What Is Lung Cancer?
Cancer is a disease in which cells in the body grow out of control. When cancer starts in the lungs, it is called lung cancer.
Lung cancer begins in the lungs and may spread to lymph nodes or other organs in the body, such as the brain. Cancer from other organs also may spread to the lungs. When cancer cells spread from one organ to another, they are called metastases.
Lung cancers usually are grouped into two main types called small cell and non-small cell. These types of lung cancer grow differently and are treated differently. Non-small cell lung cancer is more common than small cell lung cancer.
What Are the Risk Factors for Lung Cancer?
Research has found several risk factors that may increase your chances of getting lung cancer.
Cigarette smoking is the number one risk factor for lung cancer. In the United States, cigarette smoking is linked to about 80% to 90% of lung cancer deaths. Using other tobacco products such as cigars or pipes also increases the risk for lung cancer. Tobacco smoke is a toxic mix of more than 7,000 chemicals. Many are poisons. At least 70 are known to cause cancer in people or animals.
People who smoke cigarettes are 15 to 30 times more likely to get lung cancer or die from lung cancer than people who do not smoke. Even smoking a few cigarettes a day or smoking occasionally increases the risk of lung cancer. The more years a person smokes and the more cigarettes smoked each day, the more risk goes up.
People who quit smoking have a lower risk of lung cancer than if they had continued to smoke, but their risk is higher than the risk for people who never smoked. Quitting smoking at any age can lower the risk of lung cancer.
Cigarette smoking can cause cancer almost anywhere in the body. Cigarette smoking causes cancer of the mouth and throat, esophagus, stomach, colon, rectum, liver, pancreas, voicebox (larynx), trachea, bronchus, kidney and renal pelvis, urinary bladder, and cervix, and causes acute myeloid leukemia.
Secondhand smoke and the harmful chemicals in it are known causes of sudden infant death syndrome, respiratory infections, ear infections, and asthma attacks in infants and children. They are also known causes of heart disease, stroke, and lung cancer in adult nonsmokers.
Smoke from other people’s cigarettes, pipes, or cigars (secondhand smoke) also causes lung cancer. When a person breathes in secondhand smoke, it is like he or she is smoking. In the United States, two out of five adults who don’t smoke and half of children are exposed to secondhand smoke, and about 7,300 people who never smoked die from lung cancer due to secondhand smoke every year.
Radon is a naturally occurring gas that comes from rocks and dirt and can get trapped in houses and buildings. It cannot be seen, tasted, or smelled. According to the U.S. Environmental Protection Agency (EPA), radon causes about 20,000 cases of lung cancer each year, making it the second leading cause of lung cancer. Nearly one out of every 15 homes in the United States is thought to have high radon levels. The EPA recommends testing homes for radon and using proven ways to lower high radon levels.
Examples of substances found at some workplaces that increase risk include asbestos, arsenic, diesel exhaust, and some forms of silica and chromium. For many of these substances, the risk of getting lung cancer is even higher for those who smoke.
Personal or Family History of Lung Cancer
If you are a lung cancer survivor, there is a risk that you may develop another lung cancer, especially if you smoke. Your risk of lung cancer may be higher if your parents, brothers or sisters, or children have had lung cancer. This could be true because they also smoke, or they live or work in the same place where they are exposed to radon and other substances that can cause lung cancer.
Radiation Therapy to the Chest
Cancer survivors who had radiation therapy to the chest are at higher risk of lung cancer.
Scientists are studying many different foods and dietary supplements to see whether they change the risk of getting lung cancer. There is much we still need to know. We do know that smokers who take beta-carotene supplements have increased risk of lung cancer.
Also, arsenic in drinking water (primarily from private wells) can increase the risk of lung cancer.
What Are the Symptoms of Lung Cancer?
Coughing and chest pain may be symptoms of lung cancer.
Different people have different symptoms for lung cancer. Some people have symptoms related to the lungs. Some people whose lung cancer has spread to other parts of the body (metastasized) have symptoms specific to that part of the body. Some people just have general symptoms of not feeling well. Most people with lung cancer don’t have symptoms until the cancer is advanced. Lung cancer symptoms may include—
- Coughing that gets worse or doesn’t go away.
- Chest pain.
- Shortness of breath.
- Coughing up blood.
- Feeling very tired all the time.
- Weight loss with no known cause.
Other changes that can sometimes occur with lung cancer may include repeated bouts of pneumonia and swollen or enlarged lymph nodes (glands) inside the chest in the area between the lungs.
These symptoms can happen with other illnesses, too. If you have some of these symptoms, talk to your doctor, who can help find the cause.
How Is Lung Cancer Diagnosed and Treated?
Types of Lung Cancer
The two main types of lung cancer are small cell lung cancer and non-small cell lung cancer. These categories refer to what the cancer cells look like under a microscope. Non-small cell lung cancer is more common than small cell lung cancer.
If lung cancer is diagnosed, other tests are done to find out how far it has spread through the lungs, lymph nodes, and the rest of the body. This process is called staging. The type and stage of lung cancer tells doctors what kind of treatment you need.
Types of Treatment
Lung cancer is treated in several ways, depending on the type of lung cancer and how far it has spread. People with non-small cell lung cancer can be treated with surgery, chemotherapy, radiation therapy, targeted therapy, or a combination of these treatments. People with small cell lung cancer are usually treated with radiation therapy and chemotherapy.
- Surgery. An operation where doctors cut out cancer tissue.
- Chemotherapy. Using special medicines to shrink or kill the cancer. The drugs can be pills you take or medicines given in your veins, or sometimes both.
- Radiation therapy. Using high-energy rays (similar to X-rays) to kill the cancer.
- Targeted therapy. Using drugs to block the growth and spread of cancer cells. The drugs can be pills you take or medicines given in your veins.
Doctors from different specialties often work together to treat lung cancer. Pulmonologists are doctors who are experts in diseases of the lungs. Surgeons are doctors who perform operations. Thoracic surgeons specialize in chest, heart, and lung surgery. Medical oncologists are doctors who treat cancer with medicines. Radiation oncologists are doctors who treat cancers with radiation.
Complementary and Alternative Medicine
Complementary and alternative medicine are medicines and health practices that are not standard cancer treatments.
- Complementary medicine is used in addition to standard treatments. Examples include acupuncture, dietary supplements, massage therapy, hypnosis, and meditation.
- Alternative medicine is used instead of standard treatments. Examples include special diets, megadose vitamins, herbal preparations, special teas, and magnet therapy.
Many kinds of complementary and alternative medicine have not been tested scientifically and may not be safe. Talk to your doctor about the risks and benefits before you start any kind of complementary or alternative medicine.