Melanoma
Adjuvant (Additional) Treatment
For patients with Stages III and IV disease, surgery may be followed with adjuvant therapy. Ask your physician to explain the possibilities and grounds for selection of one treatment over the other.
Chemotherapy
A number of drugs that are active in fighting cancer cells are being used to treat melanoma, either one at a time or incombinations. Currently, Dacarbazine (DTIC), given by injection, is the only chemotherapy approved by the FDA. DTIC may be combined with carmustin (BCNU) and tamoxifen, or with cisplatin and vinblastine. Another drug, temozolomide, can be given orally. Unfortunately, to date, the response of melanomas to chemotherapy has been limited, but a great deal of research into new drugs and new approaches is being carried out.
Another class of drugs, based on a different principle, has come into use more recently. They are anti-angiogenic, which means that they prevent new blood vessels from forming. The reason this is important is that they cut off the blood supply that would otherwise nourish the cancer cells and enable them to grow. These drugs are still experimental and a good deal of research into improving and combining them with others is going on. Studies are underway with the anti-angiogenic drug, thalidomide, combined with the chemotherapeutic agent, temozolomide. Angiostatin and endostatin are two other drugs in this class that have shown some degree of activity against melanoma in preliminary studies.
The isolation-perfusion method is sometimes used as a palliative (pain-relieving) treatment when the melanoma is on an arm or leg. “Isolation” means that the chemotherapy is “perfused” (added to) the blood flowing through the affected limb, and no other part of the body.
Immunotherapy/Biochemotherapy
This is one of the most exciting and changing fields in medicine, based on drugs that act on the body’s immune system. A number of newly-developed treatments are now being tested with some success. Among the immunotherapies, several types of experimental melanoma vaccines are now viewed as promising. Unlike the influenza vaccine, given when you are well to prevent disease, these are given to people who already have melanoma. Clinical trials of various types of vaccine are underway with patients whose disease is in Stages III and IV. The vaccines are intended to stimulate the immune system so that it reacts more strongly against a patient’s melanoma cells, destroying the cancer or slowing the progression. These vaccines are not a part of routine treatment at this time, so patients with advanced melanomas may wish to discuss this possibility with their physicians.
Another type of immunotherapy (also known as biologic therapy) makes use of chemicals that occur naturally in the body. The one you are most likely to hear about is interferon-alpha. This is the only systemic drug with FDA approval, and it has been shown to improve five-year survival of Stage III patients. Tumor necrosis factor (tumor-killing) factor is another of these naturally occurring substances. Both of these — especially interferon-alpha — are produced by white cells (lymphocytes) when they come in contact with tumor cells, viruses or other harmful substances, and have been shown to kill a number of tumors, including melanomas. They have some anti-angiogenic properties as well. However, both drugs have significant side effects which can limit their use.
Lymphokines, which are chemicals occurring naturally in small quantities in the body, are being used for Stage IV patients. They may also be produced by white blood cells (lymphocytes) which have been specially stimulated by antigens, a basic part of the immune system, to make them better “killers” of malignant cells. The best known of these therapies uses the lymphokine, interleukin-2, with or without the addition of interferon alpha, which enters and attacks melanoma cells. However, interleukin-2 is associated with very significant side effects when given in high doses. This form of immunotherapy is still in the experimental stage.
Gene therapy
A gene is the basic unit of genetic material. It is the code or “blueprint” by which our body’s proteins are made. Alterations in these codes can result in uncontrolled cell growth as in cancer.
On the other hand, selected genes can be altered so as to correct genetic defects or enhance the cancer-fighting potential of cells. There is hope that making changes in genes will lead to successes in treating a wide range of illnesses, so this kind of therapy frequently gets newspaper headlines. However, keep in mind that this treatment is in the very early stages of research, and its effectiveness is yet to be proven.
One form of gene therapy is based on creating alterations in the white blood cells or in the tumor-infiltrating lymphocytes so that they will attack the melanoma. This is achieved by removing these cells from the patient, growing them outside the body and treating them so as to increase their number. The next step is the addition of genetic material that produces one of the many growth factors which make the lymphocytes more aggressive as cancer-fighters. These more aggressive lymphocytes are returned to the patient’s body in an effort to stimulate the immune system to kill the melanoma and its metastases.
The focus of current research is the identification of genes for specific melanoma antigens. These are molecules found on the cell wall that stimulate the production of antibodies, which are a part of the body’s immune defense system. An antibody attaches itself to only one type of antigen. By injecting the gene for the melanoma antigens, the hope is to increase their number and produce a broad attack by the patient’s immune system.
Clinical Trials
Many patients, especially those with advanced disease, are participating in clinical trials in order to get new treatments while they are still experimental and not generally available.
Patients who have Stage III and IV melanoma might consider enrolling in a clinical trial, a new or experimental treatment. There are risks involved in enrolling in a clinical trial, but there can be benefits, as well.
Read more about clinical trials here.
