BACKGROUNDTo study the specific expression of tumor-related genes (p53, bcl-2 and c-myc) in non small cell lung cancer with neuroendocrine differentiation (NSCLC-NE).

METHODSThe expression of neuron-specific enolase (NSE), chromogranin A (CgA), synaptophysin(Syn), c-myc, bcl-2 and p53 was detected in 60 surgically resected and paraffin-embedded non-small cell lung cancer (NSCLC) specimens by immunohistochemistry (S-P method).

RESULTSThe positive rates of NSE, CgA, Syn expressed in 60 cases of NSCLC were 45.00%(27/60), 13.33%(8/60), 31.67% (19/60) respectively. According to the results of these three markers, 41.67%(25/60) of 60 specimens was proved to be as NE differentiation cancer. The NE differentiation in NSCLC was remarkably related to differentiation of tumor cells (P < 0.05). NSCLC-NE had a higher metastatic rate (P < 0.05) and a higher clinical staging (P < 0.05) than NSCLC without NE differentiation. The positive rates of bcl-2, p53 and c-myc expression in NSCLC-NE were 68.00% (17/25), 80.00% (20/25), 68.00% (17/25) respectively, and the expression of bcl-2 and p53 was closely related to NE differentiation (P < 0.05).

CONCLUSIONSA certain part of NSCLC have NE differentiation, which has different biological features from NSCLC without NE differentiation. High expression of bcl-2 and mutant p53 can be observed in NSCLC-NE, and bcl-2/Bax unbalance associated with p53 mutation may play an important role in oncogenesis and development of NSCLC-NE.