Immunocryosurgery for Nonmelanoma Skin Cancer: Applications and Practical Tips

Abstract

“Immunocryosurgery” refers to the combination of cryosurgery during immunostimulatory therapy, presently with topical imiquimod. A typical cycle of immunocryosurgery consists of 5 weeks daily imiquimod and a session of cryosurgery applied at the end of the second week as 2 freeze-thaw cycle sessions (open spray, liquid N2, 10–20 s “effective freezing time” each). Immunocryosurgery has been successfully employed for the treatment of basal cell carcinoma, Bowen’s disease of the skin, actinic keratoses, solar cheilosis (actinic cheilitis), lentigo maligna, keratoacanthoma, Kaposi sarcoma, locally recurrent Merkel cell carcinoma, and in a modified, less intense scheme for benign skin conditions like genital warts and pyogenic granuloma. However, the most experience has been acquired for basal cell carcinoma in which one 5-week cycle of immunocryosurgery can achieve clearance in 95 % of tumors ≤2 cm diameter and a repeat cycle will increase this rate to 99 %. Also for larger lesions repeated cycles and/or extended treatment periods offer effective control of the tumor. Targeted adjuvants, as is the anti-vascular endothelial growth factor antibody bevacizumab, seem to enhance the efficacy of this approach. Nose, eyelids, and ears are probably the most rewarding skin areas to apply this treatment modality for the treatment of basal cell carcinoma, while treatments of perioral and lip lesions inflict a significant treatment burden on the patient for which he has to be advised. The efficacy of immunocryosurgery signifies the potential of nonsurgical, combination approaches in the treatment of skin neoplasms and particularly of basal cell carcinoma. With the exception of squamous cell carcinoma, the results from the treatment of other nonmelanoma skin cancers have been quite encouraging, and clinical trials with large series of patients are required to establish efficacy in additional indications.