Lung cancer happens when cells in the lung begin to grow out of control and can then invade nearby tissues or spread throughout the body. Large collections of cancer cells are called tumors. Cells in any of the tissues in the lung can develop cancer; but most commonly, lung cancer comes from the lining of the bronchi. Lung cancer is not really thought of as a single disease, but rather a collection of several diseases that are characterized by the cell type that makes them up, how they behave, and how they are treated. Lung cancer is divided into two main categories:
- Small cell lung cancer (SCLC) - the rarer of the two types (about 20% of all lung cancers), small cell lung cancer is more aggressive than non small cell lung cancer because is grows more quickly and is more likely to spread to other organs
- Non small cell lung cancer (NSCLC) - the more common of the two types (80% of all lung cancers), non small cell lung cancer is generally slower growing than small cell lung cancer and is divided into three different types based on how the cells look that make it up - adenocarcinoma, large cell carcinoma, and squamous cell carcinoma
Am I at risk for lung cancer?
Lung cancer is the most common cause of cancer death in the world for both men and women. In the United States alone, it is estimated that 163,510 people will die from lung cancer in 2005. In comparison, 127,500 people are expected to die from colon, breast and prostate cancer combined in 2005 (the 2nd, 3rd, and 4th most common cancers in the U.S.). In the U.S., there has been a striking increase in the number of women getting lung cancer; in the 1990s, lung cancer overtook breast cancer as the most common cause of cancer death amongst women. This probably reflects increase incidence of smoking among women.
