Melanoma is a type of cancer originating from the cells that give color to the skin. These cells are called melanocytes. Some melanomas arise in normal skin and others arise in pigmented skin (moles). Melanoma is a relatively common type of cancer.
If melanoma is not detected early, it can be fatal. Most patients can be cured with minor surgery if melanoma is found early. The four major types of melanoma are lentigo melanoma, superficial spreading melanoma, acral lentiginous melanoma and nodular melanoma.
Types of Melanoma
Lentigo maligna melanoma: occurs most often in older people with skin that has been damaged by the sun, in areas such as the face or hands. It may resemble a light brown or black freckle with a central nodule.
Superficial spreading melanoma: extends across the skin horizontally before invading the body. One may notice an irregular patch of skin in shades of black, gray, red, tan, blue or white.
Acral-lentiginous melanoma: is the least common form of melanoma. It appears as a black discoloration on palms, fingers, soles and toes (including the skin under the nails). African-Americans and Asians are more likely to develop this form of melanoma.
Nodular melanoma: are dome-shaped bumps that can appear anywhere on the body. They can be black, dark brown, red or blue, and can have a shiny or scaly texture. These growths quickly penetrate the body and have the lowest cure rates. Ten to 15 percent of all melanomas are nodular.
The ABCD Rule for Differentiating Between Melanoma and Moles
The difference between an ordinary mole and a life-threatening melanoma can be remembered with the "ABCD" rule:
- Asymmetry - most moles are symmetrical. If you drew a line through the middle, the two halves would mirror each other. Melanomas are asymmetric: their two halves are not mirror images.
- Border - most moles have a distinct border. The border of a melanoma is likely to be notched, scalloped or indistinct.
- Color - moles may be either dark or light, but they tend to be the same color. Early melanomas are more likely uneven in color or a mixture of different hues.
- Diameter - once a melanoma has acquired its A, B, and C characteristics, it is also likely to be more than six millimeters wide (the size of a pencil eraser).
The following factors affect the risk for melanoma:
- Moles - 20 percent of all malignant melanomas begin as moles, but early-stage tumors may also look identical to harmless growths.
- Sun exposure - a history of painful and blistering sunburns (especially in childhood) increases your risk. Cumulative damage from years of exposure is a hazard. Sun exposure is a major risk that can be controlled.
- Ethnic origin - Caucasians are 10 times more likely than African-Americans to develop melanoma. The risk to Caucasians increased by 50 percent between 1950 and 1980. People with the fairest skin are at the highest risk.
- Heredity - 1 in 20 cases of melanoma may be the result of genetic factors. You are at a higher risk if your grandparent, parent, aunt, uncle, sibling or child develops melanoma.
Most people have between 10 and 30 moles on their body, and the vast majority of these moles are perfectly harmless. However, a change in a mole is a sign that you should see your doctor. Thinking of "ABCD" can be very helpful.
Other signs of melanoma may include a scaling, oozing or bleeding mole, or a change in the way a mole feels. It may become hard, lumpy, itchy, swollen or tender. Melanoma may appear as a new mole on the body.
In men, melanoma most often occurs on the trunk. In women, melanoma is most often found on the arms and lower legs. It is found most often in people with fair skin. African-Americans and people with dark skin are more likely to have melanoma on the palms of the hands and the soles of the feet.
In some families, individuals have unusual moles (called dysplastic nevi) which may turn into melanoma more frequently than normal moles. These people are at increased risk of developing melanoma and should have regular checkups to detect problems early.
Because melanoma can spread, it is important to find out as soon as possible whether a suspicious-looking area is cancer. The sooner melanoma is found, the sooner treatment can begin. A biopsy is the only way to make a definite diagnosis. If melanoma is found, the doctor determines the extent (or stage) of the disease. The stage is based on the thickness of the tumor, the depth of skin penetration, and whether or not the cancer has spread (metastasized).
Treatment of melanoma that has not spread beyond the original area of growth (especially if it is thin and has not invaded the primary dermis) is highly effective, and most of these cancers can be cured. In some cases, melanoma that has spread to nearby lymph nodes also can be treated effectively. At present, however, therapy for melanoma that has spread to distant parts of the body is usually unsatisfactory, and many scientists are conducting basic research and clinical trials to find better forms of treatment.
A number of factors affect the choice of treatment for a person with melanoma. These include the location of the primary tumor, the stage of the cancer, the person's age and general health. In developing a treatment plan to meet an individual's needs, doctors may recommend one or a combination of several treatment methods, including surgery, chemotherapy, biological therapy and radiation therapy.
Surgery: About 95 percent of all patients with melanoma are treated with surgery. When the tumor is thin and has not spread beyond the initial area of growth (stage I), it is usually curable with surgery.
Chemotherapy: some melanoma patients treated with surgery face a high risk of disease recurrence. To improve the outlook for these patients, researchers are evaluating the use of adjuvant chemotherapy to kill undetectable cancer cells that remain in the body after surgery.
Biological therapy: also known as biotherapy or immunotherapy, is another method. It is based on modern molecular biology, immunology and genetics. Biological therapy works either directly against the cancer or indirectly to change the way the patient's body reacts to a tumor. It may enhance the ability of a cancer patient's immune system to fight the growth of cancer cells, eliminate or suppress body responses that permit cancer growth, or make a cancer cell more sensitive to destruction from the patient's immune system.
Radiation therapy: rarely used to treat melanoma, however, it is sometimes used as an adjunct to other forms of therapy.
Melanomas that have not spread beyond the site at which they developed are highly curable. Melanoma that has spread to distant sites is infrequently curable with standard therapy, although long-term survival is occasionally achieved by resection of metastasis. Such patients are appropriately considered candidates for clinical trials which explore new forms of chemotherapy (phase I and phase II trials) or for biological response modifiers (BRM), such as specific monoclonal antibodies.
Melanoma which has spread to distant lymph node-bearing areas may be palliated by regional lymphadenectomy. Isolated metastases to the lung, GI tract, bone and occasionally the brain, may be palliated by resection with occasional long survival. Radiation therapy may provide symptomatic relief for metastases to the brain, bones and viscera.
Deciding on further treatment depends on many factors, including prior treatment and site of recurrence, as well as individual patient considerations. Surgery is the most efficacious therapy for localized recurrence in sites where it can be accomplished (including lymph node, skin, brain, lung, liver and gastrointestinal sites). Because prior treatment with chemotherapy does not appear to substantially decrease the response rate to interferon, alpha interferon is sometimes used to treat those who have failed previous treatment with chemotherapy.
What means or tests are used to determine if the cancer has spread beyond the initial area?
Has the melanoma spread?
What method of treatment do you recommend? What is the procedure of the treatment?
Is surgery required?
What is the prognosis?
What are the chances of reoccurrence?
What can be done to prevent reoccurrence?