PROGNOSTIC VALUE OF P53 IN NSCLC: RELATIONSHIP WITH PCNA AND CIGARETTE SMOKING

P53 gene mutations are the most common genetic changes reported in human lung cancer. Although the prognostic value of altered p53 expression is still discussed it is widely accepted the prognostic value of the proliferating cell nuclear antigen (PCNA) expression. We investigated the immunohistochemical overexpression of mutant oncogenic p53 protein in formalin fixed and paraffin embedded specimens obtained from 61 surgical resected patients affected by NSCLC and related it with the expression level of PCNA and the smoking history of the patients. The antibodies used were monoclonal mouse PC-10 anti PCNA and monoclonal mouse D07 anti p53. We found p53 overexpression in 22 (36.06%) cases; in addition we observed a variability in p53 immunohistochemical detection according to the histological type (41.02% of squamous carcinomas and 27.2% of adencarcinomas). PCNA nuclear staining was detected in 98.36% cases and significatively stronger PCNA expression was found in all the p53 positive samples. Moreover we found a relationship between p53 overexpression and the smoking history of the patients. In fact none of the specimens from non smoking patients expressed immunohis- tochemically detectable p53 protein: