May is Melanoma and Skin Cancer Awareness Month
What is skin cancer?
There are 2 main types of skin cancers: keratinocyte cancers (basal and squamous cell skin cancers) and melanomas.
Basal and squamous cell cancers
Basal and squamous cell skin cancers are by far the most common cancers of the skin. They develop from cells called keratinocytes, the most common cells in the skin.
Basal cell cancers and squamous cell cancers are the most common cancers of the skin. They develop from skin cells called keratinocytes. Both basal cell and squamous cell cancers are found mainly on parts of the body exposed to the sun, such as the head and neck, and their occurrence is related to the amount of sun exposure a person has had.
These cancers (especially basal cell cancers) rarely spread elsewhere in the body and are much less likely than melanomas to be fatal. Still, it is important to find and treat them early. If left untreated, they can grow quite large and invade into nearby tissues, causing scarring, disfigurement, or even loss of function in some parts of the body.
Melanomas are cancers that develop from melanocytes, the cells that make the brown pigment that gives skin its color. Melanocytes can also form benign (non-cancerous) growths called moles.
Melanomas can occur anywhere on the body, but are more likely to start in certain locations. The trunk (chest and back) is the most common site in men. In women, the legs are the most common site. The neck and face are other common sites.
Melanomas are much less common than basal cell and squamous cell skin cancers, but they can be far more serious. Like basal cell and squamous cell cancers, melanoma is almost always curable in its early stages. But if left alone, melanoma is much more likely to spread to other parts of the body, where it can be very hard to treat.
Cancer of the skin is by far the most common of all cancers. Melanoma accounts for less than 5% of skin cancer cases but causes a large majority of skin cancer deaths.
The American Cancer Society's most recent estimates for melanoma in the United States are for 2012:
What are the risk factors for skin cancer and melanoma?
Ultraviolet (UV) radiation is thought to be the major risk factor for most skin cancers. Sunlight is the main source of UV rays, which can damage the genes in your skin cells. Tanning lamps and beds are also sources of UV radiation. People with high levels of exposure to light from these sources are at greater risk for skin cancer.
It isn't possible or practical to avoid sunlight completely, and it would be unwise to reduce your level of activity to avoid the outdoors because physical activity is important for good health. But too much sunlight can be harmful. There are some steps you can take to limit your exposure to UV rays.
When you are out in the sun, wear clothing to protect as much skin as possible. Clothes provide different levels of UV protection, depending on many factors. Long-sleeved shirts, long pants, or long skirts cover the most skin and are the most protective. Dark colors generally provide more protection than light colors. A tightly woven fabric protects better than loosely woven clothing. Dry fabric is generally more protective than wet fabric.
A sunscreen is a product that you apply to your skin for protection against the sun's UV rays. But it's important to know that sunscreen does not provide total protection against all UV rays. Even with proper sunscreen use, some rays get through, which is why using other forms of sun protection is also important.
Read the labels.When choosing a sunscreen product, be sure to read the label before you buy. Many groups, including the American Academy of Dermatology, recommend products with a sun protection factor (SPF) of at least 30. The SPF number represents the level of protection against UVB rays provided by the sunscreen – a higher number means more protection.
Wear a hat
A hat with at least a 2- to 3-inch brim all around is ideal because it protects areas such as the ears, eyes, forehead, nose, and scalp that are often exposed to intense sun. A shade cap (which looks like a baseball cap with about 7 inches of fabric draping down the sides and back) also is good, and will provide more protection for the neck. These are often sold in sports and outdoor supply stores.
Wear sunglass that block UV rays
UV-blocking sunglasses are important for protecting the delicate skin around the eyes, as well as the eyes themselves. Research has shown that long hours in the sun without protecting your eyes increase your chances of developing eye disease.
Limit direct sun exposure during mid-day
Another way to limit exposure to UV light is to avoid being outdoors in sunlight too long. UV rays are strongest when the sun is high in the sky, usually between the hours of 10 am and 4 pm. If you are unsure about the sun's intensity, use the shadow test: if your shadow is shorter than you, the sun's rays are the strongest, and protection from the sun is most important.
Avoid tanning beds and sun lamps
Many people believe the UV rays of tanning beds are harmless. This is not true. Tanning lamps give out UVA and usually UVB rays as well. Both UVA and UVB rays can cause long-term skin damage, and can contribute to skin cancer. Most skin doctors and health organizations recommend not using tanning beds and sun lamps.
Certain types of moles have an increased risk of developing into a melanoma. If you have moles, depending on how they look, your doctor may want to watch them closely with regular exams or may remove some of them if they have certain features that suggest they may be changing into a melanoma.
Routine removal of many moles is not generally recommended as a way to prevent melanoma. Some melanomas may develop from moles, but most do not. If you have many moles, getting careful, routine exams by a dermatologist, along with doing monthly skin self-exams, might be recommended.
How is skin cancer detected?
Most skin cancers can be found early with skin exams. Both regular exams by your doctor and checking your own skin frequently can help find cancers early, when they are easier to treat.
Get your skin checked by a doctor
As part of a routine cancer-related checkup, your doctor should check your skin carefully. They should be willing to discuss any concerns you might have about this exam.
How to check your own skin
It's important to check your own skin, preferably once a month. A self-exam is best done in a well-lit room in front of a full-length mirror. You can use a hand-held mirror to look at areas that are hard to see. A spouse or close friend or family member may be able to help you with these exams, especially for those hard-to-see areas like your back or scalp.
The first time you inspect your skin, spend time carefully going over the entire surface of your skin. Learn the pattern of moles, blemishes, freckles, and other marks on your skin so that you'll notice any changes next time. Any trouble spots should be seen by a doctor.
Please visit the American Cancer Society for more information on skin exams and detecting skin cancer and melanoma.
What’s new in skin cancer and melanoma research and treatment?
Scientists have made a great deal of progress during the past few years in understanding how UV light damages DNA and how changes in DNA cause normal skin cells to become cancerous.
On the other hand, some people may inherit mutated (damaged) genes from their parents. For example, changes in the CDKN2A (p16) gene cause some melanomas to run in certain families. People who have a strong family history of melanoma should speak with a cancer genetic counselor or a doctor experienced in cancer genetics to discuss the possible benefits, limitations, and downsides of testing for changes in this gene.
Advances in melanoma DNA research are also being applied to molecular staging. In ordinary staging, a lymph node removed from a patient is looked at under a microscope to see if melanoma cells have spread to the lymph node.
In molecular staging, RNA (a chemical related to DNA), is extracted from cells in the lymph node. Certain types of RNA are made by melanoma cells but not by normal lymph node cells. A sophisticated test called reverse transcription polymerase chain reaction (RT-PCR) is used to detect these types of RNA.
Early studies have found that RT-PCR is better than routine microscopic testing at detecting the spread of melanoma to lymph nodes. This test may eventually help identify some patients who might benefit from additional treatment such as immunotherapy after surgery. However, some doctors are concerned that this test may lead to unnecessary treatment for some patients, which is why this test is not currently recommended. Studies are now in progress to learn more about how results should influence choice of treatment.
Please visit the American Cancer Society for more information on skin cancer and melanoma treatment options.
Source: American Cancer Society.
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