Exams and Tests That Look for Lung Cancer

If your doctor thinks you might have lung cancer based on the results of a screening test or because of symptoms you are having, he or she will do exams and tests to find out for sure.

Medical history and physical exam

Your doctor will ask about your medical history to learn more about any symptoms you are having and possible risk factors. Your doctor will also examine you for signs of lung cancer or other health problems.

If the results of your history and physical exam suggest you might have lung cancer, more tests will be done.

Tests that might be used to look for lung cancer

Sputum cytology

For this test, a sample of mucus you cough up from the lungs (sputum) is looked at under a microscope to see if it contains cancer cells. The best way to do this is to get early morning samples from you 3 days in a row.

Chest x-ray

If you have symptoms that might be due to lung cancer, this is often the first test your doctor will do. Plain x-rays of your chest can be done at imaging centers, hospitals, and even in some doctors’ offices. If something suspicious is seen, your doctor may order more tests.

Computed tomography (CT) scan

A CT scan uses x-rays to make detailed cross-sectional images of your body. Instead of taking one picture, like a regular x-ray, a CT scanner takes many pictures as it rotates around you while you lie on a table. A computer then combines these pictures into images of slices of the part of your body being studied.

CT scans are more likely to show lung tumors than routine chest x-rays. They can also show the size, shape, and position of any lung tumors and can help find enlarged lymph nodes that might contain cancer that has spread from the lung.

Further tests if you have an abnormal screening test result

When a low-dose CT scan of the chest is done for lung cancer screening, it’s common to find small, abnormal areas (called nodules or masses) in the lungs, especially in current or former smokers. Most lung nodules seen on CT scans are not cancer. They are more often the result of old infections, scar tissue, or other causes. But tests are often needed to be sure a nodule is not cancer.

Most often the next step is to get a repeat CT scan to see if the nodule is growing over time. The time between scans might range anywhere from about a month to a year, depending on how likely your doctor thinks it is that the nodule could be cancer. This is based on the size, shape, and location of the nodule, as well as whether it appears to be solid or filled with fluid. If the nodule is larger, your doctor might also want to get another type of imaging test called a positron emission tomography (PET) scan, which can often help tell if it is cancer.

If the second scan shows that the nodule has grown, or if the nodule has other concerning features, your doctor will want to get a sample of it to check it for cancer cells. This is called a biopsy. This can be done in different ways:

  • The doctor might pass a long, thin tube (called a bronchoscope) down your throat and into the airways of your lung to reach the nodule. A small, hollow needle on the end of the bronchoscope can be used to get a sample of the nodule.
  • If the nodule is in the outer part of the lung, the doctor might pass a thin, hollow needle through the skin of the chest wall and into the nodule to get a biopsy sample.
  • If there is a higher chance that the nodule is cancer (or if the nodule can’t be biopsied with a needle), surgery might be done to remove the nodule and some surrounding lung tissue. Sometimes larger parts of the lung might be removed as well.

These types of tests, biopsies, and surgeries are described in more detail in Lung Cancer (Non-Small Cell) and Lung Cancer (Small Cell), as are the options for treatment if lung cancer is found.

Further tests if you have possible signs or symptoms of lung cancer

If your doctor is concerned you might have lung cancer because of signs or symptoms you are having, a chest x-ray or chest CT scan is likely to be the next step. Other tests that might be done include having you cough up sputum (phlegm) to have it looked at for cancer cells, or having a bronchoscopy, where the doctor puts a long, thin tube down your throat and into your lungs to look for anything abnormal.

If any of these tests are suspicious for cancer, further tests such as a biopsy or even surgery will likely be needed to get samples from any tumors.

These tests and procedures are described in more detail in Lung Cancer (Non-Small Cell) and Lung Cancer (Small Cell), along with the options for treatment if lung cancer is found.

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Last Medical Review: February 18, 2016 Last Revised: February 22, 2016

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