Chemoprevention of lung cancer: from concept to reality.

Among all cancer, lung cancer is the leading cause of cancer death in the western world. The poor lung cancer survival figures argue powerfully for new approaches to control this disease such as chemoprevention, that has been defined as the use of agents that reverse, suppress or prevent lung carcinogenesis. Over 80% of lung cancers are attributed to tobacco and carcinogens from cigarette smoke form the unquestionable link between nicotine addiction and lung cancer. Confoundedly epidemiological studies show that not more than 15% of heavy smokers will ultimately develop lung cancer. The fact that 85% of heavy smokers will not develop lung cancer points to differences in susceptibility. Dietary and genetically determined factors seem to play an important role in modulating individual susceptibility and are closely linked to the chemoprevention approach. Developments in tumor biology and chest radiology have given rise to optimism regarding to earlier diagnosis and improved possibilities for the management of preneoplastic- and early invasive lesions. The current article summarizes the chemoprevention efforts in lung cancer during the last two decades and identifies novel strategies for chemoprevention studies in high-risk individuals based on the developments in molecular targeted therapies and developments in response evaluation by using intermediate biomarker endpoints.