title: Omission of Adjuvant Chemotherapy Is Associated With Increased Mortality in Patients With T3N0 Colon Cancer With Inadequate Lymph Node Harvest.
abstract: BACKGROUND
  Adjuvant chemotherapy for T3N0 colon cancer is controversial. National guidelines recommend its use in patients with stage II with high-risk features, including lymph node harvest of less than 12, yet this treatment is underused.
  
  
  OBJECTIVE
  The purpose of this study was to demonstrate that the use of adjuvant chemotherapy in patients with T3N0 adenocarcinoma with inadequate lymph node harvest is beneficial.
  
  
  METHODS
  This was a retrospective population-based study of patients with resected T3N0 adenocarcinoma of the colon.
  
  
  METHODS
  The National Cancer Database was queried from 2003 to 2012.
  
  
  METHODS
  A total of 134,567 patients with T3N0 colon cancer were included in this analysis.
  
  
  METHODS
  The use of chemotherapy, short-term outcomes, and overall survival was evaluated. Clinicopathologic factors associated with omission of chemotherapy were also analyzed.
  
  
  RESULTS
  Inadequate lymph node harvest was observed in 23.3% of patients, and this rate decreased over the study period from 46.8% in 2003 to 12.5% in 2012 (p < 0.0001). Overall 5-year survival for patients with T3N0 cancer was 66.8%. Inadequate lymph node harvest among these patients was associated with lower overall 5-year survival (58.7% vs 69.8%; p < 0.001). The use of adjuvant chemotherapy among patients with T3N0 cancer after inadequate lymph node harvest was only 16.7%. In a multivariable analysis, factors associated with failure to receive chemotherapy included advanced age (OR = 0.44 (95% CI, 0.43-0.45)), increased comorbidities (OR = 0.7 (95% CI, 0.66-0.76)), and postoperative readmission (OR = 0.78 (95% CI, 0.67-0.91)). Patients with inadequate lymph node harvest who received adjuvant chemotherapy had improved 5-year survival (chemotherapy, 78.4% vs no chemotherapy, 54.7%; p < 0.001). Even when controlling for all of the significant variables, the administration of chemotherapy remained a predictor of decreased mortality (HR = 0.57 (95% CI, 0.54-0.60); p < 0.001).
  
  
  CONCLUSIONS
  This study was limited by its retrospective, population-based design.
  
  
  CONCLUSIONS
  Patients with T3N0 colon cancer with inadequate lymph node harvest who receive adjuvant chemotherapy have increased overall survival. Despite this survival benefit, a fraction of these patients receive adjuvant chemotherapy. Barriers to chemotherapy are multifactorial.
authors.affiliation: Department of Surgery, Section of Colon and Rectal Surgery, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Katerina O
authors.initials: KO
authors.lastname: Wells
authors.forename: Alexander T
authors.initials: AT
authors.lastname: Hawkins
authors.forename: Devi M
authors.initials: DM
authors.lastname: Krishnamurthy
authors.forename: Sekhar
authors.initials: S
authors.lastname: Dharmarajan
authors.forename: Sean C
authors.initials: SC
authors.lastname: Glasgow
authors.forename: Steven R
authors.initials: SR
authors.lastname: Hunt
authors.forename: Matthew G
authors.initials: MG
authors.lastname: Mutch
authors.forename: Paul
authors.initials: P
authors.lastname: Wise
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Silviera
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D000368:Aged; D000369:Aged, 80 and over; D017024:Chemotherapy, Adjuvant / Q000706:statistics & numerical data*; D003082:Colectomy; D003106:Colon / Q000601:surgery; D003110:Colonic Neoplasms / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D016208:Databases, Factual; D005260:Female; D019983:Guideline Adherence; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D017410:Practice Guidelines as Topic; D012189:Retrospective Studies; D015996:Survival Rate