Actinic keratoses seldom occur alone

The article by Nart et al. indicates a very important development regarding the awareness and understanding of non-melanoma skin cancer and its implications for clinical practice. It broadens our view on actinically damaged skin and cancerized fields in which actinic keratoses (AKs) resemble a crucial landmark among other signs such as atrophy, telangiectasia or pigmentation disorders. Individual AK lesion counts without consideration of the whole affected area should be abandoned. Future clinical studies should focus particularly on the global assessment of AK severity to provide treatment recommendations representing clinical reality more reliably. Two recently proposed assessment scales for AKs and the surrounding actinically damaged skin resemble a first step to adequately and comparably evaluate the entire AK field. Although first data indicate validity regarding the progression risk of invasive squamous cell carcinoma (SCC) and treatment monitoring, further research is needed to support these findings. Beyond subclinical changes, the cancerized field resembles a sort of evidence enabling the clinician to recognize an overmuch of actinic exposure. The patients’ awareness of this chronic disease should be improved, and adequate treatment modalities targeting the affected field should be considered. The acceptance of recurrent therapies could be increased, if the patients will be informed on realistic treatment aims such as controlling the cancerized field and preventing invasive carcinoma. Based on today’s data, aiming for hardly achievable complete eradication should not be the common foundation of treatment. In this context, the consequent use of sunscreens is another mandatory component to control field cancerization and, thus, the socioeconomic burden in terms of an ageing population. Various molecular/immunological/genetic alterations contribute to the complex and diverse histological and clinical findings of field cancerization. Some changes are common for both AK and SCC. Nonetheless, it is important to note that they can be clearly differentiated, and therefore, the term ‘disease continuum’ is not accurate as it supposes a linear progression. As long as we are not able to identify distinct predictive biomarkers to provide a reliable risk stratification on the development of invasive carcinoma, we should carefully evaluate AKs and the surrounding actinically damaged field. Precise knowledge on field cancerization is mandatory to determine the individual therapeutical need.