Topical fluorouracil therapy for precancers and cancers of the skin

Topical fluorouracil (FU) is an extremely effective agent for treating multiple actinic keratoses. It is also of value in the treatment of Bowen's disease, actinic cheilitis, arsenical keratoses, radiodermatitis, X-ray-induced keratoses, leukoplakia, and the erythroplasia of Queyrat. Topical FU may be successful in the treatment of superficial basal-cell carcinomas, but should not be used for nodular carcinomas of the face or neck except under unusual circumstances and with mandatory histologic follow-up evaluation. The usual method of treatment is twice daily application of a 1 percent FU solution in propylene glycol. Several modifications of various types of commonly employed preparations and the manner in which each is used are described, along with the respective indications. The considerable discomfort associated with the use of topical FU can be lessened by the stepwise approach outlined--a method extraordinarily valuable for older patients. Occasional complications are primary irritant dermatitis and allergic contact dermatitis; these must be recognized promptly and treated, as must other less frequent side effects. Topical FU appears to be of great value in the destruction of existing precancerous skin lesions. When used repeatedly, it may postpone indefinitely the development of significant precancerous and cancerous skin lesions.