Nonadherence to Referral Colonoscopy Linked With Higher Risk of Dying from CRC

In adults with a positive fecal immunochemical test (FIT), nonadherence to a referral colonoscopy was associated with increased risks of colorectal cancer (CRC) and related death over up to 16 years of follow-up, according to study results communicated in a research letter published online ahead of print in Gastroenterology.

“The higher risk of dying from CRC in colonoscopy nonadherers can be attributed to both an increased likelihood of late-stage CRC diagnosed among nonadherers and early detection and removal of precancerous lesions facilitated by colonoscopy in adherers,” wrote corresponding author Kefeng Ding, PhD, of Zhejiang University School of Medicine in China, and study coauthors.

The population-based cohort study included nearly 75,000 people in China who underwent CRC screening, had a positive FIT, and were referred for colonoscopy. Among them, 42,353 underwent colonoscopy and were considered “adherers,” and 32,070 did not undergo colonoscopy and were considered “nonadherers.”

Per 1000 cases, the 10-year cumulative incidence of CRC was 12.84 among adherers compared with 17.15 among nonadherers. Ten-year cumulative mortality was 2.48 per 1000 cases among adherers compared with 5.63 among nonadherers, according to the study. Hazard ratios were 1.25 for CRC and 1.85 for CRC-related death in nonadherers compared with adherers.

Stratification by tumor location showed an increased risk for distal CRC and distal CRC-related death in nonadherers, but not for proximal CRC. Stratification by age revealed that among 40- to 49-year-olds, nonadherers had a 2.01-fold increased risk of CRC and a similar trend in CRC mortality.  

“In conclusion, individuals with positive FIT but [who] did not adhere to the referral colonoscopy had higher risk of CRC incidence and mortality. Moreover, the risk

elevation was more pronounced among younger adults,” researchers wrote. “The disparity of site-specific effectiveness of current screening strategy should be noted, and future efforts are needed to improve the benefits of colonoscopy screening for proximal CRC.”

Reference
Zhu Y, Li X, Hu Y, et al. Non-adherence to referral colonoscopy after positive fecal immunochemical tests increases the risk of distal colorectal cancer mortality. Gastroenterology. Published online August 18, 2023. doi:10.1053/j.gastro.2023.08.013