[The clinicopathologic significance of the p16 gene expression in primary lung cancer.].

BACKGROUND: To explore the relationship between p16 gene expression and oncogenesis , and development of human lung cancer. METHODS: Immunohistochemistry was employed to detect the expression of p16 protein in 114 paraffin-embedded primary lung cancer tissues. Loss of p16 INK4 gene exon 2 (E2) was analyzed using PCR technique in 62 cancer samples with p16 protein-negative stain and 14 paracancerous lung tissues. RESULTS: The positive rates of p16 protein expression in squamous cell carcinoma , adenocarcinoma and small cell lung cancer (SCLC) were 43. 3 % , 48. 2 % and 27. 0 % respectively , and no significant difference was found among them ( P > 0. 05) . The expression level of p16 protein was closely correlated with histological grade and lymph node metastasis of lung cancer. The deletion of p16 E2 was 45. 2 % in NSCLC and closely related to lymph node metastasis and histological grade ( P < 0. 05) . No deletion was observed in 37 cases of SCLC and 14 paracancerous lung tissues. CONCLUSIONS: Alteration of p16 gene and protein is closely related to the histological grade and lymph node metastasis of NSCLC. It may play an important role in the oncogenesis , development and lymph node metastasis of NSCLC.