Skin Cancer — What You Should Know About Melanoma
Nearly one million Americans are diagnosed each year with skin cancer, the most common form of cancer. Of these, more than 40,000 people will be diagnosed with melanoma, the most serious form of skin cancer. With careful inspection of the skin, most melanomas can be detected early and treated successfully.
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 can be very dangerous. This year, about 40,300 people will be diagnosed with melanoma and about 7,300 will die from it. Since 1973, the incidence rate of melanoma has increased about 4% per year.
When diagnosed early, melanoma can be cured. But if it is not found soon enough, it can be very difficult to treat. It’s therefore important to recognize any changes in your skin which could indicate melanoma, and to report them to your physician without delay.
What is Melanoma?
Melanoma is a cancer that beings in melanocytes – the skin cells that produce the dark protective pigment called melanin. When you’re exposed to sunlight, the melanin in your skin increases and your skin darkens. 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 which rarely spread to other parts of the body, melanoma can spread if not detected at an early stage. Once colonies of melanoma cells reach vital internal organs and grow, they are much more difficult to treat. That is why this is a potentially lethal form of cancer.
While melanoma may suddenly appear in the skin without warning, 70% or more begin in or near a mole or other dark spot in the skin. That is why it’s important to know the color, size, and location of the moles on your body, so you’ll recognize any changes that might take place.
What Causes Melanoma?
Although, the most important know rish factor is unprotected exposure to the sun, melanoma may appear on skin that is not exposed to the sun. Melanoma is less common among people with darker skin who seldom become sunburned. No one is immune to the damagin effects of the sun. Everyone should avoid unprotected exposure whenever outside, not only at the beach or near water.
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 or developing into melanoma. Sometimes these moles should be removed before malignant changes can take place.
Who Is Likely to Get Melanoma?
Actually, no one can be considered entirely free from the risk or melanoma.
Often patients who develop melanoma have fair skin that burns and freckles easily, light blue/green eyes, and either red or blond hair. People who have many moles or certain types of atypical moles and those with relatives who have has melanoma are more likely to develop this skin cancer.
It was once believed that dark brown or black skin was a guarantee against melanoma. We now know that African Americans can develop this cancer, especially on the hands, the soles of the feet, and under the nails.
Aside from these factors, melanoma most often occurs among people who work or spend a great deal of recreational time in the sun – sunbathing, gardening, sailing, fishing or hiking – especially if they have been severely sunburned in their youth. (Episodic exposure to sun, especially before age 20 is also a risk factor).
The risk is also higher in places where there is intense year-round sunshine. As with most other cancers, the change of developing melanoma increases as a person gets older.
What Is the Difference Between a Melanoma and an Ordinary Mole?
An ordinary 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 (Figure 1). Moles are generally less that 6 millimeters in diameter (about the size of pencial 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 areas of the skin exposed to the sun. 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, on the 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. However, a melanoma is more complicated than a mole.
Here’s the simple ABCD rule to help you remember the important signs of melanoma:
A. Asymmetry. One half does not match the other half. (Figure 2)
B. Border Irregularity. The edges are ragged, notched, or blurred. (Figure 3)
C. Color. The pigmentation is not uniform. Shades of tan, brown, and black are present. Red, white, and blue may add to the mottled appearance. (Figure 4)
D. Diameter greater than 6 millimeters. Any sudden or continuing increase in size should be of special concern. (Figure 5)
Other Warning Signs of Melanoma
Spread of pigment from the border into surrounding skin; redness or a new swelling beyond the border; change in sensation…itchiness, tenderness, or pain. Changes in the surface of a mole – scaliness, oozing, bleeding, or the appearance of a bump or nodule (Figure 6).
How is Melanoma Diagnosed?
If your physicial suspects that a change in your skin is the sign of melanoma, a sample of the tissue willbe removed. This procedure is called a biopsy, and usually can be done quickly and easily in the physician’s office. The tissue sample is then sent to a pathology laboratory for examination under a microscpe to confirm the diagnosis.
Can Melanoma Be Treated?
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?
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. Avoid direct sun exposure especially from 10 a.m. to 4 p.m. Wear protective clothing. Use a sunscreen that’s rated SPF 15 or higher. Remember, sunscreen doesn’t provide total protection from ultraviolet rays. Also, remember to re-apply the sunscreen after swimming or sweating. Indoor sunlamps and tanning beds are not protective. Whether a tan is achieved by these artificial means or by natural sunlight, the ultraviolet dose adds to the total lifetime accumulation of UV and to the risk or skin cancer.
Do A Regular Skin Self-Exam
Get familiar with your skin and your own pattern of moles, freckles, and “beauty marks.” Be alert to changes in the number, size, shape or color of pigmented areas. The best way to do this is to give yourself a skin exam. Ask a friend, spouse, or your doctor to look at your back. Call your physician if you find any unusual changes. Make prevention and early detection of melanoma part of your life.
Reprinted from the American Cancer Society’s booklet, “Why You Should Know About Melanoma.”