Survival in colon and rectal cancer through 50 years

Global survival studies have shown favorable development in colon and rectal cancers but few studies have considered extended periods or covered populations for which medical care is essentially free of charge. In this survey colon and rectal cancer survival in Finland and Sweden over a 50-year period (1967-2016) have been analysed.  In addition to the standard 1-year and 5-year survival rates, we calculated the difference between these as a novel measure of how well survival was maintained between years 1 and 5. Overall the survival gains were higher in the early compared with the late follow-up periods, and were the smallest in the last 10 years. The difference between 1-year and 5-year survival in colon cancer was essentially unchanged over the 50-year period while in rectal cancer there was a large improvement. The gradual positive development in survival suggests a contribution by many small improvements rather than single breakthroughs. The improvement in 5-year survival in colon cancer was almost entirely driven by improvement in 1-year survival while in rectal cancer the positive development extended to survival past year 1, probably due to successful curative treatments.