Lung cancer is caused by malignant (cancer) cells that form in the tissues of the lung, usually in the cells lining air passages. The two main types are small cell lung cancer and non-small cell lung cancer. These different types are diagnosed based on how the cells look under a microscope. Doctors cannot always explain why one person develops lung cancer and another does not. However, we do know that smoking is by far the most important risk factor for lung cancer and causes most cases. 

Other factors that may increase the chance of developing lung cancer include exposure to radon (a radioactive gas) and a variety of naturally-occurring substances used in industry including asbestos, arsenic, chromium and nickel, air pollution, a family history of lung cancer, age over 65, and a history of having other lung diseases such as bronchitis or tuberculosis over time.

Screening for lung cancer
Although screening may help doctors find and treat certain cancers early, there is currently no generally accepted screening test for lung cancer. Several methods of detecting lung cancer have been studied as possible screening tests including sputum (mucus brought up from the lungs by coughing), chest x-rays or spiral CT scans.

Worth Noting: Screening tests for lung cancer may accompanied by certain risks. Although research holds some promise for the future, studies so far have not shown that screening tests lower the number of deaths from lung cancer.
Lung cancer symptoms

  • a cough that gets worse or does not go away
  • breathing trouble, such as shortness of breath
  • constant chest pain
  • coughing up blood
  • a hoarse voice
  • frequent lung infections such as pneumonia
  • feeling very tired all the time
  • weight loss with no known cause

In many cases, these symptoms are not due to cancer but are the result of other health problems can cause some of these symptoms. Anyone with such symptoms should see a doctor to be diagnosed and treated as early as possible.

Lung cancer treatment
The choice of treatment depends on the type of lung cancer and the degree to which it has spread.  People with lung cancer can have surgery where the entire lung, a lobe of the lung or a small part of the lung are removed along with nearby lymph nodes; radiation therapy (also called radiotherapy) which uses high-energy rays to kill cancer cells in the area being treated; chemotherapy which depends on drugs that kill cancer by entering the bloodstream; and targeted therapy which uses specialized drugs to block the growth and spread of cancer cells.

Three facts about lung cancer:

1. In the early stages, lung cancer is often not accompanied by pain or specific symptoms.

2. Many people diagnosed with lung cancer want a second opinion and most insurance companies will cover the cost if requested by the patient or physicians.

3. The mortality rate for lung cancer among women is nearly twice that of breast cancer.

For more information about lung cancer, visit’s Health Library.