Late effects among colorectal cancer survivors ≥5 years after diagnosis-a systematic scoping review

Colorectal cancer (CRC) survival is improving, yet long-term survivors remain at risk for cancer- and treatment-related late effects, which may emerge many years after diagnosis and treatment. We aimed to summarize evidence on late effects and their risk factors reported ≥5 years after CRC diagnosis, compared to cancer-free controls.

The literature search for this scoping review was conducted in PubMed, EMBASE, and Web of Science from inception to November 18, 2025. Primary research studies investigating late effects and providing relative risk estimates specifically ≥5 years after diagnosis were included. Risk of bias was assessed with the Newcastle-Ottawa-Scale. The study was registered with Open Science Framework, 10.17605/OSF.IO/JY6DX.

We identified 9 observational studies that reported relative risk estimates for late effects. Seven studies had a low risk of bias and 2 were at moderate risk. The most frequently investigated late effect was incidence of diabetes (5 studies). The highest relative risks were reported for immunity disorders (5-10 years hazard ratio [HR] = 4.56, 99% CI = 1.36 to 15.31), depression (>5 years HR = 2.65, 95% CI =1.61 to 4.36), and nutritional deficiency (5-10 years HR = 1.69, 99% CI = 1.38 to 2.08). Comorbidities at diagnosis, age at diagnosis, and treatment were the most common risk factors associated with late effects.

This scoping review found that even ≥5 years after diagnosis late effects requiring treatment are considerably more common among CRC survivors than cancer-free controls. The small number of studies and the broad spectrum of identified late effects highlight the need for extensive research to characterize late effects to improve long-term survivorship care.