Stages of Melanoma

There are three ways that cancer spreads in the body. (1) Through tissue. Cancer invades the surrounding normal tissue. (2) Through the lymph system. Cancer invades the lymph system and travels through the lymph vessels to other places in the body. (3) Through the blood. Cancer invades the veins and capillaries and travels through the blood to other places in the body.

When cancer cells break away from the primary tumor and travel through the lymph or blood to other places in the body, another tumor may form. This process is called metastasis. The secondary tumor is the same type of cancer as the primary tumor. For example, if breast cancer spreads to the bones, the cancer cells in the bones are actually breast cancer cells. The disease is metastatic breast cancer, not bone cancer.

The Clark levels are used for thin tumors to describe how deep the cancer has spread into the skin. In Clark Level I, the cancer is in the epidermis only. In Clark Level II, the cancer has begun to spread into the papillary dermis. In Clark Level III, the cancer has spread through the papillary dermis into the papillary-reticular dermal interface but not into the reticular dermis. In Clark Level IV, the cancer has spread into the reticular dermis. In Clark Level V, the cancer has spread into the subcutaneous tissue.

The following stages are used for melanoma. In stage 0, abnormal melanocytes are found in the epidermis (Clark level I). These abnormal melanocytes may become cancer and spread into nearby normal tissue. Stage 0 is also called melanoma in situ. In stage I, cancer has formed. Stage I is divided into stages IA and IB.

In stage IA, the tumor is not more than 1 millimeter thick, with no ulceration. The tumor is in the epidermis and the papillary dermis (Clark level II or III). In stage IB, the tumor is either: not more than 1 millimeter thick and it has ulceration or it has spread through the dermis or into the subcutaneous layer (Clark level IV or V) ; or more than 1 but not more than 2 millimeters thick, with no ulceration.

Stage II is divided into stages IIA, IIB, and IIC. In stage IIA, the tumor is either: more than 1 but not more than 2 millimeters thick, with ulceration; or more than 2 but not more than 4 millimeters thick, with no ulceration. In stage IIB, the tumor is either: more than 2 but not more than 4 millimeters thick, with ulceration; or more than 4 millimeters thick, with no ulceration. In stage IIC, the tumor is more than 4 millimeters thick, with ulceration.

In stage III, the tumor may be any thickness, with or without ulceration, and either: has spread into a nearby lymph vessel and may have spread into nearby lymph nodes; or has spread to 1 or more lymph nodes, which may be matted (not moveable). In stage IV, the cancer has spread to other places in the body.

Most of the treatments require multiple visits to the doctor. Laser and electrocautery treatments are not always effective because they only reach the outermost layers of the skin, while moles penetrate very deep into the dermal tissue, often beyond the reach of these treatments. Surgery, the other option doctors commonly offer, involves cutting out the mole. The resulting wound requires stitches, which will in turn leave a scar.