Available data are insufficient to determine whether immediate treatment of all AKs, or a strategy of selective treatment for AKs that develop suspicious characteristics, result in different outcomes. An important information gap is how often squamous cell cancer metastasizes early in its course. The highest priorities for future research are controlled trials of different strategies for the long-term management of patients who have actinic keratoses; particularly multiple lesions; registry studies to assess morbidity and mortality related to squamous cell cancer in the elderly; and patient-centered research on patients preferences for, and quality of life related to, different treatments.