Does progression from actinic keratosis and Bowen's disease end with treatment: diclofenac 3% gel, an old drug in a new environment?

Progression from actinic keratosis (AK) and Bowen's disease (BD) to invasive disease involves a complex cascade of events. The preparation of diclofenac 3% gel (Solaraze; Shire Pharmaceuticals) has been shown to be efficacious and well tolerated in AK. The inhibition of the COX enzymes results in a decrease in downstream by-products of arachidonic acid metabolism. These metabolites have been shown to play a pivotal role in promoting epithelial tumour growth. Given its mechanism of action, we hypothosize that diclofenac 3% gel may have potential to halt the progression of actinic keratoses (AKs) in the setting of field cancerisation and BD. We report a series of five patients with BD, all treated with diclofenac 3% gel with clinical and histological clearance.