According to data from 1970 to 2019, Denmark and Finland lag behind Sweden and Norway in survival from liver cancer and pancreatic cancer. A researcher says that the Nordic countries can learn from each other and improve survival rates in the lagging countries.
Since 1970, liver cancer and pancreatic cancer have evolved from being definitely fatal to hope for curative treatment and a long life. This especially applies in Sweden and Norway, where the survival trends after 1 and 5 years have improved steeply.
Denmark and Finland differ from this trend, since survival for these types of cancer does not match the potential based on survival in Sweden and Norway.
According to a researcher, the results of a study that has analysed the long-term survival trends among people with liver and pancreatic cancer over the past 50 years should inspire doctors in Denmark and Finland to discuss with their colleagues in Sweden and Norway what they can do to improve treatment and survival.
“Our results show that there is certainly potential for doctors from some countries to learn from those in other countries to improve survival for these two types of cancer. However, our study also indicates that surgery does not seem to be a way to improve survival further, and we therefore need new medicine for these people to further improve survival,” explains Kari Hemminki, European Research Area Chair for Translational Oncology, Faculty of Medicine, Charles University Medical School, Pilsen, Czechia.
The research has been published in JHEP Reports.
Examined cancer data over 50 years
The researchers used data for Denmark, Norway, Sweden and Finland from the NORDCAN database, which contains information from these national cancer registries plus those in Iceland, the Faroe Islands and Greenland.
The Nordic registries are among the oldest in the world and have complete nationwide data on everyone with cancer and therefore provide unique insight into how well people with specific types of cancer have fared long term.
The researchers analysed relative 2- and 5-year survival trends for liver cancer and pancreatic cancer between 1970 and 2019 based on 5-year intervals.
“Liver and pancreatic cancer are among the most lethal types of cancer, and previously almost no one survived them. They do today, and determining survival trends and their causes and whether the countries differ is therefore interesting,” says Kari Hemminki.
Survival best in Norway and Sweden
The results show that survival after 1 year following a diagnosis of liver cancer has improved considerably in the past 50 years.
In 1970–1974, only 5–17% survived for more than 1 year in the four Nordic countries, but that increased to 40–55% in 2015–2019. Survival after 1 year was longest in Sweden and shortest in Finland during this period and better in Norway than in Denmark.
The trend was similar after 5 years, although the relative difference in survival increased.
Only 0–7% survived after 5 years in 1970–1974 versus 10% for men in Finland and 24% for men and women in Sweden and Norway in 2015–2019. In Denmark, 5-year survival was 15%, and women fared slightly better than men in Finland, with 12% surviving after 5 years.
The researchers found the same trend for pancreatic cancer. One-year survival in 1970–1974 was 10–12%. In 2015–2019, survival had risen to 32% for men in Finland and 44% for women in Norway. Again, Sweden and Norway had better survival than Denmark and Finland.
The same also applies to survival after 5 years. Only 2% survived 5 years in 1970–1974 versus 10–13% in Denmark and Finland and 14–17% in Sweden and Norway in 2015–2019.
“The data show that survival did not begin to improve substantially until 2000, when treatment and diagnosis changed and improved survival after both 1 and 5 years,” explains Kari Hemminki.
New types of medicine required
Kari Hemminki says that the improved survival results from earlier diagnosis and improved treatment.
For both types of cancer, preventing metastasis is crucial for survival, and if the cancer is diagnosed after it has metastasised, doctors are virtually powerless.
However, early diagnosis can enable doctors to surgically remove the cancer before metastasis. This combination of better early diagnosis and improved but not curative treatment has considerably improved survival since about 2000.
Kari Hemminki speculates that the economics of healthcare may affect survival, especially in Finland. The data show that Finland was doing relatively well in survival until 2000 but was unable to keep up when treatment in the other countries improved.
“But doctors in Denmark and Finland could benefit from reaching out to their colleagues in Sweden and Norway and determining what they are doing that is so successful in ensuring optimal survival,” says Kari Hemminki, who elaborates that he also thinks that surgical intervention has become so good that 1- and 5-year survival cannot be improved much more through surgery.
“Surgery seems to have reached its zenith in improving survival. The way forward is therefore even earlier diagnosis and developing new types of medicine. Unfortunately, clinical studies have shown that immunotherapy does not work very well for people with these types of cancer, which is why other treatments for cancer and metastasis are required,” concludes Kari Hemminki.