title: Cancer Recurrence After Esophagectomy: Impact of Postoperative Infection in Propensity-Matched Cohorts.
abstract: BACKGROUND
  Postoperative infection increases cancer recurrence and worsens survival in colorectal cancer, but the relationship for esophagogastric adenocarcinoma after esophagectomy is not well defined. We aimed to determine whether recurrence and survival after minimally invasive esophagectomy for esophagogastric adenocarcinoma were influenced by postoperative infection using propensity-matched analysis.
  
  
  METHODS
  We abstracted data for 810 patients (1997-2010) and defined exposure as at least 1 in-hospital or 30-day infectious complication (n = 206 [25%]). Using 29 pretreatment/intraoperative variables, patients were propensity-score matched (caliper = 0.05). Time to cancer recurrence and survival (Kaplan-Meier curves and the Breslow test), and associated factors (Cox regression with shared frailty) were assessed.
  
  
  RESULTS
  After propensity matching (n = 167 pairs), median bias across propensity-score variables was reduced from 12.9% (p < 0.001) to 4.4% (p = 1.000). Postoperative infection was not associated with rate (n = 60 versus 63; McNemar p = 0.736) or time to recurrence in those in whom disease recurred (median, 10.7 versus 11.1 months; Wilcoxon signed-rank p = 0.455) but was associated with shorter overall survival (n = 124 versus 102 deaths; median, 26 versus 41 months; Breslow p = 0.002). After adjusting for age, body mass index, neoadjuvant therapy, sex, comorbidity score, positive resection margins, pathologic stage, R0 resection, and recurrence, postoperative infection was associated with a 44% greater hazard for death (hazard ratio, 1.44; 95% confidence interval, 1.10-1.89).
  
  
  CONCLUSIONS
  In patients with esophagogastric adenocarcinoma, infections after esophagectomy were not associated with an increased rate or earlier time to recurrence when baseline characteristics associated with infection risk were balanced using propensity-score matching. Despite this, overall survival was shorter in patients with infectious complications. After adjusting for other important survival predictors, infections after esophagectomy continued to be independently associated with worse survival.
authors.affiliation: Department of General Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania.
authors.forename: Vernissia
authors.initials: V
authors.lastname: Tam
authors.affiliation: Department of Cardiothoracic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania.
authors.forename: James D
authors.initials: JD
authors.lastname: Luketich
authors.affiliation: University of Pittsburgh Clinical and Translational Science Institute, Pittsburgh, Pennsylvania.
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Winger
authors.affiliation: Department of Cardiothoracic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania.
authors.forename: Inderpal S
authors.initials: IS
authors.lastname: Sarkaria
authors.affiliation: Department of Cardiothoracic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania.
authors.forename: Ryan M
authors.initials: RM
authors.lastname: Levy
authors.affiliation: Department of Cardiothoracic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania.
authors.forename: Neil A
authors.initials: NA
authors.lastname: Christie
authors.affiliation: Department of Cardiothoracic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania.
authors.forename: Omar
authors.initials: O
authors.lastname: Awais
authors.affiliation: Department of Cardiothoracic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania.
authors.forename: Manisha R
authors.initials: MR
authors.lastname: Shende
authors.affiliation: Department of Cardiothoracic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania. Electronic address: nasonks@upmc.edu.
authors.forename: Katie S
authors.initials: KS
authors.lastname: Nason
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis / Q000601:surgery*; D000368:Aged; D004938:Esophageal Neoplasms / Q000175:diagnosis / Q000601:surgery*; D016629:Esophagectomy / Q000009:adverse effects* / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000009:adverse effects; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D009367:Neoplasm Staging; D010414:Pennsylvania / Q000453:epidemiology; D057216:Propensity Score; D012189:Retrospective Studies; D013530:Surgical Wound Infection / Q000150:complications* / Q000453:epidemiology; D015996:Survival Rate / Q000639:trends; D013997:Time Factors; D016896:Treatment Outcome