Survival in Colon, Rectal and Small Intestinal Cancers in the Nordic Countries through a Half Century

Simple Summary Survival in colon and rectal cancers has internationally developed well, although reliable data span essentially only two decades. For small intestinal cancer, fewer data are available but survival appears to be improving. Overall, the exact causes of survival improvements are not known. During the 50-year period, 5-year survival in colon and rectal cancers improved linearly in Norway, while in Finland and Sweden the rate of improvement decreased with time, which is the opposite to Denmark where the rate increased. In small intestinal cancers, the rate of improvement was linear or increasing. The remarkable Danish achievement of improving relative survival rates more than the other counties coincided with cancer policy planning and instigating economically backed organizational and infrastructural improvements. The slowing survival rates in the other countries call for optimization of the available resources and a search for novel approaches. Background: Survival studies in intestinal cancers have generally shown favorable development, but few studies have been able to pinpoint the timing of the changes in survival over an extended period. Here, we compared the relative survival rates for colon, rectal and small intestinal cancers from Denmark (DK), Finland (FI), Norway (NO) and Sweden (SE). Design: Relative 1-, 5- and 5/1-year conditional survival data were obtained from the NORDCAN database for the years 1971-2020. Results: The 50-year survival patterns were country-specific. For colon and rectal cancers, the slopes of survival curves bended upwards for DK, were almost linear for NO and bended downwards for FI and SE; 5-year survival was the highest in DK. Survival in small intestinal cancer was initially below colon and rectal cancers but in FI and NO it caught up toward the end of the follow-up. Conclusions: Relative survival in intestinal cancers has developed well in the Nordic countries, and DK is an example of a country which in 20 years was able to achieve excellent survival rates in colon and rectal cancers. In the other countries, the increase in survival curves for colon and rectal cancer has slowed down, which may be a challenge posed by metastatic cancers.