Immunotherapy enhances and encourages a patient's immune system to recognize and destroy cancer cells more effectively. There are several types of immunotherapy used in treating patients with advanced melanoma.

Cytokine therapy: Cytokines are proteins that activate the immune system in a general way. Two cytokines, interferon-alpha and interleukin-2, can help boost immunity in patients with melanoma. Both drugs can help shrink metastatic (stage III and IV) melanomas in about 10% to 20% of patients.

Side effects of cytokine therapy may include fever, chills, aches, and severe tiredness. Interleukin-2, particularly in high doses, can cause fluid to accumulate in the body so that the person swells up and can feel quite sick. Some patients may need to be hospitalized because of this problem.

Interferon-alpha: Patients with deeper melanomas often have cancer cells that break away from the primary melanoma and travel to other parts of the body. Interferons are immune substances produced by the body in response to infection. Interferon-alpha2b can be used as an adjuvant therapy.

Studies have shown that in order for the interferon to be effective, high doses must be used; however, many patients cannot tolerate the side effects of high-dose interferon therapy. Side effects include fever, chills, aches, and severe tiredness. Interferon-alpha2b can also have effects on the heart and liver. Patients should be followed by an oncologist who is experienced with this treatment.

Interferon-alpha2b given to patients with stage III melanoma following surgery may delay the recurrence of melanoma. Decisions about adjuvant therapy by patients and their doctors should take into account the potential benefits and side effects of this treatment. Interferon may also be given as part of a biochemotherapy regimen for stage IV melanoma.

Vaccine therapy: Melanoma vaccines are experimental therapies that do not yet have proven benefit.

Antimelanoma vaccines are, in some ways, similar to the vaccines used to prevent diseases such as polio, measles, and mumps that are caused by viruses. Antivirus vaccines usually contain weakened viruses or parts of a virus that cannot cause the disease. The vaccine stimulates the body's immune system to destroy the more harmful type of virus. In the same way, or parts of melanoma cells (called antigens) can be injected into a patient in an attempt to stimulate the body's immune system to selectively destroy melanoma cells. Usually, the melanoma or antigens are mixed with substances that help stimulate the body's immune system. However, developing a vaccine against a tumor such as melanoma is more difficult than developing a vaccine to fight a virus. Clinical trials are in progress to test the value of treating stage III or stage iv melanoma patients with vaccines, sometimes combined with cytokine therapy as well. Scientists are particularly hopeful for stage III.