BACKGROUNDThe latest studies have demonstrated that postoperative adjuvant chemotherapy may improve survival in patients with stage I non-small cell lung cancer (NSCLC), so it was a challenge for clinician to choose the patients who might benefit from adjuvant chemotherapy. The aim of this study is to evaluate the prognostic implications of angiogenesis and tumor blood vessel invasion (BVI) in stage I NSCLC patients who underwent complete resection.

METHODSOne hundred and eighteen stage I NSCLC patients undergoing complete resection from 1994-2002 were retrospectively reviewed. Angiogenesis was assessed by vascular endothelial growth factor (VEGF) and microvessel density (MVD), BVI was assessed by examining the direct invasion of tumor cells marked by CD34 within vessel lumen.

RESULTSLow VEGF expression was seen in 44 patients (37.3%), high VEGF expression was in 74 patients (62.7%). The MVD of high VEGF expression cases was much higher than that of low VEGF expression ones (33.4±17.8 vs 24.7±14.8, P=0.010). There was a positive correlation between VEGF and MVD (r=0.216, P=0.019). The 5-year survival rate in patients with high VEGF expression was much lower than in those with low VEGF expression (36.48% vs 72.20%, P=0.003). The BVI was present in 32 patients (27.1%) and absent in 86 patients (72.9%). The 5-year survival rate in patients with presence of BVI was much lower than those with absence of BVI (34.38% vs 60.47%, P=0.018). Multivariate COX regression analysis showed that high VEGF expression and BVI were significantly independent predictive factors for overall survival. Finally, the presence of both risk factors, BVI and high VEGF expression was highly predictive of poor outcome (P= 0.001 ).

CONCLUSIONSTumor vessel invasion and high VEGF expression are independent prognostic factors for overall survival of postoperative stage I NSCLC. The assessment of these factors may improve prognostic stratification for adjuvant therapy or a targeted and specific treatment in stage I NSCLC.