Immunocryosurgery for basal cell carcinoma: results of a pilot, prospective, open-label study of cryosurgery during continued imiquimod application.

Background/aim: Theoretical considerations support the combination of cryosurgery and topical imiquimod to treat basal cell carcinomas (BCC). The aim of the present study was to test the feasibility and efficacy of 'cryosurgery during continued imiquimod application' ('immunocryosurgery') to treat 'high-risk-for-recurrence' BCCs.

Methods: Thirteen patients with 21 biopsy-proven tumours (4 of 21 relapses after prior surgery) were included. After 2-5 weeks (median, 3) of daily 5% imiquimod cream application, the tumours were treated by liquid N(2) cryosurgery (spray, two cycles, 10-20 s) and imiquimod was continued for additional 2-12 weeks (median, 4). The outcome after at least 18 months of follow-up (18-24 months) is currently reported.

Results: Nineteen of 21 tumours responded promptly to immunocryosurgery; two tumours required additional treatment cycles to clear. Thus, the clinical clearance rate was 100%. Only 1 of 21(5%) tumour relapsed after at least 18 months of follow-up (cumulative efficacy: 95%).

Conclusions: 'Immunocryosurgery' is a promising non-surgical combination modality to treat 'high-risk-for-recurrence BCCs'. Initial evidence is suggestive of an at least additive effect of the two combined modalities. Further studies comparing immunocryosurgery directly with cryosurgery and imiquimod monotherapies will confirm the reported results.