Performance characteristics and evaluation of an automated-developed and quantitative, immunochemical, fecal occult blood screening test

Stable hemoglobin concentration with fecal immunochemical test at high temperatures in a Caribbean colorectal cancer screening program

BACKGROUND AND AIMS

High temperatures may reduce fecal immunochemical test (FIT) positivity and colorectal cancer (CRC) detection sensitivity. We investigated the effect of temperature on hemoglobin concentration [Hb], in the FOB Gold®. Additionally, we examined FIT pick-up, storage, return times and specimen collection.

MATERIALS AND METHODS

In vitro experiments with buffer containing FIT devices, inoculated with Hb-spiked stool. For 7 days, 144 samples were stored in groups of 36 at 4 °C, 22 °C, 30 °C, and 50 °C. Additionally, 54 samples were stored in groups of 18 at 34 °C, 42 °C and 50 °C for 20 h. Paired t-tests and repeated measure ANOVA assessed [Hb] change. Sixty-five screening participants completed a FIT-handling questionnaire.

RESULTS

After 7 days, mean [Hb] was stable at 30 °C (0.8 µg Hb/g;95 %CI: -1.5 to 3.1;p = 0.50). For 50 °C, mean [Hb] decreased within 2 days (-21.3 µg Hb/g;95 %CI: -30.2 to -12.5;p < 0.001) and after 20 h (-63.0 µg Hb/g;95 %CI: -88.7 to -37.3;p < 0.001), respectively. All other temperature categories showed significant mean [Hb] increase. Same-day FIT return was reported by 80 %. Eighty-seven percent experienced specimen collection as easy and 33 % kept the FIT refrigerated after collection.

CONCLUSIONS

The FOB Gold® is suitable for CRC screening in tropical climates. Although most respondents indicated same-day sample return, we recommend avoiding FIT storage above 30 °C for longer than7 days.

Fecal immunochemical test for hemoglobin versus fecal calprotectin to monitor endoscopic activity in inflammatory bowel disease

AIM

endoscopy identifies inflammatory activity, however, it is an unpleasant test and is not always accessible. The aim of the study was to compare the usefulness of quantitative fecal immunochemical test (FIT) versus fecal calprotectin (FC) to determine endoscopic activity in patients with inflammatory bowel disease (IBD).

METHODS

cross-sectional prospective observational study. The stool samples were collected within three days before starting the preparation for the colonoscopy. We used the Mayo index for ulcerative colitis (UC) and the simplified endoscopic index for Crohn's disease (CD). Mucosal healing (MH) was defined as the score 0 points in each of the endoscopic indices.

RESULTS

eighty-four patients were included, 40 (47.6 %) with UC. In patients with IBD, FIT and FC showed a significant correlation with the presence of inflammatory activity/MH on endoscopy, with no statistically significant differences between the two receiver-operating characteristic (ROC) curves. Both tests improved their diagnostic performance when assessing patients with UC; the Spearman correlations between FIT and FC and endoscopic inflammatory activity were r = 0.6 (p = 0.0001) and r = 0.7 (p = 0.0001), respectively. In Crohn's disease, the diagnostic utility of both tests was lower.

CONCLUSIONS

FIT is an alternative to monitor endoscopic activity among ulcerative colitis patients. In Crohn's disease, more studies are needed to determine the role of fecal biomarkers.

Diagnostic Performance of a Fecal Immunochemical Test-Based Colorectal Cancer Screening Program According to Ambient Temperature and Humidity

Exposure of the fecal immunochemical test (FIT) to different ambient temperatures and humidity is unavoidable in population-based screening programs in Southern European countries, and it could lead to a decrease in target colorectal lesions. The objective was to evaluate the effect of ambient temperature and humidity on the FIT sensitivity in a population-based screening program for colorectal cancer (CRC) using an ecological design. The retrospective cohort included individuals aged 50−69 years who participated in CRC screening (Barcelona) from 2010−2015, and were followed until 2017 to identify interval CRCs. The positivity rate, and detection rates for advanced polyps and CRC were compared according to ambient temperature, humidity, and quarters of the year. A positive FIT was defined as the detection of ≥20 μg Hb/g in feces. The monthly ambient temperature and humidity were recorded on the day that the FIT was performed. In total, 92,273 FIT results from 53,860 participants were analyzed. The FIT positivity rate was lower at >24 °C than at ≤24 °C (p = 0.005) but was not affected by humidity. The temperature’s impact on positivity did not lead to a decrease in the FIT detection rate for advanced neoplasia or the interval cancer detection rate in a program where the samples were refrigerated until the analysis and screening invitations were discontinued in July and August.

Role of Biomarkers in the Diagnosis and Treatment of Inflammatory Bowel Disease

The number of patients with inflammatory bowel disease (IBD) is increasing worldwide. Endoscopy is the gold standard to assess the condition of IBD. The problem with this procedure is that the burden and cost on the patient are high. Therefore, the identification of a reliable biomarker to replace endoscopy is desired. Biomarkers are used in various situations such as diagnosis of IBD, evaluation of disease activity, prediction of therapeutic effect, and prediction of relapse. C-reactive protein and fecal calprotectin have a lot of evidence as objective biomarkers of disease activity in IBD. The usefulness of the fecal immunochemical test, serum leucine-rich glycoprotein, and urinary prostaglandin E major metabolite have also been reported. Herein, we comprehensively review the usefulness and limitations of biomarkers that can be used in daily clinical practice regarding IBD. To date, no biomarker is sufficiently accurate to replace endoscopy; however, it is important to understand the characteristics of each biomarker and use the appropriate biomarker at the right time in daily clinical practice.

A user-friendly objective prediction model in predicting colorectal cancer based on 234 044 Asian adults in a prospective cohort

BACKGROUND

Prediction models of colorectal cancer (CRC) had limited application for not being user-friendly. Whether fecal immunochemical tests (FITs) can help predict CRC has been overlooked.

PATIENTS AND METHODS

With 1972 CRCs identified, 234 044 adults aged ≥40 years were successively enrolled between 1994 and 2008. Prediction models were developed by questionnaire/medical screening and quantitative FIT. NNS (number needed to scope to find one cancer) is time dependent, spanning entire study period. Significant 'risk factors' were family history, body mass index, smoking, drinking, inactivity, hypertension, diabetes, carcinoembryonic antigen, and C-reactive protein.

RESULTS

Positive FIT (≥20 μg/g hemoglobin/feces) had cancer risk 10-fold larger than negative FIT, and within each age group, another 10-fold difference. The C statistic of FIT (0.81) with age and sex alone was superior to the 'common risk-factors' model (0.73). NNS, stratified by age and by FIT values, demonstrated a scorecard of cancer risks, like 1/15 or 1/25, in 5 years. When FIT was negative, cancer risk was small (1/750-1/3000 annually). The larger the FIT, the sooner the appearance of CRC. For every 80-μg/g increase of FIT, there were 1.5-year earlier development of CRC incidence and 1-year earlier development of CRC mortality, respectively. Given the same FIT value, CRC events appeared in the proximal colon sooner than the distal colon.

CONCLUSIONS

A simple user-friendly model based on a single FIT value to predict CRC risk was developed. When positive, NNS offered a simple quantitative value, with a better precision than most risk factors, even combined. When FIT is negative, risk is very small, but requiring a repeat every other year to rule out false negative. FIT values correlated well with CRC prognosis, with worst for proximal CRC.

Quality Improvement of Sample Collection Increases the Diagnostic Accuracy of Quantitative Fecal Immunochemical Test in Colorectal Cancer Screening: A Pilot Study

Objective: The diagnostic efficiency of the quantitative fecal immunochemical test (qFIT) has large variations in colorectal cancer (CRC) screening. We aimed to explore whether the practical sample collection operant training could improve the diagnostic accuracy of the qFIT in CRC screening.

Methods: Moderate-/high-risk individuals aged 50–75 years old were invited to participate in a prospective observational study between July 2020 and March 2021. Participants took a qFIT sample without fecal sample collection operant training in advance and then completed another qFIT sample after the operant training. The primary outcome was the sensitivity and specificity of the qFITs for CRC and advanced colorectal neoplasia (ACRN). The secondary outcome was the difference in the area under the curves (AUCs) and the concentrations of the fecal hemoglobin (Hb) between the qFIT without and after the operant training.

Results: Out of 913 patients, 81 (8.9%) patients had ACRN, including 25 (2.7%) patients with CRC. For CRC, the sensitivities of the qFIT without and after the operant training at 10 μg/g were 80.4 and 100.0%, respectively, and the specificities were 90.1 and 88.4%, respectively. For ACRN, the sensitivities were 49.4 and 69.1% and the specificities were 91.7 and 91.3%, respectively. The AUC of the qFIT after the operant training was significantly higher than that without the operant training for CRC (p = 0.027) and ACRN (p = 0.001). After the operant training, the concentration of the fecal Hb was significantly higher than that without the operant training (p = 0.009) for ACRN, but there was no significant difference for CRC (p = 0.367).

Conclusion: Practical sample collection operant training improves the diagnostic accuracy of the qFIT, which increases the detection of the low concentrations of fecal Hb. Improving the quality of the sample collection could contribute to the diagnostic efficiency of the qFIT in CRC screening.

Optimal diagnostic accuracy of quantitative faecal immunochemical test positivity thresholds for colorectal cancer detection in primary health care: A community-based cohort study

Background

Optimizing colonoscopy resources is challenging, and information regarding performing diagnostic quantitative faecal immunochemical test (FIT) in daily clinical practice in primary health care is still limited. This study aimed to assess the sensitivity, specificity, positive predictive value and negative predictive value of varying FIT positivity thresholds on colorectal cancer (CRC) detection in primary health care.

Methods

A retrospective cohort study of 38,675 asymptomatic and symptomatic patients with a FIT (OC‐Sensor™) performed between 2012 and 2016 in a primary health‐care setting, using a clinical laboratory database of two Spanish areas linked with the National Health System's Hospital Discharge Records Database. The primary outcome was 2‐year CRC incidence.

Results

The mean age of the participants was 63.2 years; 17,792 (46.0%) were male. CRC prevalence was 1.7% (650/38,675). The percentage of patients with a FIT result above the threshold was 20.7% and 14.6% for 10 μg Hb/g faeces and 20 μg Hb/g faeces thresholds, respectively. Sensitivity was 90.5% (95% confidence interval 88.0%–92.5%) at a 10 μg Hb/g faeces threshold, and this decreased by 3.1% when a 20 μg Hb/g faeces threshold was used. The negative predictive value for CRC was at least 99.2% in any subgroup analysed. At a 20 μg Hb/g faeces threshold, less than one additional CRC would be missed per 1000 patients investigated, while approximately 1.3 times more colonoscopy examinations were needed to identify an incidence of CRC using the lowest threshold for any situation analysed.

Conclusions

In primary health care, a quantitative FIT threshold should be tailored to colonoscopy capacity and CRC prevalence in specific populations.

Prostaglandin E-major urinary metabolite versus fecal immunochemical occult blood test as a biomarker for patient with ulcerative colitis

Background

Prostaglandin E-major urinary metabolite (PGE-MUM) may be a novel biomarker for evaluating disease activity in ulcerative colitis (UC). We compared its usefulness to that of the fecal immunochemical occult blood test (FIT).

Methods

PGE-MUM and FIT measurements were performed of 92 urinary and fecal samples obtained from 60 patients with UC. Endoscopic activity was determined by Mayo endoscopic subscore (eMayo) and Ulcerative Colitis Endoscopic Index of Severity (UCEIS) score.

Results

PGE-MUM levels and FIT results showed a significant correlation with respect to eMayo (P <  0.001 and P < 0.001, respectively), and there was a significant difference in PGE-MUM values between the groups below eMayo1 and above eMayo2 (P = 0.012). Both biomarkers were significantly correlated with the UCEIS score (P < 0.001 and P < 0.001, respectively), and the PGE-MUM values were significantly different between groups below UCEIS1 and above UCEIS2 (P = 0.012). PGE-MUM and FIT were significantly correlated with eMayo in the group with a disease duration < 5 years (P = 0.041 and P < 0.001, respectively). Although PGE-MUM and eMayo differed significantly between groups over 5 years (P = 0.012), FIT was not correlated with eMayo (P = 0.101).

Conclusions

PGE-MUM is useful as a biomarker as FIT for evaluating the endoscopic activity, particularly in long-term affected patients with UC.

Impact of temperature and humidity on performance of the fecal immunochemical test for advanced colorectal neoplasia

Although it is known that ambient temperature can affect the diagnostic performance of the fecal immunochemical test (FIT), the impact of other weather parameters, including humidity, on the sensitivity of FIT remains to be further investigated. We aimed to evaluate the impact of ambient temperature and humidity on the performance of FIT for screening for advanced colorectal neoplasia (ACRN). We included asymptomatic individuals who had undergone both screening colonoscopy and FIT. The diagnostic performance of FIT, including its sensitivity, was analyzed according to the ambient temperature and humidity on the day that FIT was performed. Temperature and humidity were divided into five levels. Among 35,461 participants, 589 (1.7%) had ACRN. The positivity rate of FIT was lower at ≥24 °C (3.1%) than at <0 °C (3.9%), 0–8 °C (4.3%), and 8–16 °C (3.9%). It was also lower at 80–90% humidity (3.1%) than at < 60% humidity (3.9%). Multivariable analysis showed that high ambient temperature (≥24 °C) with high ambient humidity (≥80%) was associated with a low positivity rate of FIT (odds ratio [OR] 0.62, 95% confidence interval [CI] 0.44–0.86). Sensitivity tended to decrease at high ambient temperature (<24 °C vs. ≥24 °C; 20.8% vs. 14.6%, P = 0.110) and was significantly lower at high ambient humidity (<80% vs. ≥80%; 21.0% vs. 12.5%, P = 0.044). The multivariable analysis also showed that high ambient humidity was independently associated with low sensitivity of FIT (OR 0.54, 95% CI 0.28–0.96). In conclusion, high ambient humidity decreased the sensitivity, while high ambient temperature along with high ambient humidity decreased the positivity rate of FIT.

Predictors of mucosal healing during induction therapy in patients with acute moderate-to-severe ulcerative colitis

BACKGROUND AND AIM

The treat-to-target strategy has emerged in ulcerative colitis management. Mucosal healing is the best target, albeit not in induction therapy of acute diseases as clinical conditions vary over a short duration. To determine the targets during induction therapy for acute ulcerative colitis, we identified markers to predict mucosal healing at 3 and 12 months of initiating the induction therapy.

METHODS

This single-center prospective observational study enrolling 61 adult patients hospitalized for disease exacerbation collected the partial Mayo scores, ulcerative colitis endoscopic index of severity, fecal markers, and laboratory data (0 day, 2 weeks, and 3 and 12 months) of initiating induction therapy.

RESULTS

At 2 weeks, patients with mucosal healing at 3 months had had lower partial Mayo and ulcerative colitis endoscopic index of severity scores and higher white blood cell count and total cholesterol than those without mucosal healing. At 3 months, patients with mucosal healing at 12 months had had lower partial Mayo and ulcerative colitis endoscopic index of severity scores than those without mucosal healing. A kinetic analysis demonstrated a difference in the partial Mayo scores and total cholesterol and albumin levels at 2 weeks and in the ulcerative colitis endoscopic index of severity, fecal calprotectin, and fecal immunochemical tests at 3 months between patients who achieved mucosal healing at 12 months and those who did not.

CONCLUSIONS

Partial Mayo scores and total cholesterol levels act as short-term therapeutic targets during induction therapy in patients with acute ulcerative colitis. Mucosal healing at 3 months correlates to longer time mucosal healing.

Fecal Hemoglobin Concentration, a Good Predictor of Risk of Advanced Colorectal Neoplasia in Symptomatic and Asymptomatic Patients

Background: Periodical fecal immunochemical testing (FIT) is a cost-effective strategy in colon cancer screening programmes. FIT is also used as a diagnostic test in symptomatic patients, but data, are scarce.

Aim: To determine the association between FIT-Hb concentration and the risk of advanced neoplasia (AN) detected in colonoscopy in two different populations.

Methods: The outcomes of colonoscopies performed after a positive FIT (>117 ng/ml) (Sentinel Gold test) result were analyzed in patients included within a population-based CRC screening programme (screening group) and, as diagnostic evaluation in symptomatic patients (symptomatic group). The study was performed between January 1st, 2014 and October 31, 2016. Data are reported as medians with interquartile ranges or frequencies and percentages. Positive predictive value (PPV) at arbitrary fecal hemoglobin concentrations were also reported calculated for AN.

Results: We recruited 2742 patients who underwent a colonoscopy procedure, 1515 (53.5%) of them within the CRC screening programme. Patients in the screening group were younger (65.0 ± 3.3 vs. 66.2 ± 13.4 years, p < 0.001) and more frequently male (p < 0.001) vs. the symptomatic group. Colonoscopy found more frequently neoplastic lesions in the screening compared to the symptomatic group (61.9 vs. 44.8% p < 0.001). Hb concentration in FIT was significantly higher in patients with AN compared with patients without AN in both groups (p < 0.001). The age-adjusted risk of AN increased significantly in both groups according to FIT Hb concentration in the Quartile 3 [OR (95% CI): 2.94 (2.33–3.71)] and Quartile 4 [OR: 5.52 (4.36–6.99)]. Males, in both groups showed a higher probability of presenting AN. FIT values were higher for left- than for right-sided AN in the screening, but not in the symptomatic group. Positive predictive values for AN were higher in the screening group in positive FIT tests (range 43.9–70.5%; 117 to >1,000 ng/ml) compared to those in the symptomatic group (36.3–52.5%). Similar trends were observed for cancer diagnosis alone.

Conclusions: Male gender, age, and FIT Hb concentration are predictors of risk of advanced adenoma and colorectal cancer and can be used to prioritize colonoscopy in patients with suspected advanced neoplasia, both in screening and in symptomatic patients.

Quantitative immunochemical fecal occult blood test for neoplasia in colon cancer screening

OBJECTIVE

To investigate the performance of the quantitative immunochemical fecal occult blood test (qFIT) and to determine the association between the fecal hemoglobin (Hb) level and the location and size of adenomas and the stages of colorectal cancer (CRC).

METHODS

A total of 692 participants were included in the study. Their fecal Hb level was measured using an OC-SENSA MICRO qFIT. The colonoscopy results, including the location, size, and histological features of the adenomas, as well as the relationship between the Hb level and different characteristics were analyzed. Performance of the qFIT at various thresholds of fecal Hb levels was evaluated.

RESULTS

Advanced colorectal neoplasia (ACRN) was identified in 76 patients based on the colonoscopic and pathological examinations. Large adenomas (≥10 mm) had a higher fecal Hb level than small adenomas (<10 mm). Advanced adenomas located on the left side of the colon presented with a higher fecal Hb level than those on the right side (P = 0.022). Stage III-IV CRC patients had a significantly higher Hb level than stage I-II patients (P = 0.013). The sensitivity and specificity of qFIT for ACRN was 51.3% and 86.4%，respectively, with the best cut-off level of 400 ng/mL. The sensitivity and specificity for CRC was 61.0% and 89.1%, with the best cut-off level of 500 ng/mL.

CONCLUSIONS

qFIT has an acceptable sensitivity and specificity for ACRN detection. Furthermore, the qFIT results are associated with the location and size of adenomas as well as the grade of CRC.

The novel latex agglutination turbidimetric immunoassay system for simultaneous measurements of calprotectin and hemoglobin in feces

Background/Aims

Fecal calprotectin (Fcal) as well as the fecal immunochemical test (FIT) are useful biomarkers for detecting activity and mucosal healing in inflammatory bowel diseases. Here, we report the performance of simultaneous measurements of Fcal and FIT for ulcerative colitis (UC) patients using the newly-developed latex agglutination turbidimetric immunoassay (LATIA) system.

Methods

Fcal and hemoglobin were measured by the LATIA system in 152 UC patients who underwent colonoscopy. Fcal was also quantified with a conventional enzyme-linked immunosorbent assay (ELISA). Fecal markers were evaluated in conjunction with the mucosal status of UC, which was assessed via the Mayo endoscopic subscore (MES) classification.

Results

The LATIA system could quantify calprotectin and hemoglobin simultaneously with the same fecal samples within 10 minutes. The values of the Fcal-LATIA closely correlated with those of the Fcal-ELISA (Spearman rank correlation coefficient, r=0.84; P<0.0001). The values of Fcal for each assay and the FIT all significantly correlated with the MESs (Spearman rank correlation coefficient, Fcal-LATIA: r=0.58, Fcal-ELISA: r=0.55, and FIT: r=0.72). The mucosal healing predictability (determined by an MES of 0 alone) of the Fcal-LATIA, Fcal-ELISA, and FIT-LATIA with the cutoffs determined by receiver operating characteristic curve analysis was 0.79, 0.78, and 0.92 for sensitivity, respectively, and 0.78, 0.69, and 0.73 for specificity, respectively.

Conclusions

The performance of the novel Fcal-LATIA was equivalent to that of the conventional Fcal assay. Simultaneous measurements with FITs would promote the clinical relevance of fecal biomarkers in UC.

Oncology in nephrology comes of age: A focus on chronic dialysis patients

Dialysis is the commonest modality of renal replacement therapy for patients suffering from end-stage kidney disease. Different registry studies showed that the risks of overall cancer occurrence were significantly higher in chronic dialysis patients than in the age-matched general population. However, the frequency and pattern of different cancers may vary among different geographical areas. Since chronic dialysis patients tend to have multiple comorbidities and a shorter life expectancy, routine cancer screening in all dialysis patients may not be cost-effective; rather screening should be personalized according to the patient's expected survival, candidacy for kidney transplant together with patient preferences.

Gender-specific cut-offs in colorectal cancer screening with FIT: Increased compliance and equal positivity rate

OBJECTIVE

Using quantitative Faecal Immunochemical Test (FIT) in colorectal cancer screening enables adjustment of the cut-off for a positive test. As men have higher stool blood levels and higher prevalence of colorectal neoplasia, different cut-off levels can be chosen for men and women. We evaluated participation and positivity rates switching from guaiac-based faecal occult blood test (gFOBT) (Hemoccult®) to FIT (OC-Sensor), using gender-specific cut-offs.

METHODS

The colorectal cancer screening programme of Stockholm-Gotland, Sweden, started in 2008 and invited individuals aged 60-69 to biennial testing using gFOBT. From 1 October 2015 the test was switched to FIT, with positivity cut-offs of 40 (200) and 80 (400) µg Hb/g (ng/mL) faeces for women and men, respectively. The first year was evaluated for compliance and positivity, number of reminders and incorrect/inadequate tests, compared with gFOBT in the preceding 12-month period.

RESULTS

There were 127,030 and 87,269 individuals invited to screening with gFOBT and FIT, respectively. The change of test increased overall participation by 11.9% (95% confidence interval 11.5%-12.3%) from 56.5% to 68.4% ( p < 0.001). The increase was larger in men (14.3%) than women (9.7%), and in those aged 60-64 (14.2%) than those aged 65-69 (8.7%). The positivity rate was 2.6% in women and 2.5% in men. There was a lower rate of reminders and incorrect/inadequate tests with FIT.

CONCLUSIONS

Within a well-organised colorectal cancer screening programme, changing the test from gFOBT to FIT markedly increased participation, especially among men, and in the younger age group. With a lower cut-off in women than men, the positivity rate was similar.

Usefulness of fecal immunochemical test and fecal calprotectin for detection of active ulcerative colitis

Background/Aims

Ulcerative colitis undergoes periods of exacerbation and remission. Fecal calprotectin levels increase with gut inflammation and correlate with endoscopic disease activity in ulcerative colitis. Intestinal blood loss and fecal immunochemical test levels also correlate with endoscopic disease activity. This study statistically evaluated the usefulness of fecal calprotectin, fecal immunochemical test, and C-reactive protein (CRP) as markers of disease activity.

Methods

A total 106 ulcerative colitis patients who underwent endoscopy and fecal calprotectin, fecal immunochemical test, and CRP testing, from March 2015 to August 2016, were retrospectively reviewed. Disease activity was assessed using a partial Mayo score and Mayo endoscopic score. The ability of fecal and serologic tests to reflect endoscopic disease severity was statistically evaluated.

Results

Among 106 patients, 68 underwent endoscopy and stool study within 2 weeks. In patients with mild to severe activity, fecal immunochemical test and fecal calprotectin were superior to CRP at Mayo endoscopic score detection rate. The area under the curves of fecal immunochemical test and fecal calprotectin for the detection of Mayo endoscopic score ≥1 were 0.956 and 0.942, respectively, and were superior to that of CRP (0.756). At Mayo endoscopic score, the effects of combination of fecal immunochemical test and CRP or fecal calprotectin and CRP were found to be higher than those of the independent fecal immunochemical test or fecal calprotectin.

Conclusions

Fecal immunochemical test and fecal calprotectin can effectively detect active ulcerative colitis better than remission. As these markers reflect the status of mucosal inflammation, they may reduce the requirement for invasive endoscopic examination.

The Role of Biomarkers in Clinical Trials of Inflammatory Bowel Disease

Clinical trials require valid outcome measures to assess the therapeutic benefit of investigational agents. Recently, regulatory authorities have mandated the use of patient-reported outcomes in combination with an objective measure of disease activity as primary outcome measures in inflammatory bowel disease trials. Endoscopy has commonly fulfilled the latter role; however, due to the costs and complexity of these assessments, interest has emerged in the use of noninvasive biomarkers. The role of C-reactive protein, fecal calprotectin, and fecal lactoferrin in clinical research is discussed.

Fecal immunochemical test for predicting mucosal healing in ulcerative colitis patients: A systematic review and meta-analysis

BACKGROUND AND AIM

Fecal immunochemical test (FIT) is a promising marker for assessment of inflammatory bowel disease activity. However, the utility of FIT for predicting mucosal healing (MH) of ulcerative colitis (UC) patients has yet to be clearly demonstrated. The objective of our study was to perform a diagnostic test accuracy test meta-analysis evaluating the diagnostic accuracy of FIT in predicting MH of UC patients.

METHODS

We systematically searched the databases from inception to November 2017 that evaluated MH in UC. The methodological quality of each study was assessed according to the Quality Assessment of Diagnostic Accuracy Studies checklist. The extracted data were pooled using a summary receiver operating characteristic curve model. Random-effects model was used to summarize the diagnostic odds ratio, sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio.

RESULTS

Six studies comprising 625 UC patients were included in the meta-analysis. The pooled sensitivity and specificity values for predicting MH in UC were 0.77 (95% confidence interval [CI], 0.72-0.81) and 0.81 (95% CI, 0.76-0.85), respectively. The FIT level had a high rule-in value (positive likelihood ratio, 3.79; 95% CI, 2.85-5.03) and a moderate rule-out value (negative likelihood ratio, 0.26; 95% CI, 0.16-0.43) for predicting MH in UC. The results of the receiver operating characteristic curve analysis (area under the curve, 0.88; standard error of the mean, 0.02) and diagnostic odds ratio (18.08; 95% CI, 9.57-34.13) also revealed improved discrimination for identifying MH in UC with FIT concentration.

CONCLUSION

Our meta-analysis has found that FIT is a simple, reliable non-invasive marker for predicting MH in UC patients.

Higher satisfaction with an alternative collection device for stool sampling in colorectal cancer screening with fecal immunochemical test: a cross-sectional study

BACKGROUND

Identifying preferences for stool collection devices may help increase uptake rates for colorectal cancer screening via fecal immunochemical test (FIT). This study surveyed satisfaction with different devices utilized to collect stool samples for FIT: a conventional container and a sampling bottle (Eiken OC-Sensor).

METHODS

This cross-sectional study was conducted at the National Cancer Center, Korea. Participants aged 50-74 years who used either a conventional container or a sampling bottle to collect a stool sample for FIT were asked to complete a questionnaire designed to survey their satisfaction with the stool collection process and their intentions to undergo FIT in subsequent screening rounds. In total, 1657 participants (1224 conventional container, 433 sampling bottle) were included for analysis.

RESULTS

Satisfaction with the sampling bottle was higher than that with the conventional container (79.9% vs.73.0%, p = 0.005, respectively; aOR = 1.52, 95% CI: 1.16-2.00). Participants satisfied with the sampling bottle were more likely to be female, be of younger age (50-64 years old), have higher household income, and have prior experience with FIT. Intentions to undergo subsequent screening were stronger among those given the sampling bottle than those given the conventional container (aOR = 1.78, 95% CI: 1.28-2 .48).

CONCLUSIONS

Satisfaction with the stool collection process was higher with the sampling bottle. However, additional studies are needed to validate whether the increased satisfaction and stronger intentions to undergo subsequent screening with the sampling bottle could actually lead to increased uptake in subsequent rounds, along with analysis of the device's cost effectiveness.

Impact of a new sampling buffer on faecal haemoglobin stability in a colorectal cancer screening programme by the faecal immunochemical test

Haemoglobin (Hb) stability in faecal samples is an important issue in colorectal cancer screening by the faecal immunochemical test (FIT) for Hb. This study evaluated the performance of the FIT-Hb (OC-Sensor Eiken) used in the Florence screening programme by comparing two different formulations of the buffer, both in an analytical and in a clinical setting. In the laboratory simulation, six faecal pools (three in each buffer type) were stored at different temperatures and analysed eight times in 10 replicates over 21 days. In the clinical setting, 7695 screenees returned two samples, using both the old and the new specimen collection device (SCD). In the laboratory simulation, 5 days from sample preparation with the buffer of the old SCD, the Hb concentration decreased by 40% at room temperature (25°C, range 22-28°C) and up to 60% at outside temperature (29°C, range 16-39°C), whereas with the new one, Hb concentration decreased by 10%. In the clinical setting, a higher mean Hb concentration with the new SCD compared with the old one was found (6.3 vs. 5.0 µg Hb/g faeces, respectively, P<0.001); no statistically significant difference was found in the probability of having a positive result in the two SCDs. Better Hb stability was observed with the new buffer under laboratory conditions, but no difference was found in the clinical performance. In our study, only marginal advantages arise from the new buffer. Improvements in sample stability represent a significant target in the screening setting.

Overall evaluation of an immunological latex agglutination system for fecal occult blood testing in the colorectal cancer screening program of Florence

Several immunological fecal occult blood tests (FOBT) are currently available for colorectal cancer (CRC) screening. We compared the HM Jack (Jack) (Kiowa, Japan), with the OC-Hemodia (OC) (Eiken, Japan) in use in the Florence screening program. Aims of the study were: (i) to investigate the diagnostic performance and the best cutoff value for Jack; (ii) to evaluate the handiness of sampling tubes; (iii) to compare costs. A total of 5,044 subjects were screened with both tests. Sampling tube investigation was performed running each sample on both instruments. A number of 352 subjects positive for at least one test (175 OC, 310 Jack) were selected for further investigations, while 46 subjects refused further assessments. Analysis of costs related to the assessment phase was performed on the basis of Tuscany region's fares. Amongst the 306 subjects investigated, 9 CRC and 67 advanced adenomas (AdA) were detected. Detection rates (DR) were 1.4‰ for CRC and 9.6‰ for AdA. After Jack cutoff optimization, DR for CRC+AdA resulted in 11.1‰ for OC and 13.3‰ for Jack (p=0.041). Sensitivity of the methods was 73.7 for OC and 88.2 for Jack; specificity was 97.6 for OC and 96.0 for Jack, resulting in an increase of the required assessments from 3.5% to 5.1%. No differences were observed between sampling methods. Despite the lower specificity of Jack, its greater sensitivity makes the method attractive for screening programs. An increase of the costs of 30% for every subject investigated for pathological lesion (CRC+AdA) may be thus foreseen.

A Comparison of Fecal Immunochemical and High-Sensitivity Guaiac Tests for Colorectal Cancer Screening

OBJECTIVES

Annual testing using either a high-sensitivity guaiac fecal occult blood test (HS-gFOBT) or a fecal immunochemical test (FIT) is recommended for screening average-risk people for colorectal cancer. We compared the performance characteristics of the HS-gFOBT Hemoccult II SENSA and two FITs (InSure FIT and OC FIT-CHEK) for detecting advanced colorectal neoplasia.

METHODS

The study included 1,006 asymptomatic patients, aged 50-75 years, who were scheduled to receive a screening colonoscopy at gastroenterology practices in the Minneapolis and Indianapolis metropolitan areas. Each participant was asked to complete all three stool tests before their colonoscopy. Each test's performance characteristics were evaluated using the screening colonoscopic results as the reference standard.

RESULTS

Sensitivity for detecting advanced colorectal neoplasia was highest for InSure FIT (26.3%, 95% confidence interval (CI) 15.9-40.7), followed by OC FIT-CHEK (15.1%, 95% CI 6.7-26.1) and Hemoccult II SENSA (7.4%, 95% CI 1.9-17.0). InSure FIT was statistically significantly more sensitive than both OC FIT-CHEK (absolute difference in sensitivity=11.2%, 95% CI 0.4-24.2) and Hemoccult II SENSA (difference in sensitivity=18.9%, 95% CI 10.2-32.6). Specificities were relatively high for all tests (between 96.8% and 98.6%).

CONCLUSIONS

Our results suggest that some FITs are more sensitive than the HS-gFOBT Hemoccult II SENSA, but these results need to be confirmed in larger asymptomatic populations. Comparisons between the FITs examined in this study and other FITs are needed to determine the best tests for population screening.

Effect of Temperature and Time on Fecal Hemoglobin Stability in 5 Fecal Immunochemical Test Methods and One Guaiac Method

CONTEXT

- Although promising for colorectal cancer screening, hemoglobin (Hb) stability remains a concern with fecal immunochemical tests. This study implemented a novel, standardized method to compare Hb stability across various fecal immunochemical tests. The method can be used to inform decisions when selecting a kit for use in colorectal cancer screening. In so doing, this work addressed a critical need for standardization in this field.

OBJECTIVE

- To compare the stability of Hb across 5 different immunochemical kits and one guaiac kit.

DESIGN

- The stability of Hb was analyzed in collection devices inoculated with Hb-spiked feces and (1) stored at various temperatures (frozen, refrigerated, ambient, and elevated) for more than 60 days; (2) after undergoing 3 controlled, freeze-thaw cycles; and (3) after being transported by courier or postal services in uncontrolled temperature conditions from 3 locations in Ontario, Canada, to a central testing center.

RESULTS

- The stability of Hb varied with time and temperature and by kit. Lower Hb recoveries occurred with increasing temperature and increasing time from sample collection to testing. Refrigeration provided the best stability, although results varied across kits (eg, from 4.2 days to >60 days before a prespecified threshold [<70% probability of the test results remaining positive] was reached). Freeze-thaw stability varied across kits and cycles (Hb recoveries: NS Plus [Alfresa Pharma, Chuo-ku, Osaka, Japan], 91.7% to 95.4%; OC Diana [Eiken Chemical, Taito-ku, Tokyo, Japan], 57.6% to 74.9%). Agreement regarding Hb levels before and after transportation varied across kits (from 57% to 100%).

CONCLUSIONS

- Important differences in Hb stability were found across the included fecal immunochemical tests. These findings should inform practice-based and population-based colorectal cancer screening.

Fresh vs Frozen Samples and Ambient Temperature Have Little Effect on Detection of Colorectal Cancer or Adenomas by a Fecal Immunochemical Test in a Colorectal Cancer Screening Cohort in Germany

BACKGROUND & AIMS

Fecal immunochemical tests (FITs) are used in colorectal cancer (CRC) screening. We compared detection of CRCs and colorectal neoplasms by FITs using fresh samples (collected into buffer-filled tubes) vs frozen samples, and we assessed the effects of seasonal variations in ambient temperature on test performance.

METHODS

We performed a prospective study of 3466 individuals (50% male; mean age, 62 years) undergoing screening colonoscopies at 20 gastroenterology practices in southern Germany from November 2008 through September 2014. Frozen stool samples (collected and frozen by patients through February 2012, n = 1644) and fresh stool samples (collected by patients into buffer-filled tubes after February 2012, n = 1822) were obtained; hemoglobin (Hgb) concentrations were measured by using a commercial, quantitative FIT (cutoff value for positive result, 17 μg Hgb/g feces). Colonoscopy results were used as the gold standard, with results categorized as CRC, advanced adenoma, non-advanced adenoma, or no colorectal neoplasm. Differences in detection of colorectal neoplasms with fresh vs frozen samples were compared by using Wilcoxon rank sum test (continuous variables) and Fisher exact test (categorical variables). We also compared test performance when samples were collected during different seasons (based on outdoor temperature less than 8°, 8°-15°, or more than 15°).

RESULTS

Of the samples analyzed by FIT, 12.8% of frozen stool samples (95% confidence interval [CI], 11.3%-14.5%) and 8.7% of fresh stool samples (95% CI, 7.5%-10.1%) had positive results (P value for difference < .001). When adjusting the Hgb cutoff value to produce the same percentage of positive results for fresh and frozen samples (10% and 5%), FIT with frozen vs fresh samples detected colorectal neoplasms with similar levels of sensitivity and specificity. For example, at cutoff values that produced 5% positive results for each sample type, FIT detected advanced neoplasms with 27.8% sensitivity when frozen samples were used (95% CI, 21.4%-35.1%) and 25.6% sensitivity when fresh samples were used (95% CI, 19.8%-32.1%). Specificity values were 97.7% when frozen samples were used (95% CI, 96.8%-98.4%) and 97.6% when fresh samples were used (95% CI, 96.7%-98.3%). We did not observe any differences in detection of neoplasms during different seasons that were based on outdoor temperature.

CONCLUSIONS

In a prospective study of 3466 individuals who underwent screening colonoscopies and received FITs, we found that use of fresh vs frozen samples slightly affected positivity rates and the proportions of CRCs or adenomas detected at the recommended Hgb cutoff value. However, after we adjusted Hgb cutoff values to produce equal proportions of positive results for fresh vs frozen samples, the performance of the FIT was similar with each sample type. Season of sample collection (based on outdoor temperature) did not affect detection of CRC using either sample type in this study from Middle Europe.

Performance of the Fecal Immunochemical Test for Colorectal Cancer Screening Using Different Stool-Collection Devices: Preliminary Results from a Randomized Controlled Trial

Background/Aims

We are in the process of conducting a randomized trial to determine whether compliance with the fecal immunochemical test (FIT) for colorectal cancer screening differs according to the stool-collection method. This study was an interim analysis of the performance of two stool-collection devices (sampling bottle vs conventional container).

Methods

In total, 1,701 individuals (age range, 50 to 74 years) were randomized into the sampling bottle group (intervention arm) or the conventional container group (control arm). In both groups, we evaluated the FIT positivity rate, the positive predictive value for advanced neoplasia, and the detection rate for advanced neoplasia.

Results

The FIT positivity rates were 4.1% for the sampling bottles and 2.0% for the conventional containers; these values were significantly different. The positive predictive values for advanced neoplasia in the sampling bottles and conventional containers were 11.1% (95% confidence interval [CI], −3.4 to 25.6) and 12.0% (95% CI, −0.7 to 24.7), respectively. The detection rates for advanced neoplasia in the sampling bottles and conventional containers were 4.5 per 1,000 persons (95% CI, 2.0 to 11.0) and 2.4 per 1,000 persons (95% CI, 0.0 to 5.0), respectively.

Conclusions

The impact of these findings on FIT screening performance was unclear in this interim analysis. This impact should therefore be evaluated in the final analysis following the final enrollment period.

Incidence of interval cancers in faecal immunochemical test colorectal screening programmes in Italy

Objective

In Italy, colorectal screening programmes using the faecal immunochemical test from ages 50 to 69 every two years have been in place since 2005. We aimed to measure the incidence of interval cancers in the two years after a negative faecal immunochemical test, and compare this with the pre-screening incidence of colorectal cancer.

Methods

Using data on colorectal cancers diagnosed in Italy from 2000 to 2008 collected by cancer registries in areas with active screening programmes, we identified cases that occurred within 24 months of negative screening tests. We used the number of tests with a negative result as a denominator, grouped by age and sex. Proportional incidence was calculated for the first and second year after screening.

Results

Among 579,176 and 226,738 persons with negative test results followed up at 12 and 24 months, respectively, we identified 100 interval cancers in the first year and 70 in the second year. The proportional incidence was 13% (95% confidence interval 10–15) and 23% (95% confidence interval 18–25), respectively. The estimate for the two-year incidence is 18%, which was slightly higher in females (22%; 95% confidence interval 17–26), and for proximal colon (22%; 95% confidence interval 16–28).

Conclusion

The incidence of interval cancers in the two years after a negative faecal immunochemical test in routine population-based colorectal cancer screening was less than one-fifth of the expected incidence. This is direct evidence that the faecal immunochemical test-based screening programme protocol has high sensitivity for cancers that will become symptomatic.

Strong subsite-specific variation in detecting advanced adenomas by fecal immunochemical testing for hemoglobin

Fecal immunochemical tests (FITs) for hemoglobin are increasingly recommended and used in colorectal cancer (CRC) screening. We aimed to provide a detailed assessment of the sensitivity of FIT according to type and subsite of neoplasms in a true screening setting. A quantitative FIT (FOB Gold, Sentinel Diagnostics, Milano, Italy) was applied prior to colonoscopy by 3,466 participants of the German screening colonoscopy program. Subsite specific sensitivity for various types of colorectal neoplasms was derived by comparing FIT results with findings at screening colonoscopy. The most advanced finding at colonoscopy was CRC, advanced adenoma, and nonadvanced adenoma in 29, 354 and 686 cases, respectively. Per-adenoma sensitivity for large advanced adenomas (>1 cm) strongly varied by location (p < 0.001): cecum: 0/14 (0%), ascending colon and right flexure: 11/43 (26%), transverse colon and left flexure: 2/14 (14%), descending colon: 7/12 (58%), sigmoid colon: 47/92 (51%), rectum: 14/39 (36%). By contrast, the FIT detected all of 5 proximal CRC and 23 out of 24 (96%) distal CRCs, whereas per-adenoma sensitivity of both proximal (17/259, 7%) and distal nonadvanced adenomas (20/237, 8%) essentially equaled the false positivity rate among those without neoplasms (152/2,397, 6%). In conclusion, we found a very large gradient of subsite specific FIT sensitivity for detecting large advanced adenomas ranging from 0% for advanced adenomas located in the cecum to >50% for those located in the descending or sigmoid colon. By contrast, FIT sensitivity was uniformly excellent for CRC and uniformly poor for nonadvanced adenomas, regardless of their location.

Effect of sample storage temperature and buffer formulation on faecal immunochemical test haemoglobin measurements

Objectives

Faecal immunochemical test accuracy may be adversely affected when samples are exposed to high temperatures. This study evaluated the effect of two sample collection buffer formulations (OC-Sensor, Eiken) and storage temperatures on faecal haemoglobin readings.

Methods

Faecal immunochemical test samples returned in a screening programme and with ≥10 µg Hb/g faeces in either the original or new formulation haemoglobin stabilizing buffer were stored in the freezer, refrigerator, or at room temperature (22℃–24℃), and reanalysed after 1–14 days. Samples in the new buffer were also reanalysed after storage at 35℃ and 50℃. Results were expressed as percentage of the initial concentration, and the number of days that levels were maintained to at least 80% was calculated.

Results

Haemoglobin concentrations were maintained above 80% of their initial concentration with both freezer and refrigerator storage, regardless of buffer formulation or storage duration. Stability at room temperature was significantly better in the new buffer, with haemoglobin remaining above 80% for 20 days compared with six days in the original buffer. Storage at 35℃ or 50℃ in the new buffer maintained haemoglobin above 80% for eight and two days, respectively.

Conclusion

The new formulation buffer has enhanced haemoglobin stabilizing properties when samples are exposed to temperatures greater than 22℃.

Assessment of disease activity by fecal immunochemical test in ulcerative colitis

AIM

To evaluate the efficacy of quantitative fecal immunochemical test (FIT) as biomarker of disease activity in ulcerative colitis (UC).

METHODS

Between February 2013 and November 2014, a total of 82 FIT results, obtained in conjunction with colonoscopies, were retrospectivelyevaluated for 63 patients with UC. The efficacy of FIT for evaluation of disease activity was compared to colonoscopic findings. Quantitative fecal blood with automated equipment examined from collected feces. Endoscopic disease severity were assessed using the Mayo endoscopic subscore (MES) classification. The extent of disease were classified by proctitis (E1), left sided colitis (E2), and extensive colitis (E3). Clinical activity were subgrouped by remission or active.

RESULTS

All of 21 patients with MES 0 had negative FIT (< 7 ng/mL), but 22 patients with MES 2 or 3 had a mean FIT of > 134.89 ng/mL. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of negative FIT about mucosal healing were 73.33%, 81.82%, 91.49%, 51.43% and 73.17%, respectively. The sensitivity, specificity, PPV, NPV and accuracy of predictive value of positive FIT (cutoff value > 100 ng/mL) about active disease status were 45.45%, 93.33%, 71.43%, 82.35% and 26.83%, respectively. Among patients with clinical remission, FIT was negative in 31 (81.6%) of 38 cases, with a mean fecal hemoglobin concentration of 6.12 ng/mL (range, negative to 80.9 ng/mL) for this group of patients. Among patients with clinical active disease, FIT was negative in 16 (36.4%) out of 44 cases, with a mean fecal hemoglobin concentration > 167.4 ng/mL for this group of patients. FIT was positively correlated with endoscopic activity (r = 0.626, P < 0.01) and clinical activity (r = 0.496, P < 0.01). But, FIT did not correlate with the extent of disease (r = -0.047, P = 0.676)

CONCLUSION

Quantitative FIT can be a non-invasive and effective biomarker for evaluation of clinical and endoscopic activity in UC, but not predict the extent of disease.

Clinical utility of one versus two faecal immunochemical test samples in the detection of advanced colorectal neoplasia in symptomatic patients

BACKGROUND

The utility of faecal immunochemical tests (FIT) in assessment of symptomatic patients with lower gastrointestinal symptoms has not been well explored. The aims of this study were to evaluate the diagnostic yield for advanced colorectal neoplasia (ACRN) in symptomatic patients using the first of two FIT samples (FIT/1) and the higher concentration of two FIT samples (FIT/max).

METHODS

Samples from two consecutive bowel motions from 208 symptomatic patients who required colonoscopy were analysed using the HM-JACKarc analyser (Kyowa Medex Co., Ltd., Tokyo, Japan). Patients were categorised into two groups: patients with any ACRN and individuals with other diagnoses or normal colonoscopy.

RESULTS

Colonoscopy detected ACRN in 29 patients. In these patients, FIT/1 and FIT/max were significantly higher than in patients with low-risk adenoma (p=0.006 and p=0.024), other findings (p=0.002 and p=0.002) and normal colonoscopy (p<0.001 and p<0.001). The areas under the curves (AUC) of FIT/1 and FIT/max were 0.71 and 0.69, respectively. Undetectable FIT/1 rules out 96.6% of ACRN and the specificity was 10.6%. Increasing the FIT/1 cut-off to 10 μg Hb/g faeces, sensitivity and specificity were 34.5% and 87.2%, respectively. Similar results were obtained using FIT/max with 20 μg Hb/g faeces cut-off, providing a sensitivity and specificity of 34.5% and 85.6%, respectively.

CONCLUSIONS

Undetectable FIT is a good strategy to rule-out ACRN in symptomatic patients. The diagnostic yield of collecting two samples for FIT can be achieved with one sample, but a lower faecal haemoglobin concentrations (f-Hb) cut-off is required.

Fecal immunochemical test for colorectal cancer from a prospective cohort with 513,283 individuals: Providing detailed number needed to scope (NNS) before colonoscopy

The fecal immunochemical test (FIT) is underutilized, in part, because its benefits have not been fully understood. We assessed the relationship of FIT values with cancer incidence and mortality, and explored how repeated administrations of FIT could aid clinicians. A cohort with 513,283 adults in Taiwan participated in a screening program between 1994 and the end of 2007. Colorectal cancer was identified from National Cancer Registry and not from colonoscopy. Positive FIT was FIT ≥ 100 ng/mL. Number needed to scope (NNS) to identify 1 cancer by different FIT values was calculated for the study time. Only 4% of subjects had FIT ≥ 100 ng/mL but contributed 40% of cancer cases, leading to a NNS of 25 for finding 1 in this group. However, within the same FIT ≥ 100 ng/mL, NNS was different by age: 10 for age 60 to 69 years, 42 for age 40 to 49 years, and 156 for age 20 to 39 years. Furthermore, within the same age, NNS was different by FIT values, for instance, 66 for FIT 100 to 199 ng/mL and 12 for FIT 600 to 799 ng/mL, a difference of 5-fold for age 50 to 59 years. The dose-response relationship of FIT can facilitate consultation regarding the need for colonoscopy by providing a quantitative NNS for cancer risk, an index easily understood by patients. Our conclusion made use of (a) age-dependent and (b) quantitative interpretation of FIT values. This single cutpoint practice obliterates a large amount of valuable cancer risk information available to patients.

Correlation between adenoma detection rate in colonoscopy- and fecal immunochemical testing-based colorectal cancer screening programs

BACKGROUND

The adenoma detection rate (ADR) is the main quality indicator of colonoscopy. The ADR recommended in fecal immunochemical testing (FIT)-based colorectal cancer screening programs is unknown.

METHODS

Using the COLONPREV (NCT00906997) study dataset, we performed a post-hoc analysis to determine if there was a correlation between the ADR in primary and work-up colonoscopy, and the equivalent figure to the minimal 20% ADR recommended. Colonoscopy was performed in 5722 individuals: 5059 as primary strategy and 663 after a positive FIT result (OC-Sensor™; cut-off level 15 µg/g of feces). We developed a predictive model based on a multivariable lineal regression analysis including confounding variables.

RESULTS

The median ADR was 31% (range, 14%-51%) in the colonoscopy group and 55% (range, 21%-83%) in the FIT group. There was a positive correlation in the ADR between primary and work-up colonoscopy (Pearson's coefficient 0.716; p < 0.001). ADR in the FIT group was independently related to ADR in the colonoscopy group: regression coefficient for colonoscopy ADR, 0.71 (p = 0.009); sex, 0.09 (p = 0.09); age, 0.3 (p = 0.5); and region 0.00 (p = 0.9). The equivalent figure to the 20% ADR was 45% (95% confidence interval, 35%-56%).

CONCLUSIONS

ADR in primary and work-up colonoscopy of a FIT-positive result are positively and significantly correlated.

Ambient temperature and FIT performance in the Emilia-Romagna colorectal cancer screening programme

Objective

To assess the impact of ambient temperature on faecal immunochemical test (FIT) performance in the colorectal cancer screening programme of Emilia-Romagna (Italy).

Methods

A population-based retrospective cohort study on data from 2005 to 2011. Positive rate, detection rate, and positive predictive value rate for cancers and adenomas, and incidence rate of interval cancers after negative tests were analysed using Poisson regression models. In addition to ambient temperature, gender, age, screening history, and Local Health Unit were also considered.

Results

In 1,521,819 tests analysed, the probability of a positive result decreased linearly with increasing temperature. Point estimates and 95% Confidence Intervals were estimated for six temperature classes (<5, 5 |−10, 10 |−15, 15 |−20, 20|−25 and ≥25℃), and referred to the 5|-10℃ class. The positive rate ratio was significantly related to temperature increase: 0.99 (0.97–1.02), 1, 0.98 (0.96–1.00), 0.96 (0.94–0.99), 0.93 (0.91–0.96), 0.92 (0.89–0.95). A linear trend was also evident for advanced adenoma detection rate ratio: 1.00 (0.96–1.04), 1, 0.98 (0.93–1.02), 0.96 (0.92–1.00), 0.92 (0.88–0.96), 0.94 (0.88–1.01). The effect was less linear, but still important, for cancer detection rates: 0.95 (0.85–1.06), 1, 1.00 (0.90–1.10), 0.94 (0.85–1.05), 0.81 (0.72–0.92), 0.93 (0.80–1.09). No association or linear trend was found for positive predictive values or risk of interval cancer, despite an excess of +16% in the highest temperature class for interval cancer.

Conclusions

Ambient temperatures can affect screening performance. Continued monitoring is needed to verify the effect of introducing FIT tubes with a new buffer, which should guarantee a higher stability of haemoglobin.

Fecal Immunochemical Test Versus Fecal Calprotectin for Prediction of Mucosal Healing in Crohn's Disease

BACKGROUND

Mucosal healing (MH) has been proposed as a treatment goal of inflammatory bowel disease patients. We reported recently that not only fecal calprotectin (Fcal) but also the fecal immunochemical test (FIT) can predict MH in ulcerative colitis. However, the predictive power of the fecal markers for MH in Crohn's disease (CD), particularly with small bowel lesions, has not been reported in detail. The aim of this study was to evaluate the predictability of FIT versus Fcal for MH in CD.

METHODS

Consecutive CD patients underwent colonoscopy or balloon-assisted enteroscopy according to the disease location. FIT and Fcal were examined using stool samples collected the day before endoscopy.

RESULTS

Seventy-one CD patients were analyzed, of whom 42 (59%) underwent balloon-assisted enteroscopy because of the presence of affected lesions in the small intestine. Both the Fcal and the FIT results were significantly correlated with endoscopic activity (r = 0.67 and 0.54, respectively). However, the FIT results did not correlate with the activity in patients with small bowel lesions alone, whereas Fcal did (r = 0.42 versus 0.78). Fcal predicted MH in CD with 87% sensitivity and 71% specificity, whereas the values for FIT were 96% and 48%, respectively. The specificity for MH among patients with small bowel lesions alone was low for FIT (40%) compared with Fcal (80%).

CONCLUSIONS

Both FIT and Fcal were correlated with the mucosal status of CD. However, the specificity of FIT was not satisfactory, particularly for small bowel lesions.

Disease monitoring in inflammatory bowel disease

The optimal method for monitoring quiescent disease in patients with Crohn’s disease (CD) and ulcerative colitis is yet to be determined. Endoscopic evaluation with ileocolonoscopy is the gold standard but is invasive, costly, and time-consuming. There are many commercially available biomarkers that may be used in clinical practice to evaluate disease status in patients with inflammatory bowel disease (IBD), but the most widely adopted biomarkers are C-reactive protein (CRP) and fecal calprotectin (FC). This review summarizes the evidence for utilizing CRP and FC for monitoring IBD during clinical remission and after surgical resection. Endoscopic correlation with CRP and FC is evaluated in each disease state. Advantages and drawbacks of each biomarker are discussed with special consideration of isolated ileal CD. Fecal immunochemical testing, traditionally used for colorectal cancer screening, is mentioned as a potential new alternative assay in the evaluation of IBD. Based on a mixture of information gleaned from biomarkers, clinical status, and endoscopic evaluation, the best treatment decisions can be made for the patient with IBD.

Faecal immunochemical tests versus guaiac faecal occult blood tests: what clinicians and colorectal cancer screening programme organisers need to know

Although colorectal cancer (CRC) is a common cause of cancer-related death, it is fortunately amenable to screening with faecal tests for occult blood and endoscopic tests. Despite the evidence for the efficacy of guaiac-based faecal occult blood tests (gFOBT), they have not been popular with primary care providers in many jurisdictions, in part because of poor sensitivity for advanced colorectal neoplasms (advanced adenomas and CRC). In order to address this issue, high sensitivity gFOBT have been recommended, however, these tests are limited by a reduction in specificity compared with the traditional gFOBT. Where colonoscopy is available, some providers have opted to recommend screening colonoscopy to their patients instead of faecal testing, as they believe it to be a better test. Newer methods for detecting occult human blood in faeces have been developed. These tests, called faecal immunochemical tests (FIT), are immunoassays specific for human haemoglobin. FIT hold considerable promise over the traditional guaiac methods including improved analytical and clinical sensitivity for CRC, better detection of advanced adenomas, and greater screenee participation. In addition, the quantitative FIT are more flexible than gFOBT as a numerical result is reported, allowing customisation of the positivity threshold. When compared with endoscopy, FIT are less sensitive for the detection of advanced colorectal neoplasms when only one time testing is applied to a screening population; however, this is offset by improved participation in a programme of annual or biennial screens and a better safety profile. This review will describe how gFOBT and FIT work and will present the evidence that supports the use of FIT over gFOBT, including the cost-effectiveness of FIT relative to gFOBT. Finally, specific issues related to FIT implementation will be discussed, particularly with respect to organised CRC screening programmes.

The Diagnostic Accuracy of the M2 Pyruvate Kinase Quick Stool Test--A Rapid Office Based Assay Test for the Detection of Colorectal Cancer

Background

M2 pyruvate kinase (M2PK) is an oncoprotein secreted by colorectal cancers in stools. This the first report on the accuracy of a rapid stool test in the detection of colorectal cancer (CRC).

Objective

To determine the sensitivity, specificity and positive and negative predictive value of a rapid, point of care stool test M2 PK- the M2PK Quick.

Methods

Consecutive cases of endoscopically diagnosed and histological proven CRC were recruited. Stools were collected by patients and tested with the immunochromatographic M2PK Quick Test (Schebo Biotech AC, Giessen, Germany). Controls were consecutively chosen from patients without any significant colorectal or gastrointestinal disease undergoing colonoscopy. CRC was staged according to the AJCC staging manual (7^th Edition) and location of tumor defined as proximal or distal.

Results

The sensitivity, specificity, positive predictive value, negative predictive value and overall accuracy were: 93%, 97.5%, 94.9%, 96.5% and 96.0% respectively. The positive predictive value for proximal tumors was significantly lower compared to distal tumors. No differences were seen between the different stages of the tumor.

Conclusions

The M2-PK Quick, rapid, point-of-care test is a highly accurate test in the detection of CRC. It is easy and convenient to perform and a useful diagnostic test for the detection of CRC in a clinical practice setting.

Evaluation of Mucosal Healing in Ulcerative Colitis by Fecal Calprotectin Vs. Fecal Immunochemical Test

OBJECTIVES

We previously showed that a quantitative fecal immunochemical test (FIT) can predict mucosal healing (MH) in ulcerative colitis (UC). Fecal calprotectin (Fcal) has also been reported as an important biomarker of UC activity. The aim of this study was to compare the predictive ability of these two fecal markers for MH in UC.

METHODS

FIT and Fcal were examined in stool samples from consecutive UC patients who underwent colonoscopy. Mucosal status was assessed via the Mayo endoscopic subscore (MES).

RESULTS

In total, 105 colonoscopies in 92 UC patients were evaluated in conjunction with the FIT and Fcal results. Both FIT and Fcal results were significantly correlated with MES (Spearman's rank correlation coefficient: 0.61 and 0.58, respectively). The sensitivity and specificity of the FIT values (<100 ng/ml) for predicting MH (MES 0 alone) were 0.95 and 0.62, respectively, whereas those of Fcal (<250 μg/g) were 0.82 and 0.62, respectively. The sensitivities became similar when MH was defined as MES 0 or 1 (0.86 vs. 0.86). Although the predictability of MH evaluated by the area under the receiver operating characteristics curve was similar for the two fecal markers (FIT 0.83 vs. Fcal 0.82 for MES 0 alone), the FIT results were relatively robust regardless of the cutoff value selected.

CONCLUSIONS

Both FIT and Fcal can efficiently predict MH in UC, but FIT appears to be more sensitive than Fcal for predicting MES 0 alone.

Advances in Fecal Occult Blood Tests: the FIT revolution

There is a wide choice of fecal occult blood tests (FOBTs) for colorectal cancer screening.

GOAL

To highlight the issues applicable when choosing a FOBT, in particular which FOBT is best suited to the range of screening scenarios. Four scenarios characterize the constraints and expectations of screening programs: (1) limited colonoscopy resource with a need to constrain test positivity rate; (2) a priority for maximum colorectal neoplasia detection with little need to constrain colonoscopy workload; (3) an "adequate" endoscopy resource that allows balancing the benefits of detection with the burden of service provision; and (4) a need to maximize participation in screening. Guaiac-based FOBTs (gFOBTs) have significant deficiencies, and fecal immunochemical tests (FITs) for hemoglobin have emerged as better tests. gFOBTs are not sensitive to small bleeds, specificity can be affected by diet or drugs, participant acceptance can be low, laboratory quality control opportunities are limited, and they have a fixed hemoglobin concentration cutoff determining positivity. FITs are analytically more specific, capable of quantitation and hence provide flexibility to adjust cutoff concentration for positivity and the balance between sensitivity and specificity. FITs are clinically more sensitive for cancers and advanced adenomas, and because they are easier to use, acceptance rates are high.

CONCLUSIONS

FOBT must be chosen carefully to meet the needs of the applicable screening scenario. Quantitative FIT can be adjusted to suit Scenarios 1, 2 and 3, and for each, they are the test of choice. FITs are superior to gFOBT for Scenario 4 and gFOBT is only suitable for Scenario 1.

Equivalency of fecal immunochemical tests and colonoscopy in familial colorectal cancer screening

BACKGROUND & AIMS

Colonoscopy is the recommended screening procedure for first-degree relatives of patients with colorectal cancer (CRC), but few studies have compared its efficacy for CRC detection with that of other screening strategies. We conducted a controlled randomized trial to compare the efficacy of repeated fecal immunochemical tests (FITs) and colonoscopy in detecting advanced neoplasia (advanced adenoma or CRC) in family members of patients with CRC.

METHODS

In a prospective study, 1918 first-degree relatives of patients with CRC were randomly assigned (1:1 ratio) to receive a single colonoscopy examination or 3 FITs (1/year for 3 years; OC-Sensor; cutoff ≥10 μg hemoglobin/g feces, corresponding to 50 ng hemoglobin/mL buffer). The strategies were considered to be equivalent if the 95% confidence interval of the difference for the detection of advanced neoplasia was ±3%. Follow-up analyses were performed to identify false-negative FIT results and interval CRCs.

RESULTS

Of all eligible asymptomatic first-degree relatives, 782 were included in the colonoscopy group and 784 in the FIT group. In the intention-to-screen analysis, advanced neoplasia was detected in 33 (4.2%) and 44 (5.6%) first-degree relatives in the FIT and colonoscopy groups, respectively (odds ratio = 1.41; 95% confidence interval: 0.88-2.26; P = .14). In the per-protocol analysis, 28 first-degree relatives (3.9%) in the FIT group and 43 (5.8%) in the colonoscopy group had advanced neoplasia (odds ratio = 1.56; 95% confidence interval: 0.95-2.56; P = .08). FIT missed 16 of 41 advanced adenomas but no CRCs. The FIT strategy required endoscopic evaluation of 4-fold fewer individuals to detect 1 advanced neoplasia than the colonoscopy strategy.

CONCLUSIONS

Repeated FIT screening (1/year for 3 years) detected all CRCs and proved equivalent to colonoscopy in detecting advanced neoplasia in first-degree relatives of patients with CRC. This strategy should be considered for populations where compliance with FITs is higher than with colonoscopy. ClinicalTrials.gov number: NCT01075633 (COLONFAM Study).

Risk stratification for advanced colorectal neoplasia according to fecal hemoglobin concentration in a colorectal cancer screening program

BACKGROUND & AIMS

The latest generation of fecal immunochemical tests (FIT) allows for quantitation of hemoglobin in feces, allowing for selection of optimal cut-off concentrations. We investigated whether individuals with positive results from quantitative FITs, in combination with other factors, could be identified as being at greatest risk for advanced colorectal neoplasia.

METHODS

In a retrospective study, we analyzed data from a consecutive series of 3109 participants with positive results from FITs (≥20 μg/g of feces) included in the first round of the Barcelona colorectal cancer screening program, from December 2009 through February 2012. All participants underwent colonoscopy and were assigned to groups with any advanced colorectal neoplasia or with nonadvanced colorectal neoplasia (but with another diagnosis or normal examination findings).

RESULTS

Median fecal hemoglobin concentrations were significantly higher in participants with advanced colorectal neoplasia (105 μg/g; interquartile range, 38-288 μg/g) compared with participants with nonadvanced colorectal neoplasia (47 μg/g; interquartile range, 23-119 μg/g) (P < .001). Positive predictive values for advanced colorectal neoplasia, determined using arbitrary fecal hemoglobin concentrations, differed with sex and age. Multivariate logistic regression analysis identified sex (men: odds ratio [OR], 2.07; 95% confidence interval, 1.78-2.41), age (60-69 y: OR, 1.24; 95% confidence interval, 1.07-1.44), and fecal hemoglobin concentration (>177 μg/g: OR, 3.80; 95% confidence interval, 3.07-4.71) as independent predictive factors for advanced colorectal neoplasia. Combining these factors, we identified 16 risk categories associated with different probabilities of identifying advanced colorectal neoplasia. Risk for advanced colorectal neoplasia increased 11.46-fold among individuals in the highest category compared with the lowest category; positive predictive values ranged from 21.3% to 75.6%.

CONCLUSIONS

Fecal hemoglobin concentration, in addition to sex and age, in individuals with positive results from FITs can be used to stratify probability for the detection of advanced colorectal neoplasia. These factors should be used to prioritize individuals for colonoscopy examination.

Cost-Effectiveness Analysis of CT Colonography for Colorectal Cancer Screening Program to Working Age in Japan

OBJECTIVES

To assess the cost-effectiveness of computed tomography colonography (CTC) for a colorectal cancer screening program in a working population (aged 40-60 years) from a health care payer's perspective in Japan.

METHODS

A Markov model for colorectal cancer was constructed to estimate the long-term (10-year, 20-year, and 30-year) effect of introducing CTC for three different strategies in the cohort aged 40 years on April 1, 2011. Strategy 1 (the current strategy in Japan): fecal occult blood test (FOBT) followed by optical colonoscopy (OC). In this case, 41.8% of those who were FOBT-positive did not undergo OC (uptake 58.2%). Strategy 2: All FOBT-positive cases would be offered CTC (uptake 79.1%) followed by OC. Strategy 3: Only those FOBT-positive cases who were reluctant to undergo OC (41.8%) would be offered CTC (assumed uptake 50.0%) followed by OC. Epidemiological data were obtained mainly from statistics published by the Japanese National Cancer Center. We set quality-adjusted life-year (QALY) as the primary outcome and colorectal cancer death and expected life-years as secondary ones. The discount rate for both costs and outcomes was set at 3%.

RESULTS

In the base-case (20-year) analysis, total cost was increased from Japanese yen (JPY) 65,614 million (strategy 1) to JPY 69,405 million (strategy 2) but was decreased to JPY 63,878 million (strategy 3). The total QALY increased from 28,156,046 QALYs (strategy 1) to 28,158,349 (strategy 2) and 28,159,058 QALYs (strategy 3). Therefore, the incremental cost-effectiveness ratio was JPY 1,646,000 per QALY gained for strategy 2 and strategy 3 was dominant against strategy 1, both of which were well below the Japanese threshold (JPY 5-6 million per QALY gained).

CONCLUSION

Adding CTC into the current colorectal cancer screening program for the working population seems to be a cost-effective option.

Fecal hemoglobin and calprotectin are equally effective in identifying patients with inflammatory bowel disease with active endoscopic inflammation

BACKGROUND

Fecal calprotectin can be used as a noninvasive tool to assess inflammation in patients with inflammatory bowel disease (IBD). However, the diagnostic accuracy of calprotectin is modest, and therefore additional markers are needed. We compared the efficacy of fecal hemoglobin and calprotectin as markers for endoscopic inflammation in patients with IBD.

METHODS

Consecutive patients with Crohn's disease or ulcerative colitis scheduled for surveillance colonoscopy collected a stool sample before bowel preparation. Experienced endoscopists assessed the presence of inflammation in each colonic segment. Fecal calprotectin and hemoglobin were analyzed with an enzyme-linked immunosorbent assay. Receiver operator characteristic statistics were used to determine cutoff values for calprotectin and hemoglobin.

RESULTS

A total of 176 surveillance colonoscopies were performed in 164 patients, of which 83 patients had Crohn's disease, 74 had ulcerative colitis, and 7 IBD-unclassified. Median (interquartile range) calprotectin and hemoglobin concentrations were 137 mg/kg (interquartile range, 33-494) and 0.51 μg/g (interquartile range, 0.18-8.50), respectively. For calprotectin, a cutoff value of 140 mg/kg predicted endoscopic inflammation with 86% sensitivity, 72% specificity, 64% positive predictive value, 90% negative predictive value, and an area under the curve of 0.87. For hemoglobin, a cutoff value of 1.51 μg/g indicated endoscopic inflammation with 74% sensitivity, 84% specificity, 72% positive predictive value, 84% negative predictive value, and an area under the curve of 0.81. Combining both tests did not increase the predictive accuracy substantially compared with calprotectin or hemoglobin alone (area under the curve, 0.88).

CONCLUSIONS

Fecal hemoglobin can identify patients with IBD with active inflammation with a predictive accuracy similar to calprotectin.

Fecal immunochemical test accuracy in average-risk colorectal cancer screening

AIM: To assess the fecal immunochemical test (FIT) accuracy for colorectal cancer (CRC) and advanced neoplasia (AN) detection in CRC screening.

METHODS: We performed a multicentric, prospective, double blind study of diagnostic tests on asymptomatic average-risk individuals submitted to screening colonoscopy. Two stool samples were collected and the fecal hemoglobin concentration was determined in the first sample (FIT1) and the highest level of both samples (FITmax) using the OC-sensor™. Areas under the curve (AUC) for CRC and AN were calculated. The best FIT1 and FITmax cut-off values for CRC were determined. At this threshold, number needed to scope (NNS) to detect a CRC and an AN and the cost per lesion detected were calculated.

RESULTS: About 779 individuals were included. An AN was found in 97 (12.5%) individuals: a CRC in 5 (0.6%) and an advanced adenoma (≥ 10 mm, villous histology or high grade dysplasia) in 92 (11.9%) subjects. For CRC diagnosis, FIT1 AUC was 0.96 (95%CI: 0.95-0.98) and FITmax AUC was 0.95 (95%CI: 0.93-0.97). For AN, FIT1 and FITmax AUC were similar (0.72, 95%CI: 0.66-0.78 vs 0.73, 95%CI: 0.68-0.79, respectively, P = 0.34). Depending on the number of determinations and the positivity threshold cut-off used sensitivity for AN detection ranged between 28% and 42% and specificity between 91% and 97%. At the best cut-off point for CRC detection (115 ng/mL), the NNS to detect a CRC were 10.2 and 15.8; and the cost per CRC was 1814€ and 2985€ on FIT1 and FITmax strategies respectively. At this threshold the sensitivity, NNS and cost per AN detected were 30%, 1.76, and 306€, in FIT1 strategy, and 36%, 2.26€ and 426€, in FITmax strategy, respectively.

CONCLUSION: Performing two tests does not improve diagnostic accuracy, but increases cost and NNS to detect a lesion.

Population-based colorectal cancer screening: comparison of two fecal occult blood test

BACKGROUND

The aim of screening for colorectal cancer is to improve prognosis by the detection of cancer at its early stages. In order to inform the decision on the specific test to be used in the population-based program in the Basque Autonomous Region (Spain), we compared two immunochemical fecal occult blood quantitative tests (I-FOBT).

METHODS

Residents of selected study areas, aged 50-69 years, were invited to participate in the screening. Two tests based on latex agglutination (OC-Sensor and FOB Gold) were randomly assigned to different study areas. A colonoscopy was offered to patients with a positive test result. The cut-off point used to classify a result as positive, according to manufacturer's recommendations, was 100 ng/ml for both tests.

RESULTS

The invited population included 37,999 individuals. Participation rates were 61.8% (n = 11,162) for OC-Sensor and 59.1% (n = 11,786) for FOB Gold (p = 0.008). Positive rate for OC-Sensor was 6.6% (n = 737) and 8.5% (n = 1,002) for FOB Gold (p < 0.0001). Error rates were higher for FOB gold (2.3%) than for OC-Sensor (0.2%; p < 0.0001). Predictive positive value (PPV) for total malignant and premalignant lesions was 62.4% for OC-Sensor and 58.9% for FOB Gold (p = 0.137), respectively.

CONCLUSION

OC-Sensor test appears to be superior for I-FOBT-based colorectal cancer screening, given its acceptance, ease of use, associated small number of errors and its screening accuracy. FOB Gold on the other hand, has higher rate of positive values, with more colonoscopies performed, it shows higher detection incidence rates, but involves more false positives.