The performance of three-sample qualitative immunochemical fecal test to detect colorectal adenoma and cancer in gastrointestinal outpatients: an observational study

Cost-effectiveness analysis of colorectal cancer screening in Shanghai, China: a modelling study

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The current Shanghai CRC screening program is cost-effective.

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Changing to a validated FIT would make the program more efficient.

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The results were sensitive to an increase in the cost of the validated FIT.

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The results were sensitive to more participation in screening and colonoscopy.

Background

The current community-based colorectal cancer (CRC) screening program in Shanghai, launched in 2013, invited individuals aged 50–74 years to triennial screening with a qualitative faecal immunochemical test (FIT) and questionnaire-based risk assessment (RA). We aimed to evaluate the effectiveness and cost-effectiveness of the existing Shanghai screening program and compare it to using a validated two-sample quantitative FIT.

Methods

We simulated four strategies (no screening, Shanghai FIT, Shanghai FIT + RA and validated FIT) for the Shanghai screening program and evaluated CRC incidence, CRC mortality, the number of life years gained (LYG), the number of FITs, and colonoscopies required for each. An incremental cost-effectiveness analysis was performed to assess the cost- effectiveness of each strategy.

Results

All screening modalities reduced CRC incidence and CRC mortality, gained extra number of LYG compared to no screening. Screening using the Shanghai FIT and validated FIT reduced CRC incidence from 45 cases to 43 per 1,000 simulated individuals (4.4%). Incidence was reduced to 42 cases (6.7%) using the Shanghai FIT + RA. All screening strategies reduced CRC mortality by 10.0% (from 10 to 9 deaths) and resulted in 6 to 7 LYG. The validated FIT was the most cost-effective among the evaluated strategies (ICER ¥26,461 per LYG).

Conclusions

Our findings show that the current Shanghai screening program is (cost-) effective compared to no screening, but changing to a validated FIT would make the program more efficient.

Is qFIT a useful tool in prioritising symptomatic patients referred with suspect colorectal cancer in the COVID-19 era?

Background

The COVID-19 pandemic is an evolving healthcare challenge causing secondary disruption of cancer services. Quantitative Faecal Immunochemical Testing (qFIT) has been established as a screening method in asymptomatic patients. We aim to assess its utility as a triage tool to prioritise investigations in symptomatic patients with suspected colorectal cancer.

Methods

At the commencement of the COVID-19 pandemic a database was established to include patients awaiting red flag outpatient consultation or colonic investigations and new red flag referrals from March to June 2020. Patients were supplied with qFIT kits and returned results categorised into 3 priority groups according to the qFIT value. Group 1 >150µg Hb/g, Group 2 ≥10 to ≤150µg Hb/g and Group 3 <10µg Hb/g. Subsequent colonic evaluation was offered by colonoscopy or cross-sectional imaging with urgency determined by qFIT priority group. When identified colorectal cancer, inflammatory bowel disease or high-risk polyps were recorded as "significant colorectal pathology."

Findings

Three hundred and seventeen patients were identified with data analysed on 290 patients. Colorectal malignancy was identified in 17 patients; 94% of these patients were in Group 1. A qFIT result >150 µg Hb/g had a sensitivity and specificity for colorectal cancer of 94.12% (95% CI 71.31-99.85) and 91.21% (95% CI 87.20-94.29) respectively. No malignancy was detected in Priority Group 3; negative predictive value of 100% (95% CI 98.06-100).

Conclusions

In symptomatic, suspect lower GI cancer patients qFIT is a useful adjunct for prioritising patients and can be used to determine the urgency of colorectal investigations.

Prediction of advanced colonic neoplasm in symptomatic patients: a scoring system to prioritize colonoscopy (COLONOFIT study)

BACKGROUND

Fast-track colonoscopy to detect patients with colorectal cancer based on high-risk symptoms is associated with low sensitivity and specificity. The aim was to derive a predictive score of advanced colonic neoplasia in symptomatic patients in fast-track programs.

METHODS

All patients referred for fast-track colonoscopy were evaluated. Faecal immunological haemoglobin test (3 samples; positive> 4 μg Hb/g), and a survey to register clinical variables of interest were performed. Colorectal cancer and advanced adenoma were considered as advanced colonic neoplasia. A sample size of 600 and 500 individuals were calculated for each phase 1 and phase 2 of the study, respectively (Phase 1, derivation and Phase 2, validation cohort). A Bayesian logistic regression analysis was used to derive a predictive score.

RESULTS

1495 patients were included. Age (OR, 21), maximum faecal-Hb value (OR, 2.3), and number of positive samples (OR, 28) presented the highest ORs predictive of advanced colonic neoplasia. The additional significant predictive variables adjusted for age and faecal-Hb variables in Phase 1 were previous colonoscopy (last 5 years) and smoking (no, ex/active). With these variables a predictive score of advanced colonic neoplasia was derived. Applied to Phase 2, patients with a Score > 20 had an advanced colonic neoplasia probability of 66% (colorectal cancer, 32%), while those with a Score ≤ 10, a probability of 10% (colorectal cancer, 1%). Prioritizing patients with Score > 10, 49.4% of patients would be referred for fast-track colonoscopy, diagnosing 98.3% of colorectal cancers and 77% of advanced adenomas.

CONCLUSIONS

A scoring system was derived and validated to prioritize fast-track colonoscopies according to risk, which was efficient, simple, and robust.

Colorectal Cancer Screening Modalities in Chinese Population: Practice and Lessons in Pudong New Area of Shanghai, China

Background: Parallel test of risk stratification and two-sample qualitative fecal immunochemical tests (FITs) are used to screen colorectal cancer (CRC) in Shanghai, China. This study was designed to identify an optimal initial screening modality based on available data. Methods: A total of 538,278 eligible residents participated in the program during the period of January 2013 to June 2017. Incident CRC was collected through program reporting system and by record linkage with the Shanghai Cancer Registry up to December 2017. Logistic regression model was applied to identify significant factors to calculate risk score for CRC. Cutoff points of risk score were determined based on Youden index and defined specificity. Sensitivity, specificity, and positive predictive values (PPVs) were computed to evaluate validity of assumed screening modalities. Results: A total of 446 CRC were screen-detected, and 777 interval or missed cases were identified through record linkage. The risk score system had an optimal cutoff point of 19 and performed better in detecting CRC and predicting long-term CRC risk than did the risk stratification. When using a cutoff point of 24, parallel test of risk score, and FIT were expected to avoid 56 interval CRCs with minimal decrease in PPV and increase in colonoscopy. However, the observed detection rates were much lower than those expected due to low compliance to colonoscopy. Conclusions: Risk score is superior to risk stratification used in the program, particularly when combined with FIT. Compliance to colonoscopy should be improved to guarantee the effectiveness of CRC screening in the population.

Fecal occult blood test in colorectal cancer screening

Colorectal cancer (CRC) is one of the leading causes of cancer-related mortality worldwide. Cancer screening is known to decrease mortality from CRC. One important test for CRC screening is the fecal occult blood test (FOBT), which includes guaiac FOBT and fecal immunological tests. In this review we discussed the development and application of the FOBT in CRC screening.

Faecal immunochemical tests for the diagnosis of symptomatic colorectal cancer in primary care: the benefit of more than one sample

OBJECTIVE

Faecal immunochemical tests (FITs) are used to screen for colorectal cancer (CRC) and as diagnostic aids in symptomatic patients. However, the number of samples per FIT varies. It is unclear if there is any advantage to analyse multiple-sample FITs in symptomatic patients.

DESIGN AND SETTING

This is a post hoc analysis of a retrospective study that included all cases of CRC and adenomas with high-grade dysplasia (HGD) between 2005 and 2009 in the county of Jämtland, Sweden.

SUBJECTS

All patients with CRC and adenomas with HGD that initially presented with symptoms to primary care and delivered FITs.

MAIN OUTCOME MEASURE

The likelihood of a positive FIT in cases of CRC and adenomas with HGD; when analysing one, two or three samples.

RESULTS

Of 195 patients, 160 delivered three-sample FITs. Using the 139 cases in which at least one sample was positive, the likelihood of detecting a positive sample upon analysis of only one of the three samples was 0.91 (95% CI: 0.85-0.95), indicating that 13 positive cases may have been missed.

CONCLUSION

Use of a one-sample FIT instead of a three-sample FIT as a diagnostic aid may result in the missing of one tenth of symptomatic CRCs and adenomas with HGD.

Does Low Threshold Value Use Improve Proximal Neoplasia Detection by Fecal Immunochemical Test?

BACKGROUND

Several studies have reported that the fecal immunochemical test (FIT) less sensitively detects proximal advanced neoplasia (AN) compared to distal AN. Low threshold value use may improve proximal AN detection.

AIM

To investigate whether FIT diagnostic accuracy for AN is different according to AN location and to compare FIT accuracy in proximal AN detection using different threshold values.

METHODS

This retrospective study was conducted in a university hospital in Korea from June 2013 to May 2015. Out of 34,547 participants who underwent FITs, 3990 subjects aged ≥50 years who also underwent colonoscopies were analyzed. The FIT diagnostic accuracy for AN with differing locations (proximal vs. distal) and threshold values (20, 15, and 10 mcg Hb/g feces) were assessed.

RESULTS

The sensitivity, specificity, positive predictive value, and negative predictive value of FIT in AN detection were 42.2, 84.3, 24.1, and 92.5 %, respectively. The FIT sensitivity for proximal AN detection was significantly lower than that for distal AN detection (32.7 and 49.0 %, respectively; P = 0.001). Lowering FIT threshold values tended to increase the sensitivity for proximal AN, whereas it significantly decreased the specificity for proximal AN. As a result, there was no significant difference in the accuracy for proximal AN detection (80.1, 79.3, and 78.1 % for 20, 15, and 10 mcg Hb/g feces, respectively; P = 0.107).

CONCLUSIONS

FIT was less sensitive in proximal AN detection than distal AN detection. Lowering the FIT cutoff threshold did not increase the accuracy for proximal AN detection. New biomarker development for colorectal cancer screening is required to improve proximal ACRN diagnostic accuracy.

An urgent referral strategy for symptomatic patients with suspected colorectal cancer based on a quantitative immunochemical faecal occult blood test

BACKGROUND

European health systems have developed referral guidelines for the selection of patients for the urgent investigation of suspected colorectal cancer.

AIM

To evaluate whether quantitative faecal immunochemical testing performs better than commonly used high-risk symptoms based strategies for fast-tracking cancer referrals.

METHODS

We prospectively studied 1054 symptomatic patients referred for a colonoscopy who provided a sample for faecal immunochemical testing. The usefulness of faecal immunochemical testing and two current guidelines for urgent referral were compared for their efficacy in the detection of colorectal cancer and advanced neoplasia.

RESULTS

The guidelines detected 46.7% and 43.3% of cases of colorectal cancer while faecal haemoglobin concentration ≥15μg Hb/g detected 96.7% of cases. The diagnostic accuracy of both the guidelines and faecal haemoglobin concentration ≥15μg Hb/g for the detection of advanced neoplasia was: sensitivity 38.3%, 36.1%, 57.1% and specificity 71.8%, 69.5%, 86.6%, respectively. Male gender (OR 2.35; p<0.001), age (1.34; p=0.002), and faecal haemoglobin concentration ≥10μg Hb/g (7.81; p<0.001) were independent predictive factors of advanced neoplasia.

CONCLUSIONS

A faecal immunochemical test based-strategy performs better than current high-risk symptoms based strategies for fast-tracking cancer referrals. A score that combines gender, age and a faecal immunochemical test could accurately estimate the risk of advanced neoplasia.