INTRODUCTION
Actinic cheilitis (AC), also known as actinic keratosis (AK) of the lips, is a common lesion of the lower lip caused by chronic exposure to ultraviolet light.1 Among sun-exposed populations, the prevalence of AC is nearly 10%, and most commonly affects white, older males.2 AC is characterized by scaling, dryness, edema, erythema, tenderness, fissuring, crusting, and discoloration of the affected lip.3 As a precancerous condition, anywhere from 10 to 30% of cases can potentially undergo malignant transformation into squamous cell carcinoma (SCC).4 Further, almost all SCCs located on the lower lip originate from AC.1
The current standard of care for actinic cheilitis includes cryotherapy, electrocautery, vermilionectomy, or laser ablation.5 While there are no FDA-approved topical therapies, retinoids, 5-fluorouracil, imiquimod, and photodynamic therapy are often used by practicing clinicians.6 While these procedures and topical methods confer acceptable clinical improvement, many are associated with significant side effects including pain, irritation, redness, edema, and significant downtime. The discomfort caused by these therapies often leads to patient-initiated discontinuation and, subsequent, reduced clinical efficacy. From the patient perspective, there is a need for less inflammatory, more comfortable treatment approaches for AC.
Topical DNA repair enzymes may serve as a promising option for the management of actinic cheilitis and the prevention of skin cancer development. Studies have demonstrated the efficacy of topical DNA repair enzymes, specifically, T4 endonuclease V (T4N5), in decreasing basal cell carcinomas, squamous cell carcinomas and actinic keratoses,7-9 however, these enzymes have yet to be studied in the management of AC. The
The current standard of care for actinic cheilitis includes cryotherapy, electrocautery, vermilionectomy, or laser ablation.5 While there are no FDA-approved topical therapies, retinoids, 5-fluorouracil, imiquimod, and photodynamic therapy are often used by practicing clinicians.6 While these procedures and topical methods confer acceptable clinical improvement, many are associated with significant side effects including pain, irritation, redness, edema, and significant downtime. The discomfort caused by these therapies often leads to patient-initiated discontinuation and, subsequent, reduced clinical efficacy. From the patient perspective, there is a need for less inflammatory, more comfortable treatment approaches for AC.
Topical DNA repair enzymes may serve as a promising option for the management of actinic cheilitis and the prevention of skin cancer development. Studies have demonstrated the efficacy of topical DNA repair enzymes, specifically, T4 endonuclease V (T4N5), in decreasing basal cell carcinomas, squamous cell carcinomas and actinic keratoses,7-9 however, these enzymes have yet to be studied in the management of AC. The
