Treatments for Localized Melanoma (Stages I, II and III)
Primary skin melanoma can be successfully treated in almost all cases if it is diagnosed and treated when the tumor is relatively thin. Surgery to remove the melanoma lesion is the standard treatment. Most melanomas are found when they are thin (less than 1.0mm), when outpatient surgery is often all the treatment required.
A doctor will remove the melanoma lesion and some healthy tissue around it to make sure no cancer cells remain; the amount of normal tissue that should be removed depends on the thickness of the melanoma. If the melanoma has grown deep into the skin, lymph nodes near the tumor may be removed and examined for cancer cells, frequently following the sentinel lymph node biopsy technique.
Typically, the complete excision (surgical removal) of the melanoma requires the removal of 1.0 centimeters (3/8 of an inch) to 2.0 centimeters (3/4 of an inch) of normal-appearing skin surrounding the melanoma in all directions, called the margin. In addition, the underlying fat tissue is removed. The specific size of the margin taken depends on the size, stage, and potential aggressiveness of the melanoma. If it is staged as melanoma in situ (stage 0), a margin of between 0.5 centimeters to 1.0 centimeters may be recommended. In general, a thin melanoma (measuring 1.0 millimeters or smaller in thickness) can be safely removed with a 1.0 centimeters margin of skin, while a thicker melanoma requires a 2.0 centimeters margin of skin.
Depending on the site of the surgery, a skin graft (using the skin from another part of the body to both close the wound and reduce scarring) may be necessary. Since surgery for primary melanoma is usually limited to the removal of the skin and subcutaneous tissues, rehabilitation is rarely necessary for this procedure.
To determine if the melanoma has spread to regional lymph nodes, the doctor may perform a procedure known as lymphatic mapping and sentinel lymph node biopsy. In this surgical procedure, the doctor removes one or a few sentinel lymph nodes to check for cancer cells. A sentinel lymph node is the first node into which the lymph system drains from the primary melanoma site. If cancer cells are detected in the sentinel lymph node, it means that the disease has spread to the regional lymph node basin. Other lymph nodes in the region are also at risk for spread.
When melanoma has spread to the lymph nodes, surgical removal of the remaining lymph nodes in that region is usually recommended. This is called lymph node dissection. The number of lymph nodes removed varies depending on the area of the body while the likelihood of finding additional affected lymph nodes that contain metastatic melanoma is due in part on the stage of the melanoma. People who have had a lymph node dissection around an arm or leg are at higher risk for fluid build-up in that limb, a side effect called lymphedema.
If the melanoma has spread to distant organs or recurs (comes back after treatment), surgery may be a treatment option to help control the disease.
After surgery, the surgeon or medical oncologist may also recommend adjuvant treatment (treatment given after the primary treatment) based on what information was learned about the disease during surgery. This may include immunotherapy and/or radiation therapy.
Immunotherapy (also called biologic therapy) works by helping the body’s immune system find and attack cancer cells. It uses materials either made by the body or in a laboratory to boost, target or restore immune function. Immunotherapy is aimed at reducing the risk that the melanoma will recur. Immunotherapy may be used in combination with surgery or as part of a clinical trial.
Radiation therapy is the use of high-energy x-rays or other particles to kill cancer cells. The most common type of radiation treatment is called external-beam radiation therapy, which is radiation given from a machine outside the body.
Radiation therapy for melanoma can be used in several ways. Radiation therapy is most commonly used to relieve symptoms caused by melanoma that has spread, especially to the brain and bones. It may also be used when cancer has spread to the lymph nodes, following a lymph node dissection.
Radiation therapy is also used when the extent of surgery for a larger melanoma is limited by the location of the tumor.
Radiation therapy can cause skin irritation, nausea and fatigue. A patient may experience hair loss if radiation therapy is used on the scalp. If radiation therapy is used around the head and neck, side effects, such as altered taste and dry mouth, may occur. These side effects usually go away once treatment is finished. If lymph nodes near an arm or leg were affected, the person may be at higher risk of fluid build-up in that limb, a side effect called lymphedema. Lymphedema can be a long-term, ongoing side effect.
Treatments for Metastatic Melanoma (Stage IV)
Metastatic melanoma is when cancer cells have traveled beyond the primary site and the regional lymph nodes. There can be metastasis in the distant skin and lymph nodes (called M1a), to the lung (called M1b) or to distant organs like the liver, spleen, bone or brain (called M1c).
Currently, there are only two treatments approved by the US Food and Drug Administration (FDA) for the treatment of metastatic melanoma:
- DTIC or Dacarbazine: A chemotherapy drug administered through the vein every three to four weeks without requiring hospitalization.
- High dose IL-2: An immune stimulating therapy that requires hospital admission for fiive to six days.
Multiple new avenues to treat melanoma have been tested over the past 30 years. Many have not been shown to be superior to standard therapies, like the biochemotherapy approaches (merging chemotherapy with immunotherapy agents) or tumor vaccines.
Several approaches are currently in clinical testing:
- Novel chemotherapy agents: Some of the chemotherapies being tested include temozolomide (an oral form of DTIC), combination of carboplatin-paclitaxel and nab-paclitaxel.
- Novel immunotherapies: These include different means to stimulate the immune system, like dendritic cell vaccines, CTLA4 blocking antibodies (ipilimumab, tremelimumab), and adoptive cell transfer therapy.
- Targeted therapies: These are agents that are designed to specifically block cancer genes in melanoma, like BRAF, Mek and c-kit inhibitors.
Chemotherapy is the use of drugs to kill cancer cells. Systemic chemotherapy is delivered through the bloodstream, targeting cancer cells throughout the body. For melanoma, this is typically used when there is a high risk that the melanoma may spread or to control advanced disease, although cure of widespread melanoma is rare.