Skin cancer develops when abnormal skin cells, which often form a group called a tumor, begin to grow out of control and invade other parts of the body – a process called metastasis. Benign tumors do not spread and are usually not harmful. Malignant tumors, however, spread from their sources and can grow into life-threatening cancers.
Because they develop differently and carry different risks, skin cancer (also called carcinomas) can be separated into two groups: melanoma and nonmelanoma cancers.
Melanomas, which account for about 4 percent of skin cancers, start in the pigment-producing cells that are in the skin's outer layer (the epidermis). They are usually brown or black mole-like growths. When identified early, melanomas can be successfully removed most of the time. If neglected, however, melanomas are likely to metastasize and can be deadly. Although melanomas are the least common, they are the most dangerous skin cancers.
Non-melanoma skin cancers, mostly flesh-colored to reddish-brown nodules, primarily involve two types of cells: basal cells (lower epidermis) and squamous cells (upper epidermis). About 75 percent of skin cancers are basal cell carcinomas, which are sun-induced, slow-growing and unlikely to metastasize. Squamous cell carcinomas are also caused by sun exposure and account for about 20 percent of skin cancers.
The development of squamous cell carcinomas around the anus and genital area has been associated with Human Papilloma Virus (HPV) , a sexually transmitted disease. Condoms do not provide adequate protection from HPV, the virus that causes genital warts.
Although melanomas cause the most deaths, other types of skin cancers can also be fatal. The best way to start protecting yourself against all skin cancers is learning how to examine your body for suspicious skin changes that signal precancerous growths.
Skin cancer might seem like a disease that only affects the elderly, but since young people are spending so much time in the sun and in tanning beds, more young adults are developing skin cancer than ever before. You might consider skin cancer a distant threat, but you may see the effects of today's sun damage sooner you think.
Skin cancer rates are on the rise – more than 1 million Americans were diagnosed with non-melanomas in 2005, and about 59,580 were estimated to be diagnosed with melanoma.
It was estimated that 10,250 people would die from skin cancer in 2005 –approximately 7,770 from melanoma and 2,820 from other skin cancers.
Since 1981, the rate of incidence has slowed to a little less than 3 percent per year.
Melanoma risk is more than 10 times higher for whites than African-Americans.
Approximately 50 percent of all melanomas occur in people over the age of fifty (that means that half occur in youth and middle age).
Men are twice as likely to develop basal cell carcinomas and are three times as likely to have squamous cell carcinomas.
There is a lot that you can do to protect your skin from the sun. Most skin cancers are caused by too much exposure to the sun's ultraviolet rays, but some may come from artificial sources, such as tanning beds. Some prevention tips are:
Avoid sun exposure from 10 am to 4 pm. During the middle of the day, the sun's UV rays are most intense. Try to minimize your midday sun exposure.
Always wear a waterproof, broadband sunscreen of SPF 15 or higher. Sunscreen offers some protection against the sun's harmful rays. If applied correctly, a sun-protection factor (SPF) of 15 or higher should allow you to stay in the sun 15 times longer than you would normally be able to without burning. Sunscreen does not block all of the sun's radiation, however, and most people do not use sunscreen appropriately. One mistake people make is having a false sense of "sun-invincibility." Wearing sunscreen helps protect against sun damage, but it does not give you a license to spend unlimited time in the sun. Some other common missteps include not using enough sunscreen, not using a waterproof formula, not reapplying frequently enough and not using broadband protection. To block more of the sun's rays, your sunscreen should include broadband protection. Broadband is a term that sunscreen manufacturers use to describe a product that offers protection from both UVA and UVB radiation emitted by the sun.
To completely cover your body, slather on one ounce of sunscreen. If you're hitting the beach or lying out by the pool, you should apply about an ounce — the amount of a full shot glass--of sunscreen to all exposed skin.
Apply sunscreen at least 20 minutes before going out in the sun. Since sunscreen takes at least 20 minutes to absorb into the skin, apply it prior to going outside to give it time to work.
Wear sunscreen everyday, even overcast, cloudy days. When you're outside during daylight hours, UV rays can damage skin regardless of season, location or weather. In the
Protect your eyes and lips. Facial features, especially eyes and lips, are susceptible sites for skin cancer. To protect your eyes, wear sunglasses treated to absorb UV radiation and make sure they cover the area surrounding your eyes. For lips, use a lip balm that has an SPF of at least 15.
Wear clothing with a tight weave and a wide-brimmed hat. Clothes block the sun's rays even better than commercial sunscreen products do. Dark, tightly woven fabrics offer the better sun protection than light, thin and loosely woven materials do. A wide-brimmed hat provides good coverage for your face, ears, neck and scalp. Although a cap is better than no hat at all, it doesn't shade your ears and neck.
If you have children, teach them to apply their own sunscreen (under your supervision).
Teach your children that, by using sunscreen, they can be cancer-fighters. Remember that all of the prevention tips offered here not only apply to adults, but also apply to children.
Keep babies less than six months old out of the sun. Experts dissuade against using sunscreen on infants, who may react negatively to the chemicals. Instead of using sunscreen on infants, cover them well-using a hat or bonnet and sunglasses--if they must be in the sun.
Encourage your kids to play in the shade. When you take your kids to playgrounds, look for areas that include shade trees or covered areas so they can take a break from being in the sun.
While everyone should practice sun safety, certain people are at greater risk for developing skin cancer. Risk factors include:
- Light hair color and blue, gray or green eyes.
- Fair complexion and/or freckle.
- Sun sensitivity: Skin that burns easily.
- Taking prescription medications that increase sun sensitivity.
- Family history: Approximately 10 percent of people with melanoma have a close relative with skin cancer.
- Several moles on your body : People with lots of moles, and those who have some large moles, have an increased risk for melanoma.
- Presence of a congenital mole : Having a mole since birth increases your risk.
- One or more large or irregularly pigmented lesions.
- Suppressed immune system : People who have been treated with medicines that suppress the immune system, such as transplant patients.
- Exposure to certain chemicals, such as arsenic, and to radiation therapy.
- Excessive exposure to the sun and repeated blistering sunburns before the age of 15.
- A person who has already had melanoma has a higher risk of getting another melanoma.
Once a month, give yourself a skin exam or ask your partner to examine your skin. If you are doing this yourself, use a hand mirror and a full-length mirror to look for the following signs and changes:
- A brown or black irregularly pigmented spot with uneven margins.
- A slow-growing, raised, translucent, pearly nodule that may crust, ulcerate and possibly bleed without treatment. These are typically found on the face, neck, hands and trunk.
- A change in sensation, itchiness, tenderness or pain from a mole.
- A small, smooth, shiny, pale or waxy lump on the skin.
- A flat red spot, either scaly and crusty or smooth and shiny.
- A new mole.
Asymmetry: half of the mole does not match the other half.
Border irregularity: edges of the mole are ragged.
Color: that is not uniform. There may be shades of tan, brown, or black, and sometimes patches of red, blue, or white.
Diameter: greater than 6 millimeters.
Two early detection tools should be used together to help detect an early skin cancer.
Self-examination: Once a month, give yourself a skin exam or ask your partner to examine your skin. Learn the pattern of moles and blemishes so that you will know if something is difference. If you are doing this yourself, examine your skin in a well lighted room and use a hand mirror and a full-length mirror to look at your face, scalp, ears, neck, chest, belly, arm, hands, legs and feet for the following signs and changes:
- A brown or black irregularly pigmented spot with uneven margins.
- A slow-growing, raised, translucent, pearly nodule that may crust, ulcerate and possibly bleed without treatment. These are typically found on the face, neck, hands and trunk.
- A change in sensation, itchiness, tenderness or pain from a mole.
- A small, smooth, shiny, pale or waxy lump on the skin.
- A flat red spot, either scaly and crusty or smooth and shiny.
- A new mole.
Remember the ABCD rule: asymmetry, border irregularity, color that is not uniform and a diameter greater than 6 millimeters – about the size of the tip of a pencil eraser.
If you discover a suspicious growth while conducting your monthly self-examination, however, get a clinician to inspect the area as soon as possible. Early detection can allow you to catch abnormal skin growths before they have a chance to spread.
If you have children, examine their skin regularly, too. It is possible for children to develop skin cancer just like adults, and it's never too early to start forming good habits.
Clinical examination: You should also have clinical skin cancer check-ups during routine physical examinations by a health care professional. Skin cancer is treatable if it is detected early.
Treatment for skin depends on the cancer type and stage of the cancer — whether it is confined to the skin or has spread to other parts of the body. Non-melanoma skin cancers, basal cell and squamous cell carcinoma, are usually treated by surgical removal of the tissue. These procedures may include Mohs micrographic surgery, in which the tumor is cut from the skin in layers until no more cancer is seen. Or it may be removed through a simple excision that cuts the tumor from the skin, or a shave excision that shaves the tumor off the surface of the skin until normal tissue appears. Electrodesiccation and currettage is a method that uses a needle shaped electrode to treat the area with an electric current that kill the cells.
Cryosurgery uses cold gases to freeze and destroy tissue and laser surgery used a narrow beam of intense light to cut and remove the tumor. Chemotherapy is sometimes used to treat non-melanoma skin cancers and is given orally or applied topically to the skin. Photodynamic therapy combines a light sensitive drug that mark the spot where cancer cells are so they can then be destroyed by laser light.
Surgery is used to remove the tumor and is the primary treatment. Sometimes nearby lymph nodes are also removed to determine if the cancer has spread.
Skin grafts may be needed in which skin is taken from other parts of the body to cover the wound. Chemotherapy may follow surgery either through the mouth, by injections into muscle or through the vein if the cancer has spread beyond the skin. Sometimes chemotherapy drugs may be given as a hyperthermic isolated limb perfusion, a technique that injects high doses of anti-cancer drugs directly into the affected arm or leg. Some patients receive radiation therapy following surgery for melanoma.
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