Improved survival for cancer patients in a large Nordic comparison
A comprehensive comparison of cancer survival between the Nordic countries shows improvements for all countries over time with previously observed differences attenuated. The reasons for these improvements are likely multifactorial. Previous studies comparing cancer survival between the Nordic countries have found marked differences, with a notably poorer survival in Danish patients.
In an updated comparison, researchers from Karolinska Institutet and representatives from each of the Nordic cancer registries have investigated cancer survival trends over the past 25 years. The researchers used high quality data from the population based national cancer registries of Denmark, Finland, Iceland, Norway and Sweden, including over two million patients diagnosed with cancer between 1990 and 2016. Survival at one and five years after diagnosis was estimated for cancers of the colon, rectum, lung, kidney, breast, uterus, ovary, prostate and malignant melanoma of the skin.
Both one- and five-year survival for most cancer types had continued to improve in all the Nordic countries, and previously observed differences between the countries had been attenuated. The improvements were particularly notable in Denmark, where survival is now similar to that of the other Nordic countries. The improvements are likely to reflect several different factors, such as earlier detection and diagnosis, improved treatment options and the implementation of national cancer plans, uniform treatment guidelines and patient pathways to provide optimal care.
Continued improvements in survival across countries and cancer types
“Our study shows a consistent general improvement in cancer survival in the Nordic countries across several types of cancer, indicating that the efforts made in each country to improve cancer care have been successful.” says first author Frida Lundberg, postdoctoral researcher at the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet. “Although we know there are differences between the health care systems in the Nordic countries, overall cancer survival is now very similar. Previous international comparisons have shown that the Nordic countries are among the countries with the highest cancer survival in the world. With the implementation and regular updates of national guidelines, cancer patients in the Nordic countries can expect to receive high quality care according to the best clinical practice.”
She continues: “There are still some differences between the Nordic countries, for instance in lung cancer where patients who survive the first year after diagnosis seem to have a better 5-year survival in Norway and Iceland compared to Sweden, Finland and Denmark. Our next step is to investigate lung cancer survival more closely by including information on disease characteristics. We will also investigate whether the improvements in survival are consistent over all ages.”
Why population-based cancer registries are needed
This study utilizes the NORDCAN database originating from a long-standing collaboration between the Nordic cancer registries, which are the oldest in the world.
“International cancer survival comparisons are a valuable reference resource for the National Health Services to assess the ‘state-of-play’ compared with other countries. The population-based cancer registries in the Nordic countries are key to monitor trends in cancer survival that reflect early-detection strategies, quality of clinical care, and the overall management of cancer patients, which is particularly important when new policies, practices and treatments are being introduced at large scale to patients” says author Mats Lambe, professor at the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet and contact person for the study.
”Trends in cancer survival in the Nordic countries 1990-2016: the NORDCAN survival studies”. Frida E Lundberg, Therese M-L Andersson, Mats Lambe, Gerda Engholm, Lina Steinrud Mørch, Tom Børge Johannesen, Anni Virtanen, David Pettersson, Elínborg J Ólafsdóttir, Helgi Birgisson, Anna L V Johansson, Paul C Lambert. Acta Oncologica, online 19 October 2020, doi: 10.1080/0284186X.2020.1822544