The Role of Field Cancerization in Selecting Therapies for Actinic Keratosis: An Expert Consensus Panel

Background: Actinic keratosis is a very common disease that affects over 40 million people in the United States. In addition to the clinically visible lesion, patients may present with surrounding field cancerization based on their history of ultraviolet exposure. While lesion-directed therapy such as cryosurgery can effectively treat individual actinic keratoses it does not treat subclinical lesions or field cancerization. Objective: To create consensus recommendations on the role of field cancerization in selecting appropriate therapy for actinic keratoses. Methods: A comprehensive literature search of PubMed, Google Scholar, and Embase was conducted using the keywords “actinic keratos*,” “treatment,” and “field cancerization” for English-language original research articles without date restrictions. Articles were included that either discussed the role of FC in treating AKs or compared various AK field therapies. The relevant articles were then distributed to a panel of nine dermatologists with significant expertise in managing AKs. Each panelist reviewed the articles and assigned them a level of evidence based on Strength of Recommendation Taxonomy (SORT) criteria. The panel then convened on to discuss the studies and develop consensus statements on the role of FC in selecting AK therapy. The panel utilized a modified Delphi process to approve the adoption of each statement and gave each one a strength of recommendation based on SORT criteria. Results: The initial literature search produced 243 articles that met search criteria. After a thorough screening of these articles for relevance to the research question, 21 articles were chosen to be reviewed by the panel and assigned a level of evidence. Of the 21 articles that were reviewed, the panel assigned level 1 evidence to three articles, level 2 evidence to six articles, and level 3 evidence to twelve articles. The panel created seven consensus statements related to AK management and FC. All seven statements received a unanimous (9/9) vote for adoption. Each of the statements was given a strength of recommendation according to sort criteria Conclusion: Field cancerization due to chronic ultraviolet exposure leads to subclinical AK lesions in addition to lesions that are clinically apparent. In order to address these lesions, field therapy is an important component of an adequate regimen and can be used in conjunction with lesion-directed therapy for optimal results.