What you should know about melanoma
Like every other part of your body, your skin is a place where cancer can develop. Skin cancers are most readily cured when discovered early and treated promptly. Every year, about 450,000 Americans are diagnosed with skin cancer, making this the most common form of the disease. Fortunately, these are the easiest of all cancers to detect, and most can be treated successfully. Skin cancer is linked to repeated exposure to the sun, and can be largely prevented with simple precautions.
There are three main types of skin cancer. Most are either basal cell or squamous cell carcinomas, which seldom become life-threatening. Malignant melanoma is much less common. If not detected early, and treated promptly, it is very dangerous. Every year, about 22,000 people develop melanoma, and about 5,500 die from it. If current rates continue, one out of 100 Americans will develop this form of cancer.
When diagnosed early, melanoma is easily cured. But if it is not
found soon enough, it can be very difficult or almost impossible to
cure. It is therefore important to recognize any changes in your skin
which could indicate melanoma, and to report them to your clinician
What is melanoma?
This cancer begins in melanocytes C the skin cells that produce the dark protective pigment called melanin. When you're exposed to sunlight, the melanin in your skin increases to form a protective layer in the form of a suntan. Melanoma consists of melanocytes which have been transformed into cancer cells that grow uncontrollably. Melanoma cells usually still produce melanin, which is why these cancers tend to be mixed shades of tan, brown, and black.
Unlike basal-cell and squamous-cell carcinomas of the skin, melanoma has a strong tendency to spread to other parts of the body. Once colonies of melanoma cells reach vital internal organs and grow, they are much more difficult to treat. That is why this is potentially a lethal form of cancer.
While melanoma may suddenly appear in the skin without warning, it
may also begin in or near a mole or other dark spot in the skin. That
is why it's important to know the size and location of the moles on
your body, so you will recognize any changes that may take place.
What causes melanoma?
By far the most important known risk factor is excessive exposure to the sun. How much sun is excessive varies from person to person. Melanoma is less common among people with darker skin, who seldom become sunburned. But no one is immune to the damaging effects of the sun, and everyone should avoid unnecessary exposure.
Melanoma is also linked to moles. Sometimes these are atypical moles that run in families. These moles themselves may turn into melanomas or they may serve as markers which identify the individual at higher risk for melanoma developing elsewhere in the skin.
Some birthmarks, otherwise called congenital moles, may also carry
an increased risk of melanoma. Sometimes these moles should be removed
before malignant changes can take place.
Who is likely to get melanoma?
Often, patients who develop melanoma have fair skin that burns and freckles easily, light eyes, and either red or blond hair. People who have many moles, or certain types of atypical moles, and those with relatives who have had melanoma, are more likely to develop this skin cancer.
Aside from these factors, melanomas most often occur among people
who work or spend a great deal of recreational time in the sun C sunbathing,
gardening, sailing, fishing, hiking C especially if they have been
severely sunburned in their teens or twenties.
The risk is also higher in places where there is intense year-round
sunshine. In the United States, the highest incidence is in Arizona.
As with other cancers, the chances of developing melanoma increase
as a person gets older.
It was once believed that dark brown or black skin was a guarantee
against melanoma. We now know that people with darker skin can develop
this cancer, especially on the palms of the hands, the soles of the
feet, and under the nails. No one can be considered entirely free
from the risk of melanoma.
What is the difference between a melanoma and an ordinary mole?
A normal mole is an evenly-colored brown, tan, or black spot in the skin. It is either flat or raised, its shape is round or oval, and it has sharply defined borders. Moles are generally less than 6 millimeters in diameter (about the size of a pencil eraser). A mole may be present at birth, or it may appear spontaneously, usually in the first few decades of life. Sometimes several moles appear at about the same time, especially on sun-exposed areas of the skin. Once a mole has fully developed, it normally remains the same size, shape, and color for many years. Most moles eventually fade away in older persons.
Almost everyone has moles, an average of about 25. The vast majority
of moles are perfectly harmless. A sudden or continuous change in
a mole's appearance is a sign that you should see your physician.
ABCD rule of the signs of melanoma
- Asymmetry. One half does not match the other half.
- Border irregularity. The edges are ragged, notched, or blurred.
- Color. The pigmentation is not uniform. Shades of tan, brown, and black are present. Red, white, and blue may add to the mottled appearance.
- Diameter greater than 6 millimeters. Any sudden or continuing increase in size should be of special concern.
Other warning signs of melanoma
Change in the surface of a mole - scaliness, oozing, bleeding, or the appearance of a bump or nodule; spread of pigment from the border into surrounding skin; redness or a new swelling beyond the border; change in sensation (itchiness, tenderness, or pain).
How is melanoma diagnosed?
If your clinician suspects that a change in your skin is a sign of melanoma, a sample of the tissue must be examined microscopically to confirm the diagnosis. This procedure is called a biopsy, and usually can be done quickly, and easily in the clinician's office. The biopsy sample is sent to a pathology laboratory for study, and the results are ready in a few days.
Can melanoma be treated?
Yes! In the early stages, melanoma is completely curable. Surgery is the best way to remove early melanomas. Later stages may require more extensive treatment. For advanced melanoma, treatment must be individualized. Again, the best weapon against melanoma is early detection, and prompt removal.
Is there any way to prevent melanoma?
Yes! By keeping your exposure to the sun at a minimum, you can reduce your risks. This is especially true for light-complexioned people, and those with a tendency to develop many and/or atypical moles. Use a 15+ SPF-rated sunscreen, especially from 10am to 3pm. Remember to reapply the sunscreen after swimming or sweating. Also, don't use indoor sunlamps, tanning parlors, or tanning pills. Wear a hat with a brim, long pants and long sleeved shirts whenever possible.
Perform a monthly skin exam
Get familiar with your skin, and your own pattern of moles, freckles, and beauty marks. Be alert to changes in the number or size, shape, or color of pigmented areas. The best way to do this is to give yourself a skin exam. Call your clinician if you find any unusual changes. And make prevention, and early detection of melanoma part of your life.
- Advice Nurse: (510) 643-7197
- Appointments: (510) 642-2000
- Self Care Resource Center: (510) 642-7202
For Faculty and Staff:
- Please refer questions to your health plan or primary care provider.
- American Cancer Society - About Melanoma
- Melanoma Patients' Information Page
Disclaimer: The information provided here is not intended to diagnose, treat or provide a second opinion on any health problem or disease. It is meant to support, not replace, the relationship that exists between an individual and his/her clinician.
Last reviewed: August 2005