title: Incorporating surgical quality into the AJCC 7th edition improves staging accuracy in gastric cancer.
abstract: BACKGROUND
  The staging of gastric cancer has become increasingly complex. With an emerging 15-node quality measure and a revised American Joint Committee on Cancer (AJCC) staging system, we evaluated the need for more intricate staging systems to predict survival outcomes in gastric cancer.
  
  
  METHODS
  The Surveillance, Epidemiology and End Results Program (SEER) database was used to identify 124,972 patients with gastric cancer between 2000 and 2010. Primary endpoints were 5-year disease-specific survival (DSS) and overall survival (OS). Analysis was performed on patients with ≥15 nodes evaluated. Multivariable regression with/without the inclusion of lymph node (LN) assessment and LN ratio were compared using the Akaike information criterion.
  
  
  RESULTS
  The number of patients included in the final analysis was 12,096. The proportion of patients with an adequate lymphadenectomy increased markedly from 27 % in 2000 to 52 % in 2010. Overall 5-year DSS and OS was 61.9 and 48.8 %, respectively, for patients with ≥15 nodes examined, versus 57.7 and 39.9 %, respectively, for those with <15 sampled nodes (p < 0.0001). In patients with ≥15 nodes evaluated, the addition of LN evaluation and LN ratio to the existing staging model improved its ability to predict 5-year DSS and OS (p < 0.0001). LN evaluation and LN ratio were comparable in their ability to supplement the existing AJCC 7th edition (AJCC7) staging system.
  
  
  CONCLUSIONS
  The inclusion of a minimum 15-LN quality measure improves the prognostic ability of the AJCC7 staging system, without adding significant complexity.
authors.affiliation: Gastrointestinal Research Program, John Wayne Cancer Institute at Providence Saint John's Health Center, Santa Monica, CA, USA.
authors.forename: Gary B
authors.initials: GB
authors.lastname: Deutsch
authors.forename: Victoria
authors.initials: V
authors.lastname: O'Connor
authors.forename: Myung-Shin
authors.initials: MS
authors.lastname: Sim
authors.forename: Ji Hey
authors.initials: JH
authors.lastname: Lee
authors.forename: Anton J
authors.initials: AJ
authors.lastname: Bilchik
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008197:Lymph Node Excision / Q000592:standards*; D008198:Lymph Nodes / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D058996:Quality Improvement; D019984:Quality Indicators, Health Care; D018426:SEER Program; D013274:Stomach Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D015996:Survival Rate