Understanding Your Stage of Melanoma

The biopsy and other tests will help your doctor determine the thickness of the tumor. They will also help your doctor learn the spread of melanoma, called its stage. Melanoma may be located in one specific area of the skin, but it can move quickly to the lymph nodes. Your treatment plan and chance for a good outcome--called the prognosis--depend upon the stage of your melanoma. They also depend upon your general health, the location of the tumor, and whether or not there is ulceration, which is an open wound, at the primary site.

The TNM System

Doctors use different systems to measure the thickness of a melanoma and to stage the disease. These systems summarize the extent of your cancer. The American Joint Committee on Cancer (AJCC) staging system is used most often for melanoma. It is called the TNM system.

• The T stands for tumor. This category is based on the melanoma’s thickness and whether or not it is ulcerated. The term ulcerated means that the layer of skin covering the melanoma is gone. There may be bleeding with ulceration.

• N stands for lymph nodes. Lymph nodes are small groups of cells that help the body fight infections. This category indicates whether or not the melanoma has spread to the lymph nodes.

• M stands for metastasis. This category tells whether or not the cancer has spread to distant organs.

The TNM system measures the thickness of the melanoma. The Breslow measurement uses a ruler-like device to measure the actual thickness of the melanoma in millimeters under a microscope. The Clarkmeasurement describes the thickness of the melanoma in relation to how far it penetrates into the layers of the skin. In general, thinner or lower stage melanomas have a better prognosis.

Understanding the Numbers Used in Staging

Stages are named using a combination of 0 or the Roman numerals I to IV. The letters A through C are for substages. Lower stage cancers have a better outlook.

Stage 0. The melanoma is only in the top layer of skin, called the epidermis. This is also called Clarklevel I and sometimes is called melanoma in situ. In situ means the cancer has remained confined, and has not invaded other tissues.

Stage IA. The tumor is in the epidermis and the upper part of the layer of skin under the epidermis, called the dermis. It is no more than 1 millimeter thick, with no ulceration. It may be classified as Clark level II or III.

Stage IB. The tumor is 1 to 2 millimeters thick, with no ulceration. Or, it is not more than 1 millimeter thick, with ulceration, and may have spread into the dermis or the tissues below the skin. This is classified as Clark level IV or V.

Stage IIA. The tumor is 1 to 2 millimeters thick with ulceration. Or, it is 2 to 4 millimeters thick with no ulceration.

Stage IIB. The tumor is between 2 and 4 millimeters thick, with ulceration. Or, it is more than 4 millimeters thick with no ulceration.

Stage III. The tumor may be any thickness, with or without ulceration. In addition, one of these is also true.

• Stage IIIA is when surgical removal of the lymph node confirms that the tumor has spread into one lymph node. Stage IIIB means the tumor has spread to 2 lymph nodes.

• Stage IIIC means there are additional tumors, called satellite tumors, within 2 centimeters of the original tumor, but nearby lymph nodes are not involved. Or, 4 lymph nodes are involved alone or in combination with satellite tumors.

Stage IV. The tumor may be any thickness, with or without ulceration. It has spread to one or more nearby lymph nodes, or it has spread to distant places in the body.