Resectable pancreatic head adenocarcinoma: Is R0 resection an illusion? Genetic evaluation of venous resection margin affirmed unrecognized disease

Purpose: To assess the K-ras gene mutation in the histologically negative venous margin of a pancreaticoduodenectomy (PD) specimen and its impact on survival. Method: From 2007 to 2010, 22 patients underwent R0 PD for resecable pancreatic adenocarcinoma. All specimens were stained and the portal vein (PV) bed was identified by blue ink; a 2 mm(3) sample (including the blue ink) was cut from a microscopic free-tumor block. DNA was extracted and assessed by quantitative real time polymerase chain reaction to detect the K-ras gene mutation. Twelve specimens (55%) (kras+ group) were identified with a K-ras mutation in the venous margin resection, and 10 specimens (kras-group) did not have K-ras mutation detected in the venous margin resection. Results: The two groups were comparable. Overall 3 years survival of patients of kras+ group versus patients of kras- group was 0 and 17% (P = 0.03), respectively. Median survival time of patients of kras+ group versus patients of kras-group was 16 months vs 25 months (P = 0.04; 95% confidence interval [1,11-1,88]), respectively. Conclusion: Genetic evaluation of venous resection margin affirmed unrecognized disease with strong impact on survival in more than 50% of patients with histologically R0 resection. (C) 2017 Published by Elsevier Masson SAS.