Facts
Seattle Cancer Care Alliance (SCCA) offers comprehensive treatment from a team of experts who specialize in lung cancer.
What is lung cancer?
Lung cancer is the result of damage to normal cells in the lung. Cancer that begins somewhere else in the body may spread to the lungs; this is different from lung cancer.
- Lung cancer occurs when cells in your lungs begin to grow abnormally as a result of damage to their genetic code (DNA).
- Cancer cells do not behave like normal cells — they grow abnormally and do not respond to signals to stop growing.
- Cancer cells also don’t organize normally. Instead they grow into a tumor, which may invade surrounding layers of tissue and spread to other organs.
- The cancer cells can enter your lymph system and begin to grow in lymph nodes around your bronchi and between your lungs (mediastinum).
- If lung cancer has reached your lymph nodes, it is more likely to have spread to other parts of your body, forming tumors (metastases) there.

Understanding your lungs
To understand lung cancer, it helps to know more about your lungs and lymph system.
Your lungs are sponge-like organs that work with your ribs, chest muscles and diaphragm muscle to move air in and out of your body, bringing in oxygen when you inhale and getting rid of carbon dioxide when you exhale.
- Air travels down your trachea, through your bronchi and bronchioles, into your alveoli and back out again.
- Your alveoli exchange carbon dioxide for oxygen through tiny blood vessels. The oxygen is carried to other parts of your body through your bloodstream.
Each lung has sections called lobes.
- Your right lung has three lobes and is slightly larger than your left.
- Your left lung has two lobes and is smaller because your heart takes up room on that side of your body.
Around your lungs are lymphatic vessels, small tubes that carry lymph away from your lungs.
- Lymph is clear fluid that carries waste products and immune system cells.
- In certain places along the lymphatic vessels you have lymph nodes — small, oval-shaped organs of the immune system.
- Lymphatic vessels link lymph nodes in the lungs to lymph nodes in the mediastinum.
Types
There are two main types of lung cancer:
- Non-small cell lung cancer, which accounts for about 85 percent of all lung cancers
- Small cell lung cancer, which makes up about 15 percent
Symptoms
Lung cancer symptoms may take years to develop, and often there are no symptoms at all until the later stages of the disease.
The early symptoms of lung cancer are often mistaken for less serious problems. Or, in people who smoke, they are thought to be related to tobacco use alone.
Diagnosing
SCCA’s Lung Cancer Early Detection & Prevention Clinic is your gateway to getting a diagnosis if you’re suspected of having lung cancer or to reducing your risk if you’re lung cancer–free.
Sometimes lung cancer is detected before symptoms appear through a chest X-ray or other exam ordered for reasons not related to the cancer.
Your doctor may order imaging tests, such as an endobronchial ultrasound, a chest X-ray or a computed tomography (CT) scan to help diagnose lung cancer.
To confirm the diagnosis, you will need a biopsy. This involves taking a sample of tissue and looking at the cells under a microscope. A number of methods can be used.
- Bronchoscopy — A thin, lighted tube (bronchoscope) is inserted through your mouth or nose, down your windpipe and into your breathing passages so doctors can see inside and take a tissue sample.
- Endobronchial ultrasound–guided transbronchial needle aspiration (EBUS TBNA) — A special bronchoscope with an ultrasound processor is used to see the area between your lungs and take a tissue sample without any incisions.
- Needle biopsy — A needle is inserted through your chest wall into the tumor, usually under the guidance of CT imaging, to withdraw cells. This method might also be used to withdraw cells from tumors in other areas of your body, if you have any.
- Thoracentesis — A needle is used to remove fluid surrounding your lungs.
- Mediastinoscopy — A thin, lighted tube (mediastinoscope) is inserted through a small incision in your neck just above or next to your breastbone to see your lungs and surrounding lymph nodes and take a tissue sample.
- Thoracotomy — A surgeon opens your chest surgically to access the tumor.
If a biopsy confirms that cancer is present, your doctor will determine the type of cancer and the stage — how far the cancer has spread within your lungs or to other parts of your body.
Stages
Accurate staging is probably the most important part of lung cancer treatment because it helps your doctors choose the most appropriate therapy for you (and can help you avoid ineffective therapy).
What causes lung cancer?
More than 85 percent of lung cancers are related to tobacco, either by smoking or breathing secondhand smoke, and about half of all continuing smokers will die from a disease caused by smoking.
Get help to quit smoking, and learn about early detection at SCCA, including lung cancer screening for smokers and ex-smokers.
How common is lung cancer?
Lung cancer is the most common cancer after skin cancer, and it is the leading cause of cancer death for both men and women in the United States. Each year, more Americans die of lung cancer than of breast, colorectal, ovarian and prostate cancers combined.
About 222,000 new lung cancer cases are diagnosed in the U.S. each year.