Considered an advanced form of skin cancer, a stage III melanoma may have spread beyond the original tumor to one or multiple nearby lymph nodes.

This stage also includes disease that has travelled from the primary site but not yet reached local lymph nodes. Cancer cells that have spread less than 2 cm from the original site are called “satellite tumors,” and cancer cells that have spread more than 2 cm from the original site are called “in-transit melanoma.”

When determining the degree to which the disease has advanced, your doctor will consider factors such as whether or not the tumor has spread to nearby lymph nodes, how many nodes are found to have cancer, and how many cancer cells are detected in the nodes. An additional factor is whether the metastases can be seen and felt during a physical exam, or whether they can only be found with a microscope. 

Stages IIIA, IIIB, and IIIC

In order to better describe these variable factors, stage III melanoma is further divided into the following three categories:

• Stage III A: This stage includes microscopic levels of melanoma present in lymph nodes.
• Stage III B: This stage includes an ulcerated primary tumor, microscopic levels of melanoma in the skin near the primary tumor, microscopic levels of melanoma in lymph nodes, and melanoma (that can be felt or seen with imaging) in the draining nodes.
• Stage III C: This stage includes an ulcerated primary tumor and melanoma big enough to be felt in the draining nodes.

Treatments for Stage III Melanoma

The typical treatment approach for stage III melanoma is a wide excision surgery to remove the primary tumor, as well as a dissection to remove the lymph node(s). Following surgery, further treatment may include chemotherapy, immunotherapy, targeted therapies, or radiation therapy.