Actinic Keratosis as a Marker of Field Cancerization in Excision Specimens of Cutaneous Malignancies
Field cancerization is the process in which a singular cell accumulates genetic mutations following carcinogen exposure and then divides to create a “field” of monoclonal premalignant cells. In this study, microscopically identified actinic keratoses (AKs) were used as markers of field cancerization in all excision specimens of squamous cell carcinomas (SCCs), basal cell carcinomas (BCCs), and malignant melanomas (MMs) received by our institution’s dermatopathology department over a 3- to 6-month period. Our findings provide additional evidence for the theory of field cancerization, its association with cutaneous malignancies, and the need to assess the extent of field damage when determining treatment strategies.
Practice Points
- Clinically apparent and subclinical actinic keratoses usually are present in patients, a concept known as field cancerization, and it is important to treat both types of lesions.
- Actinic keratoses are present in the field of cutaneous malignancies, including basal cell carcinoma, squamous cell carcinoma, and melanoma.
We believe our findings are clinically relevant, as they provide additional evidence for the theory of field cancerization as demonstrated by the nonnegligible rates of AKs and thus field damage with malignant potential in the skin immediately surrounding cutaneous malignancies. The limitations of our study, however, include a small sample size; no consideration of the effects of prior topical, field, or systemic treatments; and lack of a control group. Nevertheless, our findings emphasize the importance of assessing the extent of field damage when determining treatment strategies. Clinicians treating cutaneous malignancies should consider the need for field therapy, especially in sun-exposed regions, to avoid additional primary tumors.16 Further research is needed, however, to identify optimal methods for quantifying field damage clinically and determining the most effective treatment strategies.
