Microscopic lymphovascular invasion is an independent predictor of survival in resected pancreatic ductal adenocarcinoma

Background and Objectives: Despite routine inclusion of lymphovascular invasion (LVI) status in pathologic reports of resected pancreatic ductal adenocarcinomas (PDA), the clinical implications of LVI have not been well characterized. Methods: This study is a retrospective review of 2640 patients who underwent a pancreatectomy for PDA at Thomas Jefferson University Hospital, Massachusetts General Hospital, or Johns Hopkins Hospital (2003-2014). Clinical and pathologic records were extracted from institutional databases. Results: The median post-resection survival for the total cohort was 19.2 months with a 5-year survival rate of 15.2%. In a multivariate Cox proportional hazards model including conventional pathologic features, LVI was an independent predictor of survival (HR = 1.14, P = 0.017). In a stratified Kaplan-Meier survival analysis, patients with N0, LVI-PDA had a significantly improved overall survival compared to those with N0, LVI+PDA (median 31 vs 24 mo, P = 0.020). Similarly, patients with N1, LVI-PDA had superior survival to patients with N1, LVI+ disease (18.6 vs 16.5 mo, P = 0.001). Conclusions: As the first large scale study focused on the clinical impact of LVI status in PDA, these data indicate that this routinely reported pathologic feature is a bona fide and independent adverse prognostic factor.