Imiquimod: an immune response modifier in the treatment of precancerous skin lesions and skin cancer.

Actinic keratosis (AK) and basal cell carcinoma (BCC) are precancerous and cancerous skin lesions that should be treated especially when multiple or in cosmetically important areas. Apart from 5% 5-fluorouracil topical cream, which some feel is the gold standard topical treatment for AK, several invasive treatment modalities are available for AK and superficial BCC, such as cryotherapy, electrodessication, carbon dioxide laser and surgery causing patients discomfort and pain, pigmentary changes or necessitate multiple office visits. Additionally, there are precancerous lesions that necessitate non-invasive treatment with good esthetic results or skin cancer refractory to invasive techniques. Imiquimod is an immune response modifier approved by the FDA for the treatment of AK and superficial BCC lesions and its use is gradually expanded to various off-label precancerous and cancerous skin lesions.