Comparative Effectiveness of Fecal Immunochemical Tests versus Flexible Sigmoidoscopy for Colorectal Cancer Screening: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

Abstract

Background and Aims: Fecal immunochemical tests (FITs) and flexible sigmoidoscopies are commonly used modalities for colorectal cancer (CRC) screening. We performed a systematic review and meta-analysis to compare the effectiveness of FIT and sigmoidoscopy in CRC screening.
 Methods: PRISMA statement and Cochrane guidelines were followed for this review. Digital dissertation databases were searched from inception till December 1st 2020 and randomized clinical trials comparing the detection rates of CRC for FIT and sigmoidoscopy were included. Outcomes for analysis included participation rates and detection rates of CRC, advanced adenomas and advanced colorectal neoplasia for both screening modalities.
 Results: Five randomized clinical trials with a total of 261,755 patients were included for the analysis. The participation rate for FIT was significantly higher compared to flexible sigmoidoscopy (OR 2.11, 95% CI 1.29-3.44, p=0.003). In intention-to-screen analysis, the detection rate for advanced colorectal neoplasia was significantly lower with FIT (OR 0.62, 95% CI 0.45-0.84, p=0.002) as compared to flexible sigmoidoscopy but not statistically different for CRC (OR 1.15, 95% CI 0.65-2.02, p=0.63).
 Conclusion: Despite lower participation amongst patients, CRC screening with flexible sigmoidoscopy leads to higher detection of advanced colorectal neoplasia, when compared to a single round of fecal immunochemical testing.

Characteristics of nonparticipants in a randomised colorectal cancer screening trial comparing sigmoidoscopy and faecal immunochemical testing

“…Reported participation rates in the European organised screening programmes or trials targeting 50 to 70 year-old individuals vary between 10% and 73% for faecal tests, between 15% and 52% for colonoscopy screening 2,4,5 and between 19% and 52% for sigmoidoscopy screening. 6 According to studies that used public registries, vulnerable demographic characteristics and low socioeconomic status are predictors of nonparticipation. In European nationwide organised screening programmes, uptake in faecal-based screening has been shown to be higher in women than in men and to increase with age up to 70 years.…”

Clinical Effectiveness of Faecal Immunochemical Test in the Early Detection of Colorectal Cancer—An Umbrella Review

“…The criteria for inclusion in a systematic review, including the assessment of the sensitivity, specificity, and/or clinical effectiveness of FIT in the detection of CRC, met the following scientific evidence (n = 13; Forbes 2021, Lin 2021, Mutneja 2021a, Mutneja 2021b, Gini 2020, Meklin 2020, Niedermaier 2020, Zhong 2020, Imperiale 2019, Selby 2019, Stonestreet 2019, Katsoula 2017, Zhang 2017): Forbes 2021—a systematic review based on 8 observational studies, which analysed the impact of specific time intervals from a positive FIT result to colonoscopy on the presence of CRC, the presence of advanced CRC at diagnosis, overall mortality, and CRC mortality [ 7 ]; Lin 2021—a meta-analysis of 223 publications (RCT and observational studies), which analysed the effectiveness and diagnostic precision of tests, and harms related to CRC screening as part of the USPSTF recommendation [ 8 ]; Mutneja 2021a—5 RCT meta-analyses comparing the effectiveness of FIT with sigmoidoscopy in screening for CRC [ 9 ]; Mutneja 2021b—a meta-analysis of 6 observational studies, evaluating the influence of the time after a positive colonoscopy following faecal occult blood test on CRC detection [ 10 ]; Gini 2020—a systematic review of 18 RCTs and observational studies comparing the impact of CRC screening on mortality in European regions [ 11 ]; Meklin 2020—a meta-analysis of 31 single-arm clinical trials assessing the diagnostic precision of FIT and gFOBT in screening tests [ 12 ]; Niedermaier 2020—a meta-analysis of 44 observational studies, determining the diagnostic precision of FIT depending on the stage of CRC stage [ 13 ]; Zhong 2020—6 RCT meta-analyses comparing the effectiveness of FIT and colonoscopy in detecting CRC in the intermediate-risk population [ 14 ]; Imperiale 2019—a meta-analysis of 31 observational studies, defining the diagnostic precision of FIT in the detection of CRC and advanced colorectal adenomas in people from the intermediate risk group undergoing screening colonoscopy [ 15 ]; Selby 2019—a meta-analysis of 46 observational studies, defining the diagnostic precision of FIT in the detection of CRC and advanced colorectal adenoma at different diagnostic thresholds in regards to gender and age [ 16 ]; Stonestreet 2019—a meta-analysis of 17 observational studies, assessing the diagnostic precision of FIT in the detection of CRC in symptomatic and asymptomatic people [ 17 ]; Katsoula 2017—a meta-analysis of 1 RCT and 11 observational studies, determining the diagnostic precision of FIT in the detection of CRC or advanced neoplasia of the large intestine in asymptomatic people at high risk [ 18 ]; Zhang 2017—a meta-analysis of 44 RCTs and observational studies, evaluating the effectiveness of screening methods in preventing CRC disease and death [ 19 ]; …”

“…Mutneja 2021a—5 RCT meta-analyses comparing the effectiveness of FIT with sigmoidoscopy in screening for CRC [ 9 ];…”

“…This is likely due to several factors, one of them being the test reporting level. The studies showed that people were more likely to participate in the FIT screening than in the screening using colonoscopy [ 14 , 41 , 42 ] or sigmoidoscopy [ 9 ]. In countries where CRC screening is based on FIT, the median reporting rate is 54% [95% CI: (49.28%; 58.69%)] [ 43 ].…”

Acceptability of alternative technologies compared with faecal immunochemical test and/or colonoscopy in colorectal cancer screening: A systematic review

“…for early detection of CRC in symptomatic patient groups where other and willingness to accept discomfort. 11 – 12 , 43 Mutneja's meta-analysis 44 did not include Kirkoen’s study 25 and compared an additional two studies that were not eligible in this review. The bowel preparation requirement was found to be a common barrier to completing a colonoscopy.…”