ABSTRACT
Epidemiology Lung cancer is today the most frequently occurring cancer in the world. It currently accounts for approximately 5% of all deaths in most developed countries and, as such, constitutes a major public health problem. Despite the fact that prostate cancer is more common in men than lung cancer, and breast cancer more common in women than lung cancer, mortality from lung cancer exceeds these two cancers plus colorectal cancer combined. Lung cancers are estimated to account for about 15% of all cancers and represent the leading cause of death from cancer. At the beginning of the 20th century lung cancer was a very rare disease, but rates have increased so dramatically that lung cancer can be considered a major epidemic of the 20th century. Theoretically, primary prevention, quitting smoking, or, more importantly, measures to reduce starting smoking may almost totally eliminate the disease, but although several such measures have been successful, the number of lung cancer deaths each year is still unacceptably high. At the same time, the risk for lung cancer is increasing rapidly in women, and increasing rapidly in many other countries in Europe and worldwide, and smoking in adolescents is also unfortunately increasing. It is further estimated that the risk for the population remains very high for a long time after quitting smoking: in the United States, more ex-smokers now develop lung cancer than current smokers. More than two-thirds of these people are diagnosed with locally advanced or metastatic disease, and their poor prognosis is due to late diagnosis and lack of effective treatment of metastatic disease. Less than 15% of the patients are surviving 5 years, and in several European countries the 5-year survival is far less.
