Vascular endothelial growth factor C: the predicator of early recurrence in patients with N2 non-small-cell lung cancer

Abstract
Objective: Mediastinal lymph node metastasis (N2) is a key prognostic factor for lung carcinoma. This study was undertaken to investigate the relationship between vascular endothelial growth factor C (VEGF-C) expression and postoperative early recurrence in patients with N2 non-small-cell lung cancer. Methods: Cancer tissue samples from 92 patients with pN2 non-small-cell lung cancer and benign lung disease tissues samples from 30 patients were examined by reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry assays to detect VEGF-C expression. The difference of VEGF-C expression was compared by χ2 test. All patients with N2 disease were evaluated within 1 year after surgery to detect early tumour recurrence. Cox regression analysis was performed to determine the risk factors of postoperative early recurrence of N2 lung cancer. Results: VEGF-C mRNA expression was observed in 64 (70%) pN2 lung cancer tissues, but was not found in benign lung disease tissues. Early recurrence occurred in 43 patients (47%) at 1 year after operation. The main pattern was distant recurrence, and the most frequent sites were the brain and lung. The early recurrence rate in patients with positive VEGF-C expression was significantly higher than that of those with negative VEGF-C expression (P = 0.006, log-rank test). Cox regression analysis revealed that positive VEGF-C expression in tumours (hazard ratio (HR) = 2.523, P = 0.037) was an independent risk factor of postoperative early recurrence of N2 lung cancer. Conclusions: VEGF-C expression was high in N2 lung cancer, with significant correlation to postoperative early recurrence. About one-half of the patients with N2 non-small-cell lung cancer would develop recurrence disease within 1 year after surgery, frequently with mediastinal nodes, brain or lung metastases. VEGF-C might be a predictor of postoperative early recurrence in patients with N2 non-small-cell lung cancer.