Norway ranks third in the world when it comes to the incidence of melanoma and we have the highest mortality from this disease in Europe.
With the help of national data from the Cancer Registry of Norway, post-doctoral fellow Raju Rimal and professor Marit B. Veierød have studied the trend of melanoma incidence during the period 1983-2019. They both work at the Department of Biostatistics at the Institute of Basic Medical Sciences.
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 below one millimetre, and an increase in the incidence of thicker melanoma. The incidence rate 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 of rapidly growing pigmented lesions, especially in older adults and men, emphasises Veierød.
The incidence curve has an unexplained plateau
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.
– We have not yet found an explanation for the plateau in the incidence of thin melanoma, and we found no such plateau 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 the sun-smart guidelines on the Norwegian Cancer Society’s webpage (in Norwegian). 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.
The study was funded by the Research Council of Norway and was carried out at the Department of Biostatistics at UiO in collaboration with scientists at the Cancer Registry of Norway, Oslo University Hospital, QIMR Berghofer Medical Research Institute in Brisbane, Australia and the International Agency for Research on Cancer in Lyon, France.
The study was highlighted as the Editor’s Choice in October:
Trends in Invasive Melanoma Thickness in Norway, 1983–2019 | Acta Dermato-Venereologica