Faecal immunochemical tests (FIT) can help to rule out colorectal cancer in patients presenting in primary care with lower abdominal symptoms: a systematic review conducted to inform new NICE DG30 diagnostic guidance

Abstract

BackgroundThis study has attempted to assess the effectiveness of quantitative faecal immunochemical tests (FIT) for triage of people presenting with lower abdominal symptoms, where a referral to secondary care for investigation of suspected colorectal cancer (CRC) is being considered, particularly when the 2-week criteria are not met.MethodsWe conducted a systematic review following published guidelines for systematic reviews of diagnostic tests. Twenty-one resources were searched up until March 2016. Summary estimates were calculated using a bivariate model or a random-effects logistic regression model.ResultsNine studies are included in this review. One additional study, included in our systematic review, was provided as ‘academic in confidence’ and cannot be described herein.When FIT was based on a single faecal sample and a cut-off of 10 μg Hb/g faeces, sensitivity estimates indicated that a negative result using either the OC-Sensor or HM-JACKarc may be adequate to rule out nearly all CRC; the summary estimate of sensitivity for the OC-Sensor was 92.1% (95% confidence interval, CI 86.9–95.3%), based on four studies (n = 4091 participants, 176 with CRC), and the only study of HM-JACKarc to assess the 10 μg Hb/g faeces cut-off (n = 507 participants, 11 with CRC) reported a sensitivity of 100% (95% CI 71.5–100%). The corresponding specificity estimates were 85.8% (95% CI 78.3–91.0%) and 76.6% (95% CI 72.6–80.3%), respectively.When the diagnostic criterion was changed to include lower grades of neoplasia, i.e. the target condition included higher risk adenoma (HRA) as well as CRC, the rule-out performance of both FIT assays was reduced.ConclusionsThere is evidence to suggest that triage using FIT at a cut-off around 10 μg Hb/g faeces has the potential to correctly rule out CRC and avoid colonoscopy in 75–80% of symptomatic patients.Systematic review registrationPROSPERO 42016037723Electronic supplementary materialThe online version of this article (doi:10.1186/s12916-017-0944-z) contains supplementary material, which is available to authorized users.

Service evaluation of faecal immunochemical testing and anaemia for risk stratification in the 2‐week‐wait pathway for colorectal cancer

“…NICE evaluation has suggested a cut-off of 10 μg Hb/g faeces for low-risk patients 16 , but symptomatic patients may have colorectal cancer despite fHb readings below this level: 12⋅5 per cent of all colorectal cancers detected in the present cohort. This study population includes higher-risk patients than the low-risk patients referred to in the guidance.…”

“…In this context, new NICE guidance (NG12) that broadened referral criteria and aimed to ‘rule in’ more low‐risk patients by utilizing occult blood testing was seen as a double‐edged sword in many quarters. NG12 did not specify the type of occult blood testing that should be used; however, studies have suggested that faecal immunochemical testing (FIT) might be useful in symptomatic pathways and potentially more accurate than symptoms alone in predicting which patients need investigation for cancer.…”

Setting up a service for a faecal immunochemical test for haemoglobin (FIT): a review of considerations, challenges and constraints

“…The review group report was published (DG30) in 20174 and concluded that there was sufficient evidence to advocate triage of symptomatic patients using faecal haemoglobin concentration (f-Hb) at a cut-off of 10 µg Hb/g faeces and that this had the potential to correctly rule out CRC and avoid colonoscopy in 75%–80% of cases. The evidence reviewed in order to propose this cut-off of 10 µg Hb/g faeces is documented in the systematic review, which followed the publication of the DG30 guideline 5. The publication of DG30 led to an update of the 2015 NG12 guideline that now recommends that the DG30 guidance should be followed for patients at low risk of CRC using FIT; the references to gFOBT have been eliminated 2.…”

“…The publication of DG30 led to an update of the 2015 NG12 guideline that now recommends that the DG30 guidance should be followed for patients at low risk of CRC using FIT; the references to gFOBT have been eliminated 2. Since the systematic review of Westwood et al 5 there have been a small number of further publications on this topic and these have been reviewed recently6 7 …”

The contribution of a negative colorectal screening test result to symptom appraisal and help‐seeking behaviour among patients subsequently diagnosed with an interval colorectal cancer

“…Similarly, finding effective ways to engage with screening participants that complement existing initiatives in primary care with regard to symptom vigilance and prompt help‐seeking behaviour remains an important challenge; there is a need to develop nuanced health messages to inform screening participants of the importance of help‐seeking for vague as well as alarm symptoms following a negative test result, particularly in the presence of comorbidities. The use of FIT as a diagnostic tool in primary should allow more streamlined diagnostic pathways for all patients …”