Skin cancer is the most common cancer in the U.S., with more than a million non-melanoma (squamous cell and basal cell carcinoma) skin cancers diagnosed annually, while there are 68,720 new cases of melanoma in the U.S. every year. The incidence of melanoma is on the increase both in the U.S. and worldwide and, unlike other solid tumors, affects the young and middle-aged.
Causes
The main types of skin cancer are all associated with sun exposure, with squamous cell carcinoma and basal cell carcinoma associated with all your exposures accumulated. Melanoma is associated with intermittent sun exposure linked with a history of sunburn particularly as a child. Both UVA and UVB have been linked to skin cancers, with UVB known to cause sunburn and skin cancer while UVA is known to penetrate the deeper layers of your skin causing ageing and DNA damage that may result in cancer.
Sunscreen
Sunscreens are chemical agents designed when applied correctly to protect against sunburn caused by UVB and also against sun damage caused by UVA. Research has shown that sunscreens do protect you against squamous cell carcinoma but not basal cell carcinoma. The role of sunscreen and preventing melanoma is more complex. A 2000 JAMA article reported that children--particularly those at higher risk based on freckling--fared better when they used sunscreen. However sunscreen may give a false sense of security, encouraging people to spend longer in the sun.
Sunscreen Use
Sunscreens are measured with a sun protection factor (SPF) which measures the ability to prevent UVB from causing burning. However to be beneficial the sunscreen must be applied correctly. You should apply your sunscreen before you go out and you should reapply regularly--every 2 hours--but in particular after swimming or sweating. The amount of sunscreen you use is important; apply at least a teaspoon of cream to each limb, the front and back of the body and half a teaspoon to your face without forgetting your neck and ears. If you use a high SPF sunscreen, do not extend your exposure to the sun: just because you are not burning does not mean that the sun is not damaging your skin.
Prevention
There are a number of other preventative measures that you should use to reduce your sun damage. UV radiation is known to be strongest around midday, so reduce your exposure between the hours of 11 and 3. Avoid sunburn and take extra care of children, preventing them from being burnt. However, the best method of protection is covering up with clothing, large-brimmed hats and sunglasses. If you use a sun bed you increase your risk of all forms of skin cancer.
Symptoms
If you notice any change in appearance on your skin, have your doctor check it--this includes size or appearance of moles, any new growth and the spread of pigmentation beyond the margins of the mole. If your mole starts to itch, or there is a change in sensation or pain, then get the mole checked professionally. Get checked if there is an area of the skin that has persistent scaliness, or oozing or bleeding should.
