The stage of the tumor has a major impact on lung cancer prognosis. Cancer staging is the process of determining tumor size, growth rate, possible metastasis, lymph node involvement, treatment options and prognosis. While a biopsy provides proof of the presence and type of cancer, further testing is required to determine the stage of the disease.
Initial diagnosis of lung cancer may have included the use of diagnostic imaging. Computed tomography and other imaging tools are also used in cancer staging. More than one type of test may be required, especially if metastasis is suspected.
Computed Tomography: Also known as a CAT or CT scan, computed tomography uses x-rays to take multiple pictures of the lungs and generate a 3-dimensional computer image.
Magnetic Resonance Imaging: Magnetic resonance imaging (MRI) uses powerful magnets to create radio waves. The radio waves change slightly depending on the type of tissue they are aimed at, and recording these changes allows computers to build 3-dimensional images.
Positron Emission Tomography: While magnetic resonance imaging and CAT scans create images of the lungs, positron emission tomography (PET) allows doctors to view the lungs at work. A mild radioactive compound that is absorbed by different types of cells at different rates is either injected or swallowed. Positron emission tomography takes up to an hour to perform, but provides valuable information about lung function.
Radionuclide Scanning: In order to determine if metastasis to other organs has occurred, a radionuclide scan may be ordered. The scan uses radioactive materials to detect cancerous cells.
Mediastinoscopy: In a mediastinoscopy a hollow tube with a light at the end is used to examine the chest cavity and lymph node system for signs of metastasis. The tube is inserted through a small surgical incision in the neck. If additional biopsy samples are required, samples can be retrieved during the mediastinoscopy.
The severity of non small cell lung cancer (NSCLC) is determined using TNM staging. The staging is divided into three categories. T stands for tumor, N for lymph node, and M for metastases.
NSCLC staging examples might read T1N2M0, or some other combination of the above stages. The TNM data gathered is then used to divide lung cancers into four stages, the higher the stage the poorer the five-year prognosis:
Small cell lung cancer staging differs from the NSCLC TNM staging. There are three categories of SCLC: limited, extensive, and recurrent. The limited stage has no evidence of metastasis. The extensive designation means that the cancer has spread to other organs. Often limited SCLC is treated with the assumption that metastasis has occurred, just to be safe.
Two-year prognosis for limited SCLC is twenty percent and for extensive disease five percent. The average life expectancy for someone with recurrent SCLC is two to three months.
Busick, N. P., Fretz, P. C., Galvin, J. R.
Tree.com provides information on health-related topics, not medical advice, diagnosis or treatment recommendations. Please consult your physician if you have questions or concerns.