Clinical relevance of molecular abnormalities in non-small cell lung cancer. Focus on suppressor genes

Lung carcinogenesis is a multistep, long-lasting process. Genetic alterations contributing to lung carcinogenesis include chromosomal imbalance, genetic instability and mutations affecting tumour suppressor genes, proto-oncogenes, genes involved in processes of apoptosis and DNA repair. Abnormalities of tumour suppressor genes are among the most frequent molecular events in lung cancer. They lead to impaired cell cycle control, growth inhibition and finally to uncontrolled proliferation. Expression of these genes may be modified by both genetic and epigenetic changes. Allelic losses at several loci encoding for tumour suppressor genes (3p, 9p and 17p) and abnormal expression of tumour suppressor genes are common findings both in premalignant bronchial lesions and in overt lung cancer cells. The subject of this review is possible clinical applications of molecular techniques in NSCLC management, including early diagnosis, detection of subclinical disease, predicting prognosis, and targeted treatment.