MelanomaWhat Is It?

MelanomaWhat Is It?
Symptoms
Diagnosis
Expected Duration
Prevention
Treatment
When To Call A Professional
Prognosis
Additional Info


What Is It?

Melanoma is cancer of the cells that give skin its color (pigment-forming cells). It develops when these cells change and reproduce aggressively. Melanoma, the deadliest form of skin cancer, is the seventh most common cancer in the United States and is increasing at faster rates than any other cancer. Based on cancer patterns between 2000 and 2002, the U.S. National Cancer Institute predicts that 1 in 50 men and 1 in 75 women in the United States will develop melanoma during his or her lifetime. In 1960, only 1 in 600 Americans was expected to develop this cancer.

Why melanoma rates are soaring isn't known. It could be from increased exposure to the sun during recreational activities or possibly from global changes, such as the depletion of the ozone, a gas in the atmosphere that absorbs many harmful solar rays. Your pattern of sun exposure appears to affect your risk of developing melanoma more than the total amount of sun exposure in your lifetime. Short bursts of intense sun appear most dangerous, especially if you get sunburned. Sun exposure can cause changes (mutations) in skin cells' genes, the code within each cell that instructs the cell if, how and when to duplicate itself. Recently, researchers identified a gene mutation that is shared by the majority of melanoma tumor cells. It is probably this gene mutation that starts the cancer.

There are four types of melanoma:

Superficial spreading melanoma — This is the most common type, and it can cause tumors on any part of the body. This cancer spreads on the surface of the skin before it invades deeper tissues.


Nodular melanomas — This type of melanoma invades the deeper tissues, making it one of the more dangerous forms of melanoma.


Acral lentiginous melanoma — This type of melanoma is found most commonly in dark-skinned people, usually on the palms, soles and nail beds. This is the most serious form of melanoma.


Lentigo maligna melanoma — This is the slowest-growing form of melanoma. It usually occurs in elderly people on sun-damaged skin (usually the head or neck). A precancerous skin spot called lentigo maligna sometimes develops before the cancer.
Melanoma affects all age groups. Caucasians are 12 times more likely to get melanoma than are African-Americans.

Your risk of developing melanoma is higher if you have:

Red or blond hair, or green or blue eyes
Fair skin
Excessive sun exposure, especially in childhood
A first-degree relative (mother, father, sister or brother) with melanoma — If you have a first-degree relative with melanoma, you are eight times more likely to develop melanoma.
Features of freckles or moles that raise your risk of melanoma include:

New mole appearing after age 30
New mole at any age if it is in an area that is rarely exposed to the sun
Change in existing mole
One or more dysplastic nevi, also called atypical moles — This is a type of mole that looks like a melanoma. A dysplastic nevus frequently includes making it look like a fried egg.
At least 20 moles greater than 2 millimeters in diameter
At least 5 moles greater than 5 millimeters in diameter (larger than a pencil eraser)
Freckles caused by exposure to the sun
Symptoms

Melanoma is usually visible as a single dark skin spot. It may appear on any skin surface, but most commonly develops on the back, chest and legs. About two-thirds of the time, melanoma develops on normal-looking skin, and one-third of the time, it grows out of an existing mole.

Watch for the A, B, C, D and Es of melanoma:

Asymmetry
Border irregularities
Colors or shades of skin that are different within the same mole
Diameter greater than 6 millimeters (larger than a pencil eraser)
Enlargement
Also look for bleeding, crusting or numbness in this skin area.

Diagnosis

If your doctor thinks a mole may be melanoma, he or she will either do a biopsy of the skin or refer you to a specialist who does this procedure. In a biopsy, a piece of tissue is removed and examined in a laboratory. A doctor or surgeon usually will remove the entire suspicious area of skin and some surrounding skin as well. A biopsy can estimate how deeply the cancer has invaded, which is the most important factor in predicting the outcome of the disease. Before the biopsy, it is important for your doctor to feel along your skin in areas where lymph nodes normally are to see if any lymph nodes are enlarged. If your biopsy is diagnosed as a melanoma, enlarged lymph nodes are evidence that the cancer has spread. After a skin biopsy, it is possible for nearby lymph nodes to swell because the skin incision is healing.

Determining how far the cancer has spread is the next step. First, the thickness of the tumor is measured. If the melanoma is less than 1 millimeter thick, further testing is not necessary. Patients with deeper cancers may require a complete physical examination to see if the tumor has spread. Your doctor may order chest X-rays and computed tomography scans to see if your tumor has spread. You may also need blood tests.

If the cancer is advanced, the biopsy sample of your melanoma may be tested to see if it has one of several gene mutations that are common in melanoma. There are newer treatments for melanoma that have been designed to treat specific genetic subtypes of this cancer.

Expected Duration

Melanoma can be cured if it is found and treated early when the tumor is small and has not penetrated deeply into the skin. More advanced melanoma requires prolonged treatment and can be fatal. If you have been diagnosed with one melanoma, you are at risk of developing another, so you should have your skin examined regularly by a health care professional. About 1 out of 20 people who have a melanoma will develop a second melanoma within 20 years.

Prevention

To prevent melanoma, avoid sun exposure. Severe sunburn is a major risk factor. Childhood sun exposure may present the greatest risk. To be safe in the sun, take the following steps:

Apply generous amounts of sunscreen with a sun protection factor (SPF) of at least 15.
Wear protective sunglasses, clothing (long sleeves and long pants) and broad-brimmed hats.
Avoid the peak hours of sun intensity (10 a.m. to 4 p.m.).
Ask your doctor if your medications increase your sensitivity to the sun, because many medications make your skin more vulnerable to sun damage.
Avoid tanning salons. If you want to appear tan, use commercial sunless tanning creams. Many varieties are available in department and drug stores.
Melanoma is easier than other cancers to find early since it can be seen on your skin. If you are at risk of developing melanoma, ask your doctor to examine your skin. Also ask your doctor how often you should have your skin checked. Your doctor will be especially concerned about watching for skin changes if you have many dyplastic nevi (atypical moles). These moles don't have to be removed because they usually are harmless, but they have a higher chance of changing to cancer. Your doctor may take photographs to record the appearance of your moles. The doctor then can compare the photos to any future changes in the appearance of the moles.

Examine your own skin regularly, especially if you have risk factors for melanoma. Use a full-length mirror and a hand-held mirror. Have someone examine your scalp using a blow dryer to part your hair. Someone else also can examine your back and other areas that are hard to examine yourself. Watch for new moles and changes in existing moles. Keep an eye on moles that you've had since birth, because these moles are more likely to turn into melanoma.

Treatment

To treat melanoma a physician must remove the visible tumor along with some normal-looking skin that surrounds the tumor, because this skin can contain microscopic bits of the cancer. The surgeon will try to remove 1 centimeter to 2.5 centimeters of healthy skin around the tumor, depending on the size of the visible melanoma. In some cases, a specialized procedure known as Moh's micrographic surgery may be used to remove the tumor and surrounding area of healthy skin. In this surgery, the tumor is shaved away one thin layer at a time, and each layer is examined under the microscope as it is removed. This technique helps the surgeon to remove the least amount of surrounding skin possible.

If the melanoma is thicker than 1 millimeter, your doctor may want to examine nearby lymph nodes to see if the tumor has spread. One procedure that is commonly used to examine lymph nodes is called sentinel node dissection. Radioactive liquid is injected into the tumor and allowed to flow through the natural drainage pathway that connects the tumor to nearby lymph nodes. The drainage path can be tracked, and the first lymph node in the drainage path is named the sentinel node. The node is removed and examined for cancer cells. When the sentinel node has no cancer, the other nodes are almost always also cancer-free. If cancer is found in a lymph node, your doctor may recommend additional treatment.

If cancer cells have spread to one or more lymph nodes, some experts recommend that all lymph nodes in the area be removed in a procedure called an elective lymph node dissection. This procedure is controversial. Although spreading cancer cells might be removed, immune cells that are fighting the cancer also are removed. It has not been proven that this procedure makes melanoma patients more likely to survive the disease.

Additional therapies can help people with tumors that have invaded the skin deeply, people with cancer cells in the lymph nodes and people with cancer that has spread to distant organs (called metastatic disease). Treatment include chemotherapy, radiation therapy and medicines that boost your immune system's ability to fight the cancer. The most effective medicine that can stimulate your immune system to fight melanoma is interleukin-2, which is given intravenously (into a vein). This drug must be given in high doses, and people who get this treatment need to be in good health for the treatment to be safe.

Other medicines that stimulate the immune system and can treat melanoma are the drug alpha-interferon and various brands of an injected therapy known as the melanoma vaccine. It is not a vaccine that can be used for prevention. The melanoma vaccine is administered after melanoma is diagnosed. It is considered to be a vaccine because it boosts the immune system. The vaccine can help your immune system to build a strong immune reaction against melanoma cells, which may help your body to attack the cancer. Varieties of this vaccine remain in the final stages of testing.

Genetic changes that are seen in melanoma cells can make these cancer cells more resistant to chemotherapy than other cancers. Several drugs are in development that may help melanoma respond better to chemotherapy medicines.

When To Call A Professional

Early treatment of melanoma is crucial. If you detect any of the ABCDE signs or see any suspicious changes in your skin, contact your doctor right away. If you delay, melanoma can spread. If you have a family history of the disease or other risk factors, be especially alert. Have your doctor examine your skin regularly.

Prognosis

Five key factors help to determine how serious melanoma is:

Tumor thickness (depth into the skin).
Location — Melanoma on the arms or legs is not as serious as melanoma somewhere else on the body.
Age — People older than 60 are in more danger.
Gender — Males are more likely to die of the disease.
Spread of the tumor beyond the skin — Twenty percent of people with melanoma have cancer in lymph nodes at the time of their diagnosis.
The thickness of the tumor is the most important factor in predicting whether the illness is treatable. Superficial tumors usually can be cured, but deeper cancers are more difficult, sometimes impossible, to treat. If melanoma cells break away from the tumor and spread through the lymphatic system to organs such as the lungs, liver or brain, the cancer can be cured in only a small percentage of patients.

High-dose interleukin 2 treatment is the first treatment that has been shown to provide a long-term remission or cure of melanoma for some patients. Approximately 10% of people who receive this treatment have a long-term response, but it is possible for the disease to return (relapse) in some of these people.

If treatment begins in the very earliest stages (when the tumor is less than 0.75 millimeters deep), then the chance of cure is excellent. More than 95% of people with small melanomas are cancer-free when they are examined as long as 8 years later. However, for deeper melanomas, the survival rate is poor. Fewer than 50% of people with tumors thicker than 4 millimeters are able to survive for 5 years beyond their diagnosis. If melanoma cells are found within a lymph node, the 5-year survival is between 30% and 50%.