title: A Risk Prediction Model Based on Lymph-Node Metastasis in Poorly Differentiated-Type Intramucosal Gastric Cancer.
abstract: OBJECTIVE
  Endoscopic submucosal dissection (ESD) for undifferentiated type early gastric cancer is regarded as an investigational treatment. Few studies have tried to identify the risk factors that predict lymph-node metastasis (LNM) in intramucosal poorly differentiated adenocarcinomas (PDC). This study was designed to develop a risk scoring system (RSS) for predicting LNM in intramucosal PDC.
  
  
  METHODS
  From January 2002 to July 2015, patients diagnosed with mucosa-confined PDC, among those who underwent curative gastrectomy with lymph node dissection were reviewed. A risk model based on independent predicting factors of LNM was developed, and its performance was internally validated using a split sample approach.
  
  
  RESULTS
  Overall, LNM was observed in 5.2% (61) of 1169 patients. Four risk factors [Female sex, tumor size ≥ 3.2 cm, muscularis mucosa (M3) invasion, and lymphatic-vascular involvement] were significantly associated with LNM, which were incorporated into the RSS. The area under the receiver operating characteristic curve for predicting LNM after internal validation was 0.69 [95% confidence interval (CI), 0.59-0.79]. A total score of 2 points corresponded to the optimal RSS threshold with a discrimination of 0.75 (95% CI 0.69-0.81). The LNM rates were 1.6% for low risk (<2 points) and 8.9% for high-risk (≥2 points) patients, with a negative predictive value of 98.6% (95% CI 0.98-1.00).
  
  
  CONCLUSIONS
  A RSS could be useful in clinical practice to determine which patients with intramucosal PDC have low risk of LNM.
authors.affiliation: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Jeung Hui
authors.initials: JH
authors.lastname: Pyo
authors.affiliation: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Hyuk
authors.initials: H
authors.lastname: Lee
authors.affiliation: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Byung-Hoon
authors.initials: BH
authors.lastname: Min
authors.affiliation: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Jun Haeng
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Min Gew
authors.initials: MG
authors.lastname: Choi
authors.affiliation: Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Jun Ho
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Tae Sung
authors.initials: TS
authors.lastname: Sohn
authors.affiliation: Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Jae Moon
authors.initials: JM
authors.lastname: Bae
authors.affiliation: Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Kyoung-Mee
authors.initials: KM
authors.lastname: Kim
authors.affiliation: Biostatistics and Clinical Epidemiology Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Hyeon Seon
authors.initials: HS
authors.lastname: Ahn
authors.affiliation: Biostatistics and Clinical Epidemiology Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.|Department of Biostatistics and Bioinformatics, Duke University Medical Center, Durham, North Carolina, United States of America.
authors.forename: Sin-Ho
authors.initials: SH
authors.lastname: Jung
authors.affiliation: Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Sung
authors.initials: S
authors.lastname: Kim
authors.affiliation: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Jae J
authors.initials: JJ
authors.lastname: Kim
mesh_terms: D000230:Adenocarcinoma / Q000556:secondary* / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002454:Cell Differentiation; D005260:Female; D005500:Follow-Up Studies; D005743:Gastrectomy; D005753:Gastric Mucosa / Q000473:pathology*; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D011379:Prognosis; D011446:Prospective Studies; D012372:ROC Curve; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000473:pathology* / Q000601:surgery; D055815:Young Adult