Objective: Vascular endothelial growth factor (VEGF) is an important cytokine in the process of angiogenesis. Elevated serum levels of the cytokine may determine cancer patients who will benefit from adjuvant anti-angiogenic therapy in the future. To correlate serum levels of VEGF with tumour stage and established prognostic markers in patients with small cell lung cancer (SCLC), a prospective study was performed on 70 patients.
Methodology: From August 1999 to May 2000, 70 consecutive patients (51 male, 19 female) with histologically proven SCLC were enrolled into the study. Staging of the disease included clinical investigation, bronchoscopy, chest X-ray, thoracic computed tomography and ultrasound. The patients were grouped into five stages according to the Marburg classification (very limited disease (VLD), limited disease (LD), extensive disease I (EDI), extensive disease II (EDII) and extensive disease III (EDIII)). Prior to treatment, a 10 mL serum sample from each patient was examined by ELISA to quantify levels of VEGF and neuron-specific enolase (NSE). Lactate dehydrogenase (LDH) and albumin levels were determined by photomorphometric analysis. Statistical analysis was performed using the Waller-Duncan k ratio t-test and Pearson's correlation test.
Results: Serum VEGF levels correlated well with tumour stage (P < 0.0001). Albumin levels were not correlated with tumour stage, but levels of NSE and LDH increased with stage progression. When patients were divided into two groups (VLD and LD vs EDI-III), VEGF levels were significantly lower in the initial stages of the disease compared with extensive disease (P < 0.0001). Serum levels of VEGF correlated better with tumour stage than did concentrations of NSE, LDH or albumin.
Conclusion: Serum VEGF levels may serve as an additional prognostic marker in the course of patients with SCLC. Further studies are needed to determine whether these patients may benefit from additional anti-angiogenic therapy in the future.