Negative Faecal Immunochemical Test Research Articles

Harm-to-benefit ratio of fecal immunochemical test-based screening for colorectal cancer given prior fecal hemoglobin concentrations

This study aims to provide evidence on the harm-to-benefit ratio of Fecal Immunochemical Test (FIT)-based colorectal cancer (CRC) screening by previous fecal Hemoglobine (f-Hb) concentrations, as reflected in Number Needed to Screen (NNS) and Number Needed to Scope (NNSc). Participants in up to four FIT screening rounds of the Dutch CRC screening program were included. The main outcomes of this study were the NNS and NNSc to detect one CRC and/or AN in screening round two, three or four, conditional on previous f-Hb concentrations. Outcomes were compared between participants using chi-squared tests, and logistic regression. In total, 2,428,883 study participants completed at least two consecutive FITs, 1,308,684 completed three FITs, and 150,958 completed four FITs. There were 31,400, 16,060, and 2,007 AN detected by round, respectively. The NNS for individuals with vs without a history of detectable f-Hb differed significantly irrespective of screening round. Individuals without detectable f-Hb in previous negative FITs had almost nine times the NNS to detect one AN compared to those with detectable f-Hb (OR 8.71, 95%CI 8.51-8.92). A similar directional pattern was observed for NNSc, although the differences were smaller (OR 2.7, 95%CI 2.7-2.8). The harm-to-benefit ratio of FIT-based screening is substantially greater in individuals without vs. with prior detectable f-Hb. Less intensive screening should be considered for this lower-risk group.

Faecal Immunochemical Test (FIT) Sensitivity; A Five Year Audit.

Introduction: Colorectal cancer has a high prevalence and mortality rate in the United Kingdom. Cancerous colorectal lesions often bleed into the gastrointestinal lumen. The faecal immunochemical test (FIT) detects haemoglobin (Hb) in the faeces of patients and is used as a first line test in the diagnosis of colorectal cancer. Materials and Methods: A retrospective audit of all FIT performed and all colorectal cancers diagnosed in the Hull and East Riding of Yorkshire counties of the United Kingdom (population approximately 609,300) between 2018 and 2022 was conducted. FIT were performed using a HM-JACKarc analyser from Kyowa medical. The predominant symptom suggestive of colorectal cancer which prompted the FIT was recorded. Colorectal cancer was diagnosed using the gold standard of histological biopsy following colonoscopy. Results: Between 2018 and 2022, 56,202 FIT were performed on symptomatic patients. Follow on testing identified 1,511 with colorectal cancer. Of these people, only 450 people with a confirmed colorectal cancer had a FIT within the 12months preceding their diagnosis. Of these 450 FIT results, 36 had a concentration of <10μg/g and may be considered to be a false negative. The sensitivity of FIT in the patients identified was 92.00%. The most common reason stated by the clinician for a FIT being performed in patients with colorectal cancer was a change in bowel habits, followed by iron deficient anaemia. The number of patients diagnosed with colorectal cancer decreased in 2020, but increased significantly in 2021. Discussion: This study shows that 8.00% of people diagnosed with colorectal cancer in the Hull and East Riding of Yorkshire regions had a negative FIT. This study also shows that the SARS-CoV-2 pandemic affected the number of people diagnosed with colorectal cancer, and therefore skews the prevalence and pre-test probability of a positive test. There are many reasons why a FIT could produce a false negative result, the most likely being biological factors affecting the stability of haemoglobin within the gastrointestinal tract, or pre-analytical factors influencing faecal sampling preventing the detection of haemoglobin. Some colorectal lesions do not protrude into the gastrointestinal lumen and are less likely to bleed. Conclusion: This is the first study showing data from outside of a structured clinical trial and provides the largest study to date showing the sensitivity of FIT in a routine clinical setting. This study also provides evidence for the impact COVID-19 had on the rate of colorectal cancer diagnosis.

Risk of Cancers Proximal to the Colon in Fecal Immunochemical Test Positive Screenees in a Colorectal Cancer Screening Program

In more than half of the colorectal cancer screening participants with a positive fecal immunochemical test (FIT) result, no advanced neoplasia (AN) is detected at colonoscopy. The positive FIT result could also be generated by cancers located proximal to the colon: upper gastrointestinal, oral cavity, nose, and throat cancers. We evaluated screenees' risk of being diagnosed with a cancer proximal to the colon within the 3 years and compared risks between those with a positive vs those with a negative FIT. Data of Dutch colorectal cancer screening participants who underwent biennial FIT-based screening 2014-2018 were collected from the national screening database and linked to the National Cancer Registry. Screenees were classified into 3 groups: FIT-positives with AN (FIT+/AN+), FIT-positives without AN (FIT+/AN-), and FIT-negatives (FIT-). We compared the cumulative incidence of cancers proximal to the colon in each group 3 years after FIT. A Cox regression analysis with left truncation and right censoring, using FIT positivity as time-dependent variable and stratified for sex, was performed to compare the hazard of cancers proximal to the colon in participants who were FIT-positive vs FIT-negative. Three-year cumulative incidence of cancers proximal to the colon in FIT+/AN+ (n= 65,767), FIT+/AN- (n= 50,661), and FIT- (n= 1,831,647) screenees was 0.7%, 0.6%, and 0.4%, respectively (P < .001). FIT-positives were older and more frequently male than FIT-negatives (P < .001). Significantly more cancers proximal to the colon were detected among FIT-positives (P < .001; hazard ratio, 1.55; 95% CI, 1.44-1.67). FIT-positive screenees were at significantly increased risk of being diagnosed witha cancer proximal to the colon within 3 years after FIT,although the 3-year cumulative incidence was still less than 1%.

Interval colorectal cancers after negative faecal immunochemical test in the New Zealand Bowel Screening Pilot

ObjectiveEvaluate the diagnostic performance of faecal immunochemical test (FIT), identify risk factors for FIT-interval colorectal cancers (FIT-IC) and describe long-term outcomes of participants with colorectal cancers (CRC) in the New...

Interval post-colonoscopy colorectal cancer following a negative colonoscopy in a fecal immunochemical test-based screening program.

In the Dutch colorectal (CRC) screening program, fecal immunochemical test (FIT)-positive individuals are referred for colonoscopy. If no relevant findings are detected at colonoscopy, individuals are reinvited for FIT screening after 10 years. We aimed to assess CRC risk after a negative colonoscopy in FIT-positive individuals. In this cross-sectional cohort study, data were extracted from the Dutch national screening information system. Participants with a positive FIT followed by a negative colonoscopy between 2014 and 2018 were included. A negative colonoscopy was defined as a colonoscopy during which no more than one nonvillous, nonproximal adenoma < 10 mm or serrated polyp < 10 mm was found. The main outcome was interval post-colonoscopy CRC (iPCCRC) risk. iPCCRC risk was reviewed against the risk of interval CRC after a negative FIT (FIT IC) with a 2-year screening interval. 35 052 FIT-positive participants had a negative colonoscopy and 24 iPCCRCs were diagnosed, resulting in an iPCCRC risk of 6.85 (95 %CI 4.60-10.19) per 10 000 individuals after a median follow-up of 1.4 years. After 2.5 years of follow-up, age-adjusted iPCCRC risk was approximately equal to FIT IC risk at 2 years. Risk of iPCCRC within a FIT-based CRC screening program was low during the first years after colonos-copy but, after 2.5 years, was the same as the risk in FIT-negative individuals at 2 years, when they are reinvited for screening. Colonoscopy quality may therefore require further improvement and FIT screening interval may need to be reduced after negative colonoscopy.

Personalised colorectal cancer screening strategies: Information needs of the target population

Prior faecal Hemoglobin (f-Hb) concentrations of a negative fecal immunochemical test (FIT) can be used for risk stratification in colorectal cancer (CRC) screening. Individuals with higher f-Hb concentrations may benefit from a shorter screening interval (1 year), whereas individuals with undetectable f-Hb concentrations could benefit from a longer screening interval (3 year). Individuals’ views on personalised CRC screening and information needed to make a well-informed decision is unknown. We conducted three semi-structured focus groups among individuals eligible for CRC screening (i.e. men and women aged 55 to 75) in the Netherlands. Thematic analysis was used to analyse participants’ information need on personalised CRC screening strategies. Fourteen individuals took part. The majority were positive about CRC screening and indicated that they would participate in personalised CRC screening. The rationale for a longer interval among those at lowest risk was, however, unclear for many. The preferred information on individual risk was variable: ranging from full information to only information on the personalised strategy without mentioning the risk. It was not possible to address everyone’s need with a single approach. Additional communications, e.g. public media campaigns, billboards, videos on social media, were also suggested as necessary. This study showed that preferences on receiving information on individual CRC risk varied substantially and no consensus was reached. Introducing a personalised screening programme will require careful communication, particularly around the rationale for the strategy, and a layered approach to deliver information.

The accuracy of the FIT in detecting advanced neoplasm is highest in young people aged 40 to 49 years: an analysis based on sex and age

BackgroundColorectal cancer (CRC) is one of the most common cancers and is associated with high incidence and mortality rates worldwide. CRC has caused a tremendous loss of human health and wealth. The incidence and mortality of colorectal carcinoma are increasing in young adults. Early cancer detection and prevention are made possible through screening. At present, the faecal immunochemical test (FIT) is a noninvasive method that can be used for the large-scale clinical screening of CRC status. Therefore, this study, based on CRC screening results in Tianjin from 2012 to 2020, was conducted to analyse the major differences in diagnostic performance parameters according to sex and age.MethodsThis study was based on 39,991 colonoscopies performed for individuals in the Tianjin CRC screening program from 2012 to 2020. Of these individuals, they had complete FIT and colonoscopy results. The differences in FIT results were analysed by sex and age.ResultsAccording to this study, males were generally more likely to develop advanced neoplasms (ANs) than females, and the prevalence increased with age. Males with negative FIT results were more likely to have advanced neoplasms than females with positive results. The accuracy of the FIT in detecting ANs in each age group was 54.9%, 45.5%, 48.6% and 49.5% in the 40–49, 50–59, 60–69, and ≥ 70 age groups, respectively.ConclusionsThe FIT detected ANs with highest accuracy in the 40–49 age group. Our research can provide guidance to formulate CRC screening strategies.

O136 An observational cohort study of replicate faecal immunochemical tests in symptomatic two-week wait patients

Abstract Introduction Triage of patients with suspected colorectal cancer (CRC) utilises a single faecal immunochemical test (FIT) at a defined threshold. Limited evidence exists regarding whether replicate FIT improves the positive and negative predictive value in symptomatic patients. This study examines two-week wait (TWW) patients undergoing replicate FIT. Primary aim is to assess two FITs and CRC/serious bowel disease. Secondary aims are to determine correlation and utility of replicate FIT. Methods TWW patients carried out one additional FIT during COVID-19 pandemic. FIT 1 and FIT 2 (the replicate sample) were analysed in relation to symptoms, diagnoses, investigations, future colonoscopy and missed CRC. Study period was 01/03/2020-31/07/2020. Three subgroups were compared; double positive (&amp;gt;10μg Hb/g faeces), double negative, and discordant FIT (one positive). Results 111 patients had replicate FIT (50 male, 61 female). 43 (38.7%) patients had double negative, 32 (28.8%) double positive and 36 (32.4%) had discordant FITs. Median time between FITs was 14 days (IQR=11 to 19). 83% of double positive patients underwent colonoscopy/virtual colonoscopy (61% in double negative patients). Six CRC and one high-risk polyp were in double positive patients (none in other groups). One discordant patient was not investigated and a CRC missed. Conclusion Replicate FIT as a triage strategy appears most effective where both FITs are negative. CRC risk is low when FIT results are discordant. Double negative FITs are reassuring given benign associated diagnoses, or for patients where endoscopic investigation is high-risk. Larger studies are required to evaluate discordant FITs, enabling refinement of urgent investigation pathways.

Fecal Occult Blood Screening before Cardiac Surgery.

Concerns of gastrointestinal (GI) bleeding after cardiac surgery are increasing with increased use of antiplatelets and anticoagulants. We investigated the roles of preoperative screening for fecal occult blood by fecal immunochemical test (FIT) widely used to detect GI bleeding and cancer. A retrospective review was done in 1,663 consecutive patients undergoing FIT before cardiac surgery between years 2012 and 2020. One or two rounds of FIT were performed 2 to 3 weeks before surgery, when antiplatelets and anticoagulants were not suspended yet. Positive FIT (> 30 μg of hemoglobin/g of feces) was observed in 227 patients (13.7%). Preoperative risk factors for positive FIT included age > 70 years, anticoagulants, and chronic kidney disease. Of those with positive FIT, 180 patients (79%) received preoperative endoscopy, including gastroscopy (n = 139), colonoscopy (n = 9), and both (n = 32), with no findings of bleeding. The most common finding of gastroscopy was atrophic gastritis (36%) while early gastric cancer was detected in 2 patients. The most common finding of colonoscopy was colon polyps (42%) while colorectal cancer was detected in 5 patients. Of 180 FIT-positive patients receiving endoscopy, 8 (4.4%) underwent preoperative GI treatment, while postoperative GI events were documented in 28 (15.6%). Of 1,436 with negative FIT, 21 (1.5%) presented GI complications after surgery. Preoperative FIT, which is influenced by anticoagulant use, has little impacts on identification of GI bleeding sites. However, it may be useful to detect GI malignant lesions, potentially impacting operative risks, surgical strategies, and postoperative management.

Postponing colonoscopy for 6months in high-risk population increases colorectal cancer detection in China.

Colonoscopy is an important colorectal cancer (CRC) screening modality; however, not all high-risk groups identified by fecal immunochemical test (FIT) and/or high-risk factor questionnaire (HRFQ) undergo colonoscopy in time. The impact of delays in colonoscopy on CRC detection among high-risk populations remains poorly understood, warranting further clarification. A retrospective study was conducted among CRC high-risk population identified by Tianjin CRC screening program. According to the colonoscopy results after HRFQ and FIT, patients were classified into CRC, advanced adenoma, non-advanced adenoma, and normal groups. The time interval between CRC screening and colonoscopy was investigated and its relationship with colonoscopy results. Logistic regression was performed to explore the risk factors of CRC detection. Among the high-risk population without a history of CRC or polyps, 49,810 underwent HRFQ, FIT, and colonoscopy, and a time interval of fewer than 6months was found for 79.56% of patients (n=39,630). People with positive FIT were more likely to undergo colonoscopy within 6months, and detection rates of CRC and/or advanced adenoma were positively related to time intervals. Similar results were found in people with a negative FIT but positive HRFQ. A time interval longer than 6months was a significant predictor of CRC detection in high-risk populations. For high-risk people identified by CRC screening, especially those with a positive FIT, a time interval of 6months was associated with an increased probability of CRC detection. Our findings emphasize that populations at high risk should undergo colonoscopy at least within 6months.

An observational study of replicate faecal immunochemical tests in the urgently referred symptomatic cohort.

Triage of patients with suspected colorectal cancer (CRC) utilises a single faecal immunochemical test (FIT) at a defined threshold. Limited evidence exists regarding whether replicate FIT improves the positive and negative predictive value in symptomatic patients. This study examines urgently referred symptomatic patients undergoing replicate FIT. Primary aim is to assess two FITs and CRC/serious bowel disease. Secondary aims are to determine correlation and utility of replicate FIT. Patients carried out one additional FIT during COVID-19 pandemic. FIT 1 and FIT 2 (the replicate sample) were analysed in relation to symptoms, diagnoses, investigations, future colonoscopy and missed CRC. Study period was 01/03/2020-31/07/2020. Three subgroups were compared; double positive (≥10μg Hb/g faeces), double negative, and discordant FIT (one positive). 111 patients had replicate FIT (50 male, 61 female). 43 (38.7%) patients had double negative, 32 (28.8%) double positive and 36 (32.4%) had discordant FITs. Median time between FITs was 14days (IQR = 11-19). 83% of double positive patients underwent colonoscopy/virtual colonoscopy (61% in double negative patients). Six CRC and one high-risk polyp were in double positive patients (none in other groups). One discordant patient was not investigated and a CRC missed. Replicate FIT as a triage strategy appears most effective where both FITs are negative. CRC risk is low when FIT results are discordant. Double negative FITs are reassuring given benign associated diagnoses, or for patients where endoscopic investigation is high-risk. Larger studies are required to evaluate discordant FITs, enabling refinement of urgent investigation pathways.

Positive faecal immunochemical test predicts the onset of inflammatory bowel disease: A nationwide, propensity score-matched study.

The faecal immunochemical test (FIT), a non-invasive test for screening colorectal cancer (CRC), is being increasingly understood to reflect heightened inflammation. We aimed to investigate the association between abnormal FIT results and onset of inflammatory bowel disease (IBD), a disease characterized with chronic gut mucosal inflammation. Participants in the Korean National Cancer Screening Program for CRC between 2009-2013 were analysed and divided into positive and negative FIT result groups. The incidence rates of IBD after screening were calculated after excluding cases of haemorrhoids, CRC, and IBD at baseline. Cox proportional hazard analyses were used to identify independent risk factors for IBD occurrence during follow-up, and 1:2 propensity score matching was performed as a sensitivity analysis. In total, 229,594 and 815,361 participants were assigned to the positive and negative FIT result groups, respectively. The age- and sex-adjusted incidence rates of IBD in participants with positive and negative test results were 1.72 and 0.50 per 10,000 person-years, respectively. Adjusted Cox analysis revealed that FIT positivity was associated with a significantly higher risk of IBD (hazard ratio 2.93, 95% confidence interval: 2.46, 3.47, P <.001), which was consistent for both disease subtypes of ulcerative colitis and Crohn's disease. The results of Kaplan-Meier analysis in the matched population yielded identical findings. Abnormal FIT results could be a preceding sign of incident IBD in the general population. Those with positive FIT results and suspected IBD symptoms could benefit from regular screening for early disease detection.

Multiple Negative Fecal Immunochemical Tests Reduce Risk of Advanced Neoplasia in a Colonoscopy Surveillance Program

In above-average-risk individuals undergoing colonoscopy-based surveillance for colorectal cancer (CRC), screening with fecal immunochemical tests (FIT) between colonoscopies might facilitate personalization of surveillance intervals. Because a negative FIT is associated with a reduced risk for CRC, we examined the relationship between number of rounds of negative FIT and risk for advanced neoplasia in individuals undergoing surveillance colonoscopy. We conducted a retrospective cohort study on 4021 surveillance intervals in 3369 individuals (50-74 years), who had completed a 2-sample FIT between colonoscopies, from 1 to 4 rounds at 1-2 yearly intervals, each with a negative result (<20 μg hemoglobin/g feces). Incidence of advanced neoplasia (CRC or advanced adenoma) was determined at the follow-up colonoscopy. Competing-risk regression was used to assess the association between multiple negative FIT results and the risk of advanced neoplasia within 2 years. The incidence of advanced neoplasia in the cohort was 9.9% and decreased with increasing numbers of rounds of negative FIT results: 11.1% after 1 negative FIT to 5.7% after 4 negative FIT. The risk of advanced neoplasia was significantly lower in participants with 3 (subdistribution hazard ratio, 0.50; 95% confidence interval, 0.24-0.97) and 4 (subdistribution hazard ratio, 0.33; 95% confidence interval, 0.15-0.73) rounds of negative FIT compared with only 1 negative FIT. There was a low risk of advanced neoplasia after multiple rounds of negative FIT in above-average-risk people undergoing surveillance with no neoplasia or nonadvanced adenoma at prior colonoscopy. This supports the use of interval FIT to personalize surveillance by lengthening colonoscopy intervals following multiple negative FIT results.

Evaluation of 13,466 Fecal Immunochemical Tests in Patients Attending Primary Care for High- and Low-Risk Gastrointestinal Symptoms of Colorectal Cancer.

Quantitative fecal immunochemical tests (FIT) were recommended by NICE for patients in primary care presenting with low-risk symptoms of colorectal cancer (CRC). FIT is more accurate in the detection of CRC than symptom criteria. Despite this, CRC still occurs with a negative FIT and the importance of safety netting for patients with severe or persistent symptoms is paramount. We aimed to evaluate the utilization and accuracy of FIT for CRC in low and high-risk symptom groups presenting to primary care, the effectiveness of safety netting in primary care, referral practices with FIT utilization for symptomatic patients and the clinical features of FIT negative patients with CRC. Medical records and databases of all patients undertaking a FIT sample in the Herts Valleys CCG between June 2019 and November 2021 were reviewed. 13,466 consecutive FIT samples were requested for 12,231 patients between June 2019 and November 2021. Analysis of diagnostic accuracy was undertaken for the first 5341 patients with a minimum of 12months follow up. Sensitivity for CRC, in FIT ≥ 4µg Hb/g, ≥ 10µg Hb/g and ≥ 100µg Hb/g was 93% (95% CI 85-98%), 91% (95% CI 82-96%) and 72% (95% CI 60-81%) with a number needed to investigate of 36, 19 and 6, respectively. A FIT ≥ 10µg Hb/g in conjunction with ongoing GP clinical concern within 8weeks had a sensitivity for CRC of 97% (95% CI 90-100%), a PPV of 3.6% (95% CI 3.4-3.7%) and a number needed to investigate to detect one CRC of 28.

Making colonoscopy-based screening more efficient: A "gateopener" approach.

Screening colonoscopy for early detection and prevention of colorectal cancer (CRC) is mostly used inefficiently. Here, we assessed the potential of an innovative approach to colonoscopy-based screening, by use of a single, low threshold fecal immunochemical test (FIT) as a "gateopener" for screening colonoscopy. Using COSIMO, a validated simulation model, we modeled scenarios including either direct invitation to screening colonoscopy or an alternative approach involving mailing a single ("gateopener") FIT along with an invitation to colonoscopy contingent on a FIT value above a low threshold yielding a 50% positivity rate (ie, every other pretest will be positive). Under plausible assumptions on screening offer adherence, we found that such "gateopener screening" (use of screening colonoscopy contingent on a positive, low threshold gateopener FIT) approximately doubled cancer detection rates vs conventional screening. In those spared from screening colonoscopy due to a negative gateopener FIT pretest, numbers needed to screen were 10-times higher vs those for individuals with a positive FIT, peaking in >2000 and >3800 (hypothetically) needed colonoscopies to detect one case of cancer in men and women, respectively. Gateopener screening resulted in 42%-51% and 59%-65% more prevented CRC cases and deaths, respectively. In summary, by directing colonoscopy capacities to those most likely to benefit, offering screening colonoscopy contingent on a "gateopener" low-threshold FIT would substantially enhance efficiency of colonoscopy screening.

A Multi-Centre Study to Risk Stratify Colorectal Polyp Surveillance Patients Utilising Volatile Organic Compounds and Faecal Immunochemical Test.

Simple SummaryA total of 15% of the annual colonoscopies are undertaken for polyp surveillance, and this causes strain on already stretched endoscopy services in the U.K. Hence, there is an urgent need to triage and prioritise patients with high-risk findings. The performance of the faecal immunochemical test is not adequate to be used within polyp surveillance. In light of this, we investigated the usefulness of urinary volatile organic compounds for the detection of high-risk findings. We confirmed that urinary volatile organic compounds can be used to triage patients with high-risk findings. It can be used alone or in combination with faecal immunochemical tests.(1) Background: The service capacity for colonoscopy remains constrained, and while efforts are being made to recover elective services, polyp surveillance remains a challenge. (2) Methods: This is a multi-centre study recruiting patients already on polyp surveillance. Stool and urine samples were collected for the faecal immunochemical test (FIT) and volatile organic compounds (VOC) analysis, and all participants then underwent surveillance colonoscopy. (3) Results: The sensitivity and specificity of VOC for the detection of a high-risk finding ((≥2 premalignant polyps including ≥1 advanced polyp or ≥5 premalignant polyps) were 0.94 (95% CI, 0.88 to 0.98) and 0.69 (95% CI, 0.64 to 0.75) respectively. For FIT, the sensitivity was (≥10 µg of haemoglobin (Hb) / g faeces) 0.54 (95% CI, 0.43 to 0.65) and the specificity was 0.79 (95% CI, 0.73 to 0.84). The probability reduction for having a high-risk finding following both negative VOC and FIT will be 24% if both tests are applied sequentially. (4) Conclusion: The diagnostic performance of VOC is superior to FIT for the detection of a high-risk finding. The performance further improves when VOC is applied together with FIT sequentially (VOC first and then FIT). VOC alone or the combination of VOC and FIT can be used as a triage tool for patients awaiting colonoscopy within a polyp surveillance population, especially in resource-constrained healthcare systems.

Efficacy comparison among high risk factors questionnaire and Asia-Pacific colorectal screening score and their combinations with fecal immunochemical test in screening advanced colorectal tumor

Efficacy comparison among high risk factors questionnaire and Asia-Pacific colorectal screening score and their combinations with fecal immunochemical test in screening advanced colorectal tumor

Colorectal two-week wait service and quantitative FIT: it's not just about colon cancer.

The aim of this study was to assess faecal immunochemical test (FIT) negativity in terms of its effect on cancer risk in the local symptomatic two-week wait (2WW) population. FIT was introduced to the colorectal 2WW pathway at the start of the pandemic. This study analyses the FIT-negative (<10µg Hb/g) cohort and calculates the relative risk and odds ratio associated with a negative FIT test. FIT tests were sent to symptomatic 2WW patients without rectal bleeding, iron-deficient anaemia or palpable mass. Where FIT was <10µg Hb/g investigations were moved to a radiology protocol. The test return rate was 91% with a FIT-negative (<10µg Hb/g) rate of 82%. The FIT-negative group in the symptomatic referral pathway in Cornwall have a low (1.4%) risk of colon cancer but a significant risk (6.6%) when all cancer types are considered. The impact of a negative quantitative FIT changes the odds ratio of a patient having a luminal cancer by 0.26. The odds ratio for 'all cancer' risk was affected by 0.83. A negative FIT test within the local NG12 symptomatic patient group signifies a low risk of colon cancer and identifies patients who can be initially investigated with cross-sectional imaging. However, when all cancer types are considered, cancer prevalence in this group remains above 6%. In relative risk terms a negative FIT represents a small change in overall risk and this patient group still qualify for investigation through 2WW pathways.

The use of the faecal immunochemical test during the COVID-19 pandemic to triage urgent colorectal cancer referrals.

AimDuring the first wave of the COVID‐19 pandemic in 2020, elective gastrointestinal endoscopy services were abbreviated for fear of viral transmission. However, urgent suspected colorectal cancer (CRC) referrals continued. Serendipitously, a national study suggested that a new faecal immunochemical test (FIT) might be helpful in triaging patients with colorectal alarm symptoms.MethodsThis was a single centre observational study of patients referred using NG12 criteria between March and August 2020. Patients were triaged to the urgent cancer pathway for FIT ≥ 10 μg/g and investigated using the latest National Health Service England guidance. Demographic data, method of investigations, cancer and polyp detection rates were compared to patients referred in the 6 months prior to the use of FIT as a triage tool.ResultsIn all, 1192 patients (median age 70) were referred using NG12 guidelines during the pandemic period, compared with 1592 patients (median age 72) in the previous 6 months. CRC detection was similar in both groups (n = 45, 2.8% vs. n = 38, 3.5%; P = 0.248). Two patients with a negative FIT (0.36%) had CRC. Using FIT as a triage tool resulted in a significant reduction in the use of endoscopy (n = 477, 43.6% vs. n = 1186, 74.5%; P > 0.001) with a significant increase in CT scanning (n = 696, 63.6% vs. n = 750, 47.1%; P < 0.001).ConclusionThe use of FIT in NG12 patients triaged during the first wave of the COVID‐19 pandemic reduced endoscopy but not CT scanning and did not compromise CRC detection rates. It is a safe method that aids in reducing the burden on services greatly. A negative FIT test does not absolutely exclude CRC.

Interval cancers in a population-based screening program for colorectal cancer with gender-specific cut-off levels for fecal immunochemical test.

ObjectiveTo evaluate interval cancers (IC) in the population-based Swedish regional colorectal cancer (CRC) screening program of Stockholm-Gotland, which uses gender-specific cut-off levels for the fecal immunochemical test (FIT).MethodsAll individuals aged 60–69 in Stockholm-Gotland invited to the screening program in October 2015 to September 2017 were followed up 2 years after invitation. Cut-off level for a positive FIT was 40 µg/g in women and 80 µg/g in men. Those with a positive FIT were referred to colonoscopy. Screening-detected CRC (SD-CRC) and IC after negative FIT (FIT-IC) or negative screening colonoscopy (Colonoscopy-IC) were identified in the Swedish colorectal cancer register. The IC rate was calculated as IC/(FIT negatives + negative screening colonoscopies). The IC incidence rate (ICs among negatives per 100,000 person-years) in different sex and age groups was compared to the mean CRC incidence before regional screening implementation. Test sensitivity was defined as SD-CRC/(SD-CRC + FIT-IC).ResultsApproximately 214,400 individuals were invited, and in 3521 screening colonoscopies 257(6.3%) SD-CRCs were detected. During follow-up, 124 FIT-IC and 7 Colonoscopy-IC were diagnosed, yielding an IC rate of 12.6 and 6.0 per 10,000 negatives (p = 0.00005) and a test sensitivity of 62% and 75% (p = 0.01) in men and women respectively. The IC incidence rate compared to CRC incidence was non-significantly lower in women.ConclusionIn the population-based screening program of Stockholm-Gotland with a cut-off of 40 µg/g in women and 80 µg/g in men, the test sensitivity was higher and the IC rate was lower in women, which might imply lowering the cut-off level in men. However, the IC incidence rate relative to the CRC incidence was similar in both genders.