tumors According to the Pathologic Status After Initial Endoscopic Resection: A KASID Multicenter Study.
abstract: With advances in diagnostic endoscopy, the detection of rectal neuroendocrine tumors (NETs) has increased. However, clinical outcomes, especially after endoscopic treatment, are still unclear. The aim of this study was to determine the long-term clinical outcomes of endoscopically resected rectal NETs according to the pathologic status after initial resection.
  
  
  
  In this large, multicenter, retrospective cohort study, we analyzed the medical records of patients who underwent endoscopic resection of rectal NETs and were followed for ≥24 months at 16 university hospitals. The outcomes of interest were local or distant recurrence and metachronous lesions.
  
  
  
  On the pathologic assessment of 407 patients, the resection margin status was positive in 76 (18.7%) and indeterminate in 72 (17.7%) patients. Patients whose rectal NETs were diagnosed or suspected as NETs before resection showed a much higher complete resection rate than those whose tumors were resected as polyps and then diagnosed (P<0.001). Fourteen patients received salvage treatment at 1.9±2.8 months after initial treatment. During a median follow-up period of 45.0 months, local recurrence occurred in 3 (0.74%) patients, but there was no recurrence in the lymph nodes or distant organs. Metachronous rectal NETs were diagnosed in 3 (0.74%) patients. According to the pathologic status after initial resection, local recurrence and metachronous lesions occurred in 1 (0.4%) and 2 (0.8%) patients, respectively, in the pathologic tumor-free group, whereas they occurred in 2 (1.4%) and 1 (0.7%) patients, respectively, in the indeterminate group.
  
  
  
  Considering the long-term prognosis including that for recurrences or metachronous lesions, endoscopic resection is an efficient and a safe modality for the treatment of rectal NETs. This treatment may result in favorable clinical outcomes in patients with tumors of indeterminate pathology, as well as in pathologic tumor-free cases after initial resection.
authors.affiliation: Department of Internal Medicine, School of Medicine, Ewha Womans University, Seoul, South Korea.
authors.forename: Chang Mo
authors.initials: CM
authors.lastname: Moon
authors.affiliation: Department of Internal Medicine, Konyang University College of Medicine, Konyang University Hospital, Daejeon, South Korea.
authors.forename: Kyu Chan
authors.initials: KC
authors.lastname: Huh
authors.affiliation: Department of Internal Medicine, School of Medicine, Ewha Womans University, Seoul, South Korea.
authors.forename: Sung-Ae
authors.initials: SA
authors.lastname: Jung
authors.affiliation: Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Dong Il
authors.initials: DI
authors.lastname: Park
authors.affiliation: Digestive Disease Center, CHA Bundang Medical Center, CHA University, Seongnam, South Korea.
authors.forename: Won Hee
authors.initials: WH
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Hye Mi
authors.initials: HM
authors.lastname: Jung
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Boramae Medical Center, Seoul, South Korea.
authors.forename: Seong-Joon
authors.initials: SJ
authors.lastname: Koh
authors.affiliation: Department of Internal Medicine, Soonchunhyang University College of Medicine, Seoul Hospital, Seoul, South Korea.
authors.forename: Jin-Oh
authors.initials: JO
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Soonchunhyang University College of Medicine, Cheonan Hospital, Cheonan, South Korea.
authors.forename: Yunho
authors.initials: Y
authors.lastname: Jung
authors.affiliation: Department of Internal Medicine, Yeungnam University College of Medicine, Daegu, South Korea.
authors.forename: Kyeong Ok
authors.initials: KO
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Inje University College of Medicine, Ilsan Paik Hospital, Goyang, South Korea.
authors.forename: Jong Wook
authors.initials: JW
authors.lastname: Kim
authors.affiliation: Department of Gastroenterology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
authors.forename: Dong-Hoon
authors.initials: DH
authors.lastname: Yang
authors.affiliation: Department of Internal Medicine, Dankook University College of Medicine, Cheonan, South Korea.
authors.forename: Jeong Eun
authors.initials: JE
authors.lastname: Shin
authors.affiliation: Department of Internal Medicine, Ajou University School of Medicine, Suwon, South Korea.
authors.forename: Sung Jae
authors.initials: SJ
authors.lastname: Shin
authors.affiliation: Department of Internal Medicine, Keimyung University School of Medicine, Daegu, South Korea.
authors.forename: Eun Soo
authors.initials: ES
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Chonnam National University Medical School, Gwangju, South Korea.
authors.forename: Young-Eun
authors.initials: YE
authors.lastname: Joo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003113:Colonoscopy; D000069916:Endoscopic Mucosal Resection / Q000379:methods*; D005260:Female; D006801:Humans; D007417:Intestinal Polyps / Q000473:pathology / Q000601:surgery*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology*; D018358:Neuroendocrine Tumors / Q000473:pathology / Q000601:surgery*; D011379:Prognosis; D012004:Rectal Neoplasms / Q000473:pathology / Q000601:surgery*; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult