Introduction: In Denmark, malignant melanoma is among the most rapidly increasing cancer types. Malignant melanoma accounts for the majority of skin cancer-related deaths. Sunshine is the main cause of the increase seen in melanoma incidence. Within Denmark, Bornholm is the area that receives most sunshine. It is therefore relevant to compare incidence data between Denmark and Bornholm.
Material and methods: Incidence data from the period 1978-2007 were extracted from The National Cancer Database. Incidence rates were analysed to determine any difference between Bornholm and Denmark in total. A prognosis was made based on extrapolation of incidence data from 1978-2007.
Results: Incidence rates increased exponentially in Denmark as well as on Bornholm. A significant annual increase in incidence rates over the 1978-2007 period was found. The difference in incidence was estimated to be 3.4%. The annual increase was significantly higher on Bornholm than in the rest of Denmark, a 20% increase was assessed. The increase in incidence rates in malignant melanoma is supported by the literature. The difference between Bornholm and Denmark is possibly due to differences in behaviour that translate into differences in UV exposure.
Conclusion: If the current development continues, the incidence rate will increase more than 100% from 2007 to 2030. The effect of campaigns addressing behavioural sun exposure has yet to be recorded. UV exposure is expected to comprise the main reason for the difference in incidence rate between Bornholm and Denmark in total. More evidence is needed on the relation between malignant melanoma and UV radiation and socio-demographic conditions.