Definition | Causes | Risk Factors | Symptoms | Diagnosis | Treatment | Prevention

Definition

Cancer occurs when cells in the body divide without control or order. If cells keep dividing uncontrollably, a mass of tissue forms. This is called a growth or tumor. The term cancer refers to malignant tumors. They can invade nearby tissue and spread to other parts of the body.

Lung cancer is a disease in which cancer cells grow in the lungs. There are two types of lung cancers:

  • Non-small cell lung cancer—generally grows and spreads more slowly (more common form)
  • Small cell lung cancer—generally grows more quickly and is more likely to spread to other parts of the body

Lung Cancer

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Causes

The following can cause damage to the cells in the lungs, leading to lung cancer:

  • First- or second-hand smoke from cigarettes, cigars, or pipes
  • Exposure to asbestos (a type of mineral) or radon (radioactive gas)

Risk Factors

These factors increase your chance of developing lung cancer:

  • Smoking
  • Using chewing tobacco
  • Being exposed to second-hand smoke
  • Being exposed to asbestos or radon
  • Having a lung disease, such as tuberculosis
  • Having a family or personal history of lung cancer
  • Being exposed to certain air pollutants
  • Being exposed to coal dust
  • Radiation therapy that was used to treat other cancers
  • HIV infection

Symptoms

Symptoms may include:

Diagnosis

The doctor will ask about your symptoms and medical history. A physical exam will be done. The doctor will also ask about:

  • Smoking history
  • Substances that you have been exposed to
  • Family history of cancer

Tests may include:

  • Chest x-ray—a test that uses radiation to take a picture of structures inside the body
  • Sputum cytology—a test that examines of a sample of mucus from the lungs
  • Spiral CT—a special type of x-ray of the lungs
  • Biopsy—removal of a sample of lung tissue to be tested for cancer cells.
  • Positron emission tomography scan (PET scan)—an image created using a tiny amount of radiation that is put into the body
  • PET/CT scan—a type of imaging test that combines PET and CT scan techniques
  • Bone scan—a test that detects areas of increased or decreased bone activity

Treatment

Once lung cancer is found, staging tests are done to find out if the cancer has spread. The goal of treatment is to eliminate the cancer and/or control the symptoms.

Surgery involves removing the tumor and nearby tissue. Lymph nodes may also need to be removed. The type of surgery depends on the location of the tumor, such as:

Radiation therapy is the use of radiation to kill cancer cells and shrink tumors. This may also be used to relieve symptoms, such as shortness of breath. External radiation is usually used to treat lung cancer. With this treatment, radiation is directed at the tumor from a source outside of the body.

Chemotherapy is the use of drugs to kill cancer cells. This may be given in many forms, including pill, injection, and via a catheter. Chemotherapy is often used to kill lung cancer cells that have spread to other parts of the body.

Researchers continue to study ways to treat lung cancer. The National Cancer Institute considers these potential therapies:

  • Photodynamic therapy (PDT)—a type of laser therapy. A chemical is injected into the bloodstream. It is then absorbed by the cells of the body. The chemical rapidly leaves normal cells. It will remain in cancer cells for a longer time. A laser aimed at the cancer activates the chemical. This chemical then kills the cancer cells that have absorbed it. This treatment may also be used to reduce symptoms.
  • Cryosurgery—a treatment that freezes and destroys cancer tissue

Other treatments that are being researched include:

  • Targeted therapy—involves using medicines or substances to target certain molecules in the cancer cells
  • Immunotherapy—involves using medicines or substances made by the body to increase or restore the body's natural defenses against cancer

If you are diagnosed with lung cancer, follow your doctor's instructions .

Prevention

To reduce your risk of getting lung cancer:

  • Do not start smoking. If you smoke, quit.
  • Avoid places where people are smoking.
  • Test your home for radon gases and asbestos. Have these substances removed if they are in the home.
  • Do not work in a place with asbestos.

The American Lung Association and American Cancer Society both suggest that screening for lung cancer with a type of CT scan may be considered if you are a smoker (or former smoker), aged 55-74 years, and have a history of heavy smoking (such as one pack a day for 30 years).