title: Lymph node evaluation of colon cancer and its association with improved staging and survival in the Department of Defense Health Care System.
abstract: BACKGROUND
  Improved survival is associated with an increased number of lymph nodes (LNs) examined. The aim of this study was to assess whether the examination of >or=12 LNs is associated with more accurate colon cancer staging.
  
  
  METHODS
  We queried the Department of Defense Automated Central Tumor Registry database for stage I-III colon cancer patients. Logistic regression analysis was performed to determine whether the examination of >or=12 LNs is associated with increased rates of LN-positive colon cancer. Kaplan-Meier and Cox proportional hazard analysis was performed to evaluate the effect of number of LNs examined on survival.
  
  
  RESULTS
  The rate of LN-positive colon cancer is significantly higher with increasing number of LNs examined (1-3 LNs examined: 31% vs. >12 LNs examined: 41%, P<.001). Logistic regression analysis adjusting for patients, tumor, and hospital characteristics showed that examination of >or=12 LNs is associated with a >30% increase in detecting a LN-positive colon cancer (odds ratio, 1.350; 95% confidence interval, 1.175-1.511). The evaluation of >or=12 LNs is associated with improved survival in LN-negative colon cancer patients (P<.001).
  
  
  CONCLUSIONS
  Our study demonstrates that the proportion of LN-positive colon cancer is far higher when >or=12 LNs are examined. Examination of >or=12 LNs may improve staging accuracy and outcome with optimal use of systemic chemotherapy.
authors.affiliation: Department of Surgery, William Beaumont Army Medical Center, El Paso, TX, USA. Sukhyung.lee@amedd.army.mil
authors.forename: Sukhyung
authors.initials: S
authors.lastname: Lee
authors.forename: Luke J
authors.initials: LJ
authors.lastname: Hofmann
authors.forename: Kurt G
authors.initials: KG
authors.lastname: Davis
authors.forename: Brad E
authors.initials: BE
authors.lastname: Waddell
mesh_terms: D003110:Colonic Neoplasms / Q000401:mortality* / Q000473:pathology*; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D012042:Registries; D015996:Survival Rate; D016896:Treatment Outcome; D014481:United States