Vascular Endothelial Growth Factor Level as a Prognostic Determinant of Small Cell Lung Cancer in Japanese Patients

OBJECTIVE: To clarify the clinical significance of vascular endothelial growth factor (VEGF) in Japanese patients with small cell lung cancer (SCLC). MATERIALS AND METHODS: We measured serum VEGF levels using an enzyme-linked immunosorbent assay in 45 patients with SCLC before treatment and in 38 patients with benign pulmonary disease and in 32 healthy subjects (71 non-malignant subjects). VEGF immunostaining was performed in tissue biopsies obtained from 23 SCLC patients during bronchoscopic examination. RESULTS: Median serum VEGF level was 332 pg/ml in patients with SCLC and 160 pg/ml in non-malignant subjects, respectively. The 95% cut-off level to exclude non-malignant subjects was 500 pg/ml. An elevated VEGF level (>500 pg/ml) was found more frequently in patients with extensive disease of SCLC than in those with the limited disease (p<0.01). A significant positive correlation was found between the serum VEGF level and platelet count in SCLC patients (r=0.389; p=0.0083). Serum VEGF level also correlated with serum lactate dehydrogenase in SCLC patients (r=0.381; p=0.0098). However, it did not correlate with serum neuron-specific enolase and pro-gastrin-releasing peptide level. Patients with the elevated VEGF levels had significantly shorter progression-free time than those with the normal VEGF levels (p<0.05). Patients with the elevated VEGF levels had a significantly shorter overall survival time than those with the normal VEGF levels in univariate survival analysis (p<0.05). Further, the elevated VEGF level remained as a significant determinant of poor survival in multivariate analysis (p<0.01). Serum VEGF level was significantly higher in patients with positive VEGF protein immunoreactivity in tumor tissue in SCLC. CONCLUSION: Elevated serum VEGF levels were associated with poor outcome in SCLC.