Neoangiogenesis and p53 protein in lung cancer: their prognostic role and their relation with vascular endothelial growth factor (VEGF) expression

Following up-regulation of an angiogenesis inhibitor by the wild-type p53 protein proven recently, we have analysed on the one hand the prognostic impact of microvessel count (MC) and p53 protein overexpression in non-small-cell lung carcinoma (NSCLC) progression and, on the other hand, the inter-relation between the microvascular pattern and the p53 protein expression. Moreover, we assessed the expression of vascular endothelial growth factor (VEGF), one of the pivotal mediators of tumour angiogenesis, in order to investigate its relation to p53 protein expression and MC. Tumours from 73 patients resected for NSCLC between March 1991 and April 1992 (median follow-up 47 months, range 32-51 months) were analysed using an immunohistochemical method. In univariate analysis, MC and p53 accumulation were shown to affect metastatic nodal involvement, recurrence and death significantly. Multiple logistic regression analysis showed an important prognostic influence of MC and nodal status on overall (P = 0.0009; P = 0.01) and disease-free survival (P = 0.0001; P = 0.03). Interestingly, a strong statistical association was observed between p53 nuclear accumulation and MC (P = 0.0003). The same inter-relationship was found in non-squamous histotype (P = 0.002). When we analysed the concomitant influence of MC and p53 expression on overall survival, we were able to confirm a real predominant role of MC in comparison with p53. With regard to VEGF expression, p53-negative and lowly vascularized tumours showed a mean VEGF expression significantly lower than p53-positive and highly vascularized cancers (P = 0.02). These results underline the prognostic impact of MC and p53 protein accumulation in NSCLC and their reciprocal inter-relationship, supporting the hypothesis of a wild-type p53 regulation on the angiogenetic process through a VEGF up-regulation.