Cancer is the uncontrolled growth of cells in an organ, such as the lung, colon or skin. Cancer cells grow together to form a mass called a tumor. Benign (non-cancerous) cells can also grow and spread, but are not invasive. Cancer can be life threatening, because malignant cells can invade surrounding tissue and spread, or metastasize, to other parts of the body. Early detection before the cancer spreads provides the best chance of cure.
What is lung cancer?
Lung cancer is one of the most common kinds of cancer. In 2006 there will be approximately 174,470 new cases of lung cancer. About one third of all cancer deaths in the United States are due to lung cancer. Nearly 90 percent of lung cancer cases are related to smoking. Usually beginning in an airway called a bronchus, lung cancer takes many years before symptoms develop. In most cases, by the time the original lung tumor is large enough to cause breathing difficulties or other symptoms, the cancer has metastasized, or spread to organs outside the lung.
Medical researchers are beginning to unravel the complexities of lung cancer and are developing better methods for the diagnosis and treatment. Attempts at general screening for this disease have not yet improved survival and are not recommended unless in a research program. Early stage lung cancer detection, advances in treatment for lung cancer and palliative care have improved life expectancy and quality for people in later stages of lung cancer.