Tumor-positive resection margins reflect an aggressive tumor biology in pancreatic cancer

• Published in: Journal of surgical oncology Vol. 107; no. 6; pp. 602 - 607
• Main Authors: Kimbrough, Charles W., St. Hill, Charles R., Martin, Robert C.G., McMasters, Kelly M., Scoggins, Charles R.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01-05-2013; Wiley Subscription Services, Inc
• Subjects: Adenocarcinoma - mortality; Adenocarcinoma - pathology; Adenocarcinoma - surgery; Adolescent; Adult; Aged; Aged, 80 and over; Female; Follow-Up Studies; Humans; lymph nodes; Lymphatic Metastasis; Male; microvascular invasion; Middle Aged; Neoplasm Invasiveness; Pancreatectomy - methods; Pancreatic cancer; Pancreatic Neoplasms - mortality; Pancreatic Neoplasms - pathology; Pancreatic Neoplasms - surgery; Pancreaticoduodenectomy; resection margins; Retrospective Studies; Risk Factors; surgical technique; survival; Survival Analysis; Treatment Outcome; Young Adult
• ISSN: 0022-4790; 1096-9098
• DOI: 10.1002/jso.23299

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).
Conclusion
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. J. Surg. Oncol. 2013;107:602–607. © 2013 Wiley Periodicals, Inc.