RESUMEN
BACKGROUND: The cost of topical treatments for actinic keratosis (AK) has historically been evaluated in relation to the number of lesions requiring treatment or simply by the price of a single tube/sachet of the drug used. OBJECTIVE: To demonstrate a new method of costing topical treatments in AK, which takes into account the actual cancerization area treated. METHODS: In order to evaluate the actual cost of each treatment, the official approval status of the drug was used to estimate the amount of cream needed per one cm2 . This value was then applied to the hypothetical cancerization area sizes to demonstrate the impact of the size treated on the actual cost of treatment. The price considered was the ex-factory price in Italy. RESULTS: Areas which could be treated with a single tube/sachet of Metvix® , Picato® , Aldara® , Solaraze® and Zyclara® were 200, 25, 25, 33.3 and 200 cm2 , respectively. For the treatment of smaller areas (<100 cm2 ), treatment with Metvix® was the most costly topical option in Italy. However, for the treatment of cancerization areas larger than 100 cm2 , Metvix® was the least expensive treatment option. Treatment with Metvix® was least long, requiring a single day of treatment for an area of up to 200 cm2 , compared with up to 224 days of treatment with Aldara® for the treatment of a similar size. CONCLUSION: Changing treatment costing strategy in the management of multiple AKs towards costing per cancerization area instead of costing per lesion is a much more accurate representation of the 'real world cost' for AK.