title: Tumor-positive resection margins reflect an aggressive tumor biology in pancreatic cancer.
abstract: BACKGROUND
  Resection margin status has been shown to impact outcomes for pancreatic adenocarcinoma (PAC), yet it remains unknown whether margin status is a reflection of tumor biology or surgical technique.
  
  
  METHODS
  Two hundred eighty-three consecutive patients with pancreatic adenocarcinoma were identified in a prospectively maintained database. Only patients with R0 (n = 207) or R1 (n = 76) tumors were included. Each operative surgeon's first 50 cases were excluded to control for technical inexperience. Univariable and multivariable analyses of clinicopathologic and intra-operative factors were performed.
  
  
  RESULTS
  The median follow-up for the cohort was 30.3 months with a median overall survival (OS) of 19.0 months. The R1 group had a higher rate of lymph node ratio >0.2 (41% vs. 25%; P = 0.013), and more microvascular invasion (64% vs. 44%; P = 0.007). R0 resections had both improved overall survival (22.7 months vs. 15.0 months, P = 0.004) and disease free survival (13.5 months vs. 10.7 months, P = 0.026). Factors independently associated with overall survival were microvascular invasion (HR 2.26; P = 0.001), pre-existing pulmonary disease (HR 2.18, P = 0.043), and cardiac disease (HR 1.78, P = 0.033).
  
  
  CONCLUSIONS
  Factors associated with an R1 resection reflect a biologically more aggressive tumor, with a higher likelihood of microvascular invasion and increased positive lymph node ratio.
authors: Division of Surgical Oncology, The Hiram C. Polk, J.R., M.D. Department of Surgery, University of Louisville, Louisville, KY, USA.
authors: Charles W
authors: CW
authors: Kimbrough
authors: Charles R
authors: CR
authors: St Hill
authors: Robert C G
authors: RC
authors: Martin
authors: Kelly M
authors: KM
authors: McMasters
authors: Charles R
authors: CR
authors: Scoggins
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D010180:Pancreatectomy / Q000379:methods; D010190:Pancreatic Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D016577:Pancreaticoduodenectomy; D012189:Retrospective Studies; D012307:Risk Factors; D016019:Survival Analysis; D016896:Treatment Outcome; D055815:Young Adult