Lung cancer epidemiology: contemporary and future challenges worldwide.

Over the last century, lung cancer from the rarest of diseases became the biggest cancer killer of men worldwide and in some parts of the world also of women (North America, East Asia, Northern Europe, Australia and New Zealand). In 2012 over 1.6 million of people died due to lung cancer. The cause-effect relationship between tobacco smoking and lung cancer occurrence has been proven in many studies, both ecological and clinical. In global perspective one can see the increasing tobacco consumption trend followed by ascending trends of lung cancer mortality, especially in developing countries. In some more developed countries, where the tobacco epidemics was on the rise since the beginning of the 20th century and peaked in its mid, in male population lung cancer incidence trend reversed or leveled off. Despite predicted further decline of incidence rates, the absolute number of deaths will continue to grow in these countries. In the remaining parts of the world the tobacco epidemics is still evolving what brings rapid increase of the number of new lung cancer cases and deaths. Number of lung cancer deaths worldwide is expected to grow up to 3 million until 2035. The figures will double both in men (from 1.1 million in 2012 to 2.1 million in 2035) and women (from 0.5 million in 2012 to 0.9 million in 2035) and the two-fold difference between sexes will persist. The most rapid increase is expected in Africa region (AFRO) and East Mediterranean region (EMRO). The increase of the absolute number of lung cancer deaths in more developed countries is caused mostly by population aging and in less developed countries predominantly by the evolving tobacco epidemic.