Prioritisation by FIT to mitigate the impact of delays in the 2-week wait colorectal cancer referral pathway during the COVID-19 pandemic: a UK modelling study

Abstract

ObjectiveTo evaluate the impact of faecal immunochemical testing (FIT) prioritisation to mitigate the impact of delays in the colorectal cancer (CRC) urgent diagnostic (2-week-wait (2WW)) pathway consequent from the COVID-19 pandemic.DesignWe modelled the reduction in CRC survival and life years lost resultant from per-patient delays of 2–6 months in the 2WW pathway. We stratified by age group, individual-level benefit in CRC survival versus age-specific nosocomial COVID-19–related fatality per referred patient undergoing colonoscopy. We modelled mitigation strategies using thresholds of FIT triage of 2, 10 and 150 µg Hb/g to prioritise 2WW referrals for colonoscopy. To construct the underlying models, we employed 10-year net CRC survival for England 2008–2017, 2WW pathway CRC case and referral volumes and per-day-delay HRs generated from observational studies of diagnosis-to-treatment interval.ResultsDelay of 2/4/6 months across all 11 266 patients with CRC diagnosed per typical year via the 2WW pathway were estimated to result in 653/1419/2250 attributable deaths and loss of 9214/20 315/32 799 life years. Risk–benefit from urgent investigatory referral is particularly sensitive to nosocomial COVID-19 rates for patients aged >60. Prioritisation out of delay for the 18% of symptomatic referrals with FIT >10 µg Hb/g would avoid 89% of these deaths attributable to presentational/diagnostic delay while reducing immediate requirement for colonoscopy by >80%.ConclusionsDelays in the pathway to CRC diagnosis and treatment have potential to cause significant mortality and loss of life years. FIT triage of symptomatic patients in primary care could streamline access to colonoscopy, reduce delays for true-positive CRC cases and reduce nosocomial COVID-19 mortality in older true-negative 2WW referrals. However, this strategy offers benefit only in short-term rationalisation of limited endoscopy services: the appreciable false-negative rate of FIT in symptomatic patients means most colonoscopies will still be required.

Predicting endoscopic activity recovery in England after COVID-19: a national analysis

“…Enhanced vetting of referrals has been used in 77% of recovery plans and has helped to reduce demand. 23 FIT has increasingly been used across the NHS to triage patients for lower gastrointestinal investigation, and recommendations were released in March, 2020, for FIT triaging to be used for patients who were symptomatic in primary care 8 , 24 We show here that FIT could reduce the colonoscopy backlog, if patients with haemoglobin concentrations less than a set FIT threshold are not offered endoscopy. Studies have found that FIT with 10 μg or less haemoglobin per g has a negative predictive value of greater than 99%, with the colorectal cancer risk in patients who are symptomatic similar to the baseline risk.…”

“…Loveday and colleagues suggested that using a FIT cutoff of 10 μg haemoglobin per g could reduce urgent 2-week-wait suspected cancer endoscopies to 18% of usual requirements, if we assume the remaining 82% of patients are not offered endoscopy. 8 NHS England has recommended that a threshold of more than 10 μg haemoglobin per g is used to proceed to colonoscopy, with patients who have concentrations less than the threshold offered safety netting. 10 Data for the proportion of procedures that were on a 2-week-wait pathway was unavailable, but we estimated this proportion using data for indications for colonoscopy.…”

“… 7 Several strategies, such as use of faecal immunochemical testing (FIT) for triaging, have been suggested, but there is little information as to how use of this procedure might affect the endoscopy backlog nationally. 8 Since December, 2020, the rise in COVID-19 infections associated with the second peak of the pandemic has led to reports of a further reduction in endoscopic services, adding additional pressure to already overstretched services.…”

COVID-19 and Gastrointestinal Disease: Implications for the Gastroenterologist

“…Use of FIT10 would allow detection of 80–90% of the cancers in a cohort with the need to urgently colonoscope only 10% of the patients [ 128 , 129 ]. Modelling suggests that use of FIT10 could salvage 90% of the life years lost due to cancer diagnosis delays [ 130 ]. Calprotectin is already established for IBD diagnosis and monitoring [ 131 ].…”

The Impact of Changes in Service Delivery in Patients With Colorectal Cancer During the Initial Phase of the COVID-19 Pandemic

“…‘Shielding’ is a national measure to protect all those identified as ‘clinically extremely vulnerable’ from COVID-19 through a set of social restrictions including avoiding face-to-face contact, which was especially stringent during the first wave of the pandemic [ 4 ]. Significant alterations in colorectal cancer service delivery with disruptions in the screening and diagnostic pathways, the surveillance endoscopies, as well as in the delivery of radiotherapy systemic treatment to patients with diagnosed colorectal cancer have been reported [ 5 , 6 , 7 ]. Even with the provision of alternative screening tests to mitigate the risks of these unprecedented changes, the impact on the personal lives and psychological wellbeing of patients with cancer is largely unknown.…”