BACKGROUNDbcl-2 and bax are main regulators of cell apoptosis, both are downstream genes of wild-type p53 gene. This study is to investigate the expression of bcl-2, bax, P53, C-erbB-2 and nm23-H1 in neuroendocrine carcinomas of the lung (NEC) and their relationship to tumor biological characteristics and survival time of patients.

METHODSHematoxylin-eosin staining and SP immunohistochemical staining were performed on paraffin embedded tissues of 59 patients with NEC. The relationship between the expression of p53, bcl-2, bax and the clinicopathological factors was analyzed by Chi-square test, multivariate analysis and Kaplan-Meier method.

RESULTSThe following positive expression rates were observed in cancer tissue: bax 56%, bcl-2 46%, P53 27%, C-erbB-2 14%, nm23-H1 90%. Of them bcl-2 related to pathological type (P=0.037), TNM stage (P=0.011), and lymph node metastasis (P=0.020), bax didn't relate to these biological characteristics. Both bcl-2 and P53 showed negative correlation to prognosis in Kaplan-Meier survival analysis (P=0.0338 and 0.0375 respectively), the expression of which linked to poor prognosis and short survival time, while nm23-H1 showed positive correlation to prognosis (P=0.0021), but Cox survival analysis demonstrated that only bcl-2 was associated with survival time of patients (P=0.011).

CONCLUSIONSbcl-2 is an independent prognostic factor in NEC.