BACKGROUNDTo observe the relationship between non-small cell lung cancer with neuroendocrine differentiation (NSCLC-NE) and patients' postoperative survival.

METHODSDuring April 1997 to April 1999, ninety-eight patients with lung cancer who were surgical treated were enrolled in this study. The tumor specimens were stained by NE markers: neuron specific enolase (NSE) and synaptophysin (SY). The NE marker reactions were divided as +, ++ and +++ scale groups. The same specimens were also examined by electron microscope for the specific neuroendocrine granule. All enrolled patients were followed up to 36 months, and the maximum follow-up time was 60 months. The Cox proportional hazard model multivariate analysis was applied to observe the relationship between the NSCLC-NE and the patients' postoperative survival.

RESULTSNinety-one cases were diagnosed as NSCLC. In these patients, 63.7% (58/91) were positive for NE stain. Among them, 59.3% (54/91) were NSE-positive, and 24.1%(22/91) were SY-positive. The specific NE granules were found by the electron microscope examination in 33.0%(30/91). Combination of NE marker stain reaction and electronic microscope examination results, 48.4% (44/91) were considered as NSCLC-NE. The Cox proportional hazard model multivariate analysis showed that the NSCLC-NE patients' survival was significantly reduced (P=0.048). The following factors were related to NSCLC-NE patients' survival: lung cancer cell differentiation (P=0.006), stages of the cancer (P=0.001), and the NE markers reaction (P=0.054).

CONCLUSIONSNSCLC-NE is significantly related to the cancer cell differentiation and the patients' postoperative survival. The NE markers should be applied clinically as one of prognostic factors to evaluate the postoperative survival for NSCLC patients.