Impairment of colorectal cancer screening during the COVID-19 pandemic.

We welcome the Article by Lucie de Jonge and colleagues, as it conveys important information on the effects of the COVID-19 pandemic on programmatic colorectal cancer screening, and underlines the notion that health-care systems must react to these unexpected disruptions with meaningful ad-hoc strategies. de Jonge and colleagues’ comparative modelling study assessed the short-term (2020–24) and long-term (up to 2050) effects of the pandemic by use of four microsimulation models for screening programmes in Australia, Canada, and the Netherlands. Although the short-term effects were relevant, the long-term effects were particularly concerning. For a 12-month disruption, up to 20·6% fewer colorectal cancer diagnoses might occur in the first year; and a maximum of 2·0% excess colorectal cancer deaths (for the period 2020–50) were predicted in the worst-case scenario when modelled in Australia. Importantly, applying countermeasures—eg, catch-up screening with increased capacity and workload—might mitigate these negative effects, keeping the increase in colorectal cancer mortality to 0·1% or lower across all three countries.

We wonder whether, compared with other national scenarios, de Jonge and colleagues’ findings might be over-optimistic in depicting the impact of the pandemic. In a paper examining the effect of COVID-19 on colorectal cancer screening in Italy, we applied a procedural model to estimate effects on stage shift and mortality. Our work, based on real-world data rather than on simulation models, suggested that a significant upstage migration of undetected cancers (3·0%) would occur after a delay of 7–12 months in programmatic colorectal cancer screening, and a significant increase in deaths (12·0%) would occur at 5 years after a delay of longer than 12 months in access to colonoscopy.

In September, 2020, partial data concerning colorectal cancer screening delays in Italy were presented by the National Screening Observatory, covering the period from January to September, 2020. The report depicts a reduction of 1 907 789 faecal immunochemical test (FIT) invitations (–42·0%) on a national scale with respect to the number of invitations in the same period in 2019. This difference was wider for the January–May interval (1 273 885 fewer tests; –47·3%) than for the June–September interval (633 904 fewer tests; –34·2%). Meanwhile, 967 465 individuals invited for a FIT did not undergo a FIT (–52·7% compared with 2019; 681 862 [–57·8%] fewer tests from January to May, and 365 603 fewer tests [–46·1%] from June to September). Assuming a return to 2019 performance levels, 3·0 months would be required to catch up with the shortfall from January to May, and 1·7 months to catch up with the June to September shortfall, thus approaching a 5-month delay for FIT only. Based on these numbers, an estimated 1168 colorectal cancers and 6667 advanced adenomas would have been missed in the January to September timeframe. We suspect that the situation might be even more worrisome, as restrictions and lockdowns in Italy began in March, thus the data provided by the observatory includes the months of January and February during which FIT would not have been disrupted. Furthermore, data on delays to, or missed, colonoscopies for those individuals with a positive FIT are not yet available. In the absence of ad-hoc re-invitations and completion of missed FIT rounds, coupled with colonoscopy recall for those with a previously positive FIT, the estimate of increased colorectal cancer mortality based on our modelling could be even worse during 2021. This trend is further indicated by data on rates of diagnosis in 2020. A survey by the Italian Federation of the Digestive Diseases Societies has shown that, compared with the same period in 2019, 11·9% fewer colorectal cancers were diagnosed between Jan 1 and Oct 31, 2020, in gastroenterology units alone. A worrisome reduction was also seen for gastric (–15·9%) and pancreatic cancers (–9·9%).

As shown by de Jonge and colleagues, the situation is critical in several countries, and different health-care systems should actively work to adjust screening pathways. At present, data suggest that after 1 year of the pandemic, colorectal cancer epidemiology could quickly move back to the pre-screening era. While keeping screening ongoing, proper prioritisation to address backlogs is required, given that the longer the accumulated delay, the higher the risks.

We declare no competing interests. LR is in receipt of investigator grant 21723 and LL of investigator grant 22234 from the Italian Foundation for Cancer Research.