Optimizing the colorectal cancer screening programme using faecal immunochemical test (FIT) in Flanders, Belgium from the “interval cancer” perspective

Background Interval cancer (IC) is a critical issue in colorectal cancer (CRC) screening. We identified factors associated with ICs after faecal immunochemical test (FIT) screening and explored the impact of lowering FIT cut-off or shortening screening interval on FIT-ICs in Flanders. Methods FIT participants diagnosed with a CRC during 2013–2018 were included. Factors associated with FIT-ICs were identified using logistic regression. Distributions of FIT results among FIT-ICs were examined. Results In total, 10,122 screen-detected CRCs and 1534 FIT-ICs were included (FIT-IC proportion of 13%). FIT-ICs occurred more frequently in women (OR 1.58 [95% CI 1.41–1.76]) and ages 70–74 (OR 1.35 [1.14–1.59]). FIT-ICs were more often right-sided (OR 3.53 [2.98–4.20]), advanced stage (stage IV: OR 7.15 [5.76–8.88]), and high grade (poorly/undifferentiated: OR 2.57 [2.08–3.18]). The majority (83–92%) of FIT-ICs would still be missed if FIT cut-off was lowered from 15 to 10 µg Hb/g or screening interval was shortened from 2 to 1 year. Conclusions FIT-ICs were more common in women, older age, right-sided location, advanced stage and high grade. In Flanders, lowering FIT cut-off (to 10 µg Hb/g) or shortening screening interval (to 1 year) would have a minimal impact on FIT-ICs.

Odds of Incomplete Colonoscopy in Colorectal Cancer Screening Based on Socioeconomic Status

The aim of this study is to investigate the association between socioeconomic status (SES) and the risk of having an incomplete colonoscopy (IC) in the Danish Colorectal Cancer (CRC) Screening Program. In this register-based study we included 71,973 participants who underwent colonoscopy after a positive fecal immunochemical test in the Danish CRC Screening Program. The main exposure, SES, was defined by income and education, and the outcome by complete or incomplete colonoscopy. Among the participants, 5428 (7.5%) had an incomplete colonoscopy. The odds ratio (OR) for ICs due to inadequate bowel preparation was 1.67 (95% CI: 1.46; 1.91) for income in the 1 quartile compared to income in the 4th quartile. ORs for income in the 2nd quartile was 1.38 (95% CI: 1.21; 1.56) and 1.17 (95% CI: 1.03; 1.33) for income in the 3rd quartile. For the educational level, an association was seen for high school/vocational education with an OR of 0.87 (95% CI: 0.79; 0.97) compared to higher education. For ICs due to other reasons, the level of income was associated with the risk of having an IC with an OR of 1.19 (95% CI: 1.05; 1.35) in the 1st quartile and an OR of 1.19 (95% CI: 1.06; 1.34) in the 2nd quartile. For the educational level, there were no significant associations. Low income is associated with high risk of having an IC, whereas educational level does not show the same unambiguous association.

Persistent Barriers to Colorectal Cancer Screening Completion Amid Centralized Outreach: A Mixed Methods Study

Purpose To understand patient experiences and persistent barriers to colorectal cancer (CRC) screening amid centralized outreach at urban family medicine practices. Approach Following a pragmatic trial assessing mailed fecal immunochemical test (FIT) outreach, we invited a subset of participants to complete a semi-structured qualitative interview and structured questionnaire. Setting Single urban academic healthcare system. Participants Sixty patients who were eligible and overdue for CRC screening at the time of trial enrollment. Method Using Andersen’s Behavioral Model, we developed an interview guide to systematically assess factors shaping screening decisions and FIT uptake. Close-ended responses were analyzed using descriptive statistics. Qualitative data were analyzed using the constant comparative method. Results Most participants (82%) self-reported that they had ever completed any modality of CRC screening, and nearly half (43%) completed the mailed FIT during the trial. Most patients (60%) preferred FIT to colonoscopy due to its private, convenient, and non-invasive nature; however, persistent barriers related to screening beliefs including fear of test results and cancer treatment still prevented some patients from completing any form of CRC screening. Conclusions Mailed FIT can overcome many structural barriers to CRC screening, yet clear communication and follow-up amid centralized outreach are essential. For some patients, tailored outreach or navigation to address screening-related fears or other screening beliefs may be needed to ensure timely completion of CRC screening.

Faecal calprotectin is not necessarily required as a screen for significant bowel disease in primary care

Objective NICE recommends measurement of faecal haemoglobin (f-Hb) using faecal immunochemical test (FIT) when colorectal cancer is suspected and calprotectin (f-Cal) in the context of inflammatory bowel disease, though neither is disease specific. During the COVID-19 pandemic, f-Hb has been a requirement prior to referral for endoscopy in England; f-Cal is often performed simultaneously. The aim of this study was to investigate test performance of both tests for significant bowel disease in those patients referred. Design All adult patients with simultaneous measurements of f-Hb and f-Cal between April 2019 and September 2020 were included. For those referred, outcomes were determined from clinical records. Results 650 patients with simultaneous samples for f-Hb an f-Cal were managed in Primary Care; 319 patients were referred to hospital; SBD was found in 32 (10.0%) (CRC 5, high risk adenomas 5, IBD 22). At a cut-off of 10 μg/g for f-Hb and 200 μg/g for f-Cal, the sensitivity, specificity and negative predictive value for diagnosis of SBD were 84.4%, 58.2% and 96.7% and 68.8%, 89.6% and 95.7%, respectively. Performance of both tests would have enabled diagnosis of two more cases of significant, but non-malignant, bowel disease but required over 4% more referrals for investigation. Conclusion Use of FIT has become established to assist prioritisation of patients for referral from Primary Care. Whilst introduced specifically for CRC, FIT performs well as a rule out for IBD in Primary Care and the use of f-Cal is not required.

Combining the quantitative faecal immunochemical test and full blood count reliably rules out colorectal cancer in a symptomatic patient referral pathway

Purpose Faecal Immunochemical Test (FIT) has proven utility for Colorectal Cancer (CRC) detection in symptomatic patients. Most studies have examined FIT in symptomatic patients subsequently referred from primary care. We investigated associations between CRC and FIT in both referred and non-referred symptomatic patients. Methods A retrospective, observational study of all patients with a FIT submitted Aug 2018 to Jan 2019 in NHS GG&C was performed. Referral to colorectal/gastroenterology and decision to perform colonoscopy were recorded. FIT results were grouped as f-Hb < 10/10–149/150–399/ ≥ 400 μg/g. The MCN cancer registry identified new cases of CRC. Covariables were compared using the χ2 test. Multivariate binary logistic regression identified independent predictors of CRC. Results A total of 4968 patients were included. Raised FIT correlated with decision to refer (p < 0.001) and scope (p < 0.001). With 23-month median follow-up, 61 patients were diagnosed with CRC. These patients were older (median 69 vs 59 years, cancer and no cancer respectively, p = 0.001), more likely to be male (55.7% vs 42.1%, p = 0.033), and to report rectal bleeding (51.7% vs 36.1%, p = 0.013). FIT (< 10 µg/g 8.2% vs 76.7% and ≥ 400 µg/g 55.7% vs 3.8%, p < 0.001) and anaemia (45.9% vs 19.7%, p < 0.001) were associated with CRC. On multivariate analysis, age (p = 0.023), male sex (p = 0.04), FIT (≥ 400 OR 54.256 (95% CI:20.683–142.325; p < 0.001)), and anaemia (OR 1.956 (1.071–3.574; p = 0.029)) independently predicted CRC. One patient (0.04%) with a negative FIT and normal haemoglobin had CRC. Conclusion GP referral and secondary care investigation patterns were influenced by FIT. The combination of normal Hb and f-Hb excluded CRC in 99.96% of cases, providing excellent reassurance to those prioritising access to endoscopy services.

Faecal immunochemical test for patients with ‘high-risk’ bowel symptoms: a large prospective cohort study and updated literature review

Background We evaluated whether faecal immunochemical testing (FIT) can rule out colorectal cancer (CRC) among patients presenting with ‘high-risk’ symptoms requiring definitive investigation. Methods Three thousand five hundred and ninety-six symptomatic patients referred to the standard urgent CRC pathway were recruited in a multi-centre observational study. They completed FIT in addition to standard investigations. CRC miss rate (percentage of CRC cases with low quantitative faecal haemoglobin [f-Hb] measurement) and specificity (percentage of patients without cancer with low f-Hb) were calculated. We also provided an updated literature review. Results Ninety patients had CRC. At f-Hb < 10 µg/g, the miss rate was 16.7% (specificity 80.1%). At f-Hb < 4 µg/g, the miss rate was 12.2% (specificity 73%), which became 3.3% if low FIT plus the absence of anaemia and abdominal pain were considered (specificity 51%). Within meta-analyses of 9 UK studies, the pooled miss rate was 7.2% (specificity 74%) for f-Hb < 4 µg/g. Discussion FIT alone as a triage tool would miss an estimated 1 in 8 cases in our study (1 in 14 from meta-analysis), while many people without CRC could avoid investigations. FIT can focus secondary care diagnostic capacity on patients most at risk of CRC, but more work on safety netting is required before incorporating FIT triage into the urgent diagnostic pathway.