Malignant Melanoma Stage III

Stage III melanoma means the cancer has spread beyond the original site to nearby lymph nodes, lymph vessels, or skin, but has not reached distant organs. This stage carries a significant risk of recurrence, but modern treatments offer real hope for preventing the cancer from returning.

Table of contents

• What is Stage III Melanoma?
• Substages of Stage III Melanoma
• Understanding Lymph Nodes and the Lymphatic System
• How Stage III Melanoma is Diagnosed
• Treatment Options
• Risk of Cancer Returning or Spreading

What is Stage III Melanoma?

Stage III melanoma, also known as regional melanoma, has metastasized (spread) to nearby lymph nodes, lymph vessels, or skin^[1]. This means that cancer cells have traveled from the original melanoma tumor to nearby areas, but there is no evidence of distant spread^[2].

Stage III melanomas are tumors that have spread to regional lymph nodes or have developed in-transit deposits of disease, but there is no evidence of spread to distant organs^[2]. Cancer cells found between the melanoma and the nearby lymph nodes can appear in several forms: micro satellite metastases are tiny amounts of cancer cells found next to the melanoma that can only be seen through a microscope, satellite metastases are cancer cells found within 2cm of the melanoma, and in-transit metastases are cancer cells that have spread more than 2cm away from the melanoma but not as far as the nearest lymph node^[3].

Substages of Stage III Melanoma

Stage III melanoma is divided into four subgroups based on ulceration (broken skin) of the primary tumor and the extent of growth into the lymph nodes, lymph vessels, and nearby skin^[1].

Stage IIIA

Stage IIIA melanoma means the melanoma tumor is up to 1.0 millimeter thick (the size of a sharpened pencil point) with or without ulceration when looked at under a microscope, or more than 1.0 millimeter and less than 2.0 millimeters (the size of a new crayon point) without ulceration. The melanoma has spread to up to three nearby lymph nodes, detected by biopsy of the sentinel lymph node, but has not yet spread to distant sites^[1].

Stage IIIB

Stage IIIB melanoma involves a melanoma tumor that is up to 1.0 millimeter thick with or without ulceration, or more than 1.0 millimeter and less than 2.0 millimeters thick. The specific characteristics that place a melanoma in this substage depend on the number of affected lymph nodes and whether ulceration is present^[1].

Stage IIIC and IIID

Stage 3 melanoma can be further divided into stages C and D depending on whether there are micro satellite, satellite or in-transit metastases, and the number of lymph nodes containing cancer cells^[3].

Understanding Lymph Nodes and the Lymphatic System

Lymph nodes are an important part of the lymphatic system, which is a vast network of tissues and organs that helps rid the body of waste, toxins, and other unwanted materials. The lymphatic system also helps support the immune system by transporting infection-fighting white blood cells throughout the body^[1].

The lymphatic system is a network of thin tubes (vessels) and small pieces of tissue (nodes) that carry a fluid called lymph around the body. This system is an important part of the immune system and plays a role in fighting infection and destroying old or abnormal cells. Lymph nodes are bean shaped and filter the lymph fluid, trapping bacteria, viruses, and cancer cells^[3].

How Stage III Melanoma is Diagnosed

To diagnose melanoma, your doctor removes the abnormal area and a small area of surrounding skin. This is called an excision biopsy. A specialist doctor called a pathologist looks at the biopsy under a microscope. If there are melanoma cells, they will work out the stage of the cancer. You normally have some other tests and scans to help with this^[3].

Testing Lymph Nodes

Your doctor will usually recommend a test to see if there are cancer cells in the lymph nodes near the melanoma. You normally have a test called a sentinel lymph node biopsy (SLNB). Your doctor removes the first lymph node or nodes that the melanoma could have spread to. You have an SLNB at the same time as a wide local excision^[3].

If your doctor can feel that your lymph nodes near the melanoma are swollen (enlarged), you usually have an ultrasound scan instead of an SLNB. They may take a sample of tissue (biopsy) from the lymph node to check for cancer cells^[3].

Treatment Options

Surgery is the main treatment for stage 3 melanoma. Some people may have other treatments instead of an operation, including chemotherapy, targeted cancer drugs, or immunotherapy. Or they may have these treatments as well as surgery^[3].

The stage of the cancer helps your doctor decide what treatment you need. Treatment also depends on where the melanoma is located and your general health and level of fitness^[3].

Adjuvant Therapy

Patients with stage III resectable melanoma carry a high risk of melanoma recurrence that ranges from approximately 40% to 90% at 5 years following surgical management alone. Postoperative systemic adjuvant therapy targets residual micrometastatic disease that could be the source of future recurrence and death from melanoma^[10].

Adjuvant therapy is treatment given after surgery that may help prevent cancer from coming back or spreading to other parts of the body. Your doctor may recommend treatment after surgery for stage 3 melanoma to reduce the risk of the cancer returning^[9].

Risk of Cancer Returning or Spreading

Even if you’ve had surgery to remove melanoma and the lymph nodes that contained cancer, there is a chance melanoma can return or spread. When melanoma returns, it’s called recurrence. Your doctor may recommend treatment after surgery that may help prevent cancer from coming back or spreading to other parts of the body^[9].

Results from a study reviewing medical charts of patients with stage 3 melanoma who were recommended to “watch and wait” showed that 50% of people (125 out of 251) had their cancer return. Of those whose cancer returned, 53% (66 out of 125) had their cancer spread to other parts of their body. The same study also showed results of patients with stage 3 melanoma who had treatment after surgery: 33% of people (43 out of 129) had their cancer return, and 47% of those (20 out of 43) had their cancer spread to other parts of their body^[9].

Your care team may be made up of several health care providers and supporters. You may see different doctors at different times. A dermatologist is a doctor who specializes in the skin and may diagnose melanoma. They may also monitor you after surgery to check that cancer has not returned. A surgeon is a doctor who performs operations and may remove stage 3 melanoma. They may refer you to an oncologist after surgery. An oncologist is a doctor who specializes in cancer and cancer treatment. Along with your dermatologist and surgeon, an oncologist may help develop the right treatment plan for you, including whether treatment after surgery is necessary^[9].