Nuclear p53 overexpression is an independent prognostic parameter in node-negative non-small cell lung carcinoma

Abstract

The prognosis of operated patients with non-small cell lung cancer (NSCLC) is poor despite thorough pre-operative staging. An improved preselection is needed of patients likely to profit from surgery. This study was undertaken to evaluate the prognostic significance of nuclear p53 overexpression in a cohort of 247 surgically treated patients with NSCLC. It showed that the prevalence of immunohistochemically detectable p53 overexpression varied between different tumour types. p53 overexpression was equally frequent in large cell carcinoma (53 per cent) and in squamous cell carcinoma (54 per cent), but significantly less frequent in adenocarcinoma (34 per cent; P = 0.009). p53 overexpression was particularly rare in bronchioloalveolar carcinoma (positivity in 1 of 17 cases). These variations may reflect aetiological differences between the histological subtypes. p53 overexpression was also associated with high tumour grade (P = 0.0157) and the presence of lymph node metastasis (P = 0.0259), but not with advanced tumour stage. Survival analysis showed no difference in clinical outcome between p53-positive and p53-negative tumours within 101 node-positive tumours. In contrast, survival time was significantly better in p53-negative tumours than in p53-positive tumours within the group of 113 node-negative tumours (P = 0.032). Stepwise regression analysis showed that p53 overexpression is an independent prognostic factor in node-negative NSCLC.