Diagnosing and Staging Lung Cancer

Front view of male head and torso showing respiratory system with bronchoscope inserted through nose, down trachea, and into right main bronchus.If your healthcare provider thinks you may have lung cancer, he or she will most likely do a number of tests to be sure. These tests can diagnose lung cancer and reveal the type of cancer, where it’s located, and if, or how much, it has spread. Test results may also help your healthcare provider plan treatment.

What do the tests show?

Each test result for lung cancer offers a piece of information. Taken as a whole, the results reveal precise details about your cancer. For instance, do you have non-small cell or small cell lung cancer? How large is the tumor? Where is the tumor? Are there lymph nodes involved? Has the cancer spread? With these details, you and your healthcare provider can start to plan treatment.


In a biopsy, a small sample of tissue is removed. It can be taken from a tumor in the lung. Or it can be taken from other parts of your body. That sample is then studied under a microscope to learn more about your cancer. The following tests can be done to get a biopsy.

  • Bronchoscopy. A thin, lighted, flexible tube (bronchoscope) goes into the nose and down the windpipe. The healthcare provider then has a direct view of the windpipe and bronchial tubes. Tissue samples may be taken from any areas that look like they might be cancer. The walls of the windpipe and bronchial tubes may also be brushed and rinsed. This loosens cells. The cells can then be removed and studied in a lab.

  • Endobronchial ultrasound (EBUS). A bronchoscope is used with ultrasound (image made from sound waves) to look at the lymph nodes and other structures between the lungs. A similar test is called an endoscopic esophageal ultrasound. In that test, a scope is passed down the tube that carries food from your mouth to your stomach (the esophagus) to look at these structures. 

  • Fine-needle aspiration (FNA). A very thin needle is used to remove cells from a tumor. This test is done under local anesthesia to help prevent pain. This means medicines are used to make the area numb. During the FNA, you may have a CT scan. This helps the healthcare provider place the needle exactly where it needs to be.

Imaging tests

Pictures from different imaging tests can provide details about your lungs and any tumors they may have. These pictures can also show a tumor’s location and size.

  • Chest X-ray. This is one of the most common imaging tests. Other imaging tests will likely be done.

  • CT scan. This is a computer-enhanced X-ray image.

  • PET scan (positron emission tomography). This test uses a slightly radioactive liquid (tracer) to find areas where cancer cells are in the body. A PET scan is often done along with a CT scan. It can find a tumor that may not appear on a chest X-ray.

  • MRI. This test is not used as often. It uses strong magnets and computers to help form a highly detailed image.

You may also have a bone scan or other imaging tests to learn whether the cancer has spread. Your healthcare provider will tell you how to prepare for any tests.

Staging lung cancer

Staging is a process to measure how much cancer there is and whether it has spread. Your healthcare provider uses exams and tests to find out the size of the cancer and where it is. He or she can also see if the cancer has grown into nearby areas, and if it has spread to other parts of your body. The stage of a cancer is one of the most important things to know when deciding how to treat the cancer.

When staging lung cancer, the following 3 factors are considered:

  • The tumor. How large is it? Has it reached other nearby structures?

  • The nearby lymph nodes. Have they been affected? If so, which lymph nodes—the lymph nodes near the tumor, or the lymph nodes in the center of the chest (mediastinal lymph nodes)? If the mediastinal lymph nodes are affected, are both sides affected? Or are they only affected on the same side as the tumor? 

  • Metastasis. Has the cancer spread to other parts of the body?

Both non-small cell and small cell lung cancers are then put into stage groupings based on this information. These groupings give an overall description of your cancer. A stage grouping can have a value of 0 to 4 and they're written as Roman numerals 0, I, II, III, and IV. The higher the number, the more advanced the cancer is. Letters and numbers can be used after the Roman numeral to give more details.

Lung cancer staging is complex. Be sure to ask your healthcare provider to explain the stage of your cancer to you in a way you can understand.