Overexpression of c-erbB-2 and loss of p16 have molecular diagnostic relevance but no prognostic value in lung cancer

This study was designed to evaluate the expression of C-erbB-2 and p16 in lung cancers using tissue microarray technology and to determine their clinical and pathological significance. Immunohistochemical C-erbB-2 and p16 expressions and their associations with clinical and pathological features were analyzed in two tissue microarrays. The membranous and cytoplasmic expression rates of C-erbB-2 were 40.5 and 66.5% in non-small cell lung cancers (NSCLCs), and 0 and 9.5% in small cell lung cancers (SCLCs), respectively. The nuclear and cytoplasmic expression rates of p16 were 11.5 and 32.2% in NSCLs, and 45 and 80% in SCLCs, respectively. The cytoplasmic expression of both C-erbB-2 and p16 was more frequent than the membranous expression of C-erbB-2 and the nuclear expression of p16. The rates of overexpression of C-erbB-2 and loss of p16 expression were significantly higher in NSCLCs than in SCLCs (P < 0.05). Neither C-erbB-2 nor p16 expression was significantly associated with age, tumor grade or stage, presence of lymph node metastasis or survival duration. The abnormal expressions of p16 and C-erbB-2 may play a role in the progression of lung cancers. The variations in the expression patterns of C-erbB-2 and p16 between NSCLCs and SCLCs may aid the molecular classification of lung cancer. The abnormal expression of p16 may be involved in the development of NSCLCs, and the overexpression of C-erbB-2 in NSCLCs indicates that it can be a candidate target for gene therapy.