Each year, there are more than 170,000 new cases of lung cancer in the United States. Lung cancer is the uncontrolled growth of abnormal cells in one or both lungs. These abnormal cells reproduce quickly and disrupt the natural programming of the body's cells.
Tumors then form and clog the lung, making it difficult for the lung to work properly.
Lung cancer almost always begins in one lung and then spreads to lymph nodes, the other lung, or other tissues in the chest. Lung cancer also can spread, or metastasize, to the bones, brain, liver or other organs. The two main types of lung cancer, accounting for about 90 percent of all lung cancer cases, are called small cell and non-small cell cancers. The average survival from diagnosis without treatment is several months. However, compared with other types of lung cancer, SCLC is more responsive to treatment with chemotherapy and radiation.