Carcinogenic effects of solar radiation and prevention measures.

Abstract

It is well known that exposure to the sun is the major cause of cancer of the skin—the most common type of cancer encountered in this country. Little is known about the wavelengths responsible for this carcinogenic effect except that it is composed of the shortest wavelengths (290 to 320 mμ) of the solar spectrum. More quantitative information is available about wavelengths and energy requirements for induction of erythema by sun exposure. This may be pertinent to the cancer of the skin problem if it is assumed that erythema represents an early injury which ultimately develops into cancer of the skin. Protection of the individual's skin from sun exposure is the most effective preventive measure now available. This includes avoidance of intense mid-day exposure and use of topical sunscreen preparations when prolonged exposure is unavoidable. A protective effect has been demonstrated with some systemically administered agents but their use is not yet practical. Evidence that solar-induced erythema, degeneration and premalignant changes are reversible gives hope that more effective cancer preventive measures may become available for the patient with severe actinic damage.