Skin cancer is the most common form of cancer, representing 40-50% of all cancers diagnosed in the United States.
Approximately 3.5 million cases of skin cancer are diagnosed each year and that number is rising.
Skin cancer is divided into two broad types: non-melanoma skin cancers and melanoma.
Non-melanoma skin cancers include basal cell carcinoma (the most common) and squamous cell carcinoma. Melanomas represent only 4% of skin cancers but account for nearly half of all skin cancer deaths. In 2017, nearly 90,000 cases of melanoma will be diagnosed in the United States with 10,000 people dying of melanoma.
Ultraviolet radiation from the sun or tanning beds is the main risk factor for the development of basal and squamous cell carcinoma and approximately 60-70% of cutaneous malignant melanomas are thought to be caused by ultraviolet radiation exposure. The other major risk factor for skin cancer is age. Skin cancer, as with most cancers, occurs in older people.
Childhood exposure to UV radiation is a major risk factor for skin cancer development, particularly in doses high enough to achieve sunburns. Some studies suggest that childhood sunburns could as much as double the risk of melanoma. Melanoma risk may be associated with the number of sunburns throughout life.
Indoor tanning beds have further increased UV exposure to adolescents and young adults. It's estimated that 40-50% of teenagers have utilized tanning beds with approximately 70% of users being females under the age of 30. Indoor tanning before age 30 leads to a 75% increase in melanoma risk. Melanoma rates in women are nearly double that of men in the same age group.
For basal cell and squamous cell carcinoma, prior use of tanning beds more than double the risk of developing squamous cell carcinoma. It also increases the risk of developing basal cell carcinoma by 50%. The age of the initial tanning experience was also significant as the odds for developing squamous cell and basal cell carcinoma were increased by 20% and 10% respectively for each decade younger the subject was at the time of tanning.
Here are some misconceptions about indoor tanning:
1) Tanning affords protection against future sunburns. In fact, this misconception may be more dangerous than it sounds as it may lead individuals to spend more time unprotected in natural sunlight assuming that they are immune to the damaging effects of UV radiation.
2) Indoor tanning is no different than natural sun exposure. The typical tanning bed user can receive 1.2 times the average annual cumulative dose of UV radiation received from sun exposure with frequent tanners receiving up to 4.7 times annual exposure from sunlight.
Sunscreens - understanding what SPF (sun protection factor) means:
SPF is a laboratory measure of sunscreen efficacy and is defined as the amount of UV radiation required to produce sunburn on protected skin relative to that of unprotected skin. Contrary to popular belief, the SPF of a product is not related to the duration of UV exposure. UV radiation dosage depends on both the duration of exposure and the intensity of the exposure. Thus, a sunscreen with twice the SPF does not necessarily mean one can stay out in the sun twice as long before developing a sunburn. Sunscreens can help protect the skin from UV radiation but are not designed to increase sun exposure duration.
What is the bottom line?
1) Never use tanning beds, particularly if you are under the age of 30.
2) Use sunscreen, but remember that sunscreens are not designed to increase the amount of time you can spend in sun exposure.
3) Seek shade or limit sun exposure between 10 a.m. and 4 p.m. when the sun’s rays are strongest. This is particularly true the closer you are to the equator.
4) Wear protective clothing such as long sleeved shirts, pants, sunglasses and wide brimmed hats.
5) Short durations in the sun can be beneficial for health, particularly at more northern latitudes where year round sun exposure is limited.