Trends in incidence, treatment, and relative survival of colorectal cancer in the Netherlands between 2000 and 2021.

ABSTRACT

BACKGROUND: The epidemiology of colorectal cancer (CRC) has changed rapidly over the years. The aim of this study was to assess the trends in incidence, treatment, and relative survival (RS) of patients diagnosed with CRC in the Netherlands between 2000 and 2021. PATIENTS AND METHODS: 2 75667 patients diagnosed with CRC between 2000 and 2021 were included from the Netherlands Cancer Registry. Analyses were stratified for disease extent (localised T1-3N0M0; regional T4N0M0/T1-4N1-2M0; distant T1-4N0-2M1) and localisation (colon; rectum). Trends were assessed with joinpoint regression. RESULTS: CRC incidence increased until the mid-2010s but decreased strongly thereafter to rates comparable with the early 2000s. Amongst other trend changes, local excision rates increased for patients with localised colon (2021 13.6 %) and rectal cancer (2021 34.9 %). Moreover, primary tumour resection became less common in patients with distant colon (2000-2021 60.9-12.5 %) or rectal cancer (2000-2021 47.8-6.9 %), while local treatment of metastases rates increased. Five-year RS improved continuously for localised and regional colon (97.7 % and 72.0 % in 2017, respectively) and rectal cancer (95.2 % and 76.3 % in 2017, respectively). The rate of anti-cancer treatments decreased in distant colon (2010-2021 80.3 % to 67.2 %; p < 0.001) and rectal cancer (2011-2021 86.0 % to 77.0 %; p < 0.001). The improvement of five-year RS stagnated for distant colon (2010-2017 11.2 % to 11.9 %; average percentage of change [APC] 2.1, 95 % confidence interval [CI] -7.6, 4.7) and rectal cancer (2009-2017 12.7 % to 15.6 %; APC 1.4, 95 % CI -19.1, 5.5). CONCLUSIONS: Major changes in the incidence and treatment of CRC between 2000 and 2021 were identified and quantified. Five-year RS increased continuously for patients with localised and regional CRC, but stagnated for patients with distant CRC, likely caused by decreased rates of anti-cancer treatment in this group.