Background: Pancreatic ductal adenocarcinoma (PDAC) frequently invades and migrates along neural tissue, which results in local tumor recurrences, distant metastases, and poor prognosis. We evaluated whether L1 cell adhesion molecule (L1-CAM) and glial cell line-derived neurotrophic factor (GDNF) expression in PDAC correlated with neural invasion and overall survival on a large cohort of previously untreated patients.
Methods: L1-CAM and GDNF were examined by immunohistochemistry in pancreatic cancer tissue samples of 94 cases with PDAC on a tissue microarray. The molecular findings were correlated with pain, clinicopathologic characteristics, and overall survival in these patients.
Results: L1-CAM and GDNF were overexpressed in pancreatic cancer tissues compared with the adjacent normal tissues of pancreas. Positive L1-CAM expression was associated with node involvement (P = 0.007), vascular invasion (P = 0.012), perineural invasion (P = 0.001), and higher degree of pain (P = 0.005). In univariate analysis, tissue expression of L1-CAM was associated with poor survival (hazard ratio, 2.508; 95% confidence interval, 1.551-4.053; P < 0.001), and this was also significant in multivariate analysis (hazard ratio, 2.046; 95% confidence interval, 1.200-3.488; P = 0.009). Positive staining of GDNF, neural invasion, and vascular invasion were all statistically significantly related to unfavorable prognosis.
Conclusions: Enhanced expression of L1-CAM may contribute to the pain syndrome and perineural invasion and may correlate with poor overall survival in human pancreatic cancer.