Effect of venous involvement on survival in locally advanced pancreatic cancer.

Abstract

153 Background: Locally advanced pancreatic cancer is defined as tumor that extends beyond the pancreas into surrounding structures. Borderline resectable disease usually includes a description of superior mesenteric vein (SMV) or portal vein (PV) involvement, while the AJCC staging no longer includes venous involvement in the staging system. We reviewed our institutional cancer database to determine if venous involvement affects overall survival and should be included in pancreatic ductal adenocarcinoma (PDA) staging. Methods: A retrospective review was performed of all patients with stage II or III PDA identified through our institutional prospective Clinical Cancer Research Database, between 2007-2012. Patients with superior mesenteric artery (SMA) or celiac artery and/or venous (SMV or PV) involvement were compared to those without. Vascular involvement was defined as either vessel encasement or abutment on endoscopic ultrasound or CT imaging. Survival analysis was performed using the Kaplan-Meier method with log-rank test for comparison of survival curves. Results: A total of 194 patients were identified as having stage II or stage III pancreatic adenocarcinoma, with 85 having evidence of vascular involvement. In our patient population we found that in patients with stage IIA and IIB disease PV or SMV involvement did not portend statistically worse survival (median survival 14 months v 15 months p=0.63). In stage III patients survival was actually longer in patients with PV or SMV involvement, but this was not statistically significant (median survival 13 months v 7.9 months p=.066). When comparing those with PV or SMV involvement versus those with celiac axis or superior mesenteric artery (SMA) involvement in all patients with locally advanced pancreatic cancer (stage II or III), those with celiac or SMA involvement did significantly worse (mean survival 14 months v. 7.9 months p<0.001). Conclusions: Venous involvement does not portend a worse survival in patients with stage II and III pancreatic cancer. The addition of venous involvement to the current AJCC staging scheme would not provide additional survival information.