title: Multimodality Therapy Improves Survival in Resected Early Stage Gastric Cancer in the United States.
abstract: National guidelines endorse adjuvant chemotherapy ± radiotherapy (C ± RT) for early-stage gastric cancer (ESGC). Compliance with these guidelines and the specific impact of adjuvant C ± RT on overall survival (OS) in ESGC have not been extensively explored.
  
  
  
  The National Cancer Data Base was queried for stage IB-II gastric adenocarcinoma patients undergoing gastrectomy (1998-2011). Multivariable modeling identified factors associated with adjuvant C ± RT receipt and compared risk-adjusted OS by treatment type (i.e., adjuvant therapy versus surgery alone).
  
  
  
  Of 23,461 ESGC patients (1998-2011), 79.4 % and 20.6 % received surgery alone and adjuvant C ± RT (chemoradiotherapy 17.7 %; chemotherapy alone 2.9 %), respectively. Predictors of adjuvant C ± RT receipt included age <67 years, pathologic nodal positivity, and adequate lymph node staging (LNS; ≥15 nodes examined; all p < 0.001). Survival analyses included 15,748 patients (1998-2006); median, 1-, and 5-year survival were 63.5 months, 86.0 %, and 27.0 % respectively. Omission of adjuvant C ± RT conferred an increased hazard of risk-adjusted mortality in the overall cohort, and stage IB and II subgroups (all p ≤ 0.001). The benefit of adjuvant C ± RT was most pronounced in stage II and node-positive patients-regardless of LNS adequacy (all p < 0.001)-and inadequately staged IB patients (p = 0.003). While associated with a trend toward improved OS in node-negative patients overall (p = 0.051), adjuvant C ± RT did not improve OS if surgical LNS was adequate in this subgroup (p = 0.960).
  
  
  
  Adoption of adjuvant C ± RT in ESGC remains incomplete nationally. Receipt of adjuvant therapy is associated with improved risk-adjusted survival relative to surgery alone; however, in adequately staged patients without lymph node metastasis, this benefit is less certain.
authors.affiliation: Department of Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
authors.forename: Jashodeep
authors.initials: J
authors.lastname: Datta
authors.affiliation: Department of Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
authors.forename: Matthew T
authors.initials: MT
authors.lastname: McMillan
authors.affiliation: Department of Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
authors.forename: Luis
authors.initials: L
authors.lastname: Ruffolo
authors.affiliation: Department of Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
authors.forename: Lea
authors.initials: L
authors.lastname: Lowenfeld
authors.affiliation: Division of Hematology/Oncology, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
authors.forename: Ronac
authors.initials: R
authors.lastname: Mamtani
authors.affiliation: Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
authors.forename: John P
authors.initials: JP
authors.lastname: Plastaras
authors.affiliation: Department of Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
authors.forename: Daniel T
authors.initials: DT
authors.lastname: Dempsey
authors.affiliation: Department of Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
authors.forename: Giorgos C
authors.initials: GC
authors.lastname: Karakousis
authors.affiliation: Department of Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Drebin
authors.affiliation: Department of Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
authors.forename: Douglas L
authors.initials: DL
authors.lastname: Fraker
authors.affiliation: Department of Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA. robert.roses@uphs.upenn.edu.
authors.forename: Robert E
authors.initials: RE
authors.lastname: Roses
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D000368:Aged; D017024:Chemotherapy, Adjuvant; D003131:Combined Modality Therapy; D005260:Female; D005743:Gastrectomy; D019983:Guideline Adherence; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D018714:Radiotherapy, Adjuvant; D013274:Stomach Neoplasms / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D015996:Survival Rate; D014481:United States