Health professionals have come up with various methods for staging cancers. This article uses the 2002 TNM system recommended by the American Joint Commission on Cancer, the most widely used staging system in the world. Your doctor may also assign a Clark and Breslow number — measurements of tumor penetration and thickness, respectively — to further stage your melanoma and determine your prognosis.
- T = tumor. T is followed by a number corresponding to tumor thickness.
- N = node. N is followed by a number corresponding to the extent of lymph node involvement.
- M = metastasis (distant spreading). M is followed by a number corresponding to the extent of metastasis.
In addition, the "T" may be followed an "a" signifying no ulceration, or a "b" signifying ulceration. Ulceration, which indicates more severe disease and is identified under the microscope, occurs when melanoma invades the overlying skin.
In general, the thicker the lesion and the farther the cancer has spread, the higher the assigned stage. The higher the stage, the worse the long-term outlook. The earliest melanomas, which do not penetrate beneath the surface of the skin and are known as melanoma in situ, are highly curable and are called stage 0 or not given a stage. Subsequent stages are as follows:
Stage I. Cure rates are excellent with surgical removal, since they are least likely to have spread.
- Stage 1A (T1aN0M0). Tumor has not spread to the nodes. It is less than 1 mm and is not ulcerated. Five-year survival is 95%.
- Stage IB (T1bN0M0 or T2aN0M0). Tumor has not spread to the nodes. It is less than 1 mm, but is ulcerated, or the tumor is between 1.01 and 2 mm but is not ulcerated. Five-year survival is 89-91%.
- However, a tumor can be <1.0 mm and not ulcerated but still not be Stage IA -- if it has a higher Clark level of invasion. Similarly, a tumor can be T1b and < 1.0 mm without ulceration if it has an advanced Clark level.
Stage II. Melanomas can be cured, but the success rate lags behind that of Stage I because a small number of cancer cells may have spread to distant sites. In addition to surgery, other forms of therapy may be recommended.
- Stage IIA (T2bN0M0 or T3aN0M0). Tumor has not spread to the nodes. It is between 1.01 and 2 mm and is ulcerated, or it is 2.01 to 4 mm without ulceration. Five-year survival is 77-79%.
- Stage IIB (T3bN0M0 or T4aN0M0). Tumor has not spread to the nodes. It is between 2.01 and 4 mm and is ulcerated or greater than 4 mm without ulceration. Five-year survival is 63-67%.
- Stage IIC (T4bN0M0). Tumor has not spread to the nodes. It is greater than 4 mm and is ulcerated. Five-year survival is 45%.
Stage III. Since the tumor has started to metastasize, the survival rate for these stages is lower than the earlier ones.
- Stage IIIA (T1a-4a, N1a-N2a, M0). The tumor is not ulcerated. It has spread to up to 3 nodes, but they are not enlarged. The nodal spread is evident only on microscopic examination, not on clinical examination. Five-year survival is 63-69%.
- Stage IIIB. This is a complicated stage with many possible scenarios:
- T1b-T4b, N1a-N2a. The tumor is ulcerated. It has spread to up to 3 nodes, but they are not enlarged. The nodal spread is evident only on microscopic examination, not on clinical examination.
- T1a-T4a, N1b-N2b. The tumor is not ulcerated. It has spread to up to 3 nodes, and the nodes are enlarged because of the melanoma.
- T1a/b-T4a/b, N2c. The tumor can be ulcerated or not. The tumor has spread to skin near the melanoma (satellite metastasis) or to nearby lymph channels (in transit metastasis), but the lymph nodes themselves do not contain melanoma.
Overall five-year survival for this stage is 30-59%.
- Stage IIIC has two possible scenarios:
- T1b-T4b, N1b or N2b: The tumor is ulcerated. Melanoma has spread to up to 3 lymph nodes, which are enlarged because of the cancer.
- Any T, N3: Tumor can be any thickness and can be ulcerated or not. The melanoma has spread to four or more nearby nodes; or there are clumped (matted) nodes with melanoma in them; or there are satellite or in-transit metastases and spread to nearby lymph nodes.
Five-year survival is 24-29%.
Stage IV. Associated with metastasis beyond the regional lymph nodes to distant sites in the body such as the lung, liver, or brain, or to distant areas of the skin. Neither the lymph node status nor thickness is considered. 5-year survival ranges from 7% to 19%.
"How is Melanoma Staged?" American Cancer Society. June 2008. 10 October 2008.
Balch CM, Buzaid AC, Soong SJ, et al. "Final version of the American Joint Committee on cancer staging system for cutaneous melanoma." Journal of Clinical Oncology 2001 19(16):3635-3648. 10 October 2008.
The Short Version
|IA||Tumor ≤ 1.0 mm without ulceration; no lymph node involvement; no distant metastases|
|IB||Tumor ≤ 1.0 mm with ulceration or Clark level IV or V; tumor 1.01-2.0 mm without ulceration; no lymph node involvement; no distant metastases|
|IIA||Tumor 1.01-2.0 mm with ulceration; tumor 2.01-4.0 mm without ulceration; no lymph node involvement; no distant metastases|
|IIB||Tumor 2.01-4.0 mm with ulceration|
|IIB||Tumor > 4.0 mm without ulceration; no lymph node involvement; no distant metastases|
|IIC||Tumor > 4.0 mm with ulceration; no nodal involvement; no distant metastases|
|IIIA||Tumor of any thickness without ulceration with 1 positive lymph node|
|IIIB||Tumor of any thickness without ulceration with 2-3 positive lymph nodes|
|IIIC||Tumor of any thickness and 4 more metastatic lymph nodes OR matted nodes OR in-transit met(s)/satellite(s) without metastatic lymph nodes, or combinations of in-transit met(s)/satellite(s), OR ulcerated melanoma and metastatic lymph node(s)|
|IV||Tumor of any thickness with any nodes and any distant metastases|