Melanoma is a type of skin cancer that originates in the pigment-producing cells of the skin. In the early stages of the disease, cancerous cells are localized to the skin tissue; however, the cancer can spread to nearby and distant lymph nodes and organs, leading to stage IV, or metastatic melanoma. Doctors may use a variety of surgical, biologic, combined and experimental approaches in an attempt to destroy the spreading cancer cells and improve the patient's overall survival.
Surgery
According to the MD Anderson Cancer Center, some doctors may forgo surgical removal of primary and secondary skin cancer tumors because, at this late stage of the disease, there are likely to be other small, undetectable tumors throughout the body, rendering surgery ultimately ineffective. Nonetheless, the decision to remove isolated tumors is typically made on a case-by-case basis. According to the National Cancer Institute, some patients may choose to have a lymphadenectomy--a procedure in which a surgeon removes lymph nodes to which the cancer has spread. In some cases, removal of metastatic tumors in the intestines, lung, brain or bone may help to improve survival.
Immunotherapy
Immunotherapy, or biologic therapy, is a type of treatment that aims to stimulate the body's own immune system to kill cancer cells. According to the MD Anderson Cancer Center, interferon-alpha is the most common type of immunotherapy used to treat metastatic melanoma. Interleukin-2 may also be administered, according to MayoClinic.com. For approximately one month, patients receive high doses of the drug through a needle in a vein. Subsequently, they inject themselves under the skin for up to a year to complete treatment. Some patients may need a series of separate immunotherapy treatments targeting different areas of skin cancer. One advantage to immunotherapy is that the treatment is fairly specific, targeting cancerous cells and sparing most healthy tissue; however, it can cause a number of bothersome side effects, including skin redness and inflammation around the injection site, as well as flu-like symptoms such as headache, chills, fatigue and fever.
Chemotherapy and Radiation
Some patients with metastatic melanoma may benefit from system-wide chemotherapy to rid their body of cancerous cells. Chemotherapy drugs such as carmustine and dacarbazine may be administered intravenously or in oral pill form. According to MayoClinic.com, to keep the chemotherapy medication contained to the area surrounding the melanoma, doctors sometimes perform an isolated limb perfusion, a procedure in which the blood supply in an arm or leg is cut off while chemotherapy drugs are injected into a vein in that limb, in turn preventing the medication from traveling to other parts of the body.
Some patients may also undergo radiation therapy, a procedure that uses high-energy rays to target and kill skin cancer cells.
Combination Treatments
Researchers are continuing to study whether combined treatment with chemotherapy and immunotherapy is superior to treatment with either approach alone. As of 2010, results from these studies are mixed. The National Cancer Institute cites the results from a 2001 review of 20 clinical trials, where researchers determined that combination treatment with the chemotherapy drug dacarbazine--commonly referred to as DTIC--and interferon-alpha immunotherapy improved the rate of tumor shrinkage by 53 percent compared to singular treatment with either approach; however, in spite of this improvement, the overall survival rates for people receiving combination treatment were not significantly better than those receiving a single type of treatment. Other studies have also found that adding immunotherapy to chemotherapy can increase toxic effects of the treatment. More research is needed to determine whether any combinations of drugs can ultimately improve survival.
Experimental Treatment
According to the National Cancer Institute, metastatic melanoma is typically resistant to most standard cancer treatments; therefore, patients may enroll in a clinical trial to undergo experimental treatment. Currently, researchers are looking at whether complex combinations of chemotherapy and biologic therapy with both interferon-alpha and interleuken-2 improve survival among metastatic melanoma patients. Physicians are also studying the pain relief benefits of radiation to bone, spinal cord and brain metastases, as well as the efficacy of various skin cancer vaccines.
