Staging system for melanoma
The American Joint Committee on Cancer has developed a system for classifying cancers according to the extent of the cancer. Complete excision of the melanoma is followed by assessment of lymph nodes and other parts of the body to determine whether the cancer has spread. The staging system looks at other factors that have been found to affect survival, such as tumor thickness (Breslow level), depth of invasion (Clark level), and ulceration.1
Two systems are used for staging melanoma.
- The clinical staging system uses information gained from the removal of the melanoma and from blood tests and X-rays for any spread of the cancer.
- The pathologic staging system uses information gained from the removal of the melanoma and from pathological exam after lymph nodes are removed (lymphadenectomy).
The clinical staging system uses the letter T to describe primary tumors, the letter N to describe lymph node involvement, and the letter M for metastases (spread). Numbers after each of these letters indicate the seriousness of the disease.
Clinical staging system for melanoma Category Description Tumor (describes the primary tumor)
- TX: Primary tumor cannot be assessed.
- TO: No evidence of tumor
- Tis: Melanoma that invades only the outer layer of skin (melanoma in situ)
- T1: Melanoma is no more than 1.0 mm thick, with possible ulceration.
- T2: Melanoma is no more than 2.0 mm thick, with possible ulceration.
- T3: Melanoma is no more than 4.0 mm thick, with possible ulceration.
- T4: Melanoma is greater than 4.0 mm thick, with possible ulceration.
Nodes (describes whether cancer has spread into the lymph nodes)
- NX: Lymph nodes cannot be examined.
- N0: No metastasis found in lymph nodes.
- N1: Metastasis is present in one lymph node.
- N2: Metastasis present in 2 or 3 lymph nodes.
- N3: Metastasis is present in four or more lymph nodes.
Metastasis (describes the extent of cancer spread outside primary melanoma site)
- MX: Spread of cancer to other organs cannot be evaluated.
- M0: No evidence of melanoma cells elsewhere in the body
- M1: Melanoma cells found somewhere else in the body
The pathologic staging system uses all the above information and adds the pathologic evaluation of the lymph nodes and the examination of any evidence of melanoma spread.
Pathologic staging system for melanoma Pathologic stage Description Stage 0
Melanoma that invades only the outer layer of skin (melanoma in situ)
Stage 1A and 1B
Early-stage melanoma with low risk for spread of melanoma cells.
Stage IIA, IIB, and IIC
Melanoma is thicker than Stage 1, but no lymph node involvement. Intermediate risk for spread of melanoma cells.
Stage IIIA, IIIB, and IIIC
Lymph node involvement, ranging from intermediate risk to very high risk for spread of melanoma cells
Stage IV
Melanoma cells found in other parts of the body
| Author: | Shannon Erstad, MBA/MPH | Last Updated: January 11, 2007 |
| Medical Review: | Kathleen Romito, MD - Family Medicine Randall D. Burr, MD - Dermatology | |
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