Staging of Melanoma
Staging is a method clinicians use to categorize melanomas for the purpose of evaluation, treatment and prognosis. Virginia Mason uses the staging system developed by the American Joint Commission on Cancer (AJCC) that assigns categories based on tumor (T), lymph node (N) and metastatic (M) status. Melanomas are also assigned an anatomic level or "Clark's level" I to IV as a description of tumor depth into the skin.
In addition, staging of cancer may include the following descriptions:
- Stage I and stage II: Melanoma is confined to the site where the cancer occurred and has not spread to the lymph nodes or internal organs.
- Stage III: Melanoma has spread to the lymph nodes.
- Stage IV: Melanoma has spread to distant organs (metastasis).
Additional Tests and Procedures
You may also have any one or more of the following tests and procedures to determine if cancer has spread:
- Chest X-ray — A simple chest X-ray may show lesions (growths) in the lungs.
- Lab tests — You may have blood and urine tests to determine if cancer "markers" are present in your blood or urine. Markers are substances such as hormones or proteins made by your body in response to cancer or made by the tumor itself. These tests are also used to monitor treatment as well as disease status.
- Sentinel lymph node biopsy — During this procedure, the first (sentinel) node or nodes near the tumor site are removed and tested for cancer cells. Prior to the procedure, patients have an injection of a harmless blue dye that flows through the lymphatic system near the tumor. The surgeon removes only the lymph nodes that have the blue dye, which are the first nodes where cancer may have spread. If cancer is not detected by a pathologist, usually no additional lymph nodes are removed.
- CT scan (CAT scan) — A CT scan - essentially a computer and X-ray machine - provides three-dimensional images of tissues and organs within the body. For patients with melanoma, images may be taken of the chest, abdomen and pelvis. In some instances a dye is injected first to enhance the images.
- Magnetic resonance imaging (MRI) — An MRI uses a magnet, radio waves, and a computer to create detailed pictures of areas within the body. An MRI is also called nuclear magnetic resonance imaging (NMRI).
- CT/PET scan (positron emission tomography scan) — A PET scan shows areas in the body that are "taking up" sugar. These areas appear as "hot spots" on the PET scan because cancer cells use sugar at a faster rate than normal cells do. You first will have an intravenous injection of a small amount of radioactive glucose (sugar). The PET scanner is then rotated around the body to create images.