Table 3.

Summary of Main Findings of Studies Relevant to Colorectal Cancer Screening and COVID-19 Pandemic.

Authors & Reference#	Journal	Year Published	Main Findings
Johnson BA et al. [6]	Am J Surg	2020	A delay in surgeries for breast, lung, and colon cancer during the COVID-19 pandemic could decrease the chance of survival for patients.
Lantinga MA et al. [26]	Endoscopy	2021	Data from a database, encompassing 15 hospitals in the Netherlands were analyzed. Comparing the 15 March 2019–25 June 2019 period to the 15 March 2020–25 June 2020 period, it was seen that gastroscopies decreased by 57% and colonoscopies decreased by 55%.
Wassie MM et al. [27]	JGH Open	2021	A retrospective data analysis was performed to compare colonoscopy data from April–June 2019 to April–June 2020 in South Australia. Colonoscopies decreased by 51.1% in the COVID-19 time period, and 46.1% of colonoscopies were delayed by at least 6 months.
London JW et al. [28]	JCO Clin Cancer Inform	2020	Data from the TriNetX data network, encompassing 20 medical centers and more than 28 million patients total, were analyzed. Comparing March 2019 to March 2020, there was a 38.4% decrease in CRC screenings. Comparing April 2019 to April 2020, there was an 84.5% decrease.
Domper Arnal MJ [29]	Presented at: UEG Week; 3–5 October 2021 (virtual meeting)	2021	An unpublished study of hospitals in Spain found there was a 40.4% decrease in CRC diagnoses in March 2020–February 2021, as compared to March 2019–March 2020.
Maringe C et al. [30]	Lancet Oncol	2021	This UK population-based modelling study aimed to estimate the effects of COVID-19-related delays of CRC screening. Data for 24,975 people with CRC was collected, and the estimation of additional death toll was 1445 to 1563 people up to five years post-diagnosis.
Yong JH et al. [31]	J Med Screen	2021	This study utilized microsimulation models for two types of cancers, including CRC, to determine what effects COVID-19 could have on CRC in Canada. With a 6-month delay in regular screening, CRC incidence and death would increase by 2200 people and 960 people, respectively.
Kregting LM et al. [32]	Br J Cancer	2021	Microsimulation models were used to simulate screening restart strategies for different types of cancers. If delays (due to the pandemic) were not caught up with, the CRC death rate would increase by 2.5 per 100,000 people in the next 10 years.
Issaka RB et al. [33]	JAMA Netw Open	2021	A simulation model was used to predict CRC outcomes between 2020 and 2023 in the U.S., including delays associated with the COVID-19 pandemic. The model showed that there would be 1,176,942 to 2,014,164 less CRC screenings and 8346 to 12,894 fewer CRC diagnoses. Also, an increase in FIT could cause increases in CRC screenings (655,825) and diagnoses (2715).
Peprah D et al. [37]	Br J Radiol	2021	Evaluation of CTCs conducted from May to July 2020 at four English hospital trusts was performed. 224 patients were scanned; of these, 169 who were followed up with on the phone reported no COVID-19 symptoms within 14 days of the test.
MacLeod C et al. [38]	Colorectal Dis	2020	Colon capsule endoscopy is a screening method that can be carried out safely during the COVID-19 pandemic and can be used to triage for colonoscopy.
Wahezi SE et al. [39]	Best Pract Res Clin Anaesthesiol	2021	Telemedicine has greatly increased due to the COVID-19 pandemic and will continue to be practiced post-pandemic. More research on telemedicine is needed to better compare it to in-person visits.
Kadakuntla A et al. [40]	World J Gastrointest Oncol	2021	The delays in CRC screening during COVID-19 can be overcome by doing more stool-based tests, adjusting screening protocols, and implementing more telehealth. Telehealth has advantages including convenience and improving patient compliance.
Maclean W et al. [45]	Colorectal Dis	2020	An observational cohort study in the UK was conducted to evaluate how FIT could affect utilization of resources and triage to colonoscopy. They found using FIT decreased further progression to colonoscopy from 62% (pre-pandemic) to 34%, while no significant change in the diagnosis rate.
D’Souza N et al. [48]	Br J Surg	2021	From October 2017 to December 2019, a study of 50 hospitals in England including 9822 subjects showed that the sensitivity of fecal immunochemical tests for CRC was 97.7% and 92.2% at cut-off values of 2 and 10 μg hemoglobin per g of stool sample.
Carethers JM et al. [49]	Cancer Prev Res (Phila)	2020	Minority populations in the United States face additional challenges in receiving CRC screening (e.g., finances, transportation, etc.). Thus, the delays in CRC screening during the pandemic will increase their CRC risk.
Wilson R et al. [50]	Prev Med	2021	A cross-sectional online survey was conducted in the UK of over 7543 adults between August and September 2020, and follow-up interviews were conducted for 30 people. About 20% of participants indicated they would be less likely to go to a CRC screening test during the pandemic.
Mason MC et al. [51]	Cureus	2021	A cross-sectional study, done from January–April 2021, was performed (totaling 103 participants). Over 30% participants missed a routine colonoscopy during the pandemic.