title: Is preoperative staging enough to guide lymph node dissection in clinically early gastric cancer?
abstract: BACKGROUND
  Limited by the accuracy of preoperative staging, some cases of gastric cancer invading the muscularis propria (pT2) are underestimated as early gastric cancer (EGC) in the preoperative assessment. The aim of this present study was to determine prognostic factors and to propose indications for limited lymph node dissection in patients with clinically EGC (cEGC).
  
  
  METHODS
  Patients of cEGC (n = 2072) who were postoperatively diagnosed as pT1 (cT1pT1, n = 1858) and pT2 (cT1pT2, n = 214) from 2005 to 2009 at Seoul National University Hospital were retrospectively analyzed.
  
  
  RESULTS
  There was no difference in 5-year survival rate between the cT1pT1 and cT1pT2 group (95.5 % vs. 92.5 %, P = 0.059), and both groups had better overall survival than pT2 patients who were preoperatively diagnosed as locally advanced gastric cancer (cT2-4pT2), whose 5-year survival rate was 78.0 % (P < 0.001). Multivariate analysis indicated lymph node metastasis (LNM) was the independent prognostic factor for cEGC (P < 0.001). In cEGC patients, three preoperative factors, including N stage by multidetector-row computed tomography (MDCT) (P < 0.001), preoperative histological type (P < 0.001), and tumor size (P < 0.001), were associated with LNM by multivariate analysis. Regarding the possibility of LNM, low-risk (4.4 %) and high-risk (17.3 %) groups were developed based on weighted scores of the aforementioned independent three variables. Among 52 patients in the low-risk group, the extension of LNM was limited to the perigastric area.
  
  
  CONCLUSIONS
  Comprehensive evaluation based on MDCT, preoperative histological type, and tumor size is an effective method to predict LNM and guide tailored LN dissection for cEGC.
authors.affiliation: Department of Surgery, Seoul National University Hospital, Seoul, Korea.|Department of General Surgery, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Xu
authors.affiliation: Department of General Surgery, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Cao
authors.affiliation: Department of Surgery, Seoul National University Hospital, Seoul, Korea.
authors.forename: Jun-Young
authors.initials: JY
authors.lastname: Yang
authors.affiliation: Department of Surgery, Seoul National University Hospital, Seoul, Korea.
authors.forename: Yun-Suhk
authors.initials: YS
authors.lastname: Suh
authors.affiliation: Department of Surgery, Seoul National University Hospital, Seoul, Korea.
authors.forename: Seong-Ho
authors.initials: SH
authors.lastname: Kong
authors.affiliation: Department of Radiology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Se-Hyung
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Sang-Gyun
authors.initials: SG
authors.lastname: Kim
authors.affiliation: Department of Surgery, Seoul National University Hospital, Seoul, Korea.|Department of Surgery, Seoul National University College of Medicine, 101 Daehang-Ro, Jongno-Gu, Seoul, 110-744, Korea.|Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Hyuk-Joon
authors.initials: HJ
authors.lastname: Lee
authors.affiliation: Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea.|Department of Pathology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Woo-Ho
authors.initials: WH
authors.lastname: Kim
authors.affiliation: Department of Surgery, Seoul National University Hospital, Seoul, Korea. hkyang@snu.ac.kr.|Department of Surgery, Seoul National University College of Medicine, 101 Daehang-Ro, Jongno-Gu, Seoul, 110-744, Korea. hkyang@snu.ac.kr.|Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea. hkyang@snu.ac.kr.
authors.forename: Han-Kwang
authors.initials: HK
authors.lastname: Yang
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008197:Lymph Node Excision / Q000379:methods*; D008207:Lymphatic Metastasis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D011300:Preoperative Care; D011379:Prognosis; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000401:mortality* / Q000473:pathology* / Q000601:surgery; D015996:Survival Rate; D016896:Treatment Outcome
keywords: Early gastric cancer; Lymph node metastases; Lymphadenectomy; Prognosis