Diagnosis

Staging Melanomas

If melanoma is diagnosed, health professionals have devised various methods for staging (assessing the severity of) the cancer. This report now uses the new staging system recommended by American Joint Committee on Cancer, which should improve the precision of predicting outcome and determining treatments. The stages use the following abbreviations:

• T = tumor. T is followed by a number to indicate thickness.
• N = node. N is followed by numbers to indicate the number of lymph nodes involved.
• M = metastasis.

In addition a stage will include whether the melanoma is ulcerated or not, an indication of severity. Ulceration is determined 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 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. Others are staged as follows:

Stage I. Cure rates are excellent, 80% to 100%, with surgical removal, since they are least likely to have spread

• Stage 1A. Tumor has not spread to the nodes. It is less than 1 mm and is not ulcerated.
• Stage IB. 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.

Stage II. Melanomas can be cured, but the success rate (60% to 80% five-year survival) lags behind that of Stage I because a small number of cancer cells may have escaped from the original lesion and seeded distant sites. In addition to surgery, other forms of therapy may be recommended.

• Stage IIA. 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.
• Stage IIB. 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.

Stage III. Patients have a 30% to 70% five-year survival.

• Stage IIIA. Tumor has spread to 1 node and it is up to 4 mm without ulceration. Sentinel biopsy has detected microscopic evidence of tumor cells in the node (micrometastasis).
• Stage IIIB. Tumor is up to 4 mm without ulceration and has spread to one node or there is evidence of micrometastasis in two nodes.
• Stage IIIC. Tumor is any thickness and ulceration may or may not be present. It has spread to 2 or 3 nodes. Additional "satellite" melanomas on the skin more than 2 cm (about an inch) from the original lesion may be present; these are sometimes called "metastases in transit."