Skin Cancer Prevention

Skin cancer is a fast-growing epidemic in the United States with greater than 3.5 million new cases diagnosed each year.[1]. The incidence has tripled since the 1970s. Exposure to the ultraviolet (UV) rays the sun emits is the single greatest risk factor for developing a skin cancer.[2]. The 3 main types of UV rays that the sun emits are known as UVA, UVB, and UVC. Ninety-five percent of the UV radiation reaching earth is UVA rays, which are a great cause of photoaging due to their ability to penetrate deep into the skin. UVA rays are known to induce indirect DNA damage by creating free radicals via reactive oxygen species and decreasing the activity of antigen presenting cells of the epidermis.[3]. UVA rays are used in tanning booths, can also penetrate clouds and glass. They are prevalent year-round. UVB rays, also known as sunburn rays, have a 290 to 320 nm wavelength and are more associated with skin cancer than UVA tanning rays, which have a 320 to 400 nm wavelength.[4] This is because UVB rays cause direct DNA damage by inducing the formation of cyclobutane pyrimidine dimers and pyrimidine (6-4) photoproducts.[5] The third type of rays, UVC rays, although more damaging to the skin than UVA or UVB, are completely absorbed by the ozone layer, and therefore, do not increase the risk of skin cancer. In addition to directly damaging DNA, UV radiation alters the skin in ways that cause skin immunosuppression that may also lead to skin cancer, although the exact mechanism is unclear.[6]