Tretinoin and Photocarcinogenicity: An Update

Abstract

Conflicting reports have described topical tretinoin as either enhancing or inhibiting ultraviolet radiation-induced tumorigenesis in albino hairless mice. A number of reviews have addressed the issue, with two assessing the relevance of the hairless mouse model. The large body of literature that describes the antineoplastic activity of tretinoin combined with the almost 25 years' use on sun-exposed human facial skin without evidence for carcinogenicity argue for a further analysis of the paradox. In this review, several new findings call into question the appropriateness of the model.