The Characterization of the Relationship Between Field Cancerization and Number of Actinic Keratoses

Abstract

Background:

Ultraviolet radiation is responsible for actinic keratoses (AKs) and neoplastic changes surrounding AKs, known as the field of cancerization (FoC). If fields are not appropriately identified and treated, patients remain at risk for developing precancerous lesions and malignant transformation.

Objective:

To assess the relationship between FoC and the number of AKs.

Methods:

A cross-sectional study was performed on patients with AKs and FoC. Fields were measured, and field characteristics were recorded.

Results:

One hundred patients (mean age 71.2 years; 23% female) with 148 FoC participated. Fields were dry (96%), depigmented (79%), and scaly (88%). Mean number of AKs per field was 6.8 [standard deviation (SD) = 7.3]. Mean FoC size was 75.3 cm² (SD = 75 cm²). One hundred and eleven (75%) of the 148 fields exceeded the Food and Drug Administration recommendations for AK field treatment (≤25 cm²). Number of AKs positively correlated with FoC size (P < .0001). Mean FoC size and the mean number of AKs differed among Investigator Global Assessment (IGA) grades (1-3; P = .0396 and P = .0254, respectively). IGA grade positively correlated with FoC size (P = .0041) and average number of AKs (P = .0022).

Conclusion:

When selecting AK therapy, dermatologists may consider FoC size, number of AKs, location, IGA grade, and individual risk factors.