Relationship between PTEN and Vascular Endothelial Growth Factor Expression in Non-Small Cell Lung Cancer.

Purpose: This study was performed to determine the relationship between PTEN and vascular endothelial growth factor (VEGF) expression and to assess their roles in the tumor-induced angiogenesis and tumor progression in non-small cell lung cancer (NSCLC). Materials and Methods: Formalin-fixed, paraffin-embedded tissues, from 96 patients diagnosed with NSCLC, were evaluated for VEGF and PTEN expression using immunohistochemical methods. The results of the expression pattern of VEGF alone, or in combination with PTEN expression, were compared with clinicopathological parameters. Results: VEGF expression was seen in 54 (56.3%) of the 96 NSCLCs evaluated, and was significantly correlated with histological type, and seen more frequently in adenocarcinomas compared to the other histological types (p＜0.05). There were no significant associations between VEGF expression and tumor size, lymph node metastasis and stage. The microvessel density (MVD) determined by CD34 staining were significantly higher in tumors with VEGF expression (62.921.8) than those without (55.115.1). Loss of PTEN expression was seen in 33 (34.4%) of the 96 NSCLCs evaluated. VEGF expression was more frequently detected in the tumors with loss of PTEN expression (69.7%) than in those with PTEN expression (49.2%). When the combined VEGF/PTEN phenotypes were divide into two groups; group I (VEGF-/PTEN+) and group II (VEGF-/ PTEN-, VEGF+/PTEN+, VEGF+/PTEN-), a significant correlation was also seen between the groups and the histologic types. There was a trend for the tumors in group II to show more frequent lymph node metastasis (50.0%) than those in group I (31.5%), although there was no statistical significance. The MVDs were significantly higher in group II (63.120.7) than in group I (53.417.2). Conclusion: These findings demonstrate an inverse correlation between the expressions of PTEN and VEGF. It is possible that PTEN may repress VEGF expression, and modulate VEGF-mediated angiogenesis, which suggests further analysis of the complex phenomenon of neoangiogenesis in NSCLC is essential.