Superior diagnostic performance of faecal immunochemical tests for haemoglobin in a head-to-head comparison with guaiac based faecal occult blood test among 2235 participants of screening colonoscopy

Clinical performance of fecal calprotectin, lactoferrin, and hemoglobin for evaluating the disease activity of IBD and detecting colorectal tumors

Background and Aim

Recently, noninvasive fecal markers have been used as indicators of intestinal inflammation in patients with inflammatory bowel disease (IBD). We conducted a clinical validation study to measure fecal calprotectin (Cp), lactoferrin (Lf), and hemoglobin (Hb) levels using an all-in-one kit in patients with IBD and colorectal tumors and aimed to clarify the utility of these fecal markers.

Methods

In this study, 104 patients were analyzed, including 25 patients with ulcerative colitis (UC), 20 with Crohn's disease (CD), 48 with colorectal tumors, and 13 healthy controls (HC). Of the 48 patients with colorectal tumors, 14 had invasive cancer. We validated the utility of fecal Cp, Lf, and Hb levels by simultaneously measuring fecal markers in patients with IBD and colorectal tumors.

Results

Fecal Cp and Lf had almost equivalent abilities in detecting clinical remission in patients with UC; however, fecal Cp was slightly superior to Lf. Regarding colorectal tumors, fecal Cp and Lf levels tended to be higher in patients with adenomas and colorectal cancer than in HCs. Although fecal Hb alone had the best sensitivity and specificity for detecting colorectal cancer, it had relatively low sensitivity for detecting advanced neoplasms and colorectal cancer.

Conclusion

Fecal Cp and Lf can be used as almost equivalent biomarkers to assess the clinical activity in patients with UC. Fecal Hb is the most useful marker for screening colorectal cancer; however, adding fecal Cp and Lf may compensate for the low sensitivity of detecting for advanced colorectal tumors based on Hb alone.

The association between organised colorectal cancer screening strategies and reduction of its related mortality: a systematic review and meta-analysis

BACKGROUND

To assess the long-term association between organised colorectal cancer (CRC) screening strategies and CRC-relate mortality.

METHODS

We systematically reviewed studies on organised CRC screening through PubMed, Ovid Medline, Embase and Cochrane from the inception. We retrieved characteristics of organised CRC screening from included literature and matched mortality (over 50 years) of those areas from the International Agency for Research on Cancer in May 2023. The variations of mortality were reported via the age-standardised mortality ratio. A random-effects model was used to synthesis results.

RESULTS

We summarised 58 organised CRC screening programmes and recorded > 2.7 million CRC-related deaths from 22 countries where rollout screening programmes were performed. The CRC screening strategy with faecal tests (guaiac faecal occult blood test (gFOBT) or faecal immunochemical tests (FIT)) or colonoscopy as the primary screening offer was associated with a 41.8% reduction in mortality, which was higher than those offered gFOBT (4.4%), FIT (16.7%), gFOBT or FIT (16.2%), and faecal tests (gFOBT or FIT) or flexible sigmoidoscopy (16.7%) as primary screening test. The longer duration of screening was associated with a higher reduction in the pooled age-standardised mortality ratio. In particular, the pooled age-standardised mortality ratio became non-significant when the screening of FIT was implemented for less than 5 years.

CONCLUSIONS

A CRC screening programme running for > 5 years was associated with a reduction of CRC-related mortality. Countries with a heavy burden of CRC should implement sustainable, organised screening providing a choice between faecal tests and colonoscopy as a preferred primary test.

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.

Impact of colorectal cancer screening on incidence, mortality and surgery rates: Evidences from programs based on the fecal immunochemical test in Italy

Fecal immunochemical tests (FIT) are among the most commonly used tests for colorectal cancer (CRC) screening programs worldwide. However, no randomised controlled trials have been carried out evaluating the impact of FIT-based screening programs (FIT-progr) on CRC incidence and mortality rates. Italian FIT-progr represent one of the most widespread and established experience worldwide. This paper reviews the evidence on the impact of FIT-progr on CRC incidence, tumor stage at diagnosis, mortality and surgery rates, deriving from Italian routine programs, i.e., outside the research setting. Unfortunately, the application of FIT-progr in Italy can be considered as an unplanned experimental model, due to the differences between Regions, both in health system management and adherence of the target population to the screening programs. The analysis of the manuscripts considered in the review, confirms that FIT-progr are effective in reducing CRC incidence and mortality rates and in improving the rate of endoscopic treatment of early invasive lesions. The review also highlights that FIT-progr are less performing for proximal colon than for distal colon and rectum.

Sensitivity of fecal immunochemical test and risk factors for interval colorectal cancer in a French population

BACKGROUND

Colorectal cancer (CRC) screening using fecal immunochemical testing (FIT) aims to detect pre-symptomatic colorectal lesions and reduce CRC mortality.

AIMS

The objectives of this study were to determine the FIT sensitivity for diagnosis of CRC, the impact of diagnostic circumstances on treatment and survival, and risk factors for interval cancer (IC).

METHODS

This population-based study evaluated the 2016-2017 CRC screening campaign in Finistère, France. CRCs were classified according to diagnostic circumstances: screen-detected CRC (SD-CRC), CRC with delayed diagnosis, IC after negative FIT (FIT-IC), post-colonoscopy CRC, CRC in non-responders and CRC in the excluded population.

RESULTS

This study included 909 CRCs: 248 SD-CRCs (6% of positive FIT) and 60 FIT-ICs (0.07% of negative FIT). The FIT sensitivity for CRC was 80.5% (CI95%: 76.1-84.9) at the threshold of 30 µg hemoglobin/g feces used in France. In multivariate analysis, proximal (OR:6.73) and rectal locations (OR:7.52) were associated with being diagnosed with FIT-IC rather than SD-CRC. The FIT positivity threshold maximizing the sum of sensitivity and specificity was found to be 17 µg/g, with 14 additional CRCs diagnosed compared to the current threshold.

CONCLUSIONS

Our study confirms the good sensitivity of FIT. A decrease of the FIT detection threshold could optimize sensitivity.

Positive Results from the Fecal Immunochemical Test Can Be Related to Dementia: A Nationwide Population-Based Study in South Korea

BACKGROUND

The fecal immunochemical test (FIT) is widely used in screening for colorectal cancer (CRC), but FIT results can be positive for diseases other than CRC.

OBJECTIVE

We investigated the association between positive results of FIT and the incidence of dementia using a nationwide database.

METHODS

FIT-positive participants were collected from a database provided by the Korean National Health Insurance Service.

RESULTS

The incidence of all kinds of dementia was higher in FIT-positive than FIT-negative subjects (p < 0.0001). FIT-positive participants had a higher risk of Alzheimer's disease (AD) (p < 0.0001) and vascular dementia (p = 0.0002), compared to participants with FIT negativity. The risk of all kinds of dementia or AD in FIT-positive participants was higher in younger (age < 65 years) than older participants (p < 0.0001 for all kinds of dementia; p = 0.0002 for AD).

CONCLUSION

FIT positivity was correlated with an increased risk of dementia, especially in participants under 65 years of age. The study suggests that clinicians can consider dementia when FIT-positive participants fail to show any malignancies.

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

Introduction: The colorectal cancer prognosis depends on the stage of the neoplasm; therefore, its early detection plays an important role. The aim of the study is evaluation of the sensitivity, specificity, and clinical effectiveness of the faecal immunochemical test in the early colorectal cancer detection. Methods: The clinical analysis was based on the results of the studies included in a systematic review conducted in accordance with the Cochrane Collaboration guidelines. The following medical information sources were searched: Medline (via PubMed), Embase (via Ovid), The Cochrane Library. Results: From 241 citations, 13 studies were included in this review. All included studies had a low risk of bias. The faecal immunochemical test is highly specific in all analysed populations ranging from 85% to 97%. In most of the found studies, sensitivity is over 75%. The faecal immunochemical test screening also determines a reduction in death (10-59%) due to colorectal cancer. Conclusions: The faecal immunochemical test is an effective and cost-effective method of conducting population-wide colorectal cancer screening. It is an alternative or complementary to other screening tests, including colonoscopy.

Proportion and stage distribution of screen-detected and non-screen-detected colorectal cancer in nine European countries: an international, population-based study

BACKGROUND

The effects of recently implemented colorectal cancer screening programmes in Europe on colorectal cancer mortality will take several years to be fully known. We aimed to analyse the characteristics and parameters of screening programmes, proportions of colorectal cancers detected through screening, and stage distribution in screen-detected and non-screen-detected colorectal cancers to provide a timely assessment of the potential effects of screening programmes in several European countries.

METHODS

We conducted this population-based study in nine European countries for which data on mode of detection were available (Belgium, Denmark, England, France, Italy, Ireland, the Netherlands, Slovenia, and Spain). Data from 16 population-based cancer registries were included. Patients were included if they were diagnosed with colorectal cancer from the year that organised colorectal cancer screening programmes were implemented in each country until the latest year with available data at the time of analysis, and if their age at diagnosis fell within the age groups targeted by the programmes. Data collected included sex, age at diagnosis, date of diagnosis, topography, morphology, clinical and pathological TNM information based on the edition in place at time of diagnosis, and mode of detection (ie, screen detected or non-screen detected). If stage information was not available, patients were not included in stage-specific analyses. The primary outcome was proportion and stage distribution of screen-detected versus non-screen detected colorectal cancers.

FINDINGS

228 667 colorectal cancer cases were included in the analyses. Proportions of screen-detected cancers varied widely across countries and regions. The highest proportions (40-60%) were found in Slovenia and the Basque Country in Spain, where FIT-based programmes were fully rolled out, and participation rates were higher than 50%. A similar proportion of screen-detected cancers was also found for the Netherlands in 2015, where participation was over 70%, even though the programme had not yet been fully rolled out to all age groups. In most other countries and regions, proportions of screen-detected cancers were below 30%. Compared with non-screen-detected cancers, screen-detected cancers were much more often found in the distal colon (range 34·5-51·1% screen detected vs 26·4-35·7% non-screen detected) and less often in the proximal colon (19·5-29·9% screen detected vs 24·9-32·8% non-screen detected) p≤0·02 for each country, more often at stage I (35·7-52·7% screen detected vs 13·2-24·9% non-screen detected), and less often at stage IV (5·8-12·5% screen detected vs 22·5-31·9% non-screen detected) p<0·0001 for each country.

INTERPRETATION

The proportion of colorectal cancer cases detected by screening varied widely between countries. However, in all countries, screen-detected cancers had a more favourable stage distribution than cancers detected otherwise. There is still much need and scope for improving early detection of cancer across all segments of the colorectum, and particularly in the proximal colon and rectum.

FUNDING

Deutsche Krebshilfe.

A positive faecal immunochemical test result and its association with the incidence of rheumatoid arthritis, systemic lupus erythematosus, and psoriatic arthritis: an analysis of one-million national colorectal cancer screening programme results

BACKGROUND

Accumulating evidence now indicates that the presence of faecal haemoglobin, in the absence of gastrointestinal bleeding, may be an indicator of systemic inflammation and is linked to the development of human diseases. We evaluated whether a positive faecal immunochemical test (FIT) is associated with the development of immune-mediated inflammatory diseases (IMIDs).

METHODS

Data from the nationwide colorectal cancer screening programme from 2009 to 2013 were used. Participants (n=8,646,887) were divided into FIT (+) and FIT (-) groups by performing a 1:1 random sampling matched by age and sex. Participants with concurrent haemorrhoids, colorectal cancer (CRC), inflammatory bowel disease (IBD), and missed CRC and IBD were excluded using the colonoscopy results, ICD-10 codes, and the special exemption code (V code). Endpoints were the incidence of IMIDs (rheumatoid arthritis [RA], systemic lupus erythematosus [SLE], and psoriatic arthritis [PsA]) after FIT.

RESULTS

Of the 1,044,955 eligible participants, 229,594 and 815,361 individuals were included in the FIT (+) and the FIT (-) groups, respectively. During the mean follow-up period of 7.59 years, a total of 7645 (incidence rate [IR] 9.56/10,000 person-years [PY]), 208 (IR 0.26/10,000 PY), and 101 (IR 0.13/10,000 PY) patients were diagnosed with RA, SLE, and PsA, respectively. An adjusted Cox analysis demonstrated that FIT positivity conferred a 1.16 (95% confidence interval [CI] 1.09-1.24, p<0.001) times greater risk of developing RA. Kaplan-Meier analysis in the 1:2 propensity-score matched population also confirmed these results (hazard ratio [HR] 1.18, 95% CI 1.10-1.27, p<0.001).

CONCLUSIONS

Positive FIT is associated with increased risk of RA in the general population, corroborating that aberrancies of gut mucosa are associated with the development of IMIDs. Vigilant monitoring and early referral to a specialist upon medical suspicion is required in this population.

TRIAL REGISTRATION

Retrospectively registered.

Combined performance of fecal immunochemical tests and a genetic risk score for advanced neoplasia detection

Fecal immunochemical tests (FITs) are increasingly used as noninvasive screening tests in colorectal cancer (CRC) screening programs. Polygenic risk scores (PRS) are increasingly propagated for risk stratification in CRC screening. We aimed to assess the potential of combining FIT results and PRS to enhance diagnostic accuracy of detecting advanced neoplasia (AN) compared to using FIT results alone. Of 10,362 participants of screening colonoscopy in Southern Germany who conducted either one of two quantitative FITs, genotyping was done in all participants with advanced neoplasia (CRC or advanced adenoma) and a random subset of controls. Among 5,306 individuals, a PRS was calculated based on the number of risk alleles in 140 single nucleotide polymorphisms. Partial areas under the receiver operating characteristics (ROC) curves (pAUCs) were computed for FIT and PRS alone and combined, focusing on a specificity range of 100%-80%. Both FITs showed similar performance characteristics with pAUCs (95%CIs) of 0.661 (0.625-0.698) (Ridascreen Hemoglobin) and 0.682 (0.661-0.701) (FOB Gold) for AN detection. PRS alone reached a pAUC (95%CI) of 0.524 (0.499-0.550) and 0.530 (0.516-0.545), respectively, and its addition to FIT did not improve pAUCs (0.659 (0.622-0.697) and 0.667 (0.650-0.687), respectively). This finding was confirmed by investigating sensitivities at fixed specificities at 85%, 90% and 95%. Partial AUCs also did not improve when adding the weighted PRS to FIT instead of the unweighted PRS. In summary, the combination with PRS did not improve diagnostic accuracy of FIT-based screening in a large asymptomatic CRC screening population from South-Western Germany.

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

BACKGROUND

Worldwide, many countries have adopted colorectal cancer (CRC) screening programmes, often based on faecal occult blood tests (FOBTs). CRC screening aims to detect advanced neoplasia (AN), which is defined as CRC or advanced adenomas. FOBTs fall into two categories based on detection technique and the detected blood component: qualitative guaiac-based FOBTs (gFOBTs) and faecal immunochemical tests (FITs), which can be qualitative and quantitative. Screening with gFOBTs reduces CRC-related mortality.

OBJECTIVES

To compare the diagnostic test accuracy of gFOBT and FIT screening for detecting advanced colorectal neoplasia in average-risk individuals.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, BIOSIS Citation Index, Science Citation Index Expanded, and Google Scholar. We searched the reference lists and PubMed-related articles of included studies to identify additional studies.

SELECTION CRITERIA

We included prospective and retrospective studies that provided the number of true positives, false positives, false negatives, and true negatives for gFOBTs, FITs, or both, with colonoscopy as reference standard. We excluded case-control studies. We included studies in which all participants underwent both index test and reference standard ("reference standard: all"), and studies in which only participants with a positive index test underwent the reference standard while participants with a negative test were followed for at least one year for development of interval carcinomas ("reference standard: positive"). The target population consisted of asymptomatic, average-risk individuals undergoing CRC screening. The target conditions were CRC and advanced neoplasia (advanced adenomas and CRC combined).

DATA COLLECTION AND ANALYSIS

Two review authors independently screened and selected studies for inclusion. In case of disagreement, a third review author made the final decision. We used the Rutter and Gatsonis hierarchical summary receiver operating characteristic model to explore differences between tests and identify potential sources of heterogeneity, and the bivariate hierarchical model to estimate sensitivity and specificity at common thresholds: 10 µg haemoglobin (Hb)/g faeces and 20 µg Hb/g faeces. We performed indirect comparisons of the accuracy of the two tests and direct comparisons when both index tests were evaluated in the same population.

MAIN RESULTS

We ran the initial search on 25 June 2019, which yielded 63 studies for inclusion. We ran a top-up search on 14 September 2021, which yielded one potentially eligible study, currently awaiting classification. We included a total of 33 "reference standard: all" published articles involving 104,640 participants. Six studies evaluated only gFOBTs, 23 studies evaluated only FITs, and four studies included both gFOBTs and FITs. The cut-off for positivity of FITs varied between 2.4 μg and 50 µg Hb/g faeces. For each Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 domain, we assessed risk of bias as high in less than 20% of studies. The summary curve showed that FITs had a higher discriminative ability than gFOBTs for AN (P < 0.001) and CRC (P = 0.004). For the detection of AN, the summary sensitivity of gFOBTs was 15% (95% confidence interval (CI) 12% to 20%), which was significantly lower than FITs at both 10 μg and 20 μg Hb/g cut-offs with summary sensitivities of 33% (95% CI 27% to 40%; P < 0.001) and 26% (95% CI 21% to 31%, P = 0.002), respectively. Results were simulated in a hypothetical cohort of 10,000 screening participants with 1% CRC prevalence and 10% AN prevalence. Out of 1000 participants with AN, gFOBTs missed 850, while FITs missed 670 (10 μg Hb/g cut-off) and 740 (20 μg Hb/g cut-off). No significant differences in summary specificity for AN detection were found between gFOBTs (94%; 95% CI 92% to 96%), and FITs at 10 μg Hb/g cut-off (93%; 95% CI 90% to 95%) and at 20 μg Hb/g cut-off (97%; 95% CI 95% to 98%). So, among 9000 participants without AN, 540 were offered (unnecessary) colonoscopy with gFOBTs compared to 630 (10 μg Hb/g) and 270 (20 μg Hb/g) with FITs. Similarly, for the detection of CRC, the summary sensitivity of gFOBTs, 39% (95% CI 25% to 55%), was significantly lower than FITs at 10 μg and 20 μg Hb/g cut-offs: 76% (95% CI 57% to 88%: P = 0.001) and 65% (95% CI 46% to 80%; P = 0.035), respectively. So, out of 100 participants with CRC, gFOBTs missed 61, and FITs missed 24 (10 μg Hb/g) and 35 (20 μg Hb/g). No significant differences in summary specificity for CRC were found between gFOBTs (94%; 95% CI 91% to 96%), and FITs at the 10 μg Hb/g cut-off (94%; 95% CI 87% to 97%) and 20 μg Hb/g cut-off (96%; 95% CI 91% to 98%). So, out of 9900 participants without CRC, 594 were offered (unnecessary) colonoscopy with gFOBTs versus 594 (10 μg Hb/g) and 396 (20 μg Hb/g) with FITs. In five studies that compared FITs and gFOBTs in the same population, FITs showed a higher discriminative ability for AN than gFOBTs (P = 0.003). We included a total of 30 "reference standard: positive" studies involving 3,664,934 participants. Of these, eight were gFOBT-only studies, 18 were FIT-only studies, and four studies combined both gFOBTs and FITs. The cut-off for positivity of FITs varied between 5 µg to 250 µg Hb/g faeces. For each QUADAS-2 domain, we assessed risk of bias as high in less than 20% of studies. The summary curve showed that FITs had a higher discriminative ability for detecting CRC than gFOBTs (P < 0.001). The summary sensitivity for CRC of gFOBTs, 59% (95% CI 55% to 64%), was significantly lower than FITs at the 10 μg Hb/g cut-off, 89% (95% CI 80% to 95%; P < 0.001) and the 20 μg Hb/g cut-off, 89% (95% CI 85% to 92%; P < 0.001). So, in the hypothetical cohort with 100 participants with CRC, gFOBTs missed 41, while FITs missed 11 (10 μg Hb/g) and 11 (20 μg Hb/g). The summary specificity of gFOBTs was 98% (95% CI 98% to 99%), which was higher than FITs at both 10 μg and 20 μg Hb/g cut-offs: 94% (95% CI 92% to 95%; P < 0.001) and 95% (95% CI 94% to 96%; P < 0.001), respectively. So, out of 9900 participants without CRC, 198 were offered (unnecessary) colonoscopy with gFOBTs compared to 594 (10 μg Hb/g) and 495 (20 μg Hb/g) with FITs. At a specificity of 90% and 95%, FITs had a higher sensitivity than gFOBTs.

AUTHORS' CONCLUSIONS

FITs are superior to gFOBTs in detecting AN and CRC in average-risk individuals. Specificity of both tests was similar in "reference standard: all" studies, whereas specificity was significantly higher for gFOBTs than FITs in "reference standard: positive" studies. However, at pre-specified specificities, the sensitivity of FITs was significantly higher than gFOBTs.

FJX1 as a candidate diagnostic and prognostic serum biomarker for colorectal cancer

PURPOSE

Colorectal cancer (CRC) is one of the most common cancer worldwide. It is essential to identify non-invasive diagnostic and prognostic biomarkers of CRC. The aim of the present study was to screen candidate biomarkers in diagnosis and prognosis of CRC based on a novel strategy.

MATERIALS AND METHODS

The expression level of gene higher in cancer than in adjacent non-cancer tissue was defined as "positive", and the top 10% genes with "positive rate" were filtered out as candidate diagnostic biomarkers in four Gene Expression Omnibus (GEO) datasets. Then, the prognostic value of candidate biomarkers was estimated Cox regression analysis. Moreover, the concentration of biomarker in serum was detected in CRC patients.

RESULTS

Eighteen candidate biomarkers were identified with efficient diagnostic value in CRC. As a prognostic biomarker, FJX1 (four-jointed box kinase 1) showed a good performance in predicting overall survivals in CRC patients. In serum levels, FJX1 showed high sensitivity and specificity in distinguishing CRC patients from controls, and the concentration of serum FJX1 was associated with distant metastasis in CRC. In addition, serum FJX1 was significantly decreased after surgery in CRC patients. Compared with traditional CRC biomarkers CEA and CA 19-9, FJX1 still showed good efficiency in diagnosis and prognosis. Moreover, inhibition of FJX1 expression by siRNA or neutralization of secreted FJX1 by antibody could suppress cell proliferation and migration in vitro.

CONCLUSION

Our findings provided a novel strategy to identify diagnostic biomarkers based on public datasets, and suggested that FJX1 was a candidate diagnostic and prognostic biomarker in CRC patients.

Colorectal cancer mortality after randomized implementation of FIT-based screening - a nationwide cohort study

Objective

Evidence of reduction in colorectal cancer (CRC) mortality following CRC screening based on the faecal immunochemical test (FIT) is insufficient. This study aimed to analyse if CRC mortality was reduced after implementing FIT-based screening.

Setting

The Danish national CRC screening programme.

Methods

This nationwide cohort study included residents aged 50–71 years invited to the prevalence round of the screening programme. Invitation order was decided by randomising on birth month; the first two birth months to be invited were classified as invited and the five last were classified as not-yet-invited and given a pseudo invitation data. Follow-up was from (pseudo)invitation date until 31 December 2017, emigration or death. Relative risk (RR) of CRC death was calculated with 95% confidence intervals (CIs).

Results

A total of 897,812 residents were included (29% invited and 71% not-yet-invited). The median follow-up was 3.3 years. The RR of CRC death at end of follow-up was 0.83 (95% CI 0.66; 1.03) among those invited to screening compared with those not yet invited. For men aged 60–71 years, this RR was 0.68 (95% CI 0.49; 0.94). For those participating in screening compared with a similar group of not-yet-invited residents, the RR was 0.71 (95% CI 0.46–1.08). For male participants aged 60–71 years, this RR was 0.49 (95% CI 0.27−0.89). For women and men aged 50–59 years, RRs were small and statistically non-significant.

Conclusion

This nationwide study showed that even within a median follow-up of only 3.3 years, implementing FIT-based CRC screening reduced CRC mortality among older men.

A novel method for early detection of colorectal cancer based on detection of methylation of two fragments of syndecan-2 (SDC2) in stool DNA

Background

Methylated SDC2 has been proved as a diagnostic marker for human colorectal cancer (CRC), noninvasive stool DNA-based methylation testing also emerges as a novel approach for detecting CRC. The aim of this study was to evaluate the clinical performance of stool DNA-based SDC2 methylation test by a new qPCR detection reagent for early detection of CRC.

Methods

A new qPCR detection reagent contained two differentially methylated regions in SDC2 CpG islands for the detection of CRC was used in this study. Performance of the SDC2 methylation detection reagent was evaluated by analyzing limit of detection, precision, and specificity. The effect of interfering substances on assay performance was also tested. 339 subjects (102 CRC patients, 50 patients with advanced adenomas, 39 patients with non-advanced adenomas, 18 colitis patients and 130 normal individuals) from the China-Japan Friendship Hospital were evaluated. Approximately 2.5 g of stool sample was collected from each participant. Stool DNA was extracted and bisulfite-converted, followed by qPCR assay, which contained two pairs of primers for the methylation detection of two fragments of the SDC2 gene (named SDC2-A and SDC2-B). The diagnostic value of this test in CRC was evaluated by calculating receiver operating characteristic (ROC) curve, and value of the area under the curve (AUC).

Results

The test kit was able to detect methylated SDC2 in stool DNA samples with concentrations as low as 90 copies/μL in 100% of replicates. The sensitivity for detecting CRC by methylated SDC2-A alone was 85.29% (95% CI 77.03–91.00%) with a specificity of 96.15% (95% CI 91.08–98.58%). The sensitivity by methylated SDC2-B alone was 83.33% (95% CI 74.82–89.42%) with a specificity of 97.69% (95% CI 93.14–99.51%). However, when methylated SDC2-A and methylated SDC2-B were combined, the sensitivity for CRC detection improved to 87.25% (95% CI 79.27–92.53%) with a specificity of 94.62% (95% CI 89.11–97.56%). Further, the detection reagent achieved ROC-AUC 0.874 (95% CI 0.822–0.927) for SDC2-A, 0.906 (95% CI 0.859–0.952) for SDC2-B, and 0.939 (95% CI 0.902–0.977) for SDC2-Combine A&B.

Conclusions

This study validated the capability of stool DNA-based SDC2 methylation test for early screening of CRC, and combined detection of two fragments of SDC2 gene could improve detection sensitivity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02264-3.

Advances in tests for colorectal cancer screening and diagnosis

INTRODUCTION

Colorectal cancer (CRC) is the second leading cause of cancer-related deaths globally. Nonetheless, with early detection of CRC or its precancerous lesions, mortality, and CRC incidence can be reduced. Although colonoscopy is currently the gold standard for CRC screening and diagnosis, its invasive nature, and troublesome bowel preparation deter patient participation. Therefore, there is a need to expand the use of noninvasive or minimally invasive methods to increase patient compliance.

AREAS COVERED

This review summarizes advances in different methods for CRC screening, including stool bacterial and metagenomic markers, fecal proteins, genetic and epigenetic markers in blood and stools, and imaging modalities. The cost-effectiveness of these methods is also discussed. FIT is more cost-effective compared to virtual colonoscopy, mSEPT9 test, and Multitarget Stool DNA test, while the cost-effectiveness of other noninvasive methods requires further evaluation.

EXPERT OPINION

Recent evidence has well demonstrated the usefulness of gut microbiome and certain fecal bacterial markers in the noninvasive diagnosis of CRC and its precancerous lesions. Many of the fecal biomarkers, from host cells or the gut environment, show better diagnostic sensitivity than FIT. New screening tests based on these fecal biomarkers can be expected to replace FIT with higher cost-effectiveness in the near future.

Positive fecal immunochemical test results are associated with non-colorectal cancer mortality

BACKGROUND/AIMS

Studies have reported an association between fecal occult blood and increased all-cause, non-colorectal cancer (CRC) as well as CRC mortality. This study aimed to determine whether positive fecal immunochemistry test (FIT) results are associated with death from various causes in the South Korean population.

METHODS

Using the Korean National Cancer Screening Program database, we collected data on patients who underwent FIT between 2009 and 2011.

RESULTS

Of the 5,932,544 participants, 380,789 (6.4%) had positive FIT results. FIT-positive participants had a higher mortality rate than FIT-negative participants from CRC (1.33 and 0.21 per 1,000 person-years, p < 0.001, respectively) and non-CRC causes (10.40 and 7.50 per 1,000 person-years, p < 0.001, respectively). Despite adjusting for age, sex, smoking status, alcohol consumption habits, body mass index, comorbidity, and aspirin use, FIT positivity was associated with an increased risk of dying from all non-CRC causes (adjusted hazard ratio [aHR], 1.17; 95% confidence interval [CI], 1.15 to 1.18) and CRC (aHR, 5.61; 95% CI, 5.40 to 5.84). Additionally, FIT positivity was significantly associated with increased mortality from circulatory disease (aHR, 1.14; 95% CI, 1.11 to 1.17), respiratory disease (aHR, 1.14; 95% CI, 1.09 to 1.19), digestive disease (aHR, 1.57; 95% CI, 1.48 to 1.66), neuropsychological disease (aHR, 1.08; 95% CI, 1.01 to 1.16), blood and endocrine diseases (aHR, 1.10; 95% CI, 1.04 to 1.17), and external factors (aHR, 1.16; 95% CI, 1.11 to 1.20).

CONCLUSION

Positive FIT results are associated with an increased risk of mortality from CRC and various other chronic diseases, suggesting that it could be a predictor of mortality independent of its association with CRC.

Varying fecal immunochemical test screening cutoffs by age and gender: a way to increase detection rates and reduce the number of colonoscopies

BACKGROUND AND AIMS

Most colorectal cancer (CRC) screening programs based on the fecal immunochemical test (FIT) use the same cutoff value for all participants. This study aimed at finding age- and gender-specific cutoff values that can improve population-based CRC screening.

METHODS

This observational study used data from the first 2 years of the Danish FIT-based CRC screening program to estimate sensitivity, specificity, number of positive tests, number of screen-detected cancers and adenomas, and number of interval cancers for various cutoff values for different male and female age groups.

RESULTS

Data from 531,828 participants showed that lower cutoff values for older residents and higher cutoff values for younger residents increased the overall sensitivity and specificity, decreased the number of needed colonoscopies by 7%, increased the number of screen-detected cancer by 1.1%, increased the number of screen-detected adenomas by 5%, and decreased the number of interval cancers by approximately 1.5%. However, these cutoff values also increased an inequality in sensitivity and specificity. Choosing cutoff values that ensured equal sensitivity between the groups, however, did increase inequality in, for example, the interval cancer rate.

CONCLUSIONS

In a FIT-based CRC program it is possible to decrease the number of needed colonoscopies while at the same time to increase overall sensitivity and specificity and detect more cancers and adenomas by using different cutoff values for different male and female age groups. However, this increases inequality in sensitivity and specificity, whereas other strategies like ensuring equal sensitivity could be considered.

Incidence, mortality, survival, risk factor and screening of colorectal cancer: A comparison among China, Europe, and northern America

Colorectal cancer (CRC) is one of the most common malignancies worldwide. China, Europe and northern America account for more than half of the new CRC cases and associated deaths globally. This review summarizes the current status and temporal trends of CRC in China, Europe, and northern America. The potential primary preventive strategies and latest advances in CRC screening techniques and programs are discussed. Recently, the incidence and mortality of CRC in some European and northern American countries have decreased; conversely, CRC incidence and mortality continue to increase in China. The overall 5-year relative survival rate for CRC is similar between these regions, but there is considerable heterogeneity among European countries. Implementing population-based CRC screening programs can effectively address the growing disease burden. The effectiveness of nationwide CRC screening programs in these regions has been limited by relatively low coverage and participation rate. The deployment of state-of-the-art techniques and precise risk-adapted screening strategies incorporating effective risk prediction models and screening techniques may boost screening effectiveness. Our review provides novel foundations for the development and optimization of CRC preventive strategies.

Colorectal cancer incidence, mortality, tumour characteristics, and treatment before and after introduction of the faecal immunochemical testing-based screening programme in the Netherlands: a population-based study

BACKGROUND

In 2014, a population-based colorectal cancer (CRC) screening programme was stepwise implemented in the Netherlands comprising faecal immunochemical testing once every 2 years, with a cutoff value for positivity of 47 μg haemoglobin per g faeces. We aimed to assess CRC incidence, mortality, tumour characteristics, and treatment before and after introduction of this screening programme.

METHODS

We did a retrospective, observational, population-based study in the Netherlands and gathered CRC incidence data from the Netherlands Cancer Registry from Jan 1, 2010, to Dec 31, 2019, in people aged 55 years or older. Patients with a CRC diagnosis between Jan 1, 2014, and Dec 31, 2018, in the Netherlands Cancer Registry were linked with the nationwide registry of histopathology and cytopathology (PALGA) to identify mode of detection (ie, screening-detected vs clinically detected). We calculated age-standardised CRC incidence rates and used data from Statistics Netherlands to calculate CRC-related mortality in 2010-19. We compared localisation, stage distribution, and treatment of screening-detected CRCs with clinically detected CRCs diagnosed in 2014-18 in patients aged 55-75 years.

FINDINGS

Between Jan 1, 2010, and Dec 31, 2019, 125 215 CRCs were diagnosed in individuals aged 55 years or older and were included in the analyses for CRC incidence. Before the introduction of the screening programme, the age-standardised CRC incidence rate was 214·3 per 100 000 population in 2013 in people aged 55 years or older. After the introduction of the screening programme, this rate initially increased to 259·2 per 100 000 population in 2015, and subsequently decreased to 181·5 per 100 000 population in 2019. Age-standardised incidence rates for advanced CRCs (stage III and IV) were 117·0 per 100 000 population in 2013 and increased to 122·8 per 100 000 population in 2015; this rate then decreased to 94·7 per 100 000 population in 2018. Age-standardised CRC mortality decreased from 87·5 deaths per 100 000 population in 2010 to 64·8 per 100 000 population in 2019. Compared with clinically detected CRCs, screening-detected CRCs were more likely to be located in the left side of the colon (48·6% vs 35·2%) and to be detected at an early stage (I or II; 66·7% vs 46·2%). Screening-detected CRCs were more likely to be treated by local excision compared with clinically detected CRCs, and this finding persisted when stage I CRCs were analysed separately.

INTERPRETATION

After introduction of this national screening programme, a decrease in overall and advanced-stage CRC incidence was observed. In view of this observation, together with the observed shift to detection at earlier stages and more screening-detected CRCs being treated by local excision, we might cautiously conclude that, in the long-term, faecal immunochemical testing-based screening could ultimately lead to a decrease in CRC-related morbidity and mortality.

FUNDING

None.

Exploration of the Proteomic Landscape of Small Extracellular Vesicles in Serum as Biomarkers for Early Detection of Colorectal Neoplasia

Background

Patient participation in colorectal cancer (CRC) screening via a stool test and colonoscopy is suboptimal, but participation can be improved by the development of a blood test. However, the suboptimal detection abilities of blood tests for advanced neoplasia, including advanced adenoma (AA) and CRC, limit their application. We aimed to investigate the proteomic landscape of small extracellular vesicles (sEVs) from the serum of patients with colorectal neoplasia and identify specific sEV proteins that could serve as biomarkers for early diagnosis.

Materials and Methods

We enrolled 100 patients including 13 healthy subjects, 12 non-AAs, 13 AAs, and 16 stage-I, 15 stage-II, 16 stage-III, and 15 stage-IV CRCs. These patients were classified as normal control, early neoplasia, and advanced neoplasia. The sEV proteome was explored by liquid chromatography-tandem mass spectrometry. Generalized association plots were used to integrate the clustering methods, visualize the data matrix, and analyze the relationship. The specific sEV biomarkers were identified by a decision tree via Orange3 software. Functional enrichment analysis was conducted by using the Ingenuity Pathway Analysis platform.

Results

The sEV protein matrix was identified from the serum of 100 patients and contained 3353 proteins, of which 1921 proteins from 98 patients were finally analyzed. Compared with the normal control, subjects with early and advanced neoplasia exhibited a distinct proteomic distribution in the data matrix plot. Six sEV proteins were identified, namely, GCLM, KEL, APOF, CFB, PDE5A, and ATIC, which properly distinguished normal control, early neoplasia, and advanced neoplasia patients from each other. Functional enrichment analysis revealed that APOF⁺ and CFB⁺ sEV associated with clathrin-mediated endocytosis signaling and the complement system, which have critical implications for CRC carcinogenesis.

Conclusion

Patients with colorectal neoplasia had a distinct sEV proteome expression pattern in serum compared with those patients who were healthy and did not have neoplasms. Moreover, the six identified specific sEV proteins had the potential to discriminate colorectal neoplasia between early-stage and advanced neoplasia. Collectively, our study provided a six-sEV protein biomarker panel for CRC diagnosis at early or advanced stages. Furthermore, the implication of the sEV proteome in CRC carcinogenesis via specific signaling pathways was explored.

Precision Medicine for Colorectal Cancer with Liquid Biopsy and Immunotherapy

Simple Summary

There are some challenges to improve the clinical outcome of colorectal cancers (CRCs) by implementing new technologies, such as early detection of recurrence/relapse and selection of appropriate drugs based on the genomic profiles of tumors. For example, the genomic characteristics of tumors can be analyzed by blood-based tests, namely ‘liquid biopsies’, which are minimally-invasive and can be performed repeatedly during the treatment course. Hence, liquid biopsies are considered to hold great promise to fill these gaps in clinical routines. In this review, we addressed clinical usefulness of liquid biopsies in the clinical management of CRC patients, including cancer screening, detection of minimal residual disease, selection of appropriate molecular-targeted drugs, monitoring of the treatment responsiveness, and very early detection of recurrence/relapse of the disease. Furthermore, we discussed the possibility of adoptive T cell therapies and a future personalized immunotherapy based on tumor genome information.

Abstract

In the field of colorectal cancer (CRC) treatment, diagnostic modalities and chemotherapy regimens have progressed remarkably in the last two decades. However, it is still difficult to identify minimal residual disease (MRD) necessary for early detection of recurrence/relapse of tumors and to select and provide appropriate drugs timely before a tumor becomes multi-drug-resistant and more aggressive. We consider the leveraging of in-depth genomic profiles of tumors as a significant breakthrough to further improve the overall prognosis of CRC patients. With the recent technological advances in methodologies and bioinformatics, the genomic profiles can be analyzed profoundly without delay by blood-based tests—‘liquid biopsies’. From a clinical point of view, a minimally-invasive liquid biopsy is thought to be a promising method and can be implemented in routine clinical settings in order to meet unmet clinical needs. In this review, we highlighted clinical usefulness of liquid biopsies in the clinical management of CRC patients, including cancer screening, detection of MRD, selection of appropriate molecular-targeted drugs, monitoring of the treatment responsiveness, and very early detection of recurrence/relapse of the disease. In addition, we addressed a possibility of adoptive T cell therapies and a future personalized immunotherapy based on tumor genome information.

Screening and prevention of colorectal cancer

Mortality from colorectal cancer is reduced through screening and early detection; moreover, removal of neoplastic lesions can reduce cancer incidence. While understanding of the risk factors, pathogenesis, and precursor lesions of colorectal cancer has advanced, the cause of the recent increase in cancer among young adults is largely unknown. Multiple invasive, semi- and non-invasive screening modalities have emerged over the past decade. The current emphasis on quality of colonoscopy has improved the effectiveness of screening and prevention, and the role of new technologies in detection of neoplasia, such as artificial intelligence, is rapidly emerging. The overall screening rates in the US, however, are suboptimal, and few interventions have been shown to increase screening uptake. This review provides an overview of colorectal cancer, the current status of screening efforts, and the tools available to reduce mortality from colorectal cancer.

Colorectal Cancer Screening Outcomes of 2412 Prostate Cancer Patients Considered for Carbon Ion Radiotherapy

Colorectal cancer (CRC) screening is effective for detecting cancer in average-risk adults. For prostate cancer (PCa) patients considered for carbon ion radiotherapy (CIRT), pre-treatment CRC screening is performed empirically to avoid post-treatment colonoscopic manipulation. However, the outcomes of screening this population remain unclear. Here, we compared the outcomes of routine pre-CIRT CRC screening of 2412 PCa patients at average risk for CRC with data from two published datasets: the Japan National Cancer Registry (JNCR) and a series of 17 large-scale screening studies analyzing average-risk adults. The estimated prevalence rate was calculated using the pooled sensitivity elucidated by a previous meta-analysis. Consequently, 28 patients (1.16%) were diagnosed with CRC. CRC morbidity was significantly associated with high pre-treatment levels of prostate-specific antigen (p = 0.023). The screening positivity rate in this study cohort exceeded the annual incidence reported in the JNCR for most age brackets. Furthermore, the estimated prevalence rate in this study cohort (1.46%) exceeded that reported in all 17 large-scale studies, making the result an outlier (p = 0.005). These data indicate the possibility that the prevalence of CRC in PCa patients is greater than that in general average-risk adults, warranting further research in a prospective setting.

Clinical guidelines “Chronic diarrhea in adults”

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Consistent Major Differences in Sex- and Age-Specific Diagnostic Performance among Nine Faecal Immunochemical Tests Used for Colorectal Cancer Screening

Evidence on diagnostic performance of faecal immunochemical tests (FITs) by sex and age is scarce. We aimed to evaluate FIT performance for detection of advanced colorectal neoplasia (AN) by sex and age across nine different FIT brands in a colonoscopy-controlled setting. The faecal samples were obtained from 2042 participants of colonoscopy screening. All eligible cases with AN (n = 216) and 300 randomly selected participants without AN were included. Diagnostic performance for detection of AN was assessed by sex and age (50-64 vs. 65-79 years for each of the nine FITs individually and for all FITs combined. Sensitivity was consistently lower, and specificity was consistently higher for females as compared with males (pooled values at original FIT cutoffs, 25.7% vs. 34.6%, p = 0.12 and 96.2% vs. 90.8%, p < 0.01, respectively). Positive predictive values (PPVs) were similar between both sexes, but negative predictive values (NPVs) were consistently higher for females (pooled values, 91.8% vs. 86.6%, p < 0.01). Sex-specific cutoffs attenuated differences in sensitivities but increased differences in predictive values. According to age, sensitivities and specificities were similar, whereas PPVs were consistently lower and NPVs were consistently higher for the younger participants. A negative FIT is less reliable in ruling out AN among men than among women and among older than among younger participants. Comparisons of measures of diagnostic performance among studies with different sex or age distributions should be interpreted with caution.

Evaluation of a 92 multiplex protein panel in detection of colorectal cancer and high-risk adenoma in 784 symptomatic individuals

BACKGROUND

Blood-based protein biomarkers for detection of colorectal cancer (CRC) have been submitted to intense research to improve the full potential in screening for CRC.

OBJECTIVE

The aim was to explore the diagnostic performance of 92 proteins related to inflammation and carcinogenesis in detection of CRC or precancerous lesions.

METHODS

Blood-samples were collected from 4,698 individuals undergoing colonoscopy. An explorative unmatched case-control study was designed with 294 cases (individuals with CRC or high-risk colorectal adenoma) and 490 controls (individuals with low-risk colorectal adenoma, non-malignant findings or clean colorectum at colonoscopy). Protein profiling was performed by multiplex proximity extension assay. Statistical analyses were performed as univariate and multivariate logistic regression analyses.

RESULTS

Univariably, CSF-1, MMP12 and IL8 demonstrated superior performance in discrimination of individuals with CRC. Recurrently, IL8 was included as contributor in majority of multivariate models discriminating individuals with CRC. The multivariate evaluation in discrimination of individuals with CRC demonstrated AUC=ROC 0.82, sensitivity = 0.39 at specificity = 0.80. Discrimination of individuals with late stage CRC from individuals with clean colorectum demonstrated AUC=ROC 0.90, sensitivity = 0.58 at specificity = 0.80.

CONCLUSIONS

A subset of biomarker candidates, specifically IL8, investigated in the present study suggest a potential as blood-based biomarkers in screening of CRC.

Colorectal cancer incidence, mortality, and stage distribution in European countries in the colorectal cancer screening era: an international population-based study

BACKGROUND

Colorectal cancer screening programmes and uptake vary substantially across Europe. We aimed to compare changes over time in colorectal cancer incidence, mortality, and stage distribution in relation to colorectal cancer screening implementation in European countries.

METHODS

Data from nearly 3·1 million patients with colorectal cancer diagnosed from 2000 onwards (up to 2016 for most countries) were obtained from 21 European countries, and were used to analyse changes over time in age-standardised colorectal cancer incidence and stage distribution. The WHO mortality database was used to analyse changes over time in age-standardised colorectal cancer mortality over the same period for the 16 countries with nationwide data. Incidence rates were calculated for all sites of the colon and rectum combined, as well as the subsites proximal colon, distal colon, and rectum. Average annual percentage changes (AAPCs) in incidence and mortality were estimated and relevant patterns were descriptively analysed.

FINDINGS

In countries with long-standing programmes of screening colonoscopy and faecal tests (ie, Austria, the Czech Republic, and Germany), colorectal cancer incidence decreased substantially over time, with AAPCs ranging from -2·5% (95% CI -2·8 to -2·2) to -1·6% (-2·0 to -1·2) in men and from -2·4% (-2·7 to -2·1) to -1·3% (-1·7 to -0·9) in women. In countries where screening programmes were implemented during the study period, age-standardised colorectal cancer incidence either remained stable or increased up to the year screening was implemented. AAPCs for these countries ranged from -0·2% (95% CI -1·4 to 1·0) to 1·5% (1·1 to 1·8) in men and from -0·5% (-1·7 to 0·6) to 1·2% (0·8 to 1·5) in women. Where high screening coverage and uptake were rapidly achieved (ie, Denmark, the Netherlands, and Slovenia), age-standardised incidence rates initially increased but then subsequently decreased. Conversely, colorectal cancer incidence increased in most countries where no large-scale screening programmes were available (eg, Bulgaria, Estonia, Norway, and Ukraine), with AAPCs ranging from 0·3% (95% CI 0·1 to 0·5) to 1·9% (1·2 to 2·6) in men and from 0·6% (0·4 to 0·8) to 1·1% (0·8 to 1·4) in women. The largest decreases in colorectal cancer mortality were seen in countries with long-standing screening programmes.

INTERPRETATION

We observed divergent trends in colorectal cancer incidence, mortality, and stage distribution across European countries, which appear to be largely explained by different levels of colorectal cancer screening implementation.

FUNDING

German Cancer Aid (Deutsche Krebshilfe) and the German Federal Ministry of Education and Research.

Screening for Colorectal Cancer: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Colorectal cancer (CRC) remains a significant cause of morbidity and mortality in the US.

OBJECTIVE

To systematically review the effectiveness, test accuracy, and harms of screening for CRC to inform the US Preventive Services Task Force.

DATA SOURCES

MEDLINE, PubMed, and the Cochrane Central Register of Controlled Trials for relevant studies published from January 1, 2015, to December 4, 2019; surveillance through March 26, 2021.

STUDY SELECTION

English-language studies conducted in asymptomatic populations at general risk of CRC.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently appraised the articles and extracted relevant study data from fair- or good-quality studies. Random-effects meta-analyses were conducted.

MAIN OUTCOMES AND MEASURES

Colorectal cancer incidence and mortality, test accuracy in detecting cancers or adenomas, and serious adverse events.

RESULTS

The review included 33 studies (n = 10 776 276) on the effectiveness of screening, 59 (n = 3 491 045) on the test performance of screening tests, and 131 (n = 26 987 366) on the harms of screening. In randomized clinical trials (4 trials, n = 458 002), intention to screen with 1- or 2-time flexible sigmoidoscopy vs no screening was associated with a decrease in CRC-specific mortality (incidence rate ratio, 0.74 [95% CI, 0.68-0.80]). Annual or biennial guaiac fecal occult blood test (gFOBT) vs no screening (5 trials, n = 419 966) was associated with a reduction of CRC-specific mortality after 2 to 9 rounds of screening (relative risk at 19.5 years, 0.91 [95% CI, 0.84-0.98]; relative risk at 30 years, 0.78 [95% CI, 0.65-0.93]). In observational studies, receipt of screening colonoscopy (2 studies, n = 436 927) or fecal immunochemical test (FIT) (1 study, n = 5.4 million) vs no screening was associated with lower risk of CRC incidence or mortality. Nine studies (n = 6497) evaluated the test accuracy of screening computed tomography (CT) colonography, 4 of which also reported the test accuracy of colonoscopy; pooled sensitivity to detect adenomas 6 mm or larger was similar between CT colonography with bowel prep (0.86) and colonoscopy (0.89). In pooled values, commonly evaluated FITs (14 studies, n = 45 403) (sensitivity, 0.74; specificity, 0.94) and stool DNA with FIT (4 studies, n = 12 424) (sensitivity, 0.93; specificity, 0.85) performed better than high-sensitivity gFOBT (2 studies, n = 3503) (sensitivity, 0.50-0.75; specificity, 0.96-0.98) to detect cancers. Serious harms of screening colonoscopy included perforations (3.1/10 000 procedures) and major bleeding (14.6/10 000 procedures). CT colonography may have harms resulting from low-dose ionizing radiation. It is unclear if detection of extracolonic findings on CT colonography is a net benefit or harm.

CONCLUSIONS AND RELEVANCE

There are several options to screen for colorectal cancer, each with a different level of evidence demonstrating its ability to reduce cancer mortality, its ability to detect cancer or precursor lesions, and its risk of harms.

Fatty Acid Unsaturation Degree of Plasma Exosomes in Colorectal Cancer Patients: A Promising Biomarker

Even though colorectal cancer (CRC) is one of the most preventable cancers, it is currently one of the deadliest. Worryingly, incidence in people <50 years has increased unexpectedly, and for unknown causes, despite the successful implementation of screening programs in the population aged >50 years. Thus, there is a need to improve early diagnosis detection strategies by identifying more precise biomarkers. In this scenario, the analysis of exosomes is given considerable attention. Previously, we demonstrated the exosome lipidome was able to classify CRC cell lines according to their malignancy. Herein, we investigated the use of the lipidome of plasma extracellular vesicles as a potential source of non-invasive biomarkers for CRC. A plasma exosome-enriched fraction was analyzed from patients undergoing colonoscopic procedure. Patients were divided into a healthy group and four pathological groups (patients with hyperplastic polyps; adenomatous polyps; invasive neoplasia (CRC patients); or hereditary non-polyposis CRC. The results showed a shift from 34:1- to 38:4-containing species in the pathological groups. We demonstrate that the ratio Σ34:1-containing species/Σ38:4-containing species has the potential to discriminate between healthy and pathological patients. Altogether, the results reinforce the utility of plasma exosome lipid fingerprint to provide new non-invasive biomarkers in a clinical context.

Impact of Inadequate Bowel Cleansing on Colonoscopic Findings in Routine Screening Practice

INTRODUCTION

Colonoscopy is an imperfect gold standard for detecting colorectal neoplasms because some proportion of adenomas may be missed, mainly small lesions. This proportion is expected to be higher in case of inadequate bowel cleansing, which is frequently seen in routine practice. We estimated the proportions of neoplasms that are in principle detectable by colonoscopy but might be missed in case of incomplete bowel preparation.

METHODS

For 8,193 participants of screening colonoscopy in South-Western Germany, recruited between 2005 and 2016, the prevalence and numbers of different findings were extracted from colonoscopy reports and compared according to the reported bowel preparation quality.

RESULTS

Bowel preparation quality was reported as good, poor, or was unspecified in 30.3%, 11.1%, and 58.6% of colonoscopy records. Reported prevalences of nonadvanced adenomas (NAAs) were similar among participants with poor and unspecified bowel preparation quality but substantially lower than among participants with good bowel preparation (adjusted prevalence rate ratio [RR] 0.86, 95% confidence interval [CI]: 0.77-0.96). The differences were observed for proximal but not for distal NAAs (RRs 0.82, 95% CI: 0.71-0.95 and 0.95, 95% CI: 0.82-1.10).

DISCUSSION

Our study suggests that a significant proportion of NAAs located in the proximal colon might be missed during colonoscopy if bowel cleansing is not adequate. Major efforts should be made to further facilitate and enhance high-quality bowel preparation in routine screening practice.

Comparative effectiveness of five fecal immunochemical tests using colonoscopy as the gold standard: study protocol

BACKGROUND

There are nearly 50,000 colorectal cancer (CRC) deaths in the United States each year. CRC is curable if detected in its early stages. Fecal immunochemical tests (FITs) can detect precursor lesions and many can be analyzed at the point-of-care (POC) in physician offices. However, there are few data to guide test selection. Broader use of FITs could make CRC screening more accessible, especially in resource-poor settings.

METHODS

A total of 3600 racially and ethnically diverse individuals aged 50 to 85 years having either a screening or surveillance colonoscopy will be recruited. Each participant will complete five FITs on a single stool sample. Test characteristics for each FIT for advanced colorectal neoplasia (ACN) will be calculated using colonoscopy as the gold standard.

RESULTS

We have complete data from a total of 2990 individuals. Thirty percent are Latino and 5.3% are black/African American. We will present full results once the study is completed.

CONCLUSIONS

Our focus in this study is how well FITs detect ACN, using colonoscopy as the gold standard. Four of the five FITs being used are POC tests. Although FITs have been shown to have acceptable performance, there is little data to guide which ones have the best test characteristics and colonoscopy is the main CRC screening test used in the United States. Use of FITs will allow broader segments of the population to access CRC screening because these tests require no preparation, are inexpensive, and can be collected in the privacy of one's home. Increasing CRC screening uptake will reduce the burden of advanced adenomas and colorectal cancer.

Effect of long-term frozen storage and thawing of stool samples on faecal haemoglobin concentration and diagnostic performance of faecal immunochemical tests

Background Faecal samples collected and stored frozen over years may be a valuable resource for efficient retrospective evaluation of faecal immunochemical tests (FITs). We aimed to assess how prolonged frozen storage and freeze-thaw cycles might affect measures of faecal haemoglobin (Hb) and diagnostic performance of FITs. Methods From 2005 through 2010, participants of screening colonoscopy (n = 2042) and clinical colorectal cancer (CRC) cases (n = 184) provided faecal samples in stool containers (60 mL). The samples were stored at -80 °C for up to 11 years and underwent three freeze-thaw cycles. Between each cycle, a defined amount of faeces was extracted using the manufacturer's sampling device of one or two FITs (RIDASCREEN, OC-Sensor). Faecal Hb concentration and diagnostic performance were calculated and compared across freeze-thaw cycles. Results For RIDASCREEN and the OC-Sensor, repeat measurements were available for 504 and 551 study participants, respectively. Hb concentrations correlated strongly (0.77 and 0.85, respectively) and diagnostic performance indicators were similar at the repeat measurements among the same FITs. For RIDASCREEN we found even slightly higher Hb levels, sensitivities and area under the curves (AUCs) after the third than after the first freeze-thaw cycle. For the OC-Sensor the Hb levels, sensitivities and AUCs were slightly lower after prolonged storage and one additional freeze-thaw cycle. Conclusions Measures of Hb and diagnostic performance were fairly stable, even after long-term frozen storage and multiple freeze-thaw cycles of raw faecal samples. Faecal samples collected in prospective screening studies and kept frozen at -80 °C before analysis seem useful for timely and efficient retrospective evaluation of FIT performance.

The Effects of Different Invitation Schemes on the Use of Fecal Occult Blood Tests for Colorectal Cancer Screening: Systematic Review of Randomized Controlled Trials

Simple Summary

There is large heterogeneity in invitation schemes and participation rates in colorectal cancer screening programs offering fecal occult blood tests (nowadays mostly fecal immunochemical tests). It is unclear what the most effective invitation strategies are for fecal occult blood tests. In this systematic review, advance notification, mailed fecal occult blood test, and reminders had major, consistent, and complementary potential to increase participation in fecal occult blood test-based colorectal cancer screening. Our findings show that the effectiveness of invitations for fecal occult blood test-based colorectal cancer screening can be substantially increased across several settings by the implementation of comprehensive invitation strategies.

Abstract

Personal invitations for fecal occult blood tests (nowadays mostly fecal immunochemical tests) are increasingly used to raise their usage for colorectal cancer screening. However, there is a large heterogeneity in applied invitation schemes. We aimed to review evidence for the effectiveness of various invitation schemes. The main outcome was the fecal occult blood test usage rate. A systematic search was performed in Medline and Web of Science (up to 9 July 2020). Randomized controlled trials or cluster-randomized controlled trials were eligible, which reported on general invitations for fecal occult blood test-based colorectal cancer screening sent to the general population at average colorectal cancer risk. (PROSPERO 2020 CRD42020169409). Overall, 34 studies were included. Invitations with an attached, i.e., mailed fecal occult blood test consistently increased test usage by 4–19.7% points, compared to other methods of test provision. Likewise, the introduction of advance notification consistently led to a higher usage rate, with an increase of 3.3–10.8% points. Reminders showed positive but varying effects by method. With an increase of 8.5–15.8% points, letter or email reminders were more effective than reminders by phone call or text message (0.6–6.5% points). Inconsistent results were found for financial incentives ((−8.4)–20% points) and for added or changed invitation material ((−3.5)–11.8% points). With 3.5–24.7% points, the strongest increases in use were achieved by multifaceted invitation, implementing multiple components. Any invitation scheme was superior over no invitation. Advance notification, mailing of fecal occult blood test, and reminders were consistently shown to have major, complementary potential to increase participation in fecal occult blood test-based colorectal cancer screening settings.

PPV and Detection Rate of mt-sDNA Testing, FIT, and CT Colonography for Advanced Neoplasia: A Hierarchic Bayesian Meta-Analysis of the Noninvasive Colorectal Screening Tests

BACKGROUND. Noninvasive tests for colorectal cancer (CRC) screening and prevention limit the need for invasive colonoscopy to follow up positive test results. However, the relative performance characteristics of available noninvasive tests have not yet been adequately compared. OBJECTIVE. We performed a systematic review and meta-analysis to compare the diagnostic performance of the available noninvasive CRC screening tests, including multitarget stool DNA (mt-sDNA) testing, fecal immunochemical testing (FIT), and CT colonography (CTC), with an emphasis on comparison of PPV and detection rate (DR) for advanced neoplasia (AN; encompassing cases of advanced adenomas and CRC). EVIDENCE ACQUISITION. After systematic searches of MEDLINE and Google Scholar databases, 10 mt-sDNA, 27 CTC, and 88 FIT published screening studies involving 25,132, 33,493, and 2,355,958 asymptomatic adults, respectively, were included. Meta-analysis with hierarchic Bayesian modeling was conducted in accordance with Cochrane Collaboration and PRISMA guidelines to determine test positivity rates (TPRs) leading to optical colonoscopy, as well as PPVs and DRs for both AN and CRC. Different positivity thresholds were considered for FIT and CTC. EVIDENCE SYNTHESIS. Point estimates (with 95% credible intervals) from pooled Bayesian meta-analysis combining all thresholds for FIT and stratifying CTC results by a polyp size threshold of 6 mm or larger (CTC6) and 10 mm or larger (CTC10) were calculated. TPR was 13.5% (10.9-16.6%) for mt-sDNA testing, 6.4% (5.8-7.2%) for FIT, 13.4% (11.4-15.6%) for CTC6, and 6.6% (5.2-7.7%) for CTC10. AN PPV was 26.9% (95% credible interval, 21.8-33.2%) for mt-sDNA testing, 31.8% (29.3-34.5%) for FIT, 34.4% (27.2-41.0%) for CTC6, and 61.0% (54.0-70.0%) for CTC10. CRC PPV was 2.4% (1.5-3.9%) for mt-sDNA testing, 4.9% (4.3-5.3%) for FIT, 3.5% (2.5-4.8%) for CTC6, and 6.0% (4.3-8.0%) for CTC10. The DR for AN was 3.4% (95% credible interval, 2.5-4.8%) for mt-SDNA, 2.0% (1.8-2.3%) for FIT, 4.8% (4.0-6.5%) for CTC6, and 4.0% (3.0-4.6%) for CTC10. When FIT is restricted to a lower threshold (< 10 μg Hb/g feces), its performance profile is similar to that of mt-sDNA testing, although available data are limited. AN PPV odds ratios (relative to CTC10 as the reference) were 0.24 (95% credible interval, 0.17-0.33) for mt-sDNA testing, 0.30 (0.24-0.45) for FIT, and 0.33 (0.25-0.47) for CTC6. CONCLUSION. Among noninvasive CRC screening tests, CTC with a polyp size threshold of 10 mm or larger most effectively targets AN, preserving detection while also decreasing unnecessary colonoscopies compared with mt-sDNA testing and FIT. CLINICAL IMPACT. CTC performed with a polyp size threshold for colonoscopy referral set at 10 mm or larger represents the most effective and efficient noninvasive screening test for CRC prevention and detection.

Risk Stratification Score Improves Sensitivity for Advanced Colorectal Neoplasia in Colorectal Cancer Screening: The Oshima Study Workgroup

INTRODUCTION

Noninvasive colorectal cancer (CRC) screening methods with higher sensitivity for advanced colorectal neoplasia (ACN) than the fecal immunochemical test (FIT) alone are warranted. This study aimed to elucidate the diagnostic performance of a risk stratification score calculated using baseline individual characteristics and its combination with FIT for detecting ACN.

METHODS

This cross-sectional analysis of data from a prospective cohort in Izu Oshima, Japan, included asymptomatic individuals age 40-79 years who underwent both 2-day quantitative FIT and screening colonoscopy. The 8-point risk score, calculated based on age, sex, CRC family history, body mass index, and smoking history, was assessed. Colonoscopy results were used as reference.

RESULTS

Overall, 1,191 individuals were included, and 112 had ACN. The sensitivity and specificity of the 1-/2-day FIT (cutoff: 50-200 ng Hb/mL) for ACN were 17.9%-33.9% (4.9%-22.0% for right-sided ACN) and 91.8%-97.6%, respectively. The risk score's c-statistic for ACN was 0.66, and combining the score (cutoff: 5 points) with 1-/2-day FIT (cutoff: 50-200 ng Hb/mL) yielded a sensitivity and specificity for ACN of 46.4%-56.3% (43.9%-48.8% for right-sided ACN) and 76.6%-80.8%, respectively. The specificity of the risk score and FIT combination for all adenomatous lesions was 82.4%-86.4%.

DISCUSSION

The 8-point risk score remarkably increased the sensitivity for ACN, particularly for right-sided ACN. Although the specificity decreased, it was still maintained at a relatively high level. The risk score and FIT combination has the potential to become a viable noninvasive CRC screening option.

Piloting gender-oriented colorectal cancer screening with a faecal immunochemical test: population-based registry study from Finland

OBJECTIVE

To assess the feasibility and evaluate the performance of a relaunched colorectal cancer (CRC) screening programme with different cut-offs for men and women.

DESIGN

Population-based registry study.

SETTING

Nine municipalities in Finland which started CRC screening with faecal immunochemical test (FIT) in April 2019 with cut-off levels 70 µg Hg/g faeces for men and 25 µg Hg/g faeces for women.

PARTICIPANTS

Men (n=13 059) and women (n=14 669) aged 60-66 years invited to screening during the first programme year.

OUTCOME MEASURES

Participation rates, positivity rates, detection rates of CRC and advanced adenoma (AA), and positive predictive values (PPV) of FIT for CRC and AA.

RESULTS

Altogether 21 993 invitees returned stool samples. The participation rate of women (83.4%; 95% CI 82.8 to 84.0) was significantly higher than that of men (74.7%; 95% CI 73.9 to 75.4). The positivity rates were 2.4% (2.2 to 2.7) and 2.8% (2.5 to 3.1), respectively. In total, 37 CRCs and 116 AAs were detected. The detection rates of CRC and AA per 1000 participants were 1.8 (1.1 to 2.9) and 7.2 (5.6 to 9.1) for men and 1.6 (0.9 to 2.4) and 3.8 (2.8 to 5.0) for women. The PPVs per 100 positive tests were 6.6 (4.0 to 10.3) and 25.7 (20.6 to 31.4) for men and 6.4 (3.9 to 9.8) and 15.5 (11.6 to 20.2) for women.

CONCLUSIONS

The chosen FIT strategy narrowed the gap in the diagnostic performance between men and women especially in the detection of CRC. The participation rates were excellent. The levels of positivity and detection rates were moderate and need further action. The results indicate that gender-specific protocols can be introduced to organised CRC screening. It is yet to be seen whether they are more effective than a uniform screening protocol.

Fecal Immunochemical Tests Detect Screening Participants with Multiple Advanced Adenomas Better than T1 Colorectal Cancers

BACKGROUND

Fecal immunochemical tests (FITs) are widely used for colorectal cancer (CRC) screening. The detection of early-stage cancer and advanced adenoma (AA), the most important premalignant lesion, is highly relevant to reducing CRC-related deaths. We aimed to assess sensitivity for the detection of CRC and AA stratified by tumor stage; number; size; histology of AA; and by location, age, sex, and body mass index (BMI).

METHODS

Participants of screening colonoscopy (n = 2043) and newly diagnosed CRC patients (n = 184) provided a stool sample before bowel preparation or CRC surgery. Fecal hemoglobin concentration was determined in parallel by nine different quantitative FITs among 94 CRC patients, 200 AA cases, and 300 participants free of advanced neoplasm. Sensitivities were calculated at original cutoffs and at adjusted cutoffs, yielding 93% specificity among all FITs.

RESULTS

At adjusted cutoffs, UICC stage I cancers yielded consistently lower sensitivities (range: 62-68%) compared to stage II-IV cancers (range: 73-89%). An even stronger gradient was observed according to T status, with substantially lower sensitivities for T1 (range: 39-57%) than for T2-T4 cancers (range: 71-100%). Sensitivities for the detection of participants with multiple AAs ranged from 55% to 64% and were by up to 25% points higher than sensitivities for T1 cancers.

CONCLUSIONS

FITs detect stage I cancers and especially T1 cancers at substantially lower sensitivities than more advanced cancer stages. Participants with multiple AAs were detected with slightly lower sensitivities than stage I cancers and with even higher sensitivities than T1 cancers. Further research should focus on improving the detection of early-stage cancers.

Harms and Benefits of Cancer Screening

In recommending and offering screening, health services make a health claim ('it's good for you'). This article considers ethical aspects of establishing the case for cancer screening, building a service programme, monitoring its operation, improving its quality and integrating it with medical progress. The value of (first) screening is derived as a function of key parameters: prevalence of the target lesion in the detectable pre-clinical phase, the validity of the test and the respective net utilities or values attributed to four health states-true positives, false positives, false negatives and true negatives. Decision makers as diverse as public regulatory agencies, medical associations, health insurance funds or individual screenees can legitimately come up with different values even when presented with the same evidence base. The main intended benefit of screening is the reduction of cause-specific mortality. All-cause mortality is not measurably affected. Overdiagnosis and false-positive tests with their sequelae are the main harms. Harms and benefits accrue to distinct individuals. Hence the health claim is an invitation to a lottery with benefits for few and harms to many, a violation of the non-maleficence principle. While a public decision maker may still propose a justified screening programme, respect for individual rights and values requires preference-sensitive, autonomy-enhancing educational materials-even at the expense of programme effectiveness. Opt-in recommendations and more 'consumer-oriented' qualitative research are needed.

Auto-antibodies to p53 and the Subsequent Development of Colorectal Cancer in a U.S. Prospective Cohort Consortium

BACKGROUND

Auto-antibodies to tumor suppressor p53 are found in a subset of patients with colorectal cancer. A recent prospective study in the United States has reported a significant 1.8-fold increased odds for colorectal cancer development with prediagnostic seropositivity to p53. In this study, we sought to examine this association in a U.S. colorectal cancer cohort consortium to evaluate the potential utility of p53 auto-antibodies as an early biomarker for colorectal cancer.

METHODS

Auto-antibodies to p53 were measured in prediagnostic blood samples of 3,702 incident colorectal cancer cases and 3,702 controls, matched by age, race, and sex, from 9 U.S. prospective cohorts. The association of seropositivity to p53 with colorectal cancer risk, overall and by time between blood draw and diagnosis, was determined by conditional logistic regression.

RESULTS

Overall, 5% of controls and 7% of cases were seropositive to p53, resulting in a statistically significant 33% increased colorectal cancer risk [odds ratio (OR), 1.33; 95% confidence interval (CI), 1.09-1.61]. By follow-up time, the association was only significant with colorectal cancer diagnoses within 4 years after blood draw (OR, 2.27; 95% CI, 1.62-3.19), but not thereafter (OR, 0.97; 95% CI, 0.76-1.24).

CONCLUSIONS

In this large consortium of prospective cohorts, we found that prediagnostic seropositivity to tumor suppressor p53 was significantly associated with an over 2-fold increased odds of developing colorectal cancer within 4 years after blood draw.

IMPACT

Our finding suggests that p53 seropositivity may not be a useful predictor of long-term colorectal cancer risk; however, it might be considered as a marker to aid in the early diagnosis of colorectal cancer.

Accuracy of faecal immunochemical testing in patients with symptomatic colorectal cancer

BACKGROUND

The aim of this study was to determine the diagnostic accuracy of the faecal immunochemical test (FIT) for detecting colorectal cancer in symptomatic patients.

METHODS

This was a prospective study of patients with bowel symptoms. Stool samples were collected during rectal examination. The HM-JACKarc assay (Kyowa Medex, Tokyo, Japan) was used to quantify faecal haemoglobin (Hb); positive results were those with at least 10 μg Hb/g faeces. Two-by-two tables and receiver operating characteristic (ROC) curve analysis were used to determine diagnostic accuracy; χ2 and Mann-Whitney U tests were used to compare other parameters.

RESULTS

A total of 928 patients were included (M : F ratio 1 : 1·5; median age 72 (i.q.r. 64-80) years). The overall prevalence of colorectal cancer was 5·1 per cent. The FIT had sensitivity of 85·1 per cent, specificity of 83·5 per cent, positive predictive value of 22·6 per cent and negative predictive value of 99·0 per cent. ROC analysis of FIT for diagnosing colorectal cancer gave an area under the curve value of 0·89 (95 per cent c.i. 0·84 to 0·94). Significant bowel pathology was detected more frequently in FIT-positive patients (35·1 per cent versus 7·1 per cent in FIT-negative patients; P < 0·001). There were sex differences in FIT positivity (23·7 per cent in men versus 17·4 per cent in women; P = 0·019); the sensitivity of FIT for colorectal cancer in women was also low. False-negative FIT results were found mainly in women referred with iron-deficiency anaemia, who were found to have caecal cancer.

CONCLUSION

FIT effectively excluded colorectal cancer in symptomatic patients. Integration of FIT into the diagnostic pathway for colorectal cancer would direct resources appropriately to patients with a greater likelihood of having the disease.

Age-specific sequence of colorectal cancer screening options in Germany: A model-based critical evaluation

BACKGROUND

The current organized screening program for colorectal cancer in Germany offers both sexes 5 annual fecal immunochemical tests (FITs) between ages 50 and 54 years, followed by a first screening colonoscopy at age 55 years if all of these FITs were negative. We sought to assess the implications of this approach for key parameters of diagnostic performance.

METHODS AND FINDINGS

Using a multistate Markov model, we estimated the expected detection rates of advanced neoplasms (advanced adenomas and cancers) and number needed to scope (NNS) to detect 1 advanced neoplasm at a first screening colonoscopy conducted at age 55 after 5 preceding negative FITs and compared them with the corresponding estimates for a first screening colonoscopy at age 55 with no preceding FIT testing. In individuals with 5 consecutive negative FITs undergoing screening colonoscopy at age 55, expected colonoscopy detection rate (NNS) was 3.7% (27) and 0.10% (1,021) for any advanced neoplasm and cancer, respectively, in men, and 2.1% (47) and 0.05% (1,880) for any advanced neoplasm and cancer, respectively, in women. These NNS values for detecting 1 advanced neoplasm are approximately 3-fold higher, and the NNS values for detecting 1 cancer are approximately 8-fold higher, than those for a first screening colonoscopy at age 55 without prior FITs. This study is limited by model simplifying assumptions and uncertainties related to input parameters.

CONCLUSIONS

Screening colonoscopy at age 55 after 5 consecutive negative FITs at ages 50-54, as currently offered in the German cancer early detection program, is expected to have very low positive predictive value. Our results may inform efforts to enhance the design of screening programs.

Making FIT Count: Maximizing Appropriate Use of the Fecal Immunochemical Test for Colorectal Cancer Screening Programs

Colorectal cancer (CRC) remains one of the most common and deadly malignancies despite advancements in screening, diagnostic capabilities, and treatment. The ability to detect and remove precancerous and cancerous lesions via screening has altered the epidemiology of the disease, decreasing incidence, mortality, and late-stage disease presentation. The fecal immunochemical test (FIT) is a screening test that aims to detect human hemoglobin in the stool. FIT is the most common CRC screening modality worldwide and second most common in the United States. Its use in screening programs has been shown to increase screening uptake and improve CRC outcomes. However, FIT-based screening programs vary widely in quality and effectiveness. In health systems with high-quality FIT screening programs, only superior FIT formats are used, providers order FIT appropriately, annual patient participation is high, and diagnostic follow-up after an abnormal result is achieved in a timely manner. Proper utilization of FIT involves multiple steps beyond provider recommendation of the test. In this commentary, we aim to highlight ongoing challenges in FIT screening and suggest interventions to maximize FIT effectiveness. Through active engagement of patients and providers, health systems can use FIT to help optimize CRC screening rates and improve CRC outcomes.

Utilisation of Colorectal Cancer Screening Tests in European Countries by Type of Screening Offer: Results from the European Health Interview Survey

In the past two decades, an extensive rollout of colorectal cancer (CRC) screening programmes has been initiated in European countries with a large heterogeneity of screening offers. Using data from a population-based cross-sectional survey conducted between 2013 and 2016 in all European Union countries, we analysed the utilisation of faecal tests and colonoscopy among people aged 50–74 years and the factors associated with uptake by type of screening offer. We observed the highest utilisation of either test for countries with fully rolled out organised programmes with faecal tests (ranging from 29.7% in Croatia to 66.7% in the UK) and countries offering both faecal tests and colonoscopy (from 22.7% in Greece to 70.9% in Germany). Utilisation was very low for countries with no programme (from 6.3% in Romania to 30.5% in Norway). Younger age (50–54 years), longer time since last consultation with a doctor and a lifestyle score associated with increased CRC risk were significantly associated with lower test use, a pattern observed across all types of screening offers. Our results suggest that more countries should implement organised programmes with faecal immunochemical tests, in combination with alternative endoscopy offers where resources allow. Furthermore, there is a large potential for increasing screening use in Europe by better reaching the younger eligible individuals, those who have not been to the doctor recently and those at increased risk for CRC.

Biomarker measurement in non-invasively sampled colorectal mucus as a novel approach to colorectal cancer detection: screening and triage implications

Background

Faecal tests are widely applied for colorectal cancer (CRC) screening and considered for triaging symptomatic patients with suspected CRC. However, faecal tests can be inconvenient, complex and expensive. Colorectal mucus (CM) sampled using our new patient-friendly non-invasive technique is rich in CRC biomarkers. This study aimed to evaluate diagnostic accuracy of CRC detection by measuring protein biomarkers in CM.

Methods

Colorectal mucus samples were provided by 35 healthy controls, 62 CRC-free symptomatic patients and 40 CRC patients. Biomarkers were quantified by ELISA. Diagnostic performances of haemoglobin, C-reactive protein, tissue inhibitor of metalloproteinases-1, M2-pyruvate kinase, matrix metalloproteinase-9, peptidyl arginine deiminase-4, epidermal growth factor receptor, calprotectin and eosinophil-derived neurotoxin were assessed using receiver operating characteristic (ROC) curve analysis.

Results

Colorectal mucus haemoglobin was superior compared to other biomarkers. For haemoglobin, the areas under the curve for discriminating between CRC and healthy groups (‘screening’) and between CRC and symptomatic patients (‘triage’) were 0.921 and 0.854 respectively. The sensitivity of 80.0% and specificities of 94.3% and 85.5% for the two settings respectively were obtained.

Conclusions

Haemoglobin quantification in CM reliably detects CRC. This patient-friendly approach presents an attractive alternative to faecal immunochemical test; however, the two methods need to be directly compared in larger studies.

Benefits of switching from guaiac-based faecal occult blood to faecal immunochemical testing: experience from the Wallonia-Brussels colorectal cancer screening programme

Background

Faecal immunochemical tests (FITs) have replaced guaiac-based faecal occult blood test (gFOBTs) in several colorectal cancer (CRC) screening programmes. We aimed to evaluate the benefits of this transition based on the Wallonia–Brussels-organised CRC screening programme.

Methods

A total of 1,569,868 individuals aged 50–74 years, who were invited to screening during 2009–2017, were studied by linking their screening records with insurance, pathology and cancer data in the Belgian Cancer Registry. We compared neoplasm detection rates and positive predictive values (PPVs) of gFOBT and FIT at 15 µg haemoglobin per gram cut-off in screen-naive individuals. We furthermore examined the incidence rates of interval cancer in gFOBT- and FIT-based screening programme.

Results

Advanced neoplasms were detected less frequently by gFOBT (0.8%) than by FIT (1.3%), with a difference of 0.5% (P < 0.01). PPVs were lower for gFOBT (15.1%) than for FIT (21.7%) for advanced neoplasms (difference 6.6%, P < 0.01). Compared to participants with negative gFOBT, those with negative FIT were 77% less likely to develop interval cancer (incidence rate ratio 0.23, 95% confidence interval 0.16–0.33).

Conclusion

Our study demonstrated that in an organised CRC screening programme, replacing gFOBT with FIT improved neoplasm detection rate and substantially reduced interval cancer incidence.

Characteristics of Advanced Colorectal Cancer Detected by Fecal Immunochemical Test Screening in Participants with a Negative Result the Previous Year

BACKGROUND

There is sufficient evidence to show the mortality reduction effect of colorectal cancer (CRC) screening programs using the fecal occult blood test (FOBT). However, we see cases that are found to be advanced CRC despite yearly FOBT screening.

METHODS

The aim of this study was to investigate the characteristics of advanced CRC detected by a fecal immunochemical test (FIT) screening program in participants with a negative screening result the previous year, which we call "Negative advanced CRC". A total of 109,639 participants (10.0% required colonoscopy, of whom 76.9% received one) underwent a CRC screening program using a FIT from fiscal 2009 to 2017. Negative advanced CRC was compared with advanced CRC (First advanced CRC) found at the first visit in a person who had not had a FIT screening history for more than 3 years. In addition, we compared the characteristics of Negative advanced CRC with those of interval cancer: cancer cases detected after a negative screening result and before the date of the next recommended screening.

RESULTS

A total of 339 cases of CRC (175 male: 164 female, 173 early stage: 166 advanced stage) were detected in the nine-year CRC screening period. The rate of right-sided CRCs was significantly higher in female (P < 0.01), advanced stage (P < 0.01), negative result previous year (P < 0.01), and symptom-negative (P < 0.01) participants than in each counterpart, respectively. The ratio of female (22/35; 62.9%) patients in Negative advanced CRCs tended to be high compared with that (40/83; 48.2%) in First advanced CRCs (P = 0.145). Overall, 22 (62.9%) of 35 Negative advanced CRCs and 28 (33.7%) of 83 First advanced CRCs were located in the right-sided colon, and the rate was significantly higher in Negative advanced CRCs (P < 0.01). In addition, the frequency of female patients was significantly higher in right-sided Negative advanced CRCs than in right-sided First advanced CRCs (P = 0.03).

CONCLUSION

The characteristics of Negative advanced CRC cases (female and right-sided colon) were similar to those of interval cancer reported so far. In the future, it will be necessary to introduce a screening program that is highly sensitive to right-sided CRC.