Prognostic value of vascular endothelial growth factor expression in primary lung carcinoma

To investigate whether an association exists between vascular endothelial growth factor (VEGF) expression and tumor prognosis in primary lung carcinoma, we used immunohistochemical techniques to analyze microvessel density and VEGF expression in lung carcinoma tissue from 98 patients. Tissue had been fresh-frozen at the time of operation and preserved for more than 5 years. The results indicated that VEGF expression was positive for 50 of the 98 patients (51.0%), with 27 (27.6%) being weakly positive and 23 (23.5%) being strongly positive. The microvessel density in tissue showing weakly positive and strongly positive VEGF expression was significantly higher than that in VEGF-negative tumor tissue (P < 0.05: negative vs. weakly positive, P < 0.01: negative vs. strongly positive), we showed demonstrating that VEGF expression was significantly associated with intratumoral microvessel density. The 5-year survival rates were 8.7% for strongly VEGF-positive patients, 43.9% for weakly VEGF-positive patients and 79.2% for VEGF-negative patients, respectively (P < 0.01: negative vs. weakly positive or strongly positive). Furthermore, multivariate analysis employing multiple regression analysis indicated that VEGF expression correlates highly with the overall survival rates of patients with primary lung carcinoma. Two variables, N status and VEGF expression, were found to be significant prognostic factors (P < 0.01). The results of this study suggest that VEGF expression is associated with intratumoral microvessel density. VEGF expression may constitute important independent prognostic evidence that can help us in predicting the outcomes of patients with primary lung carcinomas.