

Vascular endothelial growth factor (VEGF) expression, while not universal, is an important factor of lung cell tumors. In an analysis of 72 patients with non-small cell lung cancer (NSCLC), Yuan and colleagues found VEGF mRNA levels in tumor samples to be significantly higher than in adjacent normal tissue in 100% of cases (P<0.001). They showed that adenocarcinomas had greater amounts of VEGF mRNA and were more likely to have high levels of VEGF protein compared with squamous cell carcinomas, a factor that may contribute to the high metastatic potential observed with adenocarcinomas.2
In a separate study, Imoto et al discovered VEGF to be expressed in the majority of tumors in 91 patients with completely resected stage I–III NSCLC. There was a statistically significant association between VEGF expression and microvessel counts in the tumor tissue, as microvessel counts were significantly higher in patients with VEGF–positive tumors than in patients with VEGF-negative tumors (P=0.01). Microvessel counts in this study were higher in patients with nodal metastases than in those without nodal metastases.7 Other studies have also shown a correlation between microvessel count and systemic metastases in NSCLC.8,9