Tests and diagnosisBy Mayo Clinic staff
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Testing healthy people for lung cancer
Doctors aren't sure whether people with no signs or symptoms of lung cancer should undergo screening for the disease. Some studies show that lung cancer screening may save lives by finding cancer earlier, when it may be treated more successfully. But other studies find that lung cancer screening often reveals more benign conditions that require invasive testing and expose people to unnecessary risks.
Screening for lung cancer is controversial among doctors. Studies are ongoing to determine what types of tests may be helpful and who would benefit from lung cancer screening. In the meantime, talk with your doctor if you're concerned about your risk of lung cancer. Together you can determine strategies to reduce your risk and decide whether screening tests are appropriate for you.
Tests to diagnose lung cancer
If there's reason to think that you may have lung cancer, your doctor can order a number of tests to look for cancerous cells and to rule out other conditions. In order to diagnose lung cancer, your doctor may recommend:
- Imaging tests. An X-ray image of your lungs may reveal an abnormal mass or nodule. A CT scan can reveal small lesions in your lungs that might not be detected on an X-ray.
- Sputum cytology. If you have a cough and are producing sputum, looking at the sputum under the microscope can sometimes reveal the presence of lung cancer cells.
- Tissue sample (biopsy). A sample of abnormal cells may be removed in a procedure called a biopsy. Your doctor can perform a biopsy in a number of ways, including bronchoscopy, in which your doctor examines abnormal areas of your lungs using a lighted tube that's passed down your throat and into your lungs; mediastinoscopy, in which an incision is made at the base of your neck and surgical tools are inserted behind your breastbone to take tissue samples from lymph nodes; and needle biopsy, in which your doctor uses X-ray or CT images to guide a needle through your chest wall and into the lung tissue to collect suspicious cells. A biopsy sample may also be taken from lymph nodes or other areas where cancer has spread, such as your liver.
Lung cancer staging
Once your lung cancer has been diagnosed, your doctor will work to determine the extent, or stage, of your cancer. Your cancer's stage helps you and your doctor decide what treatment is most appropriate.
Staging tests may include imaging procedures that allow your doctor to look for evidence that cancer has spread beyond your lungs. These tests include CT scans, magnetic resonance imaging (MRI), positron emission tomography (PET) and bone scans. Not every test is appropriate for every person, so talk with your doctor about which procedures are right for you.
Stages of lung cancer
- Stage I. Cancer is limited to the lung and hasn't spread to the lymph nodes. The tumor is generally smaller than 2 inches (5 centimeters) across.
- Stage II. The tumor at this stage may have grown larger than 2 inches, or it may be a smaller tumor that involves nearby structures, such as the chest wall, the diaphragm or the lining around the lungs (pleura). Cancer may also have spread to the nearby lymph nodes.
- Stage III. The tumor at this stage may have grown very large and invaded other organs near the lungs. Or this stage may indicate a smaller tumor accompanied by cancer cells in lymph nodes farther away from the lungs.
- Stage IV. Cancer has spread beyond the affected lung to the other lung or to distant areas of the body.
Small cell lung cancer is sometimes described as being limited or extensive. Limited indicates cancer is limited to one lung. Extensive indicates cancer has spread beyond the one lung.
- Non-small cell lung cancer. Fort Washington, Pa.: National Comprehensive Cancer Network. http://www.nccn.org/professionals/physician_gls/f_guidelines.asp. Accessed Oct. 12, 2011.
- Estimated new cancer cases and deaths by sex for all sites, US, 2011. American Cancer Society. http://www.cancer.org/acs/groups/content/@epidemiologysurveilance/documents/document/acspc-029817.pdf. Accessed Oct. 12, 2011.
- Small cell lung cancer. Fort Washington, Pa.: National Comprehensive Cancer Network. http://www.nccn.org/professionals/physician_gls/f_guidelines.asp. Accessed Oct. 12, 2011.
- Johnson DH, et al. Cancer of the lung: Non-small cell lung cancer and small cell lung cancer. In: Abeloff MD, et al. Abeloff's Clinical Oncology. 4th ed. Philadelphia, Pa.: Churchill Livingstone; 2008:1307.
- What you need to know about lung cancer. National Cancer Institute. http://www.cancer.gov/cancertopics/wyntk/lung/AllPages. Accessed Oct. 7, 2011.
- Lung cancer prevention (PDQ). National Cancer Institute. http://www.cancer.gov/cancertopics/pdq/prevention/lung/Patient/AllPages. Accessed Oct. 7, 2011.
- Aberle DR, et al. Reduced lung-cancer mortality with low-dose computed tomographic screening. The New England Journal of Medicine. 2011;365:395.
- Greaves SM, et al. The new staging system for lung cancer: Imaging and clinical implications. Journal of Thoracic Imaging. 2011;26:119.
- Xalkori (prescribing information). New York, N.Y.: Pfizer Labs; 2011. www.pfizerpro.com/Xalkori. Accessed Oct. 14, 2011.
- Avastin (prescribing information). South San Francisco, Calif.: Genentech Inc.; 2011. http://www.avastin.com/avastin/hcp/index.html. Accessed Oct. 14, 2011.
- Tarceva (prescribing information). Melville, N.Y.: OSI Pharmaceuticals Inc.; 2011. http://www.tarceva.com/patient/considering/index.jsp. Accessed Oct. 14, 2011.
- Kvale PA, et al. Palliative care in lung cancer. Chest. 2007;132(suppl):368S.
- Cassileth BR, et al. Complementary therapies and integrative oncology in lung cancer. Chest. 2007:132(suppl):340S.
- Stereotactic radiosurgery (SRS) and stereotactic body radiotherapy (SBRT). RadiologyInfo.org. http://www.radiologyinfo.org/en/info.cfm?pg=stereotactic. Accessed Oct. 14, 2011.
- Temel JS, et al. Early palliative care for patients with metastatic non-small-cell lung cancer. The New England Journal of Medicine. 2010;363:733.
- Li Y, et al. Effect of emphysema on lung cancer risk in smokers: A computed tomography-based assessment. Cancer Prevention Research. 2010;4:53.
- Rosenow EC (expert opinion). Mayo Clinic, Rochester, Minn. Oct. 19, 2011.
- 2008 physical activity guidelines for Americans. U.S. Department of Health and Human Services. http://www.health.gov/paguidelines/guidelines/default.aspx. Accessed Nov. 8, 2011.