INTRODUCTION
Non-melanoma skin cancer (NMSC) causes significant patient morbidity and healthcare costs; therefore, there is a vested interest in expanding the prevention armamentarium available for high risk patients.
Fractional lasers (FLs) are used to manage various dermatologic conditions including photoaging, scarring, and dyspigmentation, and are currently being studied in the context of NMSC prevention due to their ability to modulate epidermal turnover and signaling molecules crucial for the skin's protective response against UV.1,2
Herein, the mechanistic theory and evidence for use of FLs for NMSC prevention will be reviewed.
Proposed Mechanism of Effect
FL treatments are thought to reduce risk of NMSC by directly reducing burden of photodamaged keratinocytes, as well as protecting against malignant transformation of keratinocytes. FLs treat skin in a pixelated manner, creating vertical microthermal treatment zones (MTZ) with intervening spared skin.1,3 Consequently, FL-induced injury promotes extrusion of damaged keratinocytes and stimulates epidermal regeneration by initiating the wound healing cascade, contributing to a decrease in clinical and histologic signs of photodamage.4-9
Further, FL may reduce risk of keratinocyte photocarcinogenesis by stimulating insulin-like growth factor (IGF-1) signaling, which is involved in UV-induced DNA damage repair.10-13 FL resurfacing increases IGF-1 levels and decreases occurrence of proliferating UV-damaged keratinocytes.11,14-16 One study found that FL treatment increased skin IGF-1 values by 60%, and in vivo, increased expression persisted for 2 years post-treatment.17,18
Fractional Lasers for Actinic Keratoses
Ablative Fractional Lasers
Further, FL may reduce risk of keratinocyte photocarcinogenesis by stimulating insulin-like growth factor (IGF-1) signaling, which is involved in UV-induced DNA damage repair.10-13 FL resurfacing increases IGF-1 levels and decreases occurrence of proliferating UV-damaged keratinocytes.11,14-16 One study found that FL treatment increased skin IGF-1 values by 60%, and in vivo, increased expression persisted for 2 years post-treatment.17,18
Fractional Lasers for Actinic Keratoses
FLs are being considered both as monotherapy and adjunctive therapy for treating actinic keratoses (AK), precancerous lesions which can progress to NMSC.19 Both ablative and non-ablative FLs have been explored with differing treatment effects dependent on the laser type and protocol.
Ablative Fractional Lasers
Ablative FLs (AFLs) thermally ablate epidermal and dermal tissue in MTZ, causing full-thickness skin injury in treated areas of actinic damage.3 Data currently suggests that AFLs are non-inferior to other available AK management options.20 AFL monotherapy reduced AKs by 60-75% in studies on both forearms and scalp.10,17,18 Further, a single AFL treatment was associated with sustained reduction of AKs for 36 months in one study (Table 1).18
