OVEREXPRESSION OF ONCOPROTEINS IN NONSMALL CELL LUNG CARCINOMAS OF SMOKERS

Non-small cell lung carcinoma specimens of 173 previously untreated pa tients were analyzed for the expression of proteins encoded by the onc ogenes c-myc, c-fos, c-jun, c-erbB-1, c-erbB-2, c-H-ras, c-K-ras and c -N-ras. Forty-six per cent of the tumors were positive for the c-MYC p rotein, 60% for c-FOS, 50% for c-JUN, 80% for c-ERBB-1, 55% for c-ERBB -2,12% for c-H-RAS, 5% for c-K-RAS and 71% for c-N-RAS. Proteins encod ed by c-fos and c-jun are overexpressed more frequently in carcinomas of smokers (c-fos: P < 0.005; c-jun: P < 0.01). When we grouped the pa tients according to their tumor histology the results became more evid ent. Squamous cell lung carcinomas of smokers showed a higher incidenc e of c-FOS (P = 0.01), c-JUN (P < 0.01) and c-ERBB-1 (P = 0.01) protei ns than squamous cell lung carcinomas of non-smokers. The expression r ate and the intensity of staining proved not to be influenced either b y the number of cigarettes smoked daily or by cessation of smoking. In adenocarcinomas, however, we only found a trend for a more frequent o verexpression of c-fos (P = 0.07) and c-jun (P = 0.14) encoded protein s in carcinomas of smokers and no correlation between the expression o f c-erbB-1 products and smoking. No correlation was found between the expression of c-MYC, c-ERBB-2, c-H-RAS, c-K-RAS and c-N-RAS proteins a nd the smoking habits of the patients, neither in squamous cell carcin omas nor in adenocarcinomas of the lung.