The reviewed trials were highly variable in methods and quality, and the evidence provided by these studies was weak. Cure rates with several treatments were variable, and although 5-FU presents therapeutic results that are inferior to those seen with 5-FU + Inf alpha-2a (high dose) and 5-FU + CO2 Laser + Inf alpha-2a (high dose), the treatment should not be abandoned. Topical treatment with 5-FU has a therapeutic effect; however, the benefits and risks have not been determined clearly and further studies are needed.