Vascular endothelial growth factor expression in airways of patients with lung cancer - A possible diagnostic tool of responsive angiogenic status on the host side

Study objective: We evaluated the expression of vascular endothelial growth factor (VEGF) in airways in patients with lung cancer. Methods: BAL fluid (BALF) and plasma samples were obtained from 41 patients with primary lung carcinomas and 7 patients with noncancerous diseases, and were analyzed for VEGF by an enzyme-linked immunosorbent assay. After standardization with the albumin protein levels, the relative intensity (VEGF index) was determined as the ratio of VEGF expression on the disease side to that on the healthy side. Results: In all cases, VEGF concentrations in BALF were greater than those in plasma samples. On the healthy side, the mean value of VEGF in BALF was significantly greater in lung cancer patients than in patients with noncancerous diseases (p = 0.0470). While age, gender, location of cancer (right vs left), histology (adenocarcinoma vs squamous cell carcinoma), and T factor (T1/2 vs T3/4) did not affect the VEGF levels in BALF, the VEGF index was inversely associated with distant metastasis and nodal involvement. The VEGF index of patients in stage I was significantly greater than that of patients in stage IV (p = 0.0308). Conclusions: The VEGF expression in airways is likely to reflect the response to tumor angiogenesis on the host side. Of direct clinical relevance is that the assessment of VEGF concentrations in airways may provide information concerning the dependency of tumor angiogenesis on VEGF, which is variable according to tumor progression.