The Impact of Follow-up Colonoscopy on Survival in a Fecal Immunochemical Test-Based Colorectal Cancer Screening Program: A Nationwide Study.

Background: Various colorectal cancer screening programs are thought to be responsible for the decline in colorectal cancer incidence and mortality in developed countries. Few recently published studies indicate that a lot of patients do not fully complete the pre-planned colorectal cancer screening. Currently, there is a lack of high-volume data examining patient compliance and its impact on the screening program results.

Objective: To assess the relationship between participation and compliance within the program and mortality of patients that participate in the screening program.

Design: Large database cohort study.

Settings: Nationwide colorectal cancer screening program of a European Union country (Lithuania).

Patients: Data of patients aged 50-74, who participated in the colorectal cancer screening program from January 2013 to December 2019, were extracted from a national database.

Main outcome measures: Mortality data was extracted on all persons, who died from 2013 to December 2020. Patients were divided into four groups according to their adherence to the colonoscopy screening program.

Results: A total of 1,521,394 patients participated in the screening program. Positive fecal immunochemical test was detected for 127,503 (8.3%) patients, 55,202 (43.3%) of them proceeded with further colonoscopy. Patients with a negative fecal immunochemical test had the lowest mortality rates and the ones with a positive fecal immunochemical test but without undergoing a follow up colonoscopy had the worst ones with 4.9% and 8.6% respectively, p < 0.001. Logistic regression model indicated that patients with a positive fecal immunochemical test and without a subsequent colonoscopy had a significantly increased mortality risk (OR 2.18; 95% CI: 2.12-2.24; p < 0.001).

Limitations: Lack of data on timing of colonoscopy, comorbidities, lifestyle factors, or previous medical history.

Conclusions: Our study indicates that non-compliers with colonoscopy, especially women, after a positive fecal immunochemical test are at a significantly increased all-cause mortality risk. See Video Abstract.