Do sunscreens increase or decrease melanoma risk: An epidemiologic evaluation

Ultraviolet adiation is an important cause of melanoma, so the use of sunsc reen lotions has been advocated for melanoma prevention, Several arguments have been raised in opposition to this inference, Sunscreen use may interfe re with cutaneous vitamin D synthesis, which some have hypothesized may low er melanoma risk. Sunscreen users may compensate for their sunscreen use by staying out much longer in the sun, or may use sunscreen lotions inconsist antly. Published melanoma case-control studies have not consistantly demons trated a protective effect of sunscreens; however, these studies do not pro vide strong evidence, ultraviolet radiation is a known cause of melanoma, a nd ultraviolet B may be particularly potent, so on balance the evidence sup ports continued advocacy of sunscreen lotion use as part of an overall sun- protection regimen. Uncertainty will remain, however, until the action spec trum of melanoma is convincingly demonstrated or the methodologic limitatio ns of existing epidemiologic evidence are overcome. The latter may require another decade or more of experience with sunscreen use.