Lung cancer remains the most frequent tumour and cause of cancer death in worldwide. Unfortunately most of patients still discover their tumour in advanced stage. Lung cancer results from the occurrence of a number of genetic alterations in oncogenes and tumour suppressor genes that are potential markers either for screening procedures or for earlier detection in patients with non small-cell lung cancer (NSCLC). It was estimated that about 10 to 20 genetic events are required for lung tumorigenesis. These genetic changes are triggered by smoking and persist for many years after smoking cessation. Continuously, more sophisticated methods for the analysis of these genetic alterations involved in lung cancer become available. Several molecular alterations involved in lung cancer have been already identified in different biological samples (biopsy, BAL) that are collected with highly invasive techniques that make them poorly suitable for wider screening. Recently the DNA has been extracted from exhaled breath condensate, demonstrating the suitability of this sample for the study of genetic alterations and its potential role in screening programs of subjects at risk of lung cancer.
