Norway study finds incidence of thin melanoma is increasing faster than that of other kinds

Norway ranks third in the world when it comes to the incidence of melanoma (formerly called mole cancer) and has the highest mortality from this disease in Europe. University of Oslo post-doctoral fellow Raju Rimal and professor Marit B. Veierød have studied the evolution of melanoma incidence during the period 1983-2019.

They collaborated on this research at the Department of Biostatistics at the Institute of Basic Medical Sciences. Their research is published in the journal Acta Dermato-Venereologica . Important to investigate melanoma trends "In order to understand the incidence of this disease and to prevent melanoma, it is important to investigate trends in incidence," says Veierød.



"We found a substantial increase in the incidence of thin melanoma measuring under one millimeter, and an increase in the incidence of thicker melanoma. The rate of incidence of thicker melanoma is higher among men than women and this difference between the genders increases with age," explains Rimal. "The results of this study show that there is clearly a need for more awareness about skin changes that grow rapidly, especially in older adults and men," emphasizes Veierød.

The incidence curve flattens out in an inexplicable way During the period of years studied, over 45,000 patients were diagnosed with melanoma in Norway. The incidence of thin melanoma increased substantially from 1983 to 1990. This was followed by a period when there was no increase, before there was again a sharp increase from 2004.

The researchers explain that they have not yet found an explanation for this 15-year flattening out period, and found no such flat period in the incidence of thicker melanoma. Follow the advice on sun exposure and get to know your own body Melanoma can be prevented by following sun-smart rules. It is important to detect melanoma at an early stage and the Norwegian Cancer Society therefore urges people to keep a close eye on changes in their skin and changes in existing moles.

More information: Raju Rimal et al, Trends in Invasive Melanoma Thickness in Norway, 1983–2019, Acta Dermato-Venereologica (2024). DOI: 10.2340/actadv.

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