Actinic keratoses (AKs) are epidermal lesions that occur in areas of long-term sun exposure. These AK lesions have been identified as an early clinical manifestation in the disease continuum of squamous cell carcinoma (SCC). The risk for AK lesions to develop into SCC has been reported to be as high as 6% to 10%,1 with an even greater percentage of AKs containing cells with mutations in photooncogenes (eg, p53). Furthermore, visible AK lesions usually indicate a larger area of subclinical photodamage (ie, field of cancerization) that can manifest as clinical AK. Current therapies for AK, including cryosurgery and fluorouracil, provide varying long-term clearance rates and cosmetic outcomes.
Stockfleth E, Christophers E, Benninghoff B, Sterry W. Low Incidence of New Actinic Keratoses After Topical 5% Imiquimod Cream Treatment: A Long-term Follow-up Study. Arch Dermatol. 2004;140(12):1542. doi:10.1001/archderm.140.12.1542-a