Accuracy of immunochemical fecal occult blood test for detecting colorectal neoplasms in individuals undergoing health check-ups

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Potential Modifiers and Different Cut-offs in Diagnostic Accuracy of Fecal Immunochemical Test in Detecting Advanced Colon Neoplasia: A Diagnostic Test Accuracy Meta-analysis

Background: Fecal immunoglobulin test (FIT) has been advocated as the first line of screening for colorectal cancer (CRC) in several jurisdictions. Most studies have focused on CRC as the outcome of interest. Our goal was to quantify the diagnostic accuracy of different thresholds of FIT as compared with colonoscopy for detection of advanced colonic neoplasia and potential modifiers using proper Cochrane methodology. Methods: A comprehensive electronic search was performed for studies on FIT using colonoscopy as the reference standard to detect advanced neoplasia. Cochrane methodology was used to perform a diagnostic test accuracy (DTA) meta-analysis. Diagnostic accuracy of different cut-offs of FIT, including 25, 50, 75, 100, 150, and 200 ng/mL, were calculated separately. Meta-regression analysis was also performed to detect potential a priori modifiers, including age, location of the tumor, and time from FIT to colonoscopy. Results: Twenty-four studies were included with no evidence of publication bias. The sensitivity of FIT did not decrease with lowering the cut-off, although specificity increased in higher cut-offs. Commonly used cut-offs of 50 ng/mL, 75 ng/mL, and 100 ng/mL for FIT provided sensitivity of 39%, 36%, 27% and specificity of 92%, 94%, 96%, respectively. Diagnostic accuracy of FIT did not significantly differ in proximal versus distal lesions or in individuals below or over the age of 50 years. The results remained robust in a meta-regression of the location of the study, time from FIT to colonoscopy, and methodological quality. Conclusion: The sensitivity of FIT might have been overestimated in previous studies focusing on CRC, and it seems to be independent of age, location of neoplasia, or cut-offs, contrary to some previous studies. Lowering the cut-off will reduce the diagnostic odds ratio (DOR) by increasing specificity but without any effect on sensitivity.

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.

MicroRNA-based signature for diagnosis and prognosis of colorectal cancer using residuum of fecal immunochemical test

BACKGROUND

Colorectal cancer (CRC) is still among the most lethal and prevalent malignancies in the world. Despite continuous efforts, the diagnosis and prognosis of CRC have never been satisfying, especially the non-invasive assays.

METHODS

Our study comprised three independent cohorts of 835 qualified stool samples. From 46 literature-identified miRNA candidates, four miRNA ratios were selected and developed into a miRNA-based signature after applied to the training and test sets. The clinical performances of this signature were further evaluated in the prospective cohorts.

RESULTS

Four miRNA ratios with significant alterations and the highest discriminating power between the CRC and control groups in the training set were successfully validated in the test set. In the training dataset, combining these four miRNA ratios using a logistic regression model improved the area under the curve value to 0.821 and obtained a sensitivity of 73.6% and specificity of 78.9%. This miRNA signature showed consistent performances in the other two sample cohorts, with the highest sensitivity of 85.7% in the prospective cohort. Additionally, the higher miRNA signature was associated with worse disease-free survival (hazard ratio = 2.27) and overall survival (hazard ratio = 1.83) of CRC patients. For fecal immunochemical test (FIT)-positive populations, the positive predictive value for CRC detection in miRNA-positive subjects was 3.43-fold higher in the prospective cohort, compared to FIT alone.

CONCLUSION

This stool miRNA signature is highly associated with poor outcome of CRC and can be added to FIT tests to help identify the most at-risk group to receive prompt colonoscopy examination.

Comparison of colorectal cancer outcomes in young adults and octogenarians

BACKGROUND

This study aimed to characterise the outcomes associated with colorectal cancer (CRC), comparing young adults (<50 years), patients of screening age (50-79 years), and octogenarians (>80 years).

METHODS

All consecutive CRC resections with curative intent were recruited into this study from a prospectively maintained CRC database at a tertiary academic centre.

RESULTS

A total of 745 eligible cases were identified. Five-year survival in young adults was poorer than that of patients of screening age. Young adults had the highest incidence of rectal cancer resections, and presented with the most advanced tumour stages. Independent associations for poorer survival in young adults were increased nodal stage, the presence of distal metastases, and loss of MLH1/PMS2 staining on immunohistochemistry. Young adults had similar survival to octogenarians, when comparing patients treated with curative intent, regardless of oncological treatment.

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.

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.

A Simple and Highly Specific MassARRAY-Based Stool DNA Assay to Prioritize Follow-up Decisions in Fecal Immunochemical Test-Positive Individuals

BACKGROUND

Seventy-five percent of fecal immunochemical test (FIT)-positive individuals are false positives and undergo unnecessary colonoscopies. Here, we established a stool DNA (sDNA) test that uses the Single Allele Base Extension Reaction (SABER) MassARRAY platform to improve the accuracy of FIT-based CRC detection.

METHODS

Twenty-one variants in five CRC-associated genes were selected for the sDNA panel. Cell line DNA and matched mutation-confirmed tissue and stool samples from 34 patients were used for accuracy assessment (cohort 1). The clinical performance of the sDNA assay was further evaluated in 101 independent FIT-positive stool samples (cohort 2).

RESULTS

In cohort 1, we obtained a 62% mutation concordance rate in paired tissue and stool samples of the CRC group, regardless of the FIT status. In cohort 2, 100% specificity in normal controls with positive FIT results was observed. By weighting the FIT value and the presence of a given variant type in stool and then summing the two scores, we found that a one-increment increase in the score was associated with a 4.538-fold risk (95% CI = 2.121⁻9.309) for malignancy in the FIT-positive setting.

CONCLUSIONS

Our highly specific sDNA assay can help prioritize the most at-risk FIT-positive persons to receive prompt colonoscopic confirmation of CRC.

Performance Characteristics of Fecal Immunochemical Tests for Colorectal Cancer and Advanced Adenomatous Polyps: A Systematic Review and Meta-analysis

BACKGROUND

Studies report inconsistent performance of fecal immunochemical tests (FITs) for colorectal cancer (CRC) and advanced adenomas.

PURPOSE

To summarize performance characteristics of FITs for CRC and advanced adenomas in average-risk persons undergoing screening colonoscopy (reference standard) and to identify factors affecting these characteristics.

DATA SOURCES

Ovid MEDLINE, PubMed, Embase, and the Cochrane Library from inception through October 2018; reference lists of studies and reviews.

STUDY SELECTION

Two reviewers independently screened records to identify published English-language prospective or retrospective observational studies that evaluated FIT sensitivity and specificity for colonoscopic findings in asymptomatic, average-risk adults.

DATA EXTRACTION

Two authors independently extracted data and evaluated study quality.

DATA SYNTHESIS

Thirty-one studies (120 255 participants; 18 FITs) were included; all were judged to have low to moderate risk of bias. Performance characteristics depended on the threshold for a positive result. A threshold of 10 µg/g resulted in sensitivity of 0.91 (95% CI, 0.84 to 0.95) and a negative likelihood ratio of 0.10 (CI, 0.06 to 0.19) for CRC, whereas a threshold of greater than 20 µg/g resulted in specificity of 0.95 (CI, 0.94 to 0.96) and a positive likelihood ratio of 15.49 (CI, 9.82 to 22.39). For advanced adenomas, sensitivity was 0.40 (CI, 0.33 to 0.47) and the negative likelihood ratio was 0.67 (CI, 0.57 to 0.78) at 10 µg/g, and specificity was 0.95 (CI, 0.94 to 0.96) and the positive likelihood ratio was 5.86 (CI, 3.77 to 8.97) at greater than 20 µg/g. Studies had low to high heterogeneity, depending on the threshold. Although several FITs had adequate performance, sensitivity and specificity for CRC for 1 qualitative FIT were 0.90 and 0.91, respectively, at its single threshold of 10 µg/g; positive and negative likelihood ratios were 10.13 and 0.11, respectively. Comparison of 3 FITs at 3 thresholds was inconclusive: CIs overlapped, and the comparisons were across rather than within studies.

LIMITATIONS

Only English-language studies were included. Incomplete reporting limited quality assessment of some evidence. Performance characteristics are for 1-time rather than serial testing.

CONCLUSION

Single-application FITs have moderate to high sensitivity and specificity for CRC, depending on the positivity threshold. Sensitivity of 1-time testing for advanced adenomas is low, regardless of the threshold.

PRIMARY FUNDING SOURCE

Department of Medicine, Indiana University School of Medicine.

The fecal immunochemical test has high accuracy for detecting advanced colorectal neoplasia before age 50

BACKGROUND

In contrast to the decreasing incidence of colorectal cancer (CRC) in adults ≥50 years, the CRC incidence in young adults <50 years is increasing. The fecal immunochemical test (FIT) may be useful for advanced colorectal neoplasia (ACRN) screening in a young population.

AIMS

To evaluate the diagnostic accuracy of FIT in a young population.

METHODS

The diagnostic performance of FIT for detecting ACRN was compared among the following age groups who underwent FIT and colonoscopy as part of a comprehensive health screening program: 30-39, 40-49, and ≥50 years.

RESULTS

Of 26,316 participants, 464 (1.8%) had ACRN and 805 (3.1%) showed positive FIT results. No significant differences in the sensitivity (22.1%, 17.2%, and 22.0%; p=0.435) and specificity (97.2%, 97.4%, and 96.9%; p=0.344) of FIT for detecting ACRN were observed among the groups. However, 30-39 age group had a significantly higher accuracy of FIT for ACRN (96.7%) than 40-49 and ≥50 age groups (95.9% and 93.8%; p<0.001). The areas under the receiver operating characteristic curves of FIT for ACRN of three age groups were not significantly different (67.2, 66.2, and 61.7; p=0.952).

CONCLUSIONS

The diagnostic performance of FIT for ACRN in a young population (<50 years) was not inferior to that in the current screening-age population (≥50 years). The FIT may be a good choice for detecting ACRN in a young population.

Advances in Fecal Tests for Colorectal Cancer Screening

Colorectal cancer (CRC) forms an important public health problem, especially in developed countries. CRC screening tests can be used to identify asymptomatic individuals with CRC precursors and (early) cancer. Removal of these lesions reduces CRC incidence and prevents CRC-related mortality. There are a range of screening tests available, each with advantages and disadvantages. Stool screening tests can broadly be divided into fecal occult blood tests (FOBTs) and molecular biomarker test, such as DNA/RNA marker tests, protein markers, and fecal microbiome marker tests. Guaiac fecal occult blood tests (gFOBT) have been demonstrated in large randomized screening trials to reduce CRC mortality. Fecal immunochemical tests (FIT) have superior adherence, usability, and accuracy as compared to gFOBT. Advantage of the use of quantitative FITs in CRC screening programs is the cut-off level that can be adjusted. Molecular biomarker DNA tests have shown to detect significantly more cancers than FIT. By combining biomarker DNA tests with FIT, sensitivity for advanced adenomas can be increased significantly. However, it has lower specificity thus demands more colonoscopy resources, is more cumbersome, and costly. The adherence has not been assessed in population screening trials. For these reasons, FIT is therefore at present regarded as the preferred method of non-invasive CRC screening. This chapter will review the current status of fecal test-based CRC screening.

Cancer screening through a multi-analyte serum biomarker panel during health check-up examinations: Results from a 12-year experience

BACKGROUND

The use of blood-based tumor biomarkers for screening malignancies at early stages has significant advantages, including being convenient, automated, quantitative, objective, and relatively inexpensive compared with histology, endoscopy, and imaging.

METHODS

We describe our 12-year experience on the diagnostic usefulness of a biomarker panel consisting of eight molecules (i.e., α-fetoprotein, carcinoembryonic antigen, prostate-specific antigen, CA 19-9, CA125, CA 15-3, squamous cell specific antigen, and cytokeratin 19 fragment) for cancer screening in Taiwanese subjects who underwent a health check-up examination at their own expenses.

RESULTS

The sensitivity of the panel for the detection of specific cancers was higher than that of isolated cancer-specific markers. Specifically, the sensitivity of the panel for identifying the four most commonly diagnosed malignancies (i.e., liver cancer, lung cancer, prostate cancer, and colorectal cancer) was 90.9%, 75.0%, 100%, and 76.9%, respectively. The ability of the panel to detect early-stage (stage 1) hepatocellular carcinoma (HCC) or prostate cancer was similar to that observed for advanced malignancies.

CONCLUSIONS

The multi-analyte biomarker panel is clinically useful during health check-up examinations for the screening of different tumors (especially for the early detection of HCC and prostate malignancies).