Neuroendocrine differentiation as a prognostic factor in non-small cell lung cancer.

The prognostic value of clinical and pathological factors in 97 patients with non-small cell lung cancer (NSCLC), were analyzed through immunohistochemical methods. The impact on response rate and survival of age, Karnofsky performance status (PS), sex, NSCLC subtype and grade, extent of disease, objective chemotherapy response, LDH values, metastatic sites involved and immunohistochemical markers of neuroendocrine differentiation (neuron specific enolase (NSE), synaptophysin (Sy 38), chromogranin (Chr A) and Leu-7) were analyzed. Median age was 61 years and seven patients were women. Histologically, 58 had squamous cell carcinoma, 28 adenocarcinoma and 11 large cell undifferentiated carcinoma. One patient had Stage II, 35 Stage IIIa, 19 Stage IIIb and 42 Stage IV. Six patients achieved complete response, 18 partial response, 34 stable disease and 39 progressive disease. NSE was negative in 54.3% of cases as was Sy 38 (77.4%), Chr A (97.8%) and Leu-7 (95.8%). We have found correlation between neuroendocrine differentiation and absence of P-Glycoprotein expression; patients included in this subset had a higher response rate but no evidence of longer survival. The univariate analysis showed that four parameters had significant adverse effect on survival: non-responders, poor PS, abnormal LDH value and absence of NSE expression. Multivariate analysis showed that the best combination of independent prognostic factors in predicting survival was: PS and NSE expression by immunohistochemical methods.