Skin Cancer FactsDid you know that skin cancer is the most common cancer in the United States? Here are some general facts about skin cancer to help put this disease in perspective:
- Every year more than one million Americans get skin cancer.
- One in 5 Americans and 1 in 3 Caucasians will get skin cancer at some point in their lifetime.
- Sun exposure causes more than 90% of all skin cancers.
- Your risk of getting skin cancer doubles if you've had 5 or more sunburns in your life.
What is Skin Cancer?Skin cancer develops when cells in the skin become damaged and begin to grow uncontrollably. Skin cells in the top layer of the skin, the epidermis, go through a typical cycle of dividing, maturing, dying, and then sloughing off. Normally, when skin cells are damaged, the body can make repairs that keep the skin growing and dividing normally.
If the body can't repair a damaged skin cell, the cell stops going through that normal cycle and keeps dividing and growing.
- If it grows up, it causes a visible bump on the skin.
- If it grows out or down, it can damage surrounding tissue.
- If it spreads to other areas of the body, it has metastasized and it can also damage those areas.
Risk Factors for Skin CancerA risk factor is something that increases a person's chance of getting a disease. In the case of skin cancer something that causes that irreversible damage to a skin cell or prevents it from being repaired would be a risk factor. There are many risk factors for getting skin cancer but the most preventible is exposure to UV radiation from the sun, sunlamps, and tanning beds.
Precancerous GrowthsPrecancers are growths of abnormal skin cells that are more likely to turn into cancerous cells than normal skin. Precancerous cells look different from normal skin cells when viewed under a microscope, and many precancers can be seen with the naked eye. There is some controversy about whether precancerous lesions are really cancers that haven't started to spread yet. Examples of precancers include:
Types of Skin CancerThree major types of skin cancer can develop depending on which type of skin cell becomes damaged. Melanoma is the most deadly skin cancer because it can spread to other parts of the body easily. It develops in pigment cells called melanocytes.
The other two types of skin cancer are often grouped together and called non-melanoma skin cancers.
Basal cell carcinoma is the most common skin cancer. It develops in basal keratinocytes which are skin cells on the bottom layer of the epidermis. Fortunately basal cell carcinomas grow very slowly and almost never metastasize, but if not treated they can grow below the skin and damage surrounding tissue including bone.
Squamous cell carcinoma is the second most common skin cancer. It develops in keratinocytes (skin cells) in the epidermis. Squamous cell carcinoma is typically easily treatable, but it can metastasize if left alone.
Skin Cancer TreatmentThe treatment of skin cancer depends on several factors:
- Type of skin cancer
- Where on the body it's located
- How much skin is involved
- Whether it has metastasized
- Whether the person is otherwise healthy or has other medical problems
Preventing Skin CancerSince UV radiation plays such a large role in the development of skin cancer, it makes sense that reducing exposure to UV goes a long way towards preventing skin cancer. Ways that you can limit your exposure to UV radiation include
- Stay out of the sun between 10 a.m. to 4 p.m. when the sun's rays are the strongest.
- Apply a generous amount of a good sunscreen to all exposed skin and re-apply every 2 hours.
- Cover up with protective clothing including sunglasses and a hat.
- Stay away from tanning beds. They are not a safe way to get a tan.
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Miller, Stanley, and J Margaret Moresi. "Actinic Keratosis, Basal Cell Carcinoma and Squamous Cell Carcinoma." Dermatology. Ed. Jean Bolognia. New York: Mosby, 2003: 1677-96.
National Institutes of Health. "What You Need to Know About Melanoma" NIH Publication No. 02-1563. (2002): 1-50.
National Institutes of Health. "What You Need to Know About Skin Cancer" NIH Publication No. 05-1564. (2005): 1-40.
Saraiya, M et al. “Preventing Skin Cancer: Findings of the Task Force on Community Preventive Services on Reducing Exposure to Ultraviolet Light.” MMWR Recommendations & Reports. 52-RR15(2003): 1-12.