Keratinocyte Carcinoma Chemoprevention With a Combination of Imiquimod, 5-Fluorouracil, and Tretinoin.

Background: The incidence of keratinocyte carcinomas (KCs), comprising basal and squamous cell carcinomas, is rising in the United States. Chemoprevention is one modality by which patients can reduce the incidence of KCs.

Methods: We performed a retrospective review of 327 patients who employed a combination of imiquimod 5% cream, 5-fluorouracil 2% solution, and tretinoin 0.1% cream in a field therapy regimen over the face/ears or scalp for chemoprevention.

Results: Patients had dramatically lower odds of having KCs in the treatment location (face/ears or scalp) in the one-year period after field treatment than in the one-year period preceding field treatment (OR=0.06, 95% CI: [0.02, 0.15]). Patients were also at lower odds of having KCs in non-treated areas the year after field treatment than in the year preceding it (OR=0.25, 95% CI: [0.14, 0.42]). Additionally, fewer cryotherapy sessions were performed for actinic keratoses in the treatment areas in the year after treatment (mean=1.5, SD=1.21) than the year preceding treatment (mean=2.3, SD=0.99; t=11.68, P<0.001).

Conclusions: A combination of imiquimod 5% cream, 5-fluorouracil 2% solution, and tretinoin 0.1% cream were effective at reducing the incidence of new KCs for at least one year. Individualized treatment application frequency allowed for increased patient adherence. Prospective studies evaluating combination topical treatments for chemoprevention of KCs are needed to further assess the treatment effects found in this study. J Drugs Dermatol. 2023;22(5): doi:10.36849/JDD.7334.