Significance of radiographic splenic vessel involvement in pancreatic ductal adenocarcinoma of the body and tail of the gland

Background and Objectives Unlike pancreatic head tumors, little is known about the biological significance of radiographic vessel involvement with pancreatic body/tail adenocarcinoma. We hypothesized radiographic splenic vessel involvement may be an adverse prognostic factor. Methods All distal pancreatectomies performed for resectable pancreatic adenocarcinoma between 2000 and 2016 were reviewed and clinicopatholgic data were collected, retrospectively. Preoperative computed tomography imaging was re-reviewed and splenic vessel involvement was graded as none, abutment, encasement, or occlusion. Results Among a total of 71 patients, splenic artery or vein encasement/occlusion was present in 41% (29 of 71) of patients, each. There were no significant differences in tumor size or grade, margin positivity, and perineural or lymphovascular invasion. However, splenic artery encasement/occlusion (P = 0.001) and splenic vein encasement/occlusion (P = 0.038) both correlated with lymph node positivity. Splenic artery encasement was associated with a reduced median overall survival (20 vs 30 months, P = 0.033). Multivariate analysis also showed that splenic artery encasement was an independent risk factor of worse survival (hazard ratio, 2.246; 95% confidence interval, 1.118-4.513; P = 0.023). Conclusion Patients with cancer of the body or tail of the pancreas presenting with radiographic encasement of the splenic artery, but not the splenic vein, have a poorer prognosis and perhaps should be considered for neoadjuvant therapy before an attempt at curative resection.