After small cell lung cancer is diagnosed, tests will be performed to find out if the cancer has spread within the chest or has spread to other parts of the body.
The process of determining whether the cancer has spread within the lungs or to other parts of the body is called staging. The information gathered during staging ultimately determines the stage of the disease. In order to plan treatment, it is important to know the stage. Some of the tests used to diagnose non-small cell lung cancer are also used for staging. (See the “Common Information” section.)
Other tests and procedures that may be used in staging include:
MRI (magnetic resonance imaging): A process that uses magnets, radio waves, and a computer to produce detailed pictures of a series of areas inside the body, such as the brain. This process is also called nuclear magnetic resonance imaging (NMRI).
CT scan (CAT scan): A method of taking detailed images of a series of internal areas of the body, such as the brain, chest, or upper abdomen, from different angles. The images are generated by a computer that is connected to an x-ray machine. A developer is injected intravenously or swallowed to allow organs or tissues to be shown more clearly. This method is also known as computed tomography, computerized tomography imaging, or computerized x-ray axial tomography.
PET scan (positron emission tomography): A method used to detect malignant cells in the body. A small amount of radioactive glucose (sugar) is injected into a vein, and the PET scanner rotates around the body to image the part of the body that contains glucose. In the image, the image is brighter because the malignant tumor cells are more active and take up more glucose compared to normal cells. This is examined by a method called PET-CT.
Bone scan:A test that checks for the presence of rapidly dividing cells (such as cancer cells) in the bones. Trace amounts of radioactive material are injected into a vein and transferred throughout the body through the bloodstream. Radioactive material that collects in cancer lesions in the bones is detected by the scanner.
Cancer spreads through the body in three ways.
Cancer cells can spread through the tissues, the lymphatic system, and the blood:
Tissues. The cancer spreads from the primary site into neighboring tissues.
Lymphatic system. Cancer tissue invades the lymphatic system from the primary site. Cancer cells can spread to other parts of the body through the lymphatic vessels.
Blood. Cancer cells spread from where it occurs into the bloodstream. Cancer cells move from blood vessels to other parts of the body.
Cancer cells can spread from where it occurs to other parts of the body.
Cancer metastasis is the spread of cancer to other parts of the body. Cancer cells break away from the primary site (the primary tumor) and invade the lymphatic system or bloodstream.
Lymphatic system. Cancer tissue invades the lymphatic system and then forms a tumor in another part of the body through the lymphatic vessels (metastatic tumor).
Blood. Cancerous tissue invades the bloodstream and then forms a tumor in another part of the body through the bloodstream (metastatic tumor).
Metastatic tumors are the same type of tumor as the primary tumor. For example, if non-small cell lung cancer spreads to the brain, the cancer cells in the brain are actually still lung cancer cells. The disease would be called metastatic lung cancer, not brain cancer.
Many cancer deaths are due to the spread of cancer cells from the primary tumor to other tissues and organs. This is called metastatic cancer. This animation shows how cancer cells move from where they first formed in the body to other parts of the body.
The staging of small cell lung cancer is as follows:
Limited stage small cell lung cancer
In the limited stage, the malignancy may have spread to areas between the lungs where it first appeared, or to lymph nodes above the collarbone.
Extensive stage small cell lung cancer
In the extensive stage, the malignancy has spread beyond the area of the lung, or to the area between the lungs, or to the lymph nodes above the clavicle, into other parts of the body.