Staging is the process used to determine the size of the tumor and where and how far it has spread (metastasized). Staging helps the health care team plan for appropriate treatment.
- Basal cell cancer is rarely staged, because it doesn't usually spread to other organs. However, it may be staged if it is very large.
- Squamous cell cancer of the skin may rarely be staged in people who have a high risk of the cancer spreading.
- Melanoma is always staged.
A number of factors may be used to identify melanoma that is likely to spread and may be hard to treat, including:
- The thickness as well as how many layers of the skin the main cancer lesion has invaded
- Whether the lesions have ulcerated
- Primary lesions with small satellites
- Lymph node involvement, and the number of lymph nodes involved
- Various other factors revealed by looking at the cancer cells under a microscope
Health professionals have come up with various methods for staging cancer. This report uses the TNM staging system recommended by the American Joint Committee on Cancer.
- T = tumor. T is followed by a number (1-4) and a letter (a or b) to indicate tumor thickness, how "aggressive" the tumor appears under the microscope., and the presence or absence of ulceration. "Tis is an in situ tumor, one that has not penetrated beneath the skin.
- N = node. N is followed by a number (1-3 ). If 1 node is involved, it is called N1. It 2 to 3 nodes are involved, it is called N2. If 4 or more nodes are present, it is called N3. How much cancer is present in the nodes is also important.
- M = metastasis. M is followed by a 0 (no spread) or a 1 (spread). M1 is further subdivided into a, b or c.depending on the site of metastasis and LDH levels.
The melanoma is considered ulcerated if skin layers over the tumor appear indistinct under the microscope.
In general, the thicker the lesion and the farther the cancer has spread, the higher the stage. Survival rates decrease with increasing stage.
Review Date: 07/04/2010
Reviewed By: Harvey Simon, MD, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.