title: Impact of Resection Margin Distance on Survival of Pancreatic Cancer: A Systematic Review and Meta-Analysis.
abstract: OBJECTIVE
  While curative resection is the only chance of cure in pancreatic cancer, controversies exist about the impact of surgical margin status on survival. Non-standardized pathologic report and different criteria on the R1 status made it difficult to implicate adjuvant therapy after resection based on the margin status. We evaluated the influence of resection margins on survival by meta-analysis.
  
  
  METHODS
  We thoroughly searched electronic databases of PubMed, EMBASE, and Cochrane Library. We included studies reporting survival outcomes with different margin status: involved margin (R0 mm), margin clearance with ≤ 1 mm (R0-1 mm), and margin with > 1 mm (R>1 mm). Hazard ratio (HR) for overall survival was extracted, and a random-effects model was used for pooled analysis.
  
  
  RESULTS
  A total of eight retrospective studies involving 1,932 patients were included. Pooled HR for overall survival showed that patients with R>1 mm had reduced risk of death than those with R0-1 mm (HR, 0.74; 95% confidence interval [CI], 0.61 to 0.88; p=0.001). In addition, patients with R0-1 mm had reduced risk of death than those with R0 mm (HR, 0.81; 95% CI, 0.72 to 0.91; p < 0.001). There was no heterogeneity between the included studies (I2index, 42% and 0%; p=0.10 and p=0.82, respectively).
  
  
  CONCLUSIONS
  Our results suggest that stratification of the patients based on margin status is warranted in the clinical trials assessing the role of adjuvant treatment for pancreatic cancer.
authors: Department of Radiation Oncology, Dongnam Institute of Radiological and Medical Sciences, Busan, Korea.
authors: Kyung Su
authors: KS
authors: Kim
authors: Department of Radiation Oncology, Chungnam National University School of Medicine, Daejeon, Korea.
authors: Jeanny
authors: J
authors: Kwon
authors: Department of Radiation Oncology, Ewha Womans University School of Medicine, Seoul, Korea.
authors: Kyubo
authors: K
authors: Kim
authors: Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Korea.|Institute of Radiation Medicine, Medical Research Center, Seoul National University, Seoul, Korea.
authors: Eui Kyu
authors: EK
authors: Chie
mesh_terms: D006801:Humans; D000072662:Margins of Excision; D016017:Odds Ratio; D010180:Pancreatectomy; D010190:Pancreatic Neoplasms / Q000401:mortality* / Q000473:pathology* / Q000601:surgery; D011379:Prognosis; D017594:Publication Bias; D012189:Retrospective Studies
keywords: Meta-analysis; Pancreatic neoplasms; Resection margin; Systematic review