Success of Fecal Immunochemical Colorectal Cancer Screening Program Dependent on Colonoscopy Compliance

Internal view of the intestinal walls. Colonoscopy is the endoscopic examination of the large bowel and the distal part of the small bowel with a camera on a flexible tube. 3d render
Researchers analyzed whether non-compliance with colonoscopy following a positive FIT is associated with CRC incidence and mortality.

Improved intervention strategies are needed to ensure colonoscopy compliance among high-risk populations in order to decrease colorectal cancer (CRC) mortality. These findings, from a retrospective cohort study, were published in Gut.

Since 2002, a fecal immunochemical test (FIT) CRC screening program has been in operation in the Veneto region of Italy. Individuals aged 50-69 years were invited to submit a sample every 2 years. Positive FIT results (>20 mg Hb/g feces) prompted a telephone call urging the individual to schedule a pre-colonoscopy appointment. A cohort of the 1,127,093 participants were assessed for colonoscopy compliance after a positive result and for cancer outcomes.

A total of 113,008 individuals had ³1 positive result, 111,423 of whom were eligible for participation in this study.

Most participants (n=88,013) were compliant and underwent a colonoscopy while 23,410 were not. Among compliant and non-compliant individuals aged 60-69 years (50.9% and 55.1%), 56.1% and 54.6% were men, 4.03% and 3.77% were diagnosed with CRC, and 0.38% and 0.72% died from CRC, respectively.

Within 1 year of a positive FIT, 90.1% of compliers and 62.9% of non-compliers were diagnosed with CRC (P <.0001). Among compliers, CRC was diagnosed at stage 1 (46.8%), stage 2 (22.3%), stage 3 (25.7%), and stage 4 (5.2%) compared with 57.0%, 20.3%, 18.3%, and 4.4% (P =.014) among non-compliers, respectively. No differences in diagnosis stage were observed on the basis of compliance >1 year after a positive FIT (P =.90).

CRC incidence was decreased among women (adjusted hazard ratio [aHR], 0.84; 95% CI, 0.79-0.89) and individuals submitting more than 1 FIT (aHR, 0.50; 95% CI, 0.47-0.53) while it was increased among individuals aged 60-69 years during first FIT (aHR, 1.7; 95% CI, 1.59-1.80) and those non-compliant beyond 6 months (aHR, 3.68; 95% CI, 3.20-4.22).

CRC mortality was increased among individuals aged 60-69 years at first FIT (aHR, 1.88; 95% CI, 1.56-2.26).

This study may have been limited by not having access to data of colonoscopy compliance outside the program network.

These data indicated that the success of an FIT screening program was dependent on colonoscopy compliance and that the CRC mortality rate among non-compliers was double that of compliers. More effective compliance interventions are needed to decrease CRC mortality.


Zorzi M, Battagello J, Selby K, et al. Non-compliance with colonoscopy after a positive faecal immunochemical test doubles the risk of dying from colorectal cancer. Gut. Published online March 31, 2021. doi:10.1136/gutjnl-2020-322192