title: Efficacy of adjuvant chemotherapy for small bowel adenocarcinoma: A propensity score-matched analysis.
abstract: BACKGROUND
  The role of adjuvant chemotherapy (AC) in the treatment of small bowel adenocarcinoma is poorly defined. Previous analyses have been limited by small sample sizes and have failed to demonstrate a survival advantage.
  
  
  METHODS
  Patients with resected small bowel adenocarcinoma (American Joint Committee on Cancer [AJCC] pathologic stage I-III) who were receiving AC (n = 1674) or surgery alone (SA; n = 3072) were identified in the NCDB (1998-2011). Cox regression identified covariates associated with overall survival (OS). AC and SA cohorts were matched (1:1) by propensity scores based on the likelihood of receiving AC or the survival hazard from Cox modeling. OS was compared with Kaplan-Meier estimates.
  
  
  RESULTS
  The omission of AC conferred an increased risk of death (hazard ratio, 1.36; 95% confidence interval, 1.24-1.50; P < .001). After propensity score matching, there was a nonsignificant trend toward improved OS with AC in AJCC stage I patients (158.8 vs 110.7 months; P = .226) and AJCC stage II patients (104.0 vs 79.6 months; P = .185), including the subset with a T4 tumor classification (64.0 vs 47.4 months; P = .130) or a positive resection margin (44.4 vs 31.0 months; P = .333). Median OS was superior for patients with AJCC stage III disease who were receiving AC versus SA (42.4 vs 26.1 months; P < .001).
  
  
  CONCLUSIONS
  These data support the use of AC for resected stage III small bowel adenocarcinoma. The trend toward improved OS for patients without nodal metastasis, including those who have T4 tumors or have undergone positive-margin resection, may justify the use of AC in select patients with earlier stage disease. Cancer 2016;122:693-701. © 2015 American Cancer Society.
authors.affiliation: Department of Surgery, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Brett L
authors.initials: BL
authors.lastname: Ecker
authors.affiliation: Department of Surgery, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Matthew T
authors.initials: MT
authors.lastname: McMillan
authors.affiliation: Department of Surgery, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Jashodeep
authors.initials: J
authors.lastname: Datta
authors.affiliation: Division of Hematology/Oncology, Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Ronac
authors.initials: R
authors.lastname: Mamtani
authors.affiliation: Division of Hematology/Oncology, Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Bruce J
authors.initials: BJ
authors.lastname: Giantonio
authors.affiliation: Department of Surgery, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Daniel T
authors.initials: DT
authors.lastname: Dempsey
authors.affiliation: Department of Surgery, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Douglas L
authors.initials: DL
authors.lastname: Fraker
authors.affiliation: Department of Surgery, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Drebin
authors.affiliation: Department of Surgery, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Giorgos C
authors.initials: GC
authors.lastname: Karakousis
authors.affiliation: Department of Surgery, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Robert E
authors.initials: RE
authors.lastname: Roses
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy* / Q000473:pathology; D000368:Aged; D017024:Chemotherapy, Adjuvant; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007414:Intestinal Neoplasms / Q000188:drug therapy* / Q000473:pathology; D007421:Intestine, Small / Q000473:pathology / Q000601:surgery*; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D018365:Neoplasm, Residual; D057216:Propensity Score; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D015996:Survival Rate
keywords: adenocarcinoma; adjuvant therapy; chemotherapy; node positivity; propensity score; small bowel cancer