Clinical Question: Is imiquimod cream (an immune response modifier) effective in the treatment of basal cell carcinoma?

Setting: Outpatient (specialty)

Study Design: Randomized controlled trial (double-blinded)

Synopsis: The authors summarized the results of two similar randomized double-blind trials (concealed allocation assignment) comparing imiquimod 5 percent cream applied once daily five and seven times per week for six weeks with an identical, vehicle-only cream. Lesions were confirmed through biopsy to be superficial basal cell carcinomas (i.e., no evidence of aggressive growth patterns) at baseline and were located on the limbs, trunk, neck, or head (excluding the facial H-zone). The maximal lesion diameter was 2 cm. Following treatment, excisions were performed with a 3 to 4 mm margin around the original lesion to determine if the basal cell carcinoma was evident clinically. Outcomes were assessed by persons blinded to treatment group assignment.

A total of 694 patients (96 percent of the initial cohort) were available for follow-up at 12 weeks. Using intention-to-treat analysis, the combined clinical and histologic assessment of tumor clearance for the groups treated five and seven times per week was 75 percent and 73 percent, respectively, compared with 2 to 3 percent in the vehicle-only group (P < .001; number needed to treat = 1.4). In the imiquimod group, 11 patients (3 percent) discontinued treatment because of adverse effects. The most common side effects included skin erythema, erosion, and scabbing/crusting.

Bottom Line: Imiquimod 5 percent cream is an effective and relatively safe nonsurgical alternative for the treatment of superficial basal cell carcinoma. (Level of Evidence: 1b)