BACKGROUND: The prognosis of patients with lung cancer is still poor. Lung cancer exhibits a variable clinical outcome, even in those patients with same stage Numerous reports suggest that oncogene expression night play a role in explaining the variability of response and survival But many of these reports are still under debete. So we studied the clinical relevance of oncogene expression in Korean lung cancer patients. lmmunohistochemistry of p53, erbB-2, CEA expression was performed. METHOD: From March, 1992 until March, 1997, 120 patients with lung cancer were reviewed. p53, erbB-2, and CEA expression were detected on paraffin-embedded tumor blocks with the use of monoclonal antibodies. The survival arid response has correlated with the expressibility of p53, erbE-2, arid CEA oncoprotein. RESULTS: Overall, the expression rates of p53 erbB-2, and CEA were 33.7%, 59.3%, and 32.6% respectively. Expression rates were not con-elated to cell type or stage. Compared with response to chemotherapy, no correlation was found. The expression of p53, erbB-2, or CEA was not correlated with 2-year survival. With simultaneous applications of p53. erbB-2, and CEA, patients with 2 or more expressions also did not show poor response to chemotherapy. CONCLUISON: We conclude the p53, erbB-2, and CEA expression are clinically less useful in predicting response to chemotherapy or survival.