What is lung cancer?

There are two basic types of lung cancer: non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). The type of lung cancer is important because it affects how the disease is treated. Most cases of lung cancer are NSCLC, which generally grows more slowly than SCLC.

How common is lung cancer?

The American Cancer Society (ACS) estimates that more than 213,000 new cases of lung cancer will be diagnosed in 2007. The disease causes about 160,000 deaths per year, more than colon, breast and prostate cancers combined. Although the prognosis for lung cancer is often poor, there are currently about 330,000 long-term survivors.

What causes lung cancer?

About 87 percent of lung cancers are caused by tobacco products, either through direct smoking or passive exposure to smoking (secondhand smoke), according to the ACS. The number of cigarettes smoked per day and the length of time a person smokes directly impacts the risk of developing lung cancer. It may also be caused by exposure to air pollution, radon gas and other chemicals, though this occurs much less frequently. It is believed that genetics may play a role in the likelihood of developing lung cancer. However, the extent of this role is unclear.

What are the symptoms of lung cancer?

Unfortunately, many times lung cancer has already spread to other parts of the body by the time symptoms are noticed. Common symptoms of lung cancer include persistent cough (often called smoker's cough), breathing problems, blood in sputum, pneumonia and other respiratory infections, chest pain, weight loss and fatigue.