In a nationwide Danish cohort study reported in JAMA Oncology, Nors et al found the 5-year risk of recurrence after surgery for stage I to III colorectal cancer decreased over time and the time to recurrence was shorter with a more advanced disease stage.
Study Details
The study used the Danish Colorectal Cancer Group Database to identify patients with stage I to III colorectal cancer who underwent primary surgery between January 2004 and December 2019. Stage-specific 5-year recurrence—reported as the cumulative incidence function of recurrence—was assessed for the surgery periods of 2004 to 2008, 2009 to 2013, and 2014 to 2019.
Key Findings
Among 34,166 patients with stage I to III colorectal cancer, 7,027 (20.6%) developed recurrence within 5 years after primary surgery. Among all patients, the 5-year cumulative incidence function of recurrence for colorectal cancer decreased over the three time periods from 26.9% to 22.2% (adjusted subdistribution hazard ratio [HR] vs first period = 0.82, 95% confidence interval [CI] = 0.78–0.87) and to 15.8% (adjusted subdistribution HR vs first period = 0.59, 95% CI = 0.56–0.62).
For colon cancer, the 5-year cumulative incidence function of recurrence decreased over the three time periods from 16.3% to 6.8% for stage I disease, from 21.9% to 11.6% for stage II disease, and from 35.3% to 24.6% for stage III disease. For rectal cancer, the 5-year cumulative incidence function of recurrence decreased over the three time periods from 19.9% to 9.5% for stage I disease, 25.8% to 18.4% for stage II disease, and 38.7% to 28.8% for stage III disease.
The median time from surgery to recurrence was 22.6 months in patients with stage I disease, 18.2 months in those with stage II disease (time ratio = 0.58, 95% CI =0.54–0.62, vs stage I disease), and 15.9 months in those with stage III disease (time ratio = 0.30, 95% CI = 0.28–0.32, vs stage I disease). The differences were consistent across all time periods.
Colorectal cancer detected through screening was associated with lower stage-adjusted risks of recurrence (subdistribution HR = 0.81, 95% CI = 0.73–0.91) vs colorectal cancer not detected through screening.
The investigators concluded: “In this cohort of patients with colorectal cancer, the risk of recurrence decreased in patients with stages I to III disease during the study period. Cancer detection by screening was associated with an even lower risk of recurrence. Time to recurrence differed according to…stage. Because the risk of recurrence was so low in selected patient groups, future research is warranted to explore risk-stratified surveillance protocols in patients with colorectal cancer.”
Claus Lindbjerg Andersen, PhD, of the Department of Molecular Medicine, Aarhus University Hospital, is the corresponding author of the JAMA Oncology article.
Disclosure: The study was funded by Novo Nordisk Foundation, Innovation Fund Denmark, Danish Cancer Society, and others. For full disclosures of the study authors, visit jamanetwork.com.
