Lung cancer is responsible for the most cancer-related deaths for both men and women throughout the world. The American Cancer Society estimated that 228,190 new cases of lung cancer in the U.S. were diagnosed and 159,480 deaths due to lung cancer occurred in 2013.
Lung cancer was not common prior to the 1930s, but increased dramatically over the following decades as tobacco smoking increased. In many developing countries, the incidence of lung cancer is beginning to fall because of education about the dangers of cigarette smoking and effective smoking cessation programs. Nevertheless, lung cancer remains the most common form of cancer in men worldwide and the fifth most common form of cancer in women.
Malignant non-small cell epithelial tumors of the lung are classified by the World Health Organization (WHO)/International Association for the Study of Lung Cancer (IASLC). There are three main subtypes of non-small cell lung cancer (NSCLC), including the following:
Squamous cell carcinoma (25% of lung cancers).
Adenocarcinoma (40% of lung cancers).
Large cell carcinoma (10% of lung cancers).
There are numerous additional subtypes of decreasing frequency.