Guaiac-based faecal occult blood tests versus faecal immunochemical tests for colorectal cancer screening in average-risk individuals

Routine Fecal Occult Blood Screening and Colorectal Cancer Mortality in Sweden

Importance

Population-based colorectal cancer (CRC) screening programs are implemented worldwide, but there are difficulties evaluating their effectiveness. The magnitude of routine CRC screening effectiveness regarding cancer-specific mortality is unclear.

Objective

To evaluate cancer-specific mortality associated with early vs late or no invitation for routine CRC screening using fecal occult blood testing.

Design, Setting, and Participants

This prospective cohort study was performed in the region of Stockholm-Gotland, Sweden, between January 1, 2008, and December 31, 2021. All individuals of the target population of screening born from 1938 to 1954 were included. Data were analyzed from December 12, 2022, to June 25, 2023.

Exposures

Individuals were invited early (2008-2012), late (2013-2015), or not at all to screening with biennial guaiac-based fecal occult blood test. The early invitation group was considered the exposure group and the late or no invitation group was considered the control group.

Main Outcomes and Measures

The main outcome was cancer-specific mortality, defined as CRC registered in the Cancer Register with CRC as underlying cause of death in the Cause of Death Register. Excess mortality was calculated as all-cause deaths among the individuals with CRC subtracted from the expected number of deaths had they not had CRC. Poisson regression analysis based on deaths and person-years was used to estimated mortality rate ratio (RR) with 95% CIs, adjusted for follow-up years and attained age.

Results

In total, 379 448 individuals (193 436 [51.0%] female) were invited for CRC screening, including 203 670 individuals in the exposure group and 175 778 in the control group. The mean screening participation rate was 63.3%, and there was a maximum of 14 years follow-up. There were 834 CRC deaths in 2 190 589 person-years in the exposure group, compared with 889 CRC deaths in 2 249 939 person-years in the control group. Individuals who underwent early CRC screening had reduced adjusted risk of CRC mortality (RR, 0.86; 95% CI, 0.78-0.95) and excess mortality (RR, 0.84; 95% CI, 0.75-0.93).

Conclusions and Relevance

This prospective cohort study of routine screening with fecal occult blood testing found a 14% decrease in CRC mortality associated with screening. The true association of screening with reduced mortality is expected to be higher due to some coexistence of testing in the control group and CRC deaths diagnosed more than 2 years after screening.

Reduction in colorectal cancer incidence by screening endoscopy

Colorectal cancer (CRC) incidence rates decreased by up to 50% in older age groups in the USA in the era of the widespread uptake of screening colonoscopy, despite adverse trends in CRC risk factors and increasing CRC incidence at younger ages. However, reported first results from a randomized trial, the NordICC study, suggested rather modest effects of screening colonoscopy. As outlined in this Perspective, the apparent discrepancy between real-world and trial evidence could be explained by strong attenuation of effect estimates from screening endoscopy trials by several factors, including limited screening adherence, widespread uptake of colonoscopy outside the screening offers and the inclusion of prevalent, non-preventable CRC cases in reported numbers of incident cases. Alternative interpretations of screening endoscopy trial results accounting for prevalence bias are in line with trends in CRC incidence reduction in countries offering CRC screening, and should encourage more widespread implementation and uptake of effective CRC screening.

A Review on Emerging Techniques for Diagnosis of Colorectal Cancer

Common detection methods in practice for diagnosing colorectal cancer (CRC) are painful and invasive leading to less participation of individuals for CRC diagnosis. Whereas, improved or enhanced imaging systems and other minimally invasive techniques with shorter detection times deliver greater detail and less discomfort in individuals. Thus, this review is a summary of the diagnostic tests, ranging from the simple potential use in developing a flexible CRC treatment to the patient's potential benefits in receiving less invasive procedures and the advanced treatments that might provide a better assessment for the diagnosis of CRC and reduce the mortality related to CRC.

Role of Artificial Intelligence in Colonoscopy Detection of Advanced Neoplasias : A Randomized Trial

BACKGROUND

The role of computer-aided detection in identifying advanced colorectal neoplasia is unknown.

OBJECTIVE

To evaluate the contribution of computer-aided detection to colonoscopic detection of advanced colorectal neoplasias as well as adenomas, serrated polyps, and nonpolypoid and right-sided lesions.

DESIGN

Multicenter, parallel, randomized controlled trial. (ClinicalTrials.gov: NCT04673136).

SETTING

Spanish colorectal cancer screening program.

PARTICIPANTS

3213 persons with a positive fecal immunochemical test.

INTERVENTION

Enrollees were randomly assigned to colonoscopy with or without computer-aided detection.

MEASUREMENTS

Advanced colorectal neoplasia was defined as advanced adenoma and/or advanced serrated polyp.

RESULTS

The 2 comparison groups showed no significant difference in advanced colorectal neoplasia detection rate (34.8% with intervention vs. 34.6% for controls; adjusted risk ratio [aRR], 1.01 [95% CI, 0.92 to 1.10]) or the mean number of advanced colorectal neoplasias detected per colonoscopy (0.54 [SD, 0.95] with intervention vs. 0.52 [SD, 0.95] for controls; adjusted rate ratio, 1.04 [99.9% CI, 0.88 to 1.22]). Adenoma detection rate also did not differ (64.2% with intervention vs. 62.0% for controls; aRR, 1.06 [99.9% CI, 0.91 to 1.23]). Computer-aided detection increased the mean number of nonpolypoid lesions (0.56 [SD, 1.25] vs. 0.47 [SD, 1.18] for controls; adjusted rate ratio, 1.19 [99.9% CI, 1.01 to 1.41]), proximal adenomas (0.94 [SD, 1.62] vs. 0.81 [SD, 1.52] for controls; adjusted rate ratio, 1.17 [99.9% CI, 1.03 to 1.33]), and lesions of 5 mm or smaller (polyps in general and adenomas and serrated lesions in particular) detected per colonoscopy.

LIMITATIONS

The high adenoma detection rate in the control group may limit the generalizability of the findings to endoscopists with low detection rates.

CONCLUSION

Computer-aided detection did not improve colonoscopic identification of advanced colorectal neoplasias.

PRIMARY FUNDING SOURCE

Medtronic.

Whole-Bacterium SELEX Aptamer Selection of Fusobacterium nucleatum and Application to Colorectal Cancer Noninvasive Screening in Human Feces

In terms of cancer diagnoses and cancer-related deaths worldwide, colorectal cancer (CRC) is now the third most common malignancy. The drawbacks of current screening methods are their exorbitant costs, difficult procedures, and lengthy implementation timelines. The benefits of fecal screening for CRC are ease of operation, noninvasiveness, cost-effectiveness, and superior sensitivity. As a result of its enrichment in the malignant tissues and feces of CRC patients, Fusobacterium nucleatum (F. nucleatum) has emerged as a crucial biomarker for the incipient detection, identification, and prognostic prediction of CRC. Here, for the first time, the whole-bacterium SELEX method was used to screen the highly specific and affinity aptamers against F. nucleatum by 13 cycles of selection. The Apt-S-5 linear correlation equation is y = 0.7363x2.8315 (R2 = 0.9864) with a limit of detection (LOD) of 851 CFU/mL. The results of the experiment using fecal samples revealed a substantial disparity between the microorganisms in the CRC patients' feces and those in the feces of healthy individuals and were consistent with those of qPCR. The aptamers may therefore offer a crucial approach to identifying F. nucleatum and hold tremendous promise for CRC diagnosis and prognostic prediction.

Performance of the Fecal Immunochemical Test in Detecting Advanced Colorectal Neoplasms and Colorectal Cancers in People Aged 40-49 Years: A Systematic Review and Meta-Analysis

BACKGROUND

The incidence of early-onset colorectal cancer (CRC) is increasing. Many guidelines recommend initiating screening at 45 years. This study investigated the detection rate of advanced colorectal neoplasm (ACRN) by using fecal immunochemical tests (FITs) in individuals aged 40-49 years.

METHODS

PubMed, Embase, and Cochrane Library databases were searched from inception to May 2022. The primary outcomes were the detection rates and positive predictive values of FITs for ACRN and CRC in people aged 40-49 (younger age group) and ≥50 years (average risk group).

RESULTS

Ten studies with 664,159 FITs were included. The FIT positivity rate was 4.9% and 7.3% for the younger age and average risk groups, respectively. Younger individuals with positive FIT results had significantly higher risks of ACRN (odds ratio [OR] 2.58, 95% confidence interval [CI] 1.79-3.73) or CRC (OR 2.86, 95% CI 1.59-5.13) than did individuals in the average-risk group, regardless of FIT results. Individuals aged 45-49 years with positive FIT results had a similar risk of ACRN (OR 0.80, 95% CI 0.49-1.29) to that of people aged 50-59 years with positive FIT results, although significant heterogeneity was observed. The positive predictive values of the FIT were 10-28.1% for ACRN and 2.7-6.8% for CRC in the younger age group.

CONCLUSION

The detection rate of ACRN and CRC based on FITs in individuals aged 40-49 years is acceptable, and the yield of ACRN might be similar between individuals aged 45-49 and 50-59 years. Further prospective cohort and cost-effective analysis are warranted.

Joint Asian Pacific Association of Gastroenterology (APAGE)-Asian Pacific Society of Digestive Endoscopy (APSDE) clinical practice guidelines on the use of non-invasive biomarkers for diagnosis of colorectal neoplasia

Screening for colorectal cancer (CRC) is effective in reducing CRC related mortality. Current screening methods include endoscopy based and biomarker based approaches. This guideline is a joint official statement of the Asian Pacific Association of Gastroenterology (APAGE) and the Asian Pacific Society of Digestive Endoscopy (APSDE), developed in response to the increasing use of, and accumulating supportive evidence for the role of, non-invasive biomarkers for the diagnosis of CRC and its precursor lesions. A systematic review of 678 publications and a two stage Delphi consensus process involving 16 clinicians in various disciplines was undertaken to develop 32 evidence based and expert opinion based recommendations for the use of faecal immunochemical tests, faecal based tumour biomarkers or microbial biomarkers, and blood based tumour biomarkers for the detection of CRC and adenoma. Comprehensive up-to-date guidance is provided on indications, patient selection and strengths and limitations of each screening tool. Future research to inform clinical applications are discussed alongside objective measurement of research priorities. This joint APAGE-APSDE practice guideline is intended to provide an up-to-date guide to assist clinicians worldwide in utilising non-invasive biomarkers for CRC screening; it has particular salience for clinicians in the Asia-Pacific region.

Uptake patterns and predictors of colorectal cancer screening among adults resident in Spain: A population-based study from 2017 to 2020

Background

Although population screening has improved the early diagnosis of colorectal cancer (CRC), most cases are diagnosed in symptomatic patients. This study aimed to estimate the prevalence and evolution over time of uptake patterns to fecal immunochemical test (FIT) as a screening test for CRC among individuals aged 50-69 in Spain, and to determine the predictive factors for uptake patterns to this type of screening based on sociodemographic, health, and lifestyle characteristics.

Methods

A cross-sectional study with 14,163 individuals from the 2017 Spanish National Health Survey and the 2020 European Health Survey was performed, including as the main variable uptake pattern to FIT screening within the last 2 years, with which we analyzed sociodemographic factors, health status and lifestyle habits.

Results

38.01% of participants had undergone FIT in the previous 2 years, and from 2017 to 2020, a significant increase in the uptake rate for CRC was observed (2017: 32.35%, 2020: 43.92%, p < 0.001). The positive predictors to FIT uptake pattern included factors such as being between 57 and 69 years, having a higher educational level or a higher social class, having at least one chronic illness, frequent contact with the primary care physician, alcohol consumption and physical activity, while immigration and smoking habit were negative predictors.

Conclusion

In Spain, although the evolution of FIT uptake pattern over time is positive, the prevalence of FIT uptake is still low (38.01%), not reaching the level considered as acceptable in the European guidelines. Moreover, there are disparities in CRC screening uptake among individuals.

The multitarget fecal immunochemical test versus the fecal immunochemical test for programmatic colorectal cancer screening: a cross-sectional intervention study with paired design

BACKGROUND

Many screening programs for colorectal cancer (CRC) use the fecal immunochemical test (FIT) to triage individuals for colonoscopy. Although these programs reduce CRC incidence and CRC-related mortality, the detection of advanced precursor lesions (advanced adenomas and advanced serrated polyps) by FIT could be improved. As an alternative for FIT, the antibody-based multitargetFIT (mtFIT) has been proposed. The mtFIT measures three protein markers: hemoglobin, calprotectin, and serpin family F member 2. In a retrospective diagnostic accuracy study in a large colonoscopy-controlled series (n = 1284), mtFIT showed increased sensitivity for advanced neoplasia (AN), at equal specificity, compared to FIT (42.9% versus 37.3%; p = 0.025). This increase was mainly due to a higher sensitivity of mtFIT for advanced adenomas (37.8% versus 28.1% for FIT; p = 0.006). The present mtFIT study aims to prospectively validate these findings in the context of the Dutch national CRC screening program.

METHOD

The mtFIT study is a cross-sectional intervention study with a paired design. Eligible subjects for the Dutch FIT-based national CRC screening program are invited to perform mtFIT in addition to FIT. Samples are collected at home, from the same bowel movement, and are shipped to a central laboratory by postal mail. If either one or both tests are positive, participants are referred for colonoscopy. Detailed colonoscopy and pathology data are centrally stored in a national screening database (ScreenIT; Topicus, Deventer, the Netherlands) that is managed by the screening organization, and will be retrieved for this study. We aim to determine the relative sensitivity for AN, comprising of CRC, advanced adenomas and advanced serrated polyps, of mtFIT compared to FIT at an equal positivity rate. Additionally, we will use the Adenoma and Serrated Pathway to Colorectal CAncer model to predict lifetime health effects and costs for programmatic mtFIT- versus FIT-based screening. The target sample size is 13,131 participants.

DISCUSSION

The outcome of this study will inform on the comparative clinical utility of mtFIT versus FIT in the Dutch national CRC screening program and is an important step forward in the development of a new non-invasive stool test for CRC screening.

TRIAL REGISTRATION

Clinicaltrials.gov ; NCT05314309, registered April 6th 2022, first inclusions March 25th 2022 https://clinicaltrials.gov/ct2/results?cond=&term=NCT05314309&cntry=&state=&city=&dist =.