Abstract
Actinic keratosis is a complex clinical disease for which no clear method exists to predict whether a given lesion will regress, remain stable or progress to non-melanoma skin cancer. Treating all (including subclinical) lesions with field-directed therapy to lower the risk of malignant transformation has been an important evolution in actinic keratosis management. In selected patients, lesion-directed approaches continue to occupy an important role. Despite the associated issues, cryotherapy remains standard of care. Early evidence with a new topical lesion-directed treatment containing low-dose-5-fluorouracil 0.5%/salicylic acid 10% suggests relevant advantages over cryotherapy in terms of sustained lesion clearance. For a condition with such a high global prevalence, remarkably little is known about the economic burden of actinic keratosis and relative cost–effectiveness of the various treatment modalities. Several questions need to be addressed if the challenges of increasing numbers of cases in years ahead are to be met.
Financial & competing interests disclosure
B Thiers, J-C Simon and M Augustin received honoraria from Laboratorios Almirall, SA (Barcelona, Spain) for participating in the symposium and producing this review article. J-C Simon has served as an advisory board member to, has received speakers honoraria from and has participated in clinical trials sponsored by Laboratorios Almirall. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.
Writing assistance was provided by Content Ed Net, with funding from Laboratorios Almirall, SA.
Key issues
• Actinic keratosis is one of the most common diagnoses made by dermatologists.
• The clinical significance of actinic keratosis relates to its high prevalence, increasing incidence and risk of transformation to non-melanoma skin cancer.
• Visible lesions are generally accompanied by multiple subclinical lesions in the surrounding photo-damaged skin.
• There is no method, either clinical or histopathological, of determining which lesion/s will progress to squamous cell carcinoma.
• Cryotherapy has been the treatment of choice for lesion-directed therapy of actinic keratosis but the method is not standardized and lesion recurrence is common.
• In a pilot Phase II study, recurrence rates 6 months after the end of treatment were significantly lower with low-dose-5-fluorouracil 0.5%/salicylic acid 10% (low-dose 5-FU/SA) than with cryotherapy (39 vs 85%; p < 0.0001).
• Given the expected increase in the number of actinic keratosis cases as the population ages, economic evaluation of the burden of disease and cost–effectiveness of treatment options is clearly warranted.