Actinic keratoses progress more quickly to squamous cell carcinoma than basal cell carcinoma

Actinic keratoses (AK) are common, costly, and may evolve to keratinocyte carcinoma (KC): basal cell (BCC) and squamous cell carcinoma (SCC) of the skin. Time to malignant transformation is controversial. We used data from the placebo arm (n=166) of a randomized trial of veterans with multiple prior KCs. Study dermatologists examined participants’ faces/ears at enrollment and semiannual visits. Clinically diagnosed AKs were marked, photographed,...