Lung cancer will remain a major cause of worldwide cancer death, this is a prospective study including eligible patients presenting to NEMROCK from December 2000 to December 2002 with NSCLC, stages IIIB and IV (WHO), study was designed for 38 patients received cisplatin and vinorelbine, screening of 68 cases for anti p53 antibody by ELISA test was done, aim is to determine overall survival, correlation with presence of anti p53 antibody and nature of the toxicity of chemotherapy.