Melanoma Skin Cancer: Staging and Treatment
What is staging for cancer?
Staging is the process of learning how much cancer is in your body and where it is. For melanoma skin cancer, tests like biopsy, blood tests and gene testing (especially BRAF mutation), and physical exam will be done to check for melanoma. Other tests, such as X-Ray, CT scan, MRI, PET scan, and ultrasound may be used to check for cancer spread (metastasis) and to help stage your cancer. Your providers need to know about your cancer and your health so that they can plan the best treatment for you.
Staging looks at the size of the tumor and where it is, and if it has spread to other organs. The staging system for melanoma is called the “TNM system,” as described by the American Joint Committee on Cancer:
- T-describes the extent of the primary tumor. For melanoma, the extent shows:
- How thick, or deep, the melanoma goes into the skin.
- If the melanoma is ulcerated, meaning having open or broken skin on top of the tumor.
- N-describes if the cancer has spread to the lymph nodes.
- M-describes if the cancer has spread to other organs (metastases).
Your healthcare provider will use the results of the tests you had to determine your TNM result and combine these to get a stage from 0 to IV.
How is melanoma staged?
Staging of melanoma skin cancer is based on:
- The size of your tumor.
- If the cancer has spread to the lymph nodes, and if it has, how many lymph nodes are affected.
- If the cancer has spread to other organs. This is called metastasis.
Staging may be done at different times during your treatment.
The staging system is very complex. Below is a summary. Talk to your provider about the stage of your cancer.
Stage IA (T1a, N0, M0): The tumor is less than 0.8 millimeters (mm) thick. There is no ulceration (T1a). No cancer found in regional lymph nodes (N0). No distant metastasis (M0).
Stage IB (T1b-T2a, N0, M0): The tumor is either less than 0.8mm thick with ulceration (T1B), or the tumor is 0.8mm to 1mm thick, with or without ulceration (T2A). No cancer found in regional lymph nodes (N0). No distant metastasis (M0).
Stage IIA (T2b-T3a, N0, M0): The tumor is either 1.0 to 2.0mm with ulceration (T2b), or the tumor is 2.0 to 4.0mm with or without ulceration (T3a). No cancer found in regional lymph nodes (N0). No distant metastasis (M0).
Stage IIB (T3b-T4a, N0, M0): The tumor is either 2.0-4.0mm with ulceration (T3b), or larger than 4.0mm with or without ulceration (T4A). No cancer found in regional lymph nodes (N0). No distant metastasis (M0).
Stage IIC (T4b, N0, M0): The tumor is larger than 4.0mm with ulceration (T4b). No cancer found in regional lymph nodes (N0). No distant metastasis (M0).
Stage III (Any T, N1-N3, M0): The tumor is any size (Any T). There may or may not be regional spread to lymph nodes (N1-N3). No distant metastasis (M0).
Stage IV (Any T, Any N, M1): The tumor is any size (Any T). There may or may not be regional spread to lymph nodes (Any N). It has spread to distant lymph nodes or to organs such as the lungs, liver, or brain (M1).
How is melanoma skin cancer treated?
Treatment for melanoma depends on many factors, like your cancer stage, age, overall health, and testing results. Your treatment may include:
Surgery
Surgery is the most common treatment for melanoma skin cancer. In early stages of melanoma, surgery is done to remove as much tumor as possible. A small, thin melanoma may be able to be removed during the biopsy to diagnose it. If there is still some cancer left after you’ve had a skin biopsy, surgical procedures you may need include:
- Wide excision: The tumor and part of the area around it are removed. "Margins" refer to the tissue around a tumor. Your provider will try to remove enough tissue so that the sample has "negative margins.” This means that a small amount of normal tissue around the tumor was also removed—this ensures that all of the melanoma is removed.
- Sentinel lymph node biopsy: A blue dye with a radioactive tracer is injected into the site of the known tumor. The dye spreads to the "sentinel node(s)" (the first few nodes to which the cancer would spread). These blue/radioactive lymph nodes are removed, looked at under a microscope, and tested for cancer.
- If any of these lymph nodes are positive, the rest of the lymph nodes in the area are removed using a procedure known as a lymph node dissection or lymphadenectomy.
- If the sentinel nodes do not have melanoma in them, a lymph node dissection is not needed.
- Mohs Micrographic Surgery: This procedure is used mainly for other types of skin cancer but may be used in some cases for melanoma. During this procedure, skin cancer is removed layer by layer. Each layer of tissue is looked at under a microscope until the margins are clear. Mohs can often be done in an outpatient office.
- Amputation: Very rarely, the melanoma grows deeply into a smaller area of your body, such as a finger or a toe. These may need to be removed with surgery.
Your provider will talk to you about what type of surgery you will need.
Immunotherapy
Immunotherapy is the use of medication to help your immune system fight cancer. Examples of immunotherapy medications used to treat melanoma are pembrolizumab and dostarlimab. Both of these medications are immune checkpoint inhibitor medications that block a protein called PD-1. By blocking PD-1, these medications help your immune system decrease tumor size or slow down cancer cell division. Other immune checkpoint inhibitors that may be used are atezolizumab (blocks PD-L1), ipilimumab (blocks CTLA-4), and relatlimab (blocks LAG-3).
Other immunotherapies that may be used to treat melanoma are interleukin-2 (IL-2), talimogene laherparepvec, and imiquimod cream.
Targeted Therapy
Targeted therapy are medications that target something specific to the cancer cells, stopping them from growing and dividing. About half of all melanoma skin cancers have a mutation (change) in the BRAF gene. Your tumor will be tested for this mutation. If found, BRAF inhibitor medications such as vemurafenib, dabrafenib, and encorafenib may be used.
The BRAF gene works with another protein called MEK. In tumors that have BRAF changes, targeting MEK may help slow or stop the cancer. MEK inhibitors are trametinib, cobimetinib, and binimetinib.
Other examples of targeted therapy sometimes used to treat melanoma are imatinib and nilotinib. These target changes to C-KIT gene.
Chemotherapy
Chemotherapy is used to kill or damage cancer cells. Examples of chemotherapy medications that may be used to treat melanoma are dacarbazine, temozolomide, paclitaxel, paclitaxel (protein-bound), cisplatin, and carboplatin. These medications go throughout your whole body to kill cancer cells.
Radiation Therapy
Radiation is the use of high-energy x-rays to kill cancer cells. Radiation is not used often to treat melanoma, but can be used:
- If surgery is not an option for some reason. Radiation can be used to treat very early-stage melanoma.
- After surgery to prevent the cancer from coming back (recurrence) or to treat cancer that has already come back.
- To help with symptoms of the cancer. This is called palliative radiation.
Clinical Trials
You may be offered a clinical trial as part of your treatment plan. To find out more about current clinical trials, visit the OncoLink Clinical Trials Matching Service.
Making Treatment Decisions
Your care team will make sure you are included in choosing your treatment plan. This can be overwhelming as you may be given a few options to choose from. It feels like an emergency, but you can take a few weeks to meet with different providers and think about your options and what is best for you. This is a personal decision. Friends and family can help you talk through the options and the pros and cons of each, but they cannot make the decision for you. You need to be comfortable with your decision – this will help you move on to the next steps. If you ever have any questions or concerns, be sure to call your team.
You can learn more about skin cancer at OncoLink.org.