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

The participation in the FIT-based colorectal cancer screening programme and subsequent compliance to colonoscopy after a positive FIT test was only slightly affected during the COVID-19 pandemic in Denmark.

Background: The current guideline does not recommend upper gastrointestinal evaluation for patients with a positive fecal immunochemical test (FIT) and negative colonoscopy results. However, this indication was based on low-quality evidence as data on this issue are very limited. We assessed the risk of proximal cancers (oral or throat, esophageal, stomach, and small intestine cancers) after negative or positive FIT results in the Korean National Cancer Screening Program (NCSP). Methods: Using the NCSP databases, we collected data on participants who underwent FIT between 2009 and 2011. Participants were classified based on FIT results and colorectal cancer (CRC) diagnosed within 1 year after FIT as FIT− (n = 5,551,755), FIT+/CRC− (n = 368,553), and FIT+/CRC+ (n = 12,236). Results: The incidence rates of overall proximal cancers in FIT−, FIT+/CRC−, and FIT+/CRC+ patients within 1, 2, and 3 years after FIT were 0.38%, 0.68%, and 2.26%; 0.57%, 0.93%, and 2.74%; and 0.79%, 1.21%, and 3.15%, respectively. After adjusting confounding variables, the risks of esophageal, stomach, and small intestine cancers as well as overall proximal cancers within 1, 2, and 3 years after FIT were higher in FIT+/CRC− patients than those in FIT− patients. However, the risk of oral or throat cancer did not differ between FIT− and FIT+/CRC− patients. The risks for oral or throat cancer and small intestine cancer were higher in FIT+/CRC+ patients than those in FIT+/CRC− patients. Conclusions: In this population-based study, FIT+/CRC− patients were at higher risk for esophageal, stomach, and small intestine cancers than were FIT− patients, suggesting that positive FIT results were associated with these cancers.

Background:Early colorectal cancer (CRC) detection helps reduce the mortality rate. This study aimed to investigate colon lesions in individuals with positive and negative fecal immunochemical test (FIT) results among the (PERSIAN) Guilan cohort study (PGCS) population.Methods:This cross-sectional study was conducted on 1158 participants over 50 who were volunteers for the FIT stool test at the Endoscopy Department of Razi Hospital, Rasht, Iran, from 2021 to 2022. The FIT test was screened for all participants, and for 172 individuals (86 individuals from each group with positive and negative FIT results), a colonoscopy was performed to investigate the colon lesions. Demographic/clinical characteristics, FIT results, colonoscopy findings, and the Bristol Stool Chart were completed. All data were analyzed using SPSS Version 16, considering a significant level<0.05.Results:Out of 1,158 participants, 86 had positive FIT results, and 172 (52.3%) were females. The colonoscopy results showed that 34.3% of the patients had colon lesions. Individuals with positive FIT exhibited a significantly higher prevalence of colon lesions (p<0.001). No statistically significant differences were observed between positive and negative FIT results, demographic and clinical characteristics, and the location of lesions in individuals with colon lesions (p>0.05). Moreover, there was a significant difference in pathological findings and the presence of adenomatous polyps regarding the FIT results (p<0.001).Conclusion:The effectiveness of FIT in the initial stages of screening for early lesion detection is considerable, especially for individuals with upper age.

PurposeA substantial proportion of patients with colorectal cancer (CRC) present with iron deficiency anemia (IDA), and fecal immunochemical test (FIT) has proven to be an effective method for detecting the majority of CRC cases. A combination strategy of FIT results and IDA may be useful for risk stratification for detecting advanced colorectal neoplasia (ACRN). We compared the prevalence of ACRN among four groups stratified by FIT results and the presence of IDA.Materials and MethodsA cross-sectional study was performed on asymptomatic male participants who underwent both FIT and colonoscopy between 2010 and 2014 as part of a comprehensive health screening program in Korea.ResultsOf 17236 participants, 522 (3.0%) showed positive FIT results and 26 (0.2%) had IDA. The mean age of the study participants was 40.8 years. The participants were classified into four groups: positive FIT result/IDA (G1, n=7), positive FIT result/no IDA (G2, n=515), negative FIT result/IDA (G3, n=19), and negative FIT result/no IDA (G4, n=16695). The prevalences of ACRN in G1, G2, G3, and G4 were 28.6, 13.4, 5.3, and 1.5%, respectively (p<0.001) and those of CRC were 28.6, 1.6, 0.0, and 0.01%, respectively (p<0.001). Subjects with positive FIT results and IDA had an increased risk of ACRN and CRC in both group aged <50 and ≥50 years.ConclusionSubjects with positive FIT results and IDA had an increased risk of ACRN. Our results suggest that a combination strategy of FIT and IDA may be helpful in selecting and prioritizing asymptomatic men for colonoscopy.

Mo1177 Participation, FIT-Result and Yield in Three Rounds of Biannual FIT-Based Screening in the Netherlands

COVID-19: An Opportunity to Reimagine Colorectal Cancer Diagnostic Testing—A New Paradigm Shift

BACKGROUNDFaecal immunochemical test (FIT) has been recommended to assess symptomatic patients for colorectal cancer (CRC) detection. Nevertheless, some conditions could theoretically favour blood originating in proximal areas of the gastrointestinal tract passing through the colon unmetabolized. A positive FIT result could be related to other gastrointestinal cancers (GIC).AIMTo assess the risk of GIC detection and related death in FIT-positive symptomatic patients (threshold 10 μg Hb/g faeces) without CRC.METHODSPost hoc cohort analysis performed within two prospective diagnostic test studies evaluating the diagnostic accuracy of different FIT analytical systems for CRC and significant colonic lesion detection. Ambulatory patients with gastrointestinal symptoms referred consecutively for colonoscopy from primary and secondary healthcare, underwent a quantitative FIT before undergoing a complete colonoscopy. Patients without CRC were divided into two groups (positive and negative FIT) using the threshold of 10 μg Hb/g of faeces and data from follow-up were retrieved from electronic medical records of the public hospitals involved in the research. We determined the cumulative risk of GIC, CRC and upper GIC. Hazard rate (HR) was calculated adjusted by age, sex and presence of significant colonic lesion.RESULTSWe included 2709 patients without CRC and a complete baseline colonoscopy, 730 (26.9%) with FIT ≥ 10 µgr Hb/gr. During a mean time of 45.5 ± 20.0 mo, a GIC was detected in 57 (2.1%) patients: An upper GIC in 35 (1.3%) and a CRC in 14 (0.5%). Thirty-six patients (1.3%) died due to GIC: 22 (0.8%) due to an upper GIC and 9 (0.3%) due to CRC. FIT-positive subjects showed a higher CRC risk (HR 3.8, 95%CI: 1.2-11.9) with no differences in GIC (HR 1.5, 95%CI: 0.8-2.7) or upper GIC risk (HR 1.0, 95%CI: 0.5-2.2). Patients with a positive FIT had only an increased risk of CRC-related death (HR 10.8, 95%CI: 2.1-57.1) and GIC-related death (HR 2.2, 95%CI: 1.1-4.3), with no differences in upper GIC-related death (HR 1.4, 95%CI: 0.6-3.3). An upper GIC was detected in 22 (0.8%) patients during the first year. Two variables were independently associated: anaemia (OR 5.6, 95%CI: 2.2-13.9) and age ≥ 70 years (OR 2.7, 95%CI: 1.1-7.0).CONCLUSIONSymptomatic patients without CRC have a moderate risk increase in upper GIC, regardless of the FIT result. Patients with a positive FIT have an increased risk of post-colonoscopy CRC.

Fecal immunochemical test (FIT)-based screening has been recommended as an option for population colorectal cancer (CRC) screening. However, the studies on factors associated with false-positive FIT results are still limited. To identify the clinical and endoscopic factors associated with false-positive results of FIT for advanced neoplasia (AN) and to evaluate whether false-positive FIT results would be indicative of other digestive tract diseases. We prospectively enrolled 929 participants aged 50 years or older at Qilu Hospital of Shandong University between April 2020 and April 2021. The two-sample FIT was used in this study and ≥ 10 μg/g in either of two stool samples was regarded as the positive FIT result. All these participants underwent subsequent gastroscopy and colonoscopy. False positive FIT results were defined as positive FITs without AN detected in colonoscopies. With a cut-off value of 10 µg/g, the positive rate of FIT was 16.0%. For detecting AN, the sensitivity and specificity were 64.6% and 87.6%, respectively. After adjusting confounding factors, male (OR = 1.61; 95% CI, 1.05–2.48; P = 0.030), colorectal inflammation (OR = 2.99; 95% CI, 1.38–6.04; P = 0.003), presence of three or more non-advanced adenomas (OR = 1.78; 95% CI, 1.11–2.82; P = 0.015) and gastric cancer (OR = 11.33; 95% CI, 2.40–59.52; P = 0.002) were associated with higher risk of false-positive FIT results. Although the FIT results may be false-positive for detecting AN, they may still suggest medical issues that warrant closer medical follow-up and intervention. Meanwhile, routine upper endoscopy investigation for false positive patients was not recommended. Upper endoscopy may be considered conditionally in FIT-positive/AN-negative patients with additional risk factors. Large-scale research is required to clarify this issue. (ClinicalTrials.gov ID: NCT04454099) Trial identification number: ClinicalTrials.gov ID: NCT04454099 (URL: https://clinicaltrials.gov/ct2/show/NCT04454099) registered on July 1, 2020.

ObjectiveTo explore the performance of a protocol combining fecal immunochemical test (FIT) and a high-risk factor questionnaire (HRFQ) for selecting patients requiring colonoscopy as part of a population-based colorectal cancer (CRC) screening program in China.MethodsFrom 2015 to 2016, we conducted a CRC screening program for all residents aged 45 years or older in Tianhe District, Guangzhou City, China. Participants underwent an FIT and received an HRFQ as part of primary screening. Those with positive FIT and/or HRFQ results were considered to be at high risk and were recommended to undergo colonoscopy.ResultsA total of 10 074 subjects were recruited and enrolled in the screening program. In the enrolled population, 17.5% had positive FIT results and 19.4% had positive HRFQ results. Of those recommended to undergo diagnostic colonoscopy, 773 did so. The screening method’s overall positive predictive value (PPV) was 4.9% for non-adenomatous polyps, 11.4% for low-risk adenomas (LRAs), 15.9% for high-risk adenomas (HRAs) and 1.6% for CRC. The PPVs of positive FIT results for non-adenomatous polyps, LRAs, HRAs and CRC were 5.2%, 15.9%, 22.5% and 2.5%, respectively. The PPVs of positive HRFQ results for non-adenomatous polyps, LRA, HRA and CRC were 4.1%, 10.2%, 14.3% and 1.4%, respectively. The PPVs associated with combined positive FIT and HRFQ results for non-adenomatous polyps, LRAs, HRAs and CRC were 4.5%, 16.4%, 23.7% and 2.8%, respectively.ConclusionOur results suggest that this two-step CRC screening strategy, involving a combination of FIT and HRFQ followed by colonoscopy, is useful to identify early-stage CRC. The high detection rates and PPVs for CRC and adenomas encourage this strategy’s use in ongoing screening programs.

A combination of clinical risk stratification and fecal immunochemical test results to prioritize colonoscopy screening in asymptomatic participants

A Quarter of Participants With Advanced Neoplasia Have Discordant Results From 2-Sample Fecal Immunochemical Tests for Colorectal Cancer Screening

Purpose: Early-onset colorectal cancer (EOCRC) incidence is rising in a predominantly symptomatic population of young adults. Effective triage tools are needed to identify high-risk individuals in this relatively low incidence population. We examined fecal immunochemical test (FIT) use among adults ages &amp;lt;50 with red flag signs and symptoms for EOCRC and evaluated whether FIT use is predictive of EOCRC risk. Methods: Retrospective cohort study of US Veterans (ages 18-49) receiving Veterans Health Administration (VHA) care during 1999-2022 with a documented EOCRC red flag sign or symptom (abdominal distension, abdominal pain, anemia [non-specific and iron-deficiency], change in bowel habits, constipation, diarrhea, hematochezia, nausea/vomiting) based on International Classification of Diseases, 9th (ICD-9) or 10th (ICD-10) Revision codes, or lab results. The primary exposure was FIT uptake and result, documented via lab results, shown as a three-level variable (no FIT use, negative FIT or positive FIT). The primary outcome was EOCRC diagnosis, derived from linkages to the VA Oncology Domain and National Death Index. Covariates included age at symptom presentation, sex, race and ethnicity, and number of symptoms within 60 days of first symptom presentation. Participants entered the study at first symptom onset and were followed until the first of: incident or fatal EOCRC diagnosis, non-EOCRC-related death, 2 years follow-up, age 50 or December 31, 2022. We derived cumulative CRC incidence estimates using Kaplan-Meier estimation. Multivariable, mixed-effects Cox regression models were used to estimate adjusted hazard ratios (aHR) and 95% confidence intervals (CI) for CRC risk among those who received a FIT test. Results: Among 751,116 Veterans, 38,019 (5.1%) received a FIT. The most common symptoms yielding a FIT were abdominal pain (29.6%), anemia (20.4%), hematochezia (18.5%), and diarrhea (16.4%). Approximately 76% of patients who received a FIT had one symptom at presentation. Among 38,019 patients who received a FIT, 6,191 (16.3%) had a positive finding. Approximately 1,295 (21%) of 6,191 FIT-positive patients received a diagnostic colonoscopy compared to 46,693 (6.6%) of 713,097 non-FIT patients. After two years of follow-up, patients with a positive FIT had a 1.44% cumulative EOCRC incidence (95% CI: 1.12%-1.77%), compared to a 0.12% among those with a negative FIT (95% CI; 0.08%-0.16%) and 0.12% among those who did not receive a FIT (95% CI: 0.12%-0.13%). The findings correspond to an aHR for EOCRC of 12.81 (95% CI: 8.47-19.36) for FIT-positive patients compared to those with a negative FIT. Conclusions: Among adults ages 18-49 presenting with a red flag sign or symptom to VHA care, FIT use was low. However, a positive FIT result was linked to a substantially elevated EOCRC risk relative to a negative result. To address potential concerns about generalizability, future research should confirm whether systematic use of FIT as a clinical triage tool could help identify symptomatic adults at high EOCRC risk who need a diagnostic colonoscopy. Citation Format: Daniel Sabater Minarim, Kylie Morgan, Lin Liu, Matthew P. Banegas, Maria Elena Martinez, Samir Gupta, Josh Demb. FIT for red flag signs and symptoms of early onset colorectal cancer: low value or viable diagnostic tool? [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: The Rise in Early-Onset Cancers—Knowledge Gaps and Research Opportunities; 2025 Dec 10-13; Montreal, QC, Canada. Philadelphia (PA): AACR; Clin Cancer Res 2025;31(23_Suppl):Abstract nr PR014.

Introduction: The fecal immunochemical test (FIT) has been established as a cost-effective test in colon cancer screening programmes. This test could also be helpful in symptomatic patients prior to colonoscopy, but data about diagnostic performance, and accurate cut-off values for these patients are still scarce.Materials and Methods: Prospective study that included consecutive unselected patients with gastrointestinal symptoms referred for colonoscopy between November 2016 and June 2018. We performed a FIT (FOB Gold® test, cut-off 20 micrograms of Hb/gram of feces) prior to colonoscopy and determined the accuracy of FIT in terms of sensitivity, specificity, positive and negative predictive value for clinically significant pathology, advanced neoplasia, and colorectal cancer in symptomatic patients, using two different cut-off values.Results: A total of 727 patients (44.3% men, aged 58.5 ± 14.9 years) was included in the study. The main symptom was history of previous (non-active) rectal bleeding (34.7%), followed by diarrhea (15.0%). Over one quarter of the patients (25.9%) had a positive FIT result. The caecal intubation rate was 95.5%. Clinically significant pathology was identified in 142 colonoscopies (19.5%), advanced neoplasia in 115 (15.8%) and colorectal cancer in 36 colonoscopies (5.0%). FIT performed very well for clinically significant pathology, advanced neoplasia and cancer, with a high negative predictive value (NPV). Reducing the cut-off value to 10 μg/g yielded similar NPV results, with a decrease in specificity. Using a combination of symptoms with a positive FIT result did not improve FIT performance. Only specificity was slightly higher compared to FIT alone, but this was paralleled by a decrease in sensitivity and NPV for cancer and clinically significant pathology. The odds of presenting clinically significant pathology, advanced neoplasia, or cancer increased with FIT concentration.Conclusions: The specificity and NPV of FIT for clinically significant pathology, advanced neoplasia, and cancer are high in symptomatic patients. FIT is a helpful test for determining the need to perform further studies. It may not be necessary to reduce the cut-off value for symptomatic patients, since FIT performance with the current standard cut-off value used in colorectal cancer screening was accurate. FIT can be used to avoid or prioritize colonoscopy procedures.

The National Cancer Screening Program of Korea provides an annual fecal immunochemical test (FIT) for adults aged ≥50 years. We evaluated the diagnostic performance of colonoscopy and the prevalence ratio (PR) of advanced neoplasia (AN) in participants with positive FIT results under the National Cancer Screening Program between 2007 and 2024. The PR of AN was compared between binary groups created based on age, sex, waiting time to colonoscopy, FIT cutoff value, and anemia. Among the 2445 participants with positive FIT results, 1237 (50.6%) underwent colonoscopy. The positive predictive values for non-AN, AN, and sessile serrated lesions were 31.2%, 15.4%, and 14.6%, respectively. The PR of AN was 1.8 times higher in males than in females (P < .001) and 1.9 times higher in the standard FIT cutoff group than in the low FIT cutoff group (P < .001). In the multivariable analysis, male sex (PR = 1.84, 95% confidence interval: 1.36–2.50) and FIT positivity based on the standard cutoff (PR = 1.86, 95% confidence interval: 1.33–2.61) were significantly associated with AN (both P < .001). ANs were more frequently detected in male participants and when the standard FIT cutoff value was used in FIT-based colorectal cancer screening. Given the low colonoscopy completion rate of only 50.6%, colonoscopy completion should be recommended, particularly for male participants and those with positive FIT results based on the standard cutoff value.

High vacuum plant for electron microscope preparation