title: Risk factors for residual cancer and lymph node metastasis after noncurative endoscopic resection of early colorectal cancer.
abstract: BACKGROUND
  Endoscopic resection could be a curative treatment for early colorectal cancer without the possibility of lymph node metastasis. However, if the resection margin is positive, and there is a risk of lymph node metastasis, additional surgery should be performed.
  
  
  OBJECTIVE
  The aim of this study was to investigate the characteristics of patients who underwent additional surgery to determine risk factors associated with residual tumor and lymph node metastasis.
  
  
  METHODS
  This study is a retrospective analysis.
  
  
  METHODS
  This study was conducted at a tertiary academic hospital.
  
  
  METHODS
  We evaluated 85 patients who underwent additional surgery with curative intent after endoscopic resection for early colorectal cancer at the Samsung Medical Center, Seoul, South Korea, between January 2001 and April 2010.
  
  
  METHODS
  We identified risk factors associated with residual tumor or lymph node metastasis in surgical specimens after noncurative endoscopic resection for early colorectal cancer.
  
  
  RESULTS
  Among 85 patients who underwent additional surgery after noncurative endoscopic resection, 76 (89.4%) had submucosal invasion greater than 1000 μm. Twenty-one (24.7%) and 25 patients (29.4%) had a positive lateral or vertical resection margin, and 11 patients (12.9%) had inadequate lifting sign. After additional surgery, patients were divided into 2 groups according to the presence or absence of residual tumor and/or lymph node metastasis. There was no significant difference between the groups in positive lateral margin, but there was a significant difference in positive vertical margin (p = 0.015 with an OR of 15.02). In patients with inadequate lifting sign, the OR was 13.68 (p = 0.013).
  
  
  CONCLUSIONS
  This study was limited by its retrospective nature.
  
  
  CONCLUSIONS
  There is a greater need for additional surgery in cases with positive vertical resection margin or inadequate lifting sign, because the risk of residual tumor and lymph node metastasis is higher than in other cases.
authors.affiliation: Department of Medicine, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, Korea.
authors.forename: Kwang Min
authors.initials: KM
authors.lastname: Kim
authors.forename: Sung June
authors.initials: SJ
authors.lastname: Eo
authors.forename: Sang Goon
authors.initials: SG
authors.lastname: Shim
authors.forename: Dong Kyung
authors.initials: DK
authors.lastname: Chang
authors.forename: Young-Ho
authors.initials: YH
authors.lastname: Kim
authors.forename: Poong-Lyul
authors.initials: PL
authors.lastname: Rhee
authors.forename: Jae J
authors.initials: JJ
authors.lastname: Kim
authors.forename: Jin Yong
authors.initials: JY
authors.lastname: Kim
mesh_terms: D000230:Adenocarcinoma / Q000453:epidemiology / Q000473:pathology / Q000601:surgery; D000368:Aged; D015179:Colorectal Neoplasms / Q000453:epidemiology / Q000473:pathology / Q000601:surgery; D004210:Dissection / Q000009:adverse effects* / Q000379:methods / Q000706:statistics & numerical data; D061345:Early Medical Intervention; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology / Q000601:surgery*; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D018365:Neoplasm, Residual; D011183:Postoperative Complications / Q000453:epidemiology / Q000473:pathology / Q000601:surgery; D011351:Proctoscopy / Q000009:adverse effects* / Q000379:methods / Q000706:statistics & numerical data; D012086:Reoperation; D056910:Republic of Korea / Q000453:epidemiology; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors