title: Predictors of Locoregional Failure and Impact on Overall Survival in Patients With Resected Exocrine Pancreatic Cancer.
abstract: OBJECTIVE
  Resection of exocrine pancreatic cancer is necessary for cure, but locoregional and distant relapse is common. We evaluated our institutional experience to better understand risk factors for locoregional failure (LRF) and its impact on overall survival (OS).
  
  
  METHODS
  We reviewed 1051 consecutive patients with nonmetastatic exocrine pancreatic cancer who underwent resection at our institution between March 1987 and January 2011. Among them, 458 had adequate follow-up and evaluation for study inclusion. All patients received adjuvant chemotherapy (n=80 [17.5%]) or chemoradiation therapy (n=378 [82.5%]). Chemotherapy and chemoradiation therapy most frequently consisted of 6 cycles of gemcitabine and 50.4 Gy in 28 fractions with concurrent 5-fluorouracil, respectively. Locoregional control (LRC) and OS were estimated with the Kaplan-Meier method. Univariate and multivariate analyses were performed with Cox proportional hazards regression models incorporating propensity score.
  
  
  RESULTS
  Median patient age was 64.5 years (range: 29-88 years). Median follow-up for living patients was 84 months (range: 6-300 months). Extent of resection was R0 (83.8%) or R1 (16.2%). Overall crude incidence of LRF was 17% (n=79). The 5-year LRC for patients with and without radiation therapy was 80% and 68%, respectively (P=.003; hazard ratio [HR]: 0.45; 95% confidence interval [CI]: 0.28-0.76). Multivariate analysis, incorporating propensity score, indicated radiation therapy (P<.0001; HR: 0.23; 95% CI: 0.12-0.42) and positive lymph node ratio of ≥0.2 (P=.02; HR: 1.78; 95% CI: 1.10-2.9) were associated with LRC. In addition, LRF was associated with worse OS (P<.0001; HR: 5.0; 95% CI: 3.9-6.3).
  
  
  CONCLUSIONS
  In our analysis of 458 patients with resected pancreatic cancer, positive lymph node ratio of ≥0.2 and no adjuvant chemoradiation therapy were associated with increased LRF risk. LRF was associated with poor OS. Radiation therapy should be considered as adjuvant locoregional treatment following pancreatic cancer resection.
authors: Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota.
authors: Kenneth W
authors: KW
authors: Merrell
authors: Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota.
authors: Michael G
authors: MG
authors: Haddock
authors: Division of Medical Oncology, Mayo Clinic, Rochester, Minnesota.
authors: J Fernando
authors: JF
authors: Quevedo
authors: Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota.
authors: William S
authors: WS
authors: Harmsen
authors: Department of General Surgery, Mayo Clinic, Rochester, Minnesota.
authors: Michael L
authors: ML
authors: Kendrick
authors: Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota.
authors: Robert C
authors: RC
authors: Miller
authors: Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota. Electronic address: hallemeier.christopher@mayo.edu.
authors: Christopher L
authors: CL
authors: Hallemeier
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D000964:Antimetabolites, Antineoplastic / Q000627:therapeutic use; D059248:Chemoradiotherapy; D003841:Deoxycytidine / Q000031:analogs & derivatives / Q000627:therapeutic use; D005260:Female; D005472:Fluorouracil / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D046790:Pancreas, Exocrine / Q000601:surgery; D010180:Pancreatectomy; D010190:Pancreatic Neoplasms / Q000401:mortality / Q000628:therapy*; D011182:Postoperative Care; D057216:Propensity Score; D011838:Radiation-Sensitizing Agents / Q000627:therapeutic use; D018714:Radiotherapy, Adjuvant; D012189:Retrospective Studies; D000093542:Gemcitabine
chemical_list: D000964:Antimetabolites, Antineoplastic; D011838:Radiation-Sensitizing Agents; D003841:Deoxycytidine; D005472:Fluorouracil; D000093542:Gemcitabine