Definition Melanoma is a type of skin cancer. It is an aggressive skin cancer that can spread to other parts of the body. The incidence of melanoma has been increasing over the last several decades.
What is going on in the body? It is normal to have moles or other benign growths on the skin. No one knows why these moles, called naevi, occur. Damage to skin cells can cause the cells to grow uncontrollably and become cancer cells. Melanoma arises from cells in the superficial layers of the skin that have pigment. Sometimes the tumours look very much like moles. However, the tumours often look black or have many colours. The borders may not be smooth like normal moles because the tumour is invading the tissue around it. Melanoma most often occurs on the visible skin but can occur inside the eye or around the anus. This kind of skin cancer is very aggressive. Cancer cells from the tumour may enter the blood stream even when the tumour is very small and spread to other parts of the body. New tumours then and destroy the affected tissue.
Very rarely ,some people may inherit a predisposition to develop melanoma. Most people who develop melanoma are less than 70 years old. It is most common in fair-skinned people but can occur in anyone.
What are the signs and symptoms of the disease? The most common symptom is a mole that undergoes a change in colour or shape, becoming darker and larger. Any growth on the skin that changes colour, grows unusually, or undergoes any change should be reported to a physician.
become lighter or darker
become variable in colour
increase in size
have irregular borders
become ulcerated and bleed
What are the causes and risks of the disease? Melanoma is strongly related to sun exposure. The risk for melanoma increases with the amount of unprotected sun exposure, especially as children. As people increasingly spend prolonged recreational time in the sun, the incidence has increased. Blistering sunburns as children may significantly increase the risk of melanoma. Very fair-skinned, light-haired people are most at risk. Others at risk are those with a family history of multiple dysplastic naevi.
What can be done to prevent the disease? Avoiding sun exposure, especially in children is critically important. Each person should also report skin changes promptly to a physician. As with any cancer, early detection of a melanoma will make it easier to successfully treat.
How is the disease diagnosed? If a melanoma is suspected, the entire lesion must be removed with extra tissue around it. The lesion must be carefully examined under a microscope to determine if it is a melanoma. The acronym ABCD is an easy way to remember how to distinguish if a suspicious skin lesion needs the attention of a doctor. ABCD stands for:
A= asymmetry: typically irregular
B= borders: uneven, ragged or irregular
C= colour: varying shades of black and brown
D= diameter: larger than a pencil eraser (6mm)
What are the long-term effects of the disease? Untreated melanoma is fatal.
What are the risks to others? There are no risks to others. Melanoma is not spread from one to another.
What are the treatments for the disease? Complete removal of the melanoma is the first step. The size and depth of the melanoma will indicate the next step. Extra tissue around the tumour is also taken to make sure no cancer is left. Lymph nodes near the tumour will also be removed if it is suspected that the cancer may have spread. If the melanoma occurs somewhere other than the skin, the entire affected area may need to be removed. Treatment after surgery that is designed to decrease the recurrence is known as adjuvant treatment. The most common adjuvant treatment is interferon, a medication that helps the body's immune system prevent the cancer from returning. Melanoma that has returned cannot be cured. Therapy is designed to reduce the size of the tumour. Chemotherapy and other medications similar to interferon are used. Radiation therapy may be used when the melanoma has spread to the brain.
What are the side effects of the treatments? Surgery for melanoma may involve taking a large amount of skin, which will leave a scar. Sometimes skin grafts must be used to cover the area. Interferon and similar medications can cause fatigue and severe flu-symptoms. Chemotherapy side effects are specific to the medications given. Most of the side effects can be managed but they can be severe.
What happens after treatment for the disease? People who have had melanoma must be closely followed to make sure the melanoma does not return. The person should also be monitored to make sure no new melanomas occur. If the person has widespread disease, careful follow-up will be necessary to make sure that treatment is effective.
How is the disease monitored? Examination of the skin following surgery will monitor for new melanomas. Routine CT scans are not necessary unless disease spread is suspected. The frequency of monitoring will depend on the severity of the disease. A person with advanced melanoma will need more frequent monitoring to assure the best possible supportive care.
Author: Miriam P. Rogers, EdD, RN, AOCN, CNS Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request
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