Determination of Biological Parameters on Fine-Needle Aspirates from Non-Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) accounts for approximately 75% of all human lung carcinomas and is a major cause of mortality worldwide (1 ). About 70% of the cases are diagnosed at an advanced stage, thus being suitable only for chemotherapy. Twenty-five percent of NSCLC patients are candidates for radical surgery, although even the stage I cases have a five year overall survival rate of only 40%. Unfortunately, conventional clinical and pathological factors alone cannot reliably predict the outcome of the disease, nor can they assist in the selection of patients who might require an alternative or additional therapy to surgery. Recent insights into the molecular events involved in the malignant progression of NSCLC may lead to the identification of significant predictors of prognosis and response to chemotherapy. The most widely investigated biomarkers in NSCLC (2 ) are the p53 tumor-suppressor gene, K-ras gene, bcl-2 and c-erbB-2 protein expression, Ki67 growth fraction, DNA ploidy, and S-phase fraction (SPF). Several studies have identified some of these biological markers as being independent predictors of recurrence (3 ,4 ), response to chemotherapy (5 ,6 ), or to radiotherapy (7 ). Furthermore, recent reports suggest that microsatellite instability may allow for a more accurate prediction of tumor behavior and patient outcome in stage I NSCLC (8 ,9 ).