Risk of gastrointestinal cancer in a symptomatic cohort after a complete colonoscopy: Role of faecal immunochemical test

Exploring the utility and acceptability of Faecal immunochemical testing (FIT) as a novel intervention for the improvement of colorectal Cancer (CRC) surveillance in individuals with lynch syndrome (FIT for lynch study): a single-arm, prospective, multi-centre, non-randomised study

BACKGROUND

Lynch Syndrome (LS) is an inherited cancer predisposition syndrome defined by pathogenic variants in the mismatch repair (MMR) or EPCAM genes. In the United Kingdom, people with LS are advised to undergo biennial colonoscopy from as early as 25 until 75 years of age to mitigate a high lifetime colorectal cancer (CRC) risk, though the consideration of additional surveillance intervention(s) through the application of non-invasive diagnostic devices has yet to be longitudinally observed in LS patients. In this study, we will examine the role of annual faecal immunochemical testing (FIT) alongside biennial colonoscopy for CRC surveillance in people with LS.

METHODS/DESIGN

In this single-arm, prospective, non-randomised study, 400 LS patients will be recruited across 11 National Health Service (NHS) Trusts throughout the United Kingdom. Study inclusion requires a LS diagnosis, between 25 and 73 years old, and a routine surveillance colonoscopy scheduled during the recruitment period. Eligible patients will receive a baseline OC-Sensor™ FIT kit ahead of their colonoscopy, and annually for 3 years thereafter. A pre-paid envelope addressed to the central lab will be included within all patient mailings for the return of FIT kits and relevant study documents. A questionnaire assessing attitudes and perception of FIT will also be included at baseline. All study samples received by the central lab will be assayed on an OC-Sensor™ PLEDIA Analyser. Patients with FIT results of ≥6 μg of Haemoglobin per gram of faeces (f-Hb) at Years 1 and/or 3 will be referred for colonoscopy via an urgent colonoscopy triage pathway. 16S rRNA gene V4 amplicon sequencing will be carried out on residual faecal DNA of eligible archived FIT samples to characterise the faecal microbiome.

DISCUSSION

FIT may have clinical utility alongside colonoscopic surveillance in people with LS. We have designed a longitudinal study to examine the efficacy of FIT as a non-invasive modality. Potential limitations of this method will be assessed, including false negative or false positive FIT results related to specific morphological features of LS neoplasia or the presence of post-resection anastomotic inflammation. The potential for additional colonoscopies in a subset of participants may also impact on colonoscopic resources and patient acceptability.

TRIAL REGISTRATION

Trial Registration: ISRCTN, ISRCTN15740250 . Registered 13 July 2021.

Faecal immunochemical tests safely enhance rational use of resources during the assessment of suspected symptomatic colorectal cancer in primary care: systematic review and meta-analysis

OBJECTIVE

Implementation of faecal immunochemical tests (FIT) as a triage test in primary healthcare may improve the efficiency of referrals without missing cases of colorectal cancer (CRC). We aim to summarise the performance characteristics of FITs for CRC in symptomatic patients presenting to primary healthcare.

DESIGN

We performed a systematic literature review of Medline and EMBASE databases from May 2018 to November 2020. Previous related systematic searches were also adapted to this aim and completed with reference screening. We identified studies performed on adult patients consulting for abdominal symptoms in primary care which reported data such that the FIT diagnostic performance parameters for CRC could be obtained. Bivariate models were used to synthesise available evidence. Meta-regression analysis was performed to evaluate the causes of heterogeneity.

RESULTS

Twenty-three studies (69 536 participants) were included (CRC prevalence 0.3%-6.2%). Six studies (n=34 691) assessed FIT as rule in test (threshold of ≥150 µg Hb/g faeces) showing a sensitivity of 64.1% (95% CI 57.8% to 69.9%) and a specificity of 95.0% (95% CI 91.2% to 97.2%). A threshold of 10 µg/g (15 studies; n=48 872) resulted in a sensitivity of 87.2% (95% CI 81.0% to 91.6%) and a specificity of 84.4% (95% CI 79.4% to 88.3%) for CRC. At a 20 µg Hb/g faeces threshold (five studies; n=24 187) less than one additional CRC would be missed per 1000 patients investigated compared with 10 µg Hb/g faeces threshold (CRC prevalence 2%).

CONCLUSION

FIT is the test of choice to evaluate patients with new-onset lower gastrointestinal symptoms in primary healthcare.

Not FIT for Use: Fecal Immunochemical Testing in the Inpatient and Emergency Settings

BACKGROUND

Fecal immunochemical testing (FIT) is widely used for colorectal cancer screening, its only indication. Its effect on clinical decision-making beyond screening is unknown. We studied the use of FIT in emergency and inpatient settings and its impact on patient care.

METHODS

Using electronic medical records, we reviewed all non-ambulatory FITs performed from November 2017 to October 2019 at a tertiary care community hospital. We collected data on demographics, indications, gastroenterology consultations, and endoscopic procedures. Multivariate logistic regression was performed to determine the effect of FIT on gastroenterology consultation and endoscopy.

RESULTS

We identified 550 patients with at least 1 FIT test. Only 3 FITs (0.5%) were performed for colorectal cancer screening. FITs were primarily ordered from the emergency department (45.3%) or inpatient hospital floor (42.2%). Anemia (44.0%), followed by gastrointestinal bleeding (40.9%), were the most common indications. FIT was positive in 253 patients (46.0%), and gastroenterology consultation was obtained for 47.4% (n = 120), compared with 14.5% (n = 43) of the 297 FIT-negative patients (odds ratio 3.28; 95% confidence interval, 2.23-4.82, P < .0001). A potential bleeding source was identified in 80% of patients with reported or witnessed overt gastrointestinal bleeding, a similar proportion (80.7%; P = .92) to patients who were FIT positive with overt gastrointestinal bleeding. Multivariate analysis showed that melena, hematemesis, and a positive FIT were associated with gastroenterology consultation (all P < .05), while only melena (odds ratio 3.34; 95% confidence interval, 1.48-7.54) was associated with endoscopy.

CONCLUSIONS

Nearly all emergency department and inpatient FIT use was inappropriate. FIT resulted in more gastroenterology consultation but was not independently associated with inpatient endoscopy.

Faecal immunochemical test outside colorectal cancer screening?

Faecal immunochemical tests (FITs) are the most widely colorectal cancer (CRC) diagnostic biomarker available. Many population screening programmes are based on this biomarker, with the goal of reducing CRC mortality. Moreover, in recent years, a large amount of evidence has been produced on the use of FIT to detect CRC in patients with abdominal symptoms in primary healthcare as well as in surveillance after adenoma resection. The aim of this review is to highlight the available evidence on these two topics. We will summarize the evidence on diagnostic yield in symptomatic patients with CRC and significant colonic lesion and the different options to use this (thresholds, brands, number of determinations, prediction models and combinations). We will include recommendations on FIT strategies in primary healthcare proposed by regulatory bodies and scientific societies and their potential effects on healthcare resources and CRC prognosis. Finally, we will show information regarding FIT-based surveillance as an alternative to endoscopic surveillance after high-risk polyp resection. To conclude, due to the coronavirus disease 2019 pandemic, FIT-based strategies have become extremely relevant since they enable a reduction of colonoscopy demand and access to the healthcare system by selecting individuals with the highest risk of CRC.

The Value of Quantitative Faecal Immunochemical Testing as a Prioritisation Tool for the Endoscopic Investigation of Patients With Iron Deficiency

Difficulty in providing endoscopy for patients with iron deficiency anaemia (IDA) during the COVID-19 pandemic has highlighted the requirement for a prioritisation tool. We aimed to test the validity of qFIT as a prioritisation tool in patients with iron deficiency and its ability to identify patients with advanced neoplastic lesions (ANLs). Data collected from patients referred with biochemically proven iron deficiency (ferritin ≤ 15 μg/L) and synchronous qFIT who underwent full gastrointestinal investigation within NHS Greater Glasgow and Clyde was analysed retrospectively. Patients who did not undergo full investigation, defined as gastroscopy and colonoscopy or CT colonography, were excluded. ANLs were defined as defined as upper GI cancer, colorectal adenoma ≥ 1 cm or colorectal cancer. Area under the curve (AUC) analysis was performed on qFIT results and outcome, defined as the presence of an ANL. AUC analysis guided cut-off scores for qFIT. Patients with a qFIT of <10, 10-200, >200, were allocated a score of 1, 2, and 3, respectively. A total of 575 patients met criteria for inclusion into the study. Overall, qFIT results strongly predicted the presence of ANLs (AUC 0.87, CI 0.81-0.92; P < 0.001). The prevalence of ANLs in patients with scores 1-3 was 1.2, 13.5, and 38.9% respectfully. When controlled for other significant variables, patients with a higher qFIT score were statistically more likely to have an ANL (qFIT score = 2; OR 12.8; P < 0.001, qFIT score = 3, OR 50.0; P < 0.001). A negative qFIT had a high NPV for the presence of ANLs (98.8%, CI 97.0-99.5%). These results strongly suggest that qFIT has validity as a prioritisation tool in patients with iron deficiency; both allowing for a more informed decision of investigation of patients with very low risk of malignancy, and in identifying higher risk patients who may benefit from more urgent endoscopy.

Systematic upper endoscopy concomitant with colonoscopy performed within the colorectal cancer screening program: Impact on the patients' management

BACKGROUND AND AIMS

The French colorectal cancer screening program is based on a fecal immunochemical test, followed by colonoscopy in case of positivity. The benefit of adding a concomitant upper endoscopy to detect upper digestive lesions (precancerous or others) is still debated. Our aim was to evaluate the frequency of upper digestive lesions detected by upper endoscopy performed concomitantly with colonoscopy following a positive fecal immunochemical test, and their impact on the patients' management (i.e., surveillance, medical treatment, endoscopic or surgical procedure).

METHODS

Data of all the patients who consulted for a positive test between May 2016 and May 2019 in our center, and for whom concomitant upper endoscopy and colonoscopy were performed, were analyzed retrospectively. Patients with significant history of upper gastrointestinal diseases or with current gastrointestinal symptoms were excluded.

RESULTS

One hundred patients were included [median age (min-max): 62 (50-75), men 64%]. Macroscopic and/or microscopic upper digestive lesions were found in 58 of them (58%): Helicobacter pylori infection in 17 patients, gastric precancerous lesions in 9 patients (chronic atrophic gastritis with intestinal metaplasia, n=8, low grade dysplasia, n=1), Barrett's esophagus requiring surveillance in 4 patients, and 1 duodenal adenoma with low-grade dysplasia. In 44 patients (44%), the upper endoscopy findings had an impact on patients' management, with no significant difference between the groups with positive (CRC or advanced adenoma)- or negative (any other lesions or normal) colonoscopy.

CONCLUSION

A systematic upper endoscopy combined with colonoscopy for positive fecal immunochemical test could represent an efficient strategy for upper digestive lesions screening in France. Further studies are necessary to confirm these results and to evaluate cost-effectiveness of this approach.

Predictive Value of Carcinoembryonic Antigen in Symptomatic Patients without Colorectal Cancer: A Post-Hoc Analysis within the COLONPREDICT Cohort

We aimed to assess the risk of cancer in patients with abdominal symptoms after a complete colonoscopy without colorectal cancer (CRC), according to the carcinoembryonic antigen (CEA) concentration, as well as its diagnostic accuracy. For this purpose, we performed a post-hoc analysis within a cohort of 1431 patients from the COLONPREDICT study, prospectively designed to assess the fecal immunochemical test accuracy in detecting CRC. Over 36.5 ± 8.4 months, cancer was detected in 115 (8%) patients. Patients with CEA values higher than 3 ng/mL revealed an increased risk of cancer (HR 2.0, 95% CI 1.3-3.1), CRC (HR 4.4, 95% CI 1.1-17.7) and non-gastrointestinal cancer (HR 1.7, 95% CI 1.0-2.8). A new malignancy was detected in 51 (3.6%) patients during the first year and three variables were independently associated: anemia (OR 2.8, 95% CI 1.3-5.8), rectal bleeding (OR 0.3, 95% CI 0.1-0.7) and CEA level >3 ng/mL (OR 3.4, 95% CI 1.7-7.1). However, CEA was increased only in 31.8% (95% CI, 16.4-52.7%) and 50% (95% CI, 25.4-74.6%) of patients with and without anemia, respectively, who would be diagnosed with cancer during the first year of follow-up. On the basis of this information, CEA should not be used to assist in the triage of patients presenting with lower bowel symptoms who have recently been ruled out a CRC.