Topical fluorouracil better than imiquimod in preventing keratinocyte carcinoma
Overall, 5-fluorouracil is more effective than imiquimod in reducing the risk of keratinocyte carcinoma, but there are no differences in the short- or long-term risk of subsequent site-specific keratinocyte carcinoma in a real-world practice setting, according to a new study.
Compared with imiquimod, 5-fluorouracil correlated with a statistically significant lower risk of any keratinocyte carcinoma (adjusted hazard ratio [aHR], 0.86; 95 percent CI, 0.76–0.97). However, no significant differences were seen in risk by tumour subtype (for squamous cell carcinoma: aHR, 0.89; 0.74–1.07; for basal cell carcinoma: aHR, 0.87; 0.74–1.03) or site-specific keratinocyte carcinoma (aHR, 0.96; 0.81–1.14).
In addition, there were no significant between-group differences found in 2- or 5-year cumulative risk of keratinocyte carcinoma among patients.
In a previous study, results showed that 5-fluorouracil was significantly more effective than imiquimod in the short-term, but not long-term, prevention of subsequent actinic keratosis. [J Am Acad Dermatol 2018;78:710-716]
In the current study, the authors identified 5,700 patients who filled prescriptions for 5-fluorouracil or imiquimod for the treatment of actinic keratosis in 2007 to compare the effectiveness of the two agents in preventing keratinocyte carcinoma in a real-world practice setting.
They also calculated 2- and 5-year cumulative risk differences for subsequent keratinocyte carcinoma overall and in field-treated areas using an intention-to-treat analysis controlling for potential confounding variables.
“Generalizability to other practice settings may be limited,” the authors said.