Speculations on the role of ultraviolet radiation in the development of malignant melanoma.

Abstract

Interest in the etiology of human malignant melanoma has increased considerably in recent years. The basis for this heightened concern can be attributed to two seemingly unrelated issues. The first is that the incidence of malignant melanoma is increasing at an alarming rate. At the present time, both the incidence of melanoma and the mortality rate are doubling every 10 to 17 years. Thus identification of causal factors in the development of melanoma is an urgent necessity if this upward trend is to be curbed. The second issue that has directed attention to the identification of etiologic factors in malignant melanoma is ozone depletion. The layer of ozone surrounding the earth shields it from solar uv radiation. Anticipated decreases in stratospheric ozone, resulting from high-altitude aircraft, nuclear explosions, and the release into the atmosphere of chlorofluoromethanes from refrigerants and aerosol sprays, raised concerns about the effects of an increased exposure of all life forms to uv light. One anticipated effect of increased exposure of humans to uv light is a corresponding increase in some types of skin cancer in humans. If malignant melanoma is included among the types of skin cancer at risk of increasing, then the impact of ozonemore » depletion on humans is serious indeed. In the prognosis for melanoma is less favorable, particularly in cases in which the tumor is already invasive at the time of diagnosis. Thus the threat of an increased level of exposure to light has stimulated a careful reevaluation of the role of radiation in the induction of melanoma.« less