A Non-Surgical And Cost-Effective Treatment Approach Employing Topical Imiquimod, 5-Fluorouracil, And Tretinoin For Primary Non-Melanoma Skin Cancers

Background: Minimally invasive alternative approaches to treat non-melanoma skin cancers remain limited and unproven. Objective: We aim to assess the efficacy of varying combinations of anti-tumor agents-imiquimod 5% cream, 5-fluorouracil 2% solution, and tretinoin 0.1% cream-with brief cryotherapy in treating non-melanoma skin cancers.Methods: This retrospective study included 690 cases of non-melanoma skin cancers in 480 patients who received a diagnosis of a basal cell carcinoma or squamous cell carcinoma during a ten-year period. During treatment period, patients applied 30 applications of one of three combinations (imiquimod/tretinoin, 5-fluorouracil/tretinoin, or imiquimod/5-fluorouracil/tretinoin) and had cryotherapy every 2 weeks. Each patient had a clinical examination at least three years post-treatment or documented treatment failure. Clearance was defined by a lack of persistence or recurrence for 3 years following the completion of treatment. The likelihood of lesion clearance was evaluated using multivariable logistic regression analysis.Results: A total of 186 cases (97; basal cell carcinoma and 89; squamous cell carcinoma) in 133 patients (37% women and 63% men; median (interquartile range) age, 77 (69, 83) years) met the inclusion criteria. Multivariable logistic regression analysis adjusting for clinical and lesion variables demonstrated that, relative to the imiquimod/5-fluorouracil/tretinoin treatment approach, imiquimod/tretinoin (odds ratio, 0.05; 95% confidence interval, 0.00-0.99) and 5-fluorouracil/tretinoin (0.02; 0.00-0.45) were associated with lower likelihoods of lesion clearance. Likewise, morpheaform basal cell carcinoma had a lower probability of clearance (0.05; 0.00-0.72).Conclusions: The combination of imiquimod/5-fluorouracil/tretinoin with cryotherapy had high clearance rates and was the most effective treatment regimen.