Recurring Actinic Keratosis Reduced With Topical Fluorouracil vs Topical Imiquimod

A comparison of 5-fluorouracil (5-FU) and imiquimod, the 2 most commonly prescribed topical agents for the treatment of actinic keratosis (AK), suggests 5-FU may be more effective in the prevention of subsequent AKs in the short term, but not in the long term. Results of the retrospective study were published in the Journal of the American Academy of Dermatology.

The investigators identified a total of 5700 adult health plan members who had received an AK diagnosis in 2007 and had filled a prescription for either 5-FU or imiquimod. Of the 5700 participants, 5062 were exposed to 5-FU and 638 were exposed to imiquimod.

All participants were followed for the development of subsequent AKs; 2-year (short-term) and 5-year (long-term) differences in cumulative risk for AKs were estimated while controlling for potential confounding pretreatment variables.

The crude (unadjusted) estimate of cumulative risk difference with 5-FU vs imiquimod therapy was −4.78% at 2 years (P =.006) and −1.11% at 5 years (P =.27). In addition, the adjusted estimate based on inverse probability weighting estimation demonstrated that treatment with 5-FU was associated with a significant reduction in the short-term incidence of subsequent AKs (cumulative risk difference, −4.54%; 95% CI, −7.91% to −1.17%). 

However, no statistically significant evidence of a long-term decreased risk for subsequent AKs with 5-FU vs imiquimod was reported (cumulative risk difference, −1.43%; 95% CI, −3.43% to −0.05%).

The investigators concluded that this direct comparison of 5-FU vs imiquimod conducted in a real-world setting implies that 5-FU should be considered over imiquimod for the short-term reduction in risk for subsequent AKs.

Reference

Neugebauer R, Levandoski KA, Zhu Z, et al. A real-world, community-based cohort study comparing the effectiveness of topical fluorouracil vs. topical imiquimod for the treatment of actinic keratosis [published online December 22, 2017]. J Am Acad Dermatol. doi: 10.1016/j.jaad.2017.12.042