title: Evaluation of the adequacy of lymph node dissection in pylorus-preserving gastrectomy for early gastric cancer using the maruyama index.
abstract: BACKGROUND
  The Maruyama computer program predicts the percentage likelihood of disease in lymph node stations left undissected by a surgeon, according to the age and sex of the patient and the gross type, size, location, depth of invasion, and histology of the tumor. The Maruyama index (MI) is defined as the sum of the predictions of the percentage likelihood of disease in undissected regional lymph node station (station 1-12). It has been shown that an MI < 5 is a strong predictor of survival and that the MI is an independent predictor of overall survival and relapse risk. We used the MI to evaluate the adequacy of lymph nodes dissection in pylorus-preserving gastrectomy (PPG) for early gastric cancer (EGC) performed at Seoul National University Hospital.
  
  
  METHODS
  From March 2003 to September 2007, PPG was performed for patients with EGC of the middle third of the stomach when the distal resection margin was greater than 2 cm and preservation of 3 cm antral segment was possible. MIs and pathologic data such as TNM stage and the presence of metastatic lymph node for each station were reviewed.
  
  
  RESULTS
  PPG were performed on 24 patients. The mean age of the patients was 55 years. The median tumor size was 2.1 cm. The median and mean MI were 0 and 0.8, respectively. There were 23 cases of T1N0M0 tumor and one case of T2N0M0 tumor postoperatively. There were no recurrences (mean follow-up period: 27.2 months).
  
  
  CONCLUSIONS
  The MI indicates that lymph node dissection during PPG performed in these 24 patients was adequate.
authors.affiliation: Department of Surgery, Seoul National University College of Medicine, 101 Daehakno, Jongno-Gu, Seoul, 110-744, Korea.
authors.forename: Moon-Won
authors.initials: MW
authors.lastname: Yoo
authors.forename: Do Joong
authors.initials: DJ
authors.lastname: Park
authors.forename: Hye Seong
authors.initials: HS
authors.lastname: Ahn
authors.forename: Sang-Ho
authors.initials: SH
authors.lastname: Jeong
authors.forename: Hyuk-Joon
authors.initials: HJ
authors.lastname: Lee
authors.forename: Woo Ho
authors.initials: WH
authors.lastname: Kim
authors.forename: Hyung-Ho
authors.initials: HH
authors.lastname: Kim
authors.forename: Kuhn Uk
authors.initials: KU
authors.lastname: Lee
authors.forename: Han-Kwang
authors.initials: HK
authors.lastname: Yang
mesh_terms: D016009:Chi-Square Distribution; D005260:Female; D005743:Gastrectomy; D006801:Humans; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D011708:Pylorus / Q000473:pathology* / Q000601:surgery*; D012984:Software; D013274:Stomach Neoplasms / Q000473:pathology* / Q000601:surgery*; D016019:Survival Analysis