Phototherapy with ultraviolet radiation is gaining importance in hospital dermatology departments because of its high therapeutic efficacy in various skin diseases and its relatively low cost. Narrowband UV-B phototherapy involves simple exposure of the skin to various doses of a light source that emits electromagnetic radiation at around 311nm. Consequently, cumulative exposure to UV-B could lead to adverse effects on chromophores such as cellular DNA and expose the patient to a risk of photocarcinogenesis in the long term.

In the present study, Ortiz-Salvador et al1 provide a complete retrospective analysis of the potential impact of narrowband UV-B phototherapy on the generation of skin cancer in a series of 474 patients followed for a mean of 5.8 years after cumulative exposure to this type of radiation. Although the results cannot be extrapolated to the general population, the number of patients included and the duration of follow-up point us toward conclusions that are at least locally interesting, namely, application of high-dose narrowband UV-B phototherapy over a specific period does not seem to significantly increase the risk of nonmelanoma skin cancer beyond the normal risk of cumulative actinic damage sustained during an individual's lifetime.