The impact of delayed screening colonoscopies during the COVID-19 pandemic on clinical outcomes.

Background: Colorectal cancer (CRC) screening services in Ireland were cancelled or postponed for periods during the COVID-19 pandemic. The aim of this study was to assess the impact of screening colonoscopy delays after a positive FIT on clinical and histopathological outcomes due to these restrictions.

Methods: Participants in the Irish National Bowel Screening Programme with a positive Immunochemical Faecal Test (FIT) during the COVID-19 pandemic (March 2020-December 2021) were included. Patients were categorised into attended for a colonoscopy <3 months and attended for colonoscopy ≥3-17 months post positive FIT. Chi-Square Test of independence was performed using WinPepi.

Results: 3227 individuals had a complete index colonoscopy <3 months and 262 attended colonoscopy from ≥3 to 17 months post positive FIT. Of the clients whose colonoscopy was between ≥3-17 months from positive FIT, the median wait time was 3 months. There was no significant difference found between the two groups for CRC (5.8 % vs 5.0 %, p=0.544) or for the proportion of cancer stage I, stage II and unknown (33.7 %, 40.6 %, 25.7 %, p=0.411). There was no difference in the proportions of adenomas (57.8 % vs 58.4 %, p=0.849) and the proportion of advanced adenomas (7.7 % vs 10.7 %, p=0.077) detected between the two groups. A similar proportion of polyps were detected in individuals whose index colonoscopies were postponed <3 months from positive FIT (66.9 % vs 66 %, p=0.786).

Conclusion: A median delay of 3 months in screening colonoscopies after a positive FIT does not adversely impact clinical or histopathological outcomes. There was no significant difference in cancer staging, advanced adenomas or polyps detected between those who attended colonoscopies <3 months and ≥3-17 months post positive FIT. COVID-19 related disruptions to the normal functioning of the Irish bowel screening programme did not compromise our key objectives of advanced adenoma and cancer detection.