title: Evaluation of preoperative therapy for pancreatic cancer using a prognostic nomogram.
abstract: BACKGROUND
  Theoretical benefits of preoperative chemoradiation therapy (preop CRT) for pancreatic cancer include improved efficacy, resectability, and patient selection. The goal of this study was to evaluate the applicability of a nomogram, which was developed for patients undergoing resection without preop CRT and which incorporates several post-resection pathological factors, to a population of patients who received preop CRT prior to resection.
  
  
  METHODS
  From 1994 to 2004, 82 patients with biopsy-proven, radiographically localized adenocarcinoma of the pancreatic head underwent preop CRT followed by pancreaticoduodenectomy (PD); 50 concurrent patients underwent PD without preop CRT. Mean nomogram-predicted disease-specific survival (DSS) rates were compared with observed DSS rates from the time of resection.
  
  
  RESULTS
  Despite having more locally advanced tumors on initial staging (21 vs. 8%; P < .05), patients who received preop CRT had smaller resected tumors (mean 2.3 vs. 3.1 cm; P < .01), were less likely to have T3 tumors (54 vs. 80%, P < .01), were less likely to have positive lymph nodes (29 vs. 58%, P < .01), and had fewer positive lymph nodes (mean .4 vs. 1.9, P < .01), all factors that imply treatment effect and favorably impact on nomogram-predicted DSS. Observed DSS was similar to predicted DSS in both groups.
  
  
  CONCLUSIONS
  The similarity in observed and predicted DSS following resection in patients who received preop CRT suggests that the effects of preop CRT-whether treatment, selection, or no effect-are reflected by the nomogram. The ability of the nomogram to evaluate the effects of preop CRT on survival is limited by the potential effects of preop CRT on factors within the nomogram.
authors.affiliation: Department of Surgical Oncology, Memorial Sloan-Kettering Cancer Center, New York 10021, USA.
authors.forename: Rebekah R
authors.initials: RR
authors.lastname: White
authors.forename: Michael W
authors.initials: MW
authors.lastname: Kattan
authors.forename: John C
authors.initials: JC
authors.lastname: Haney
authors.forename: Bryan M
authors.initials: BM
authors.lastname: Clary
authors.forename: Theodore N
authors.initials: TN
authors.lastname: Pappas
authors.forename: Douglas S
authors.initials: DS
authors.lastname: Tyler
authors.forename: Murray F
authors.initials: MF
authors.lastname: Brennan
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy / Q000532:radiotherapy / Q000601:surgery; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D017024:Chemotherapy, Adjuvant; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D049451:Nomograms; D010190:Pancreatic Neoplasms / Q000188:drug therapy / Q000532:radiotherapy / Q000601:surgery / Q000628:therapy*; D016577:Pancreaticoduodenectomy; D011300:Preoperative Care; D011379:Prognosis; D018714:Radiotherapy, Adjuvant