P53 PROTEIN IN NON-SMALL-CELL LUNG-CANCER AS QUANTITATED BY ENZYME-LINKED-IMMUNOSORBENT-ASSAY - RELATION TO PROGNOSIS

The prognostic value of p53 protein in tumor extracts as measured by E LISA was studied retrospectively in 228 non-small cell lung cancer (NS CLC) patients, The assay measures both wild-type and mutated p53. The specimens on which this study was performed have been used earlier to analyze the prognostic impact of components of the plasminogen activat ion system, which enabled an analysis of relationships between these c omponents and p53 protein, The median of the p53 protein values in the 228 patients was 0.10 (range, 0-0.70) ng/mg protein. Survival analysi s comparing patients with p53 levels below versus above the median sho wed no significant difference (P = 0.67), When analyzing the histologi cal types, adenocarcinoma (n = 106), squamous cell carcinoma (n = 84), and large cell carcinoma of the lung (n = 38) separately, similarly, no significant differences in survival between patients having low ver sus high tumor p53 levels were found, When comparing levels of p53 pro tein in the three histological types, a significant difference (P < 0. 0001) was found, with adenocarcinomas having the lowest levels, There was a weak positive correlation (r = 0.22) between p53 protein and pla sminogen activator inhibitor type 1 (PAI-1), Multivariate analysis pro ved no impact of p53 on survival; tumor size, PAI-1, and lymph node in volvement were the only variables with significant influence on surviv al, These data indicate that p53 protein quantitated with a sandwich E LISA in tumor extracts from NSCLC has no prognostic value, but the obs erved statistically significant difference of p53 protein content betw een histological subgroups may be related to differences in etiology a nd biology in different NSCLC subtypes, In addition, the weak associat ion found between p53 protein and the independent prognostic marker PA I-1 could suggest yet undefined interactions in lung cancer.