From the Guidelines
The scientific consensus strongly supports that UV radiation from sunlight is carcinogenic, and thus, it is recommended to minimize exposure to ultraviolet radiation to reduce the risk of skin cancer, as stated by the USPSTF 1.
Key Points to Consider
- UV radiation from both solar and artificial sources has been classified as a human carcinogen by national and international organizations 1.
- Epidemiologic evidence suggests that the effect of UV radiation exposure from typical doses of sunlight varies over the life span, with some evidence of a window of biological vulnerability in early life that translates into risk for skin cancer decades later 1.
- The USPSTF recommends counseling children, adolescents, and young adults 10 to 24 years of age who have fair skin about minimizing their exposure to ultraviolet (UV) radiation to reduce the risk of skin cancer 1.
Mechanisms of UV Damage
- UV radiation damages DNA by creating specific mutations called "UV signature mutations," particularly cyclobutane pyrimidine dimers and 6-4 photoproducts.
- The molecular mechanisms of UV damage are consistent regardless of source, though the context of exposure (intensity, duration, other wavelengths present) may modify outcomes.
Recommendations for Practice
- Health organizations worldwide recommend sun protection to reduce the risk of skin cancer.
- Counseling to decrease UV exposure is recommended for children, adolescents, and young adults aged 10 to 24 years, as it has moderate net benefits for reducing the risk of skin cancer 1.
From the FDA Drug Label
The effects of the sun on your skin. As you know, overexposure to natural sunlight or the artificial sunlight of a sunlamp can cause sunburn. Overexposure to the sun over many years may cause premature aging of the skin and even skin cancer. Therapy with tretinoin gel may make your skin more susceptible to sunburn and other adverse effects of the sun, so unprotected exposure to natural or artificial sunlight should be minimized.
The FDA drug label indicates that overexposure to natural sunlight can cause sunburn and may lead to premature aging of the skin and even skin cancer. Additionally, therapy with tretinoin gel may increase the skin's susceptibility to these effects. Therefore, it is recommended to minimize unprotected exposure to natural or artificial sunlight.
- Key points:
- Overexposure to natural sunlight can cause sunburn and skin cancer
- Tretinoin gel therapy may increase skin susceptibility to sunburn and other adverse effects
- Minimize unprotected exposure to natural or artificial sunlight 2
From the Research
UV Radiation and DNA Damage
- UV radiation is known to cause DNA damage, which can lead to skin cancer 3, 4
- Studies have shown that UV radiation can activate various oncogenes while inactivating tumor suppressor genes, resulting in inappropriate survival and proliferation of keratinocytes that harbor these damages 3
- The use of topical sunscreens has been shown to decrease the amount of UV radiation-induced DNA damage in human skin 5
Natural Sunlight vs. Artificial UV Radiation
- @Raban claims that natural sunlight is mostly IR and includes other wavelengths, and that isolated UV/artificial lab light has significantly different results/impacts than sunlight
- However, studies have shown that UV radiation, regardless of its source, can cause DNA damage and increase the risk of skin cancer [@2@, @3@]
- There is evidence that UV-induced DNA damage formation and repair are affected by chromatin state, and that chronic UV exposure leads to high mutation burden in skin and consequently the development of skin cancer [@3@]
Prevention and Treatment of Skin Cancer
- Elucidating the molecular mechanisms of UV-induced DNA damage responses will be useful for preventing and treating skin cancer with greater precision [@3@]
- Nicotinamide has been shown to enhance repair of ultraviolet radiation-induced DNA damage in primary melanocytes, and may be a potential agent for the chemoprevention of cutaneous melanoma [@5@]
- The use of sunscreens and other protective measures can help reduce the risk of skin cancer caused by UV radiation [@1@, @4