About Lung Cancer
There are two types of lung cancer — non-small cell and small cell.
Each type of non-small cell lung cancer has different kinds of cancer cells. The cancer cells of each type grow and spread in different ways. The types of non-small cell lung cancer are named for the kinds of cells found in the cancer and how the cells look under a microscope:
- Adenocarcinoma: Cancer that begins in the cells that line the alveoli and make substances such as mucus.
- Large cell carcinoma: Cancer that may begin in several types of large cells.
- Squamous cell carcinoma: Cancer that begins in squamous cells, which are thin, flat cells that look like fish scales. This is also called epidermoid carcinoma.
Other less common types of non-small cell lung cancer are: pleomorphic, carcinoid tumor, salivary gland carcinoma and unclassified carcinoma.
There are two main types of small cell lung cancer. These two types include many different types of cells. The cancer cells of each type grow and spread in different ways. The types of small cell lung cancer are named for the kinds of cells found in the cancer and how the cells look when viewed under a microscope:
- Combined small cell carcinoma
- Small cell carcinoma (oat cell cancer)
- A cough that doesn’t go away or gets worse over time
- Blood in sputum (mucus coughed up from the lungs)
- Chest discomfort or pain
- Feeling very tired
- Loss of appetite
- Swelling in the face and/or veins in the neck
- Trouble breathing
- Trouble swallowing
- Weight loss for no known reason
Older age is the main risk factor for most cancers. The chance of getting cancer increases as you get older. When smoking is combined with other risk factors, the risk of lung cancer is increased. The earlier in life a person starts smoking, the more often a person smokes, and the more years a person smokes, the greater the risk of lung cancer.
Other risk factors include:
- Being exposed to asbestos, chromium, nickel, beryllium, arsenic, soot, or tar in the workplace
- Being exposed to radiation from any of the following:
- Radiation therapy to the breast or chest
- Radon in the home or workplace
- Imaging tests such as CT scans
- Atomic bomb radiation
- Being exposed to secondhand smoke
- Being infected with the human immunodeficiency virus (HIV)
- Having a family history of lung cancer
- Living where there is air pollution
- Taking beta carotene supplements and being a heavy smoker