Melanoma is an agressive type of 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?
Melanocytes are pigment cells that are usually found in the skin. They produce melanin, the pigment that gives skin its color. Clusters of melanocytes and surrounding skin sometimes form moles.
Moles are benign, or noncancerous, growths. Most people have between 10 to 40 moles on their skin. Moles may be brown, pink, or tan. Moles may be flat or raised and are usually round or oval.
Melanoma, on the other hand, is a cancerous growth. It occurs when pigment cells become malignant, divide without control, and invade the tissue around them. Melanoma is usually found on visible skin but can also occur inside the eye or around the anus.
This kind of skin cancer is very aggressive. Cancer cells from the tumor may enter either the blood stream or the lymphatic system, which has tissues and organs that make and store cells to fight infection. Cancer thus spreads to other parts of the body and forms new destructive tumors. This spread of the disease is called metastasis.
What are the causes and risks of the disease?
Melanoma is strongly related to sun exposure. The incidence of melanoma has increased in recent decades as people have spent more and more recreational time in the sun. A history of blistering sunburns in childhood may significantly raise the risk of melanoma.
Other risk factors that increase a person's risk for melanoma are:
- fair skin, freckles, blue eyes, and red hair
- giant congenital moles
- more than 100 ordinary moles
- a personal or family history of melanoma or dysplastic (abnormal) moles
- weakened immune systems, as from immunodeficiency disorders such as HIV
The incidence of melanoma has increased in all age groups in both men and women from 1973 to 2002. This trend has been most pronounced in older men, with over a four fold increase among those aged 55 through 64 years and over a five fold increase in men aged 65 years or older.
What can be done to prevent the disease?
- Avoid unnecessary sun exposure, especially between 10 A.M. and 3 P.M., when ultraviolet radiation (sunlight) is most intense. Remember that ultraviolet rays penetrate through a light cloud cover.
- Do not try to tan if your skin burns easily.
- Use a sunscreen with an SPF of 15 or higher. The SPF, or sun protection factor, indicates how much longer you can stay in the sun before getting burned.
- Apply sunscreens at least 10 to 15 minutes before sun exposure, as they take some time to begin working.
- Use sunscreens that protect against both ultraviolet-A (UVA) and ultraviolet-B (UVB) light.
- Reapply water-resistant sunscreens after swimming, if sweating heavily, as well as every 2 hours during periods of sun exposure.
- Use a lip balm with a sunscreen.
- Wear protective clothing, such as long sleeves and a hat with a wide brim. Keep in mind that up to 50% of ultraviolet rays can penetrate loosely woven clothing. Some clothing is SPF rated.
- Avoid the use of sun lamps or commercial tanning booths.
- Do a regular skin self-exam in a well-lighted room using a full-length mirror and a hand-held mirror. Check all areas of the skin, including the scalp, back, armpits, bottom of the feet, between the toes, between the buttocks, and the genital area.
- Teach children ways to protect their skin for life.
Early detection and treatment of melanoma is also critical. Melanoma can be cured if treated while the tumor is thin and superficial. Advanced, thick, deep tumors are more difficult to control and more often spread to other parts of the body. People at higher risk of melanoma may be advised to have checkups more frequently. The healthcare provider may take photos of a person's skin to help in detecting changes that occur over time.
How is the disease diagnosed?
If a melanoma is suspected, a biopsy will be done. The entire lesion will be removed along with extra tissue around it. If the growth is too large to remove entirely, a sample will be taken. The lesion must be carefully examined under a microscope to determine if it is a melanoma.
If melanoma is found, additional tests or surgery may be ordered to determine the extent, or stage, of the disease. These tests may include:
- a chest X-ray
- a complete blood count or CBC
- liver function tests, LDH
- specialized scans
Nearby lymph nodes may be removed for examination under a microscope. A procedure known as sentinel lymph node biopsy helps to reduce the number of lymph nodes that need to be removed for study. Dye is injected near the tumor area. The lymph node to which the dye flows first is called the sentinel node. The sentinel node or nodes are the areas to which the cancer was likely to spread first. If the sentinel node has no cancer, the remaining lymph nodes may be left in place.
Long Term Effects
What are the long-term effects of the disease?
Melanoma left untreated is fatal. The prognosis for people who receive treatment for melanoma is affected by many factors, including the person's general condition, response to treatment, and extent of disease. The person's healthcare provider is in the best position to explain what can be expected in each situation.
Concerns over psychological, emotional, and financial problems are common for those with cancer. Help is available from healthcare providers, social workers, and others for those in need.
What are the risks to others?
Melanoma is not contagious and poses no risk to others.
What are the treatments for the disease?
Complete surgical removal of the melanoma is the first step. The size and depth of the melanoma will indicate the next step. Extra tissue around the tumor is also taken to make sure no cancer is left. If a very large area of skin is removed, a skin graft may be done. Skin is taken from another part of the body to replace the removed skin. Fortunately, many patients with melanoma are diagnosed in early stages and surgery alone is likely to be curative.
Lymph nodes near the tumor will also be removed if it is suspected that the cancer has spread. Surgery is not effective in curing melanoma that has spread to other parts of the body. Other methods of treatment, such as chemotherapy, biological response modifiers, or radiation therapy might be used in these cases.
When these other methods are used after surgery has been done to remove all primary cancerous tissue, the treatment is called adjuvant therapy. Its purpose is to target cancer cells that may remain in the body even though they cannot be detected.
Biological response modifiers, or BRMs, use the body's immune system to fight cancer or decrease side effects caused by other cancer treatments. Interferon alpha 2b and interleukin-2 may be recommended after surgery for those with metastatic melanoma or a high risk of recurrent disease.
When the melanoma is located in an extremity, regional perfusion of chemotherapy might be used. The medicine is injected directly into the area that contains the melanoma using a perfusion pump for 1 hour. This technique helps to prevent systemic side effects.
Chemotherapy uses medicines to kill cancer cells. One or more anticancer drugs are given by mouth or by injection into the bloodstream. Medicines used might include dacarbazine (i.e., DTIC), temozolomide (i.e., Temodar), nitrosourea, and cisplatin (i.e., Platinol AQ). These medicines work systemically, or throughout the body.
Radiation therapy is used to help relieve symptoms caused by melanoma. It can be used to help control disease that has spread to the brain, bones, and other body parts. Melanoma that has returned cannot be cured. Therapy is designed to reduce the size of the tumor.
Other medical treatments are being investigated for treatment of advanced and widespread (metastatic) melanoma. These include monoclonal antibodies (specially formed antibodies designed to attack cancer cells), melanoma vaccines, gene therapies, cellular therapies (adoptive immunotherapy) as well as various targeted and anti-angiogenic agents.
What are the side effects of the treatments?
Surgery for melanoma may involve taking a large amount of skin, which will leave a scar. Interferon and other BRMs can cause fatigue and severe flu symptoms. Radiation can cause fatigue and hair loss in the treated area. Chemotherapy side effects are specific to the medicines given. It is helpful to know that side effects eventually go away after treatment stops. Also, the healthcare provider can provide measures to treat or control side effects.
What happens after treatment for the disease?
People who have had melanoma are closely followed to make sure the melanoma does not recur, either in its original location or somewhere else on the body. If the person has widespread disease, careful follow-up will be necessary to make sure that treatment is effective.
How is the disease monitored?
The frequency and type of monitoring will depend on the severity of the disease. In all cases, follow-up physical examinations are recommended at least annually and skin self-examinations at regular intervals are encouraged.
A person with advanced melanoma will need more frequent monitoring to assure the best possible supportive care. Frequent skin self-exams will be encouraged.
For those with a high risk of recurrence, tests ordered might include X-rays, blood tests, and scans of the chest, bones, brain, and liver. Any new or worsening symptoms should be reported to the healthcare provider.
Sondak, V.K.;&Margolin, K.A. (1996). Melanoma and other skin cancers in Cancer Management: A Multidisciplinary Approach. PRR: Huntington, NY. pp. 347-369.