ABSTRACT
Lung cancer, which was rare at the beginning of the 20th century, is now a global problem. It is the most frequent cancer in the world. 1 Presently, 1.2 million people die of lung cancer each year and the global incidence of lung cancer is increasing. A major contribution to this trend comes from the former socialist economies and developing countries where smoking rates are still high. Consequently, lung cancer will remain a major cause of cancer death worldwide in the 21st century even though the prevalence of tobacco use has declined in many high-income countries.
