July 6, 2009
Dr. Himalaya E. Lele and Dr. Leonard James Wudel
Cancer begins in cells, the building blocks that make up tissues. Normal, healthy cells grow and divide to form new cells as the body needs them. When normal cells grow old or become damaged, they die, and new cells take their place.
Sometimes, this orderly process goes wrong. New cells form when the body does not need them, and old or damaged cells do not die as they should. The buildup of extra cells often forms a mass of tissue called a growth or tumor.
Tumor cells can be benign (not cancer) or malignant (cancer). Benign lung tumors are rarely a threat to life, usually do not need to be removed and do not spread to other parts of the body. Malignant lung tumors may be life threatening, may grow back after being removed, and can spread to other parts of the body.
Studies have found the following risk factors for lung cancer:
Tobacco smoke: Tobacco smoke causes most cases of lung cancer. It's by far the most important risk factor for lung cancer. Harmful substances in smoke damage lung cells. The more a person is exposed to smoke, the greater the risk of lung cancer.
Radon: Radon is a radioactive gas you cannot see, smell or taste. It forms in soil and rocks. People who work in mines may be exposed to radon. In some parts of the country, radon is found in houses. Radon damages lung cells, and people exposed to radon are at increased risk of lung cancer. The risk of lung cancer from radon is even higher for smokers.
Asbestos and other substances: People who have certain jobs (such as those who work in the construction and chemical industries) have an increased risk of lung cancer. Exposure to asbestos, arsenic, chromium, nickel, soot, tar and other substances can cause lung cancer. The risk is highest for those with years of exposure. The risk of lung cancer from these substances is even higher for smokers.
Air pollution: Air pollution may slightly increase the risk of lung cancer. The risk from air pollution is higher for smokers.
Family history of lung cancer: People with a father, mother, brother or sister who had lung cancer may be at slightly increased risk of the disease, even if they don't smoke.
Personal history of lung cancer: People who have had lung cancer are at increased risk of developing a second lung tumor.
Age over 65: Most people are older than 65 years when diagnosed with lung cancer.
People who think they may be at risk for developing lung cancer should talk to their doctor. The doctor may be able to suggest ways to reduce their risk and can plan an appropriate schedule for checkups.
Currently, there is no generally accepted screening test for lung cancer. Several methods of detecting lung cancer have been studied as possible screening tests. The methods under study include tests of sputum (mucus brought up from the lungs by coughing), chest x-rays or CT scans.
However, screening tests have risks. For example, an abnormal x-ray result could lead to other procedures, but a person with an abnormal test result might not have lung cancer. Studies so far have not shown that screening tests lower the number of deaths from lung cancer.
Early lung cancer often does not cause symptoms. But as the cancer grows, common symptoms may include:
Most often these symptoms are not due to cancer. 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.
If you have a symptom that suggests lung cancer, your doctor must find out whether it's from cancer or something else. Your doctor may ask about your personal and family medical history. Your doctor may order blood tests, and you may have one or more of the following tests:
Physical exam: Your doctor checks for general signs of health, listens to your breathing, and checks for fluid in the lungs.
Chest x-ray: X-ray pictures of your chest may show tumors or abnormal fluid.
CT scan: Doctors often use CT scans to take pictures of tissue inside the chest.
The types of lung cancer are treated differently. The most common types are named for how the lung cancer cells look under a microscope:
Small cell lung cancer: About 13 percent of lung cancers are small cell lung cancers. This type tends to spread quickly.
Non-small cell lung cancer: Most lung cancers (about 87 percent) are non-small cell lung cancers. This type spreads more slowly than small cell lung cancer.
Your doctor may refer you to a specialist who has experience treating lung cancer, or you may ask for a referral. You may have a team of specialists. The choice of treatment depends mainly on the type of lung cancer and its stage. People with lung cancer may have surgery, chemotherapy, radiation therapy, targeted therapy or a combination of treatments.
People with limited-stage small cell lung cancer usually have radiation therapy and chemotherapy. For a very small lung tumor, a person may have surgery and chemotherapy. Most people with extensive stage small cell lung cancer are treated with chemotherapy only.
People with non-small cell lung cancer may have surgery, chemotherapy, radiation therapy, or a combination of treatments. The treatment choices are different for each stage. Some people with advanced cancer receive targeted therapy.
Your doctor can describe your treatment choices and the expected results. You may want to know about side effects and how treatment may change your normal activities. Because cancer treatments often damage healthy cells and tissues, side effects are common. Before treatment starts, your health care team will explain possible side effects and suggest ways to help you manage them.
You and your doctor can work together to develop a treatment plan that meets your medical and personal needs.