Neutrophil-to-lymphocyte Ratio and CA 19.9 as Predictors of Perineural Invasion in Pancreatic Cancer

Pancreatic cancer has an incidence of 1,401,450 new cases diagnosed annually worldwide and is the third leading cause of cancer-related death in Spain. This disease is associated with a poor prognosis, reflected by a 5-year survival rate of less than 5% when all stages are grouped together. Several prognostic factors for pancreatic cancer have been identified. The most relevant include preoperative levels of carbohydrate antigen 19-9 (CA 19.9), surgical margins after resection, venous and/or arterial vascular involvement, and histopathological features such as affected locoregional lymph nodes, or perineural and lymphovascular invasion. Among all these factors, perineural invasion may be the primary independent factor affecting prognosis, particularly in patients with relatively favorable pathological features. The identification of perineural invasion before surgery could influence th