Recurrence rate of superficial basal cell carcinoma following treatment with imiquimod 5% cream: conclusion of a 5-year long-term follow-up study in Europe.

Imiquimod 5% cream is an immune response modifier approved for the treatment of superficial basal cell carcinoma (sBCC) once daily, 5 x per week for 6 weeks. This report reveals the final results of a 5-year follow-up study to evaluate the recurrence rate of sBCCs treated with imiquimod. As previously reported, 182 patients were enrolled in the study and 163 (89.6%) had no clinical evidence of their target sBCC at the 12-week post-treatment assessment; these 163 were followed for up to 5 years. During the follow-up period, 18 clinical recurrences occurred at the target tumour site, 8 and 10 of which occurred during the first 6 and 12 months of follow-up, respectively. The 5-year Kaplan-Meier and life-table estimates for sustained clinical clearance of those patients initially cleared were 84.5% and 86.9%, respectively, and 90.3% considering histology. The estimate of overall treatment success for all treated patients at the end of follow-up was 77.9% (80.9% considering histology). The data support clinical assessment of initial response as predictive of long-term outcome. Most of the recurrences occurred early, indicating that careful follow-up is important during the first year after treatment.