title: Adjuvant radiotherapy in the treatment of invasive intraductal papillary mucinous neoplasm of the pancreas: an analysis of the surveillance, epidemiology, and end results registry.
abstract: BACKGROUND
  Management and outcomes of patients with invasive intraductal papillary mucinous neoplasm (IPMN) of the pancreas are not well established. We investigated whether adjuvant radiotherapy (RT) improved cancer-specific survival (CSS) and overall survival (OS) among patients undergoing surgical resection for invasive IPMN.
  
  
  METHODS
  The Surveillance, Epidemiology, and End Results (SEER) registry was used in this retrospective cohort study. All adult patients with resection of invasive IPMN from 1988 to 2007 were included. CSS and OS were analyzed using Kaplan-Meier curves. Unadjusted and propensity-score-adjusted Cox proportional-hazards modeling were used for subgroup analyses.
  
  
  RESULTS
  972 patients were included. Adjuvant RT was administered to 31.8% (n=309) of patients. There was no difference in overall median CSS or OS in patients who received adjuvant RT (5-year CSS: 26.5 months; 5-year OS: 23.5 months) versus those who did not (CSS: 28.5 months, P=0.17; OS: 23.5 months, P=0.23). Univariate predictors of survival were lymph node (LN) involvement, T4-classified tumors, and poorly differentiated tumor grade (all P<0.05). In the propensity-score-adjusted analysis, adjuvant RT was associated with improved 5-year CSS [hazard ratio (HR): 0.67, P=0.004] and 5-year OS (HR: 0.73, P=0.014) among all patients with LN involvement, though further analysis by T-classification demonstrated no survival differences among patients with T1/T2 disease; patients with T3/T4-classified tumors had improved CSS (HR: 0.71, P=0.022) but no difference in OS (HR: 0.76, P=0.06).
  
  
  CONCLUSIONS
  On propensity-score-adjusted analysis, adjuvant RT was associated with improved survival in selected subsets of patients with invasive IPMN, particularly those with T3/T4 tumors and LN involvement.
authors: Research on Research, Department of Surgery, Duke University Medical Center, Durham, NC, USA. mathias.worni@duke.edu
authors: Mathias
authors: M
authors: Worni
authors: Igor
authors: I
authors: Akushevich
authors: Beat
authors: B
authors: Gloor
authors: John
authors: J
authors: Scarborough
authors: Junzo P
authors: JP
authors: Chino
authors: Danny O
authors: DO
authors: Jacobs
authors: Stephen M
authors: SM
authors: Hahn
authors: Bryan M
authors: BM
authors: Clary
authors: Ricardo
authors: R
authors: Pietrobon
authors: Anand
authors: A
authors: Shah
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000401:mortality* / Q000473:pathology / Q000532:radiotherapy* / Q000556:secondary / Q000601:surgery; D000368:Aged; D021441:Carcinoma, Pancreatic Ductal / Q000401:mortality* / Q000473:pathology / Q000532:radiotherapy* / Q000556:secondary / Q000601:surgery; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D010190:Pancreatic Neoplasms / Q000401:mortality* / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D018714:Radiotherapy, Adjuvant; D012042:Registries; D012189:Retrospective Studies; D015996:Survival Rate