Trials in rectal cancer have shown that radiotherapy (RT) decreases local recurrence rates, whereas the effects on survival are uncertain. Swedish and Norwegian oncologists have had different treatment recommendations. The aim was to evaluate local recurrence rates and survival in the two countries.
Between 1995 and 2012 rectal cancer patients registered in Sweden and Norway were analyzed, presenting population-based "real world" data.
Totally 29,029 Swedish and 15,456 Norwegian patients were analyzed. Resection for cure was performed in two-thirds of the patients. RT was given to 49% of Swedish patients, mainly short-course RT and to 26% of Norwegian patients, predominantly chemoradiotherapy (CRT). In Sweden, the proportion irradiated was stable whereas in Norway, an increase from 10% to 40% was seen. Local 5-year recurrence rates were initially higher in Norway (12%) than in Sweden (8%), whereas they were equally low (4%) during the latter time. No survival differences were seen, however, survival improved with time in both countries.
Two entirely different approaches to preoperative therapy resulted in similar survival with initially higher local recurrence rates in Norway, but similarly low rates in later years. This raises questions about optimal RT rates and regimens.