Non-melanoma Skin Cancer in Canada Chapter 3: Management of Actinic Keratoses

Abstract

Background Actinic keratosis (AK) and cheilitis (AC) are lesions that develop on photodamaged skin and may progress to form invasive squamous cell carcinomas (SCCs). Objective To provide guidance to Canadian health care practitioners regarding management of AKs and ACs. Methods Literature searches and development of graded recommendations were carried out as discussed in the accompanying introduction (chapter 1 of the NMSC guidelines). Results Treatment of AKs allows for secondary prevention of skin cancer in sun-damaged skin. Because it is impossible to predict whether a given AK will regress, persist, or progress, AKs should ideally be treated. This chapter discusses options for the management of AKs and ACs. Conclusions Treatment options include surgical removal, topical treatment, and photodynamic therapy. Combined modalities may be used in case of inadequate response. AKs are particularly common following the longterm immunosuppression in organ transplant patients, who should be monitored frequently to identify emerging lesions that require surgery.

Non-melanoma Skin Cancer in Canada Chapter 1: Introduction to the Guidelines

“…AKs (see chapter 3), 15 often referred to as solar keratoses, are premalignant keratotic lesions that occur mostly on sun-exposed skin of adults and carry a risk for progressing to invasive SCCs. 3,16 BCCs (see chapter 4) 17 and SCCs (see chapter 5) 18 are known collectively as keratinocyte carcinomas 19 : BCCs derive from basal keratinocytes, which normally reside at the deepest layer of the epidermis; SCCs arise from keratinocytes in the more superficial epidermal layers.…”

Essential Thrombocythemia: The Dermatologic Point of View

“…Diclofenac is a cyclooxygenase (COX) inhibitor, exerting its antitumor effects by inhibition of the COX-2 pathway and by inhibiting upregulation of the arachidonic acid cascade. 62 AKs can also be prevented by daily application of specific photoprotective creams with photolyase, which repairs DNA from the actinic damage.…”

“…However, the procedure is limited by the need for a sufficient light dose and an outdoor temperature. 62,63 Cryotherapy or cryosurgery with liquid nitrogen for individual lesions is quick and easily performed by the physician. The treatment is delivered using either spray or contact to destroy the epidermal keratinocytes by freezing.…”

“…The short-term cosmetic outcomes have been good. 62 Another treatment option is topical imiquimod cream, which acts as a toll-like receptor-7 agonist and inhibits tumor proliferation by modifying the immune response and promoting apoptosis. 66 For persistent lesions, surgery is required.…”

“…Ingenol mebutate offers patients field cancerization treatment within 2 or 3 days, depending on the distribution. 62 Diclofenac 3% gel is a nonsteroidal anti-inflammatory drug formulated with 2.5% hyaluronic acid. Diclofenac is a cyclooxygenase (COX) inhibitor, exerting its antitumor effects by inhibition of the COX-2 pathway and by inhibiting upregulation of the arachidonic acid cascade.…”