VEGF and Id-1 in Pancreatic Adenocarcinoma: Prognostic Significance and Impact on Angiogenesis

Objectives: The significance of vascular endothelial growth factor (VEGF) and inhibitor of differentiation/DNA synthesis (Id-1) in tumor neoangiogenesis and tumor progression in pancreatic ductal adenocarcinoma (PDAC) is still unclear. Given the central role of VEGF in cancer angiogenesis and the inconclusive results on Id-1 expression in PDAC, it is of great interest to investigate whether Id-1 and VEGF expression are associated with angiogenesis and prognosis in PDAC.

Methods: Paraffin-embedded specimens from 60 consecutive patients with PDAC were immunostained for VEGF, Id-1 and CD34 and staining quantification was assessed by Image analysis system. The correlations among the expression of individual angiogenic factors and microvessel density (MVD), clinicopathologic features and clinical prognosis were analyzed.

Results: Id-1 and VEGF Positive Activity Indices (PAIs) closely correlated with each other. MVD positively correlated with both Id-1 and VEGF expression. More advanced T and N status correlated with more intense expression of Id-1, VEGF and higher MVD. With regard to prognostic significance higher Id-1 PAI (adjusted HR = 1.69, 95%CI: 1.10-2.59, p = 0.017), higher VEGF PAI (adjusted HR = 2.66, 95%CI: 1.09-6.50, p = 0.032), and MVD (adjusted HR = 1.55, 95%CI: 1.27-1.88, p < 0.001) were associated with poorer survival.

Conclusions: VEGF and Id-1 overexpression were found to be associated with high MVD and emerged as adverse prognostic factors in terms of patient survival in PDAC. The potential of selective anti-angiogenic targeting therapy for pancreatic malignancies should prompt further validation of the present findings in studies encompassing larger samples and more elaborate techniques.