Faecal immunochemical test to triage patients with possible colorectal cancer symptoms: meta-analysis

Unlocking Early Cancer Detection: Exploring Biomarkers, Circulating DNA, and Innovative Technological Approaches

Research and development improvements in early cancer diagnosis have had a significant positive impact on health. In the treatment and prevention of cancer, early detection is essential. In this context, biomarkers are essential because they offer important information on the state of cells at any particular time. Cells go through unique changes when they shift from a healthy condition to a malignant state, changes that appropriate biomarkers may pick up. Recent advancements have been made to identify and characterize circulating cancer-specific mutations in cell-free circulating DNA derived from tumors and tumor cells. A patient's delay between the time they first detect symptoms and the time they contact a doctor has been noted for many cancer forms. The tumor's location and features significantly impact the presentation of symptoms judged appropriate for early diagnosis. Lack of knowledge of the severity of the symptoms may be one cause for this delay. Our review is largely focused on the ongoing developments of early diagnosis in the study of biomarkers, circulating DNA for diagnosis, the biology of early challenges, early symptoms, liquid biopsies, detectable by imaging, established tumor markers, plasma DNA technologies, gender differences, and artificial intelligence (AI) in diagnosis. This review aims to determine and evaluate Indicators for detecting early cancer, assessing medical conditions, and evaluating potential risks. For Individuals with a heightened likelihood of developing cancer or who have already been diagnosed, early identification is crucial for enhancing prognosis and raising the likelihood of effective treatment.

Sociodemographic variations in the uptake of faecal immunochemical tests in primary care: a retrospective study

BACKGROUND

Faecal immunochemical test (FIT) usage for symptomatic patients is increasing, but variations in use caused by sociodemographic factors are unknown. A clinical pathway for colorectal cancer (CRC) was introduced in primary care for symptomatic patients in November 2017. The pathway was commissioned to provide GPs with direct access to FITs.

AIM

To identify whether sociodemographic factors affect FIT return in symptomatic patients.

DESIGN AND SETTING

A retrospective study was undertaken in Nottingham, UK, following the introduction of FIT as triage tool in primary care. It was mandated for all colorectal referrals (except rectal bleeding or mass) to secondary care. FIT was used, alongside full blood count and ferritin, to stratify CRC risk.

METHOD

All referrals from November 2017 to December 2021 were retrospectively reviewed. Sociodemographic factors affecting FIT return were analysed by multivariate logistic regression.

RESULTS

A total of 35 289 (90.7%) patients returned their index FIT, while 3631 (9.3%) did not. On multivariate analysis, males were less likely to return an FIT (odds ratio [OR] 1.11, 95% confidence interval [CI] = 1.03 to 1.19). Patients aged ≥65 years were more likely to return an FIT (OR 0.78 for non-return, 95% CI = 0.72 to 0.83). Unreturned FIT more than doubled in the most compared with the least deprived quintile (OR 2.20, 95% CI = 1.99 to 2.43). Patients from Asian (OR 1.82, 95% CI = 1.58 to 2.10), Black (OR 1.21, 95% CI = 0.98 to 1.49), and mixed or other ethnic groups (OR 1.29, 95% CI = 1.05 to 1.59) were more likely to not return an FIT compared with patients from a White ethnic group. A total of 599 (1.5%) CRCs were detected; 561 in those who returned a first FIT request.

CONCLUSION

FIT return in those suspected of having CRC varied by sex, age, ethnic group, and socioeconomic deprivation. Strategies to mitigate effects on FIT return and CRC detection should be considered as FIT usage expands.

Understanding colorectal cancer risk for symptomatic patients in primary care: A cohort study utilising faecal immunochemical tests and blood results in England

BACKGROUND

A faecal immunochemical tests (FIT) cut-off of ≥10 μg Hb/g faeces is now recommended in the UK as a gateway to urgent (suspected cancer) investigation for colorectal cancer (CRC), based on an expected CRC risk threshold of 3%.

AIMS

To quantify the risk of CRC at FIT cut-offs by age, haemoglobin and platelet strata.

METHODS

A cohort study of a symptomatic CRC pathway based on primary care FIT tests in Nottingham, UK (November 2017-2021) with 1-year follow-up. Heat maps showed the cumulative 1-year CRC risk using Kaplan-Meier estimates.

RESULTS

In total, 514 (1.5%) CRCs were diagnosed following 33,694 index FIT requests. Individuals with a FIT ≥ 10 μg Hb/g faeces had a >3% risk of CRC, except patients under the age of 40 years (CRC risk 1.45% [95% CI: 0.03%-2.86%]). Non-anaemic patients with a FIT < 100 μg Hb/g faeces had a CRC risk of <3%, except those between the age of 70 and 85 years (5.26% 95% CI: 2.72%-7.73%). Using a ≥3% CRC threshold in patients <55 years calculated using FIT, age and anaemia might allow 160-220 colonoscopies per 10,000 FITs to be re-purposed, at a cost of missing 1-2 CRCs.

CONCLUSIONS

FIT alone with a single cut-off is unlikely to be a panacea for optimising CRC diagnosis, as risk varies by FIT, age and anaemia when faecal haemoglobin levels are below 100 μg Hb/g. Tailored FIT cut-offs for investigation on a CRC pathway could reduce the number of investigations needed at a 3% CRC risk threshold.

Performance of the fecal immunochemical test for colorectal cancer and advanced neoplasia in individuals under age 50

The increased demand for colonoscopy combined with increased incidence of colorectal cancer (CRC) among younger populations presents a need to determine FIT performance among individuals in this age group. We conducted a systematic review to assess test performance characteristics of FIT in detecting CRC and advanced neoplasia in younger age populations. A search through December 2022 identified published articles assessing the sensitivity and specificity of FIT for advanced neoplasia or CRC among populations under age 50. Following the search, 3 studies were included in the systematic review. Sensitivity to detect advanced neoplasia ranged from 0.19 to 0.36 and specificity between 0.94 and 0.97 and the overall sensitivity and specificity were 0.23 (0.17-0.30) and 0.96 (0.94-0.98), respectively. Two studies that assessed these metrics in multiple age categories found similar sensitivity and specificity across all age groups 30-49. Sensitivity and specificity to detect CRC was assessed in one study and found no significant differences by age groups. These results suggest that FIT performance may be lower for younger individuals compared to those typically screened for CRC. However, there were few studies available for analysis. Given increasing recommendations to expand screening in younger age groups, more research is needed to determine whether FIT is an adequate screening tool in this population.

Role of the faecal immunochemical test in patients with risk-stratified suspected colorectal cancer symptoms: A systematic review and meta-analysis to inform the ACPGBI/BSG guidelines

Background

The UK National Institute for Health and Care Excellence (NICE), recommended in 2017 the use of the faecal immunochemical test (FIT) to guide investigations in patients presenting with NICE-defined low-risk symptoms suspicious for colorectal cancer (CRC). At that time, NICE did not recommend FIT use for high-risk symptoms. This is the first systematic review to evaluate the diagnostic accuracy of FIT in NICE-defined high and low-risk symptoms and was designed to inform the joint ACPGBI/BSG guidelines.

Methods

We performed a systematic literature review and meta-analysis. PROSPERO registration number CRD42021224674. Medline and EMBASE databases were searched from inception to 31st March 2022. We included studies recruiting adult patients presenting with suspected CRC symptoms in whom FIT was performed and diagnostic accuracy data for CRC detection could be derived at a limit of detection (LoD) and/or 10 µg haemoglobin/gram faeces threshold in four commonly used analysers. FIT performance was assessed for high-risk, low-risk and individual symptoms where possible. Bivariate meta-analysis was performed where study numbers allowed.

Findings

Thirty-one studies (79566 patients) met inclusion criteria. At 10 µg/g, for "all symptoms" (n = 35,945) sensitivity and specificity were 91.0% (95% CI: 88.9, 92.7) and 75.2% (95% CI: 69.6, 80.1); for "high-risk" symptoms (n = 18,264), 88.7% (95% CI: 84.4, 92.0) and 78.5% (95% CI: 73.0, 83.2); and for "low-risk" symptoms (n = 2161), 88.7% (95% CI: 78.1, 95.3) and 88.5% (95% CI: 87.1, 89.9), respectively. At LoD, for "all symptoms" (n = 26,056) sensitivity and specificity were 94.7% (95% CI: 90.5, 97.1) and 66.5% (95% CI: 58.7, 73.6); for "high-risk" symptoms (n = 16,768), 92.8% (95% CI: 86.4, 96.3) and 70.3% (95% CI: 66.5, 73.8); and for "low-risk" symptoms (n = 2082), 94.7% (95% CI: 85.4, 98.9) and 71.9% (95% CI: 69.9, 73.9), respectively. Summary estimates were similar across different analysers.

Interpretation

FIT sensitivity for CRC detection is maximised at the LoD; its performance is similar in high and low-risk symptoms, and across different analysers where a common threshold is used. FIT performance for CRC detection is adequate and transferrable to clinical diagnostic pathways.

Funding

This review was part-funded by NHS England awarded to RM Partners. RB and RC were funded by research fellowships awarded by Croydon University Hospital.

Introduction of an integrated primary care faecal immunochemical test referral pathway for patients with suspected colorectal cancer symptoms

AIM

To determine the efficacy of a new 2-week wait pathway that uses the faecal immunochemical test (FIT) in primary care to triage patients with high and low risk symptoms suspicious of colorectal cancer (CRC). This service improvement pilot follows 2017 National Institute for Health and Care Excellence guidance, that recommended using FIT to guide referral of patients with low risk, but not high risk symptoms, which continue to be referrred on the 2-week pathway.

METHOD

Patients with high- and low-risk CRC symptoms were tested with FIT and those with faecal haemoglobin (f-Hb) ≥9.5 μg haemoglobin/g faeces (hereafter μg/g) were referred to secondary care. Results were tracked and primary care prompted to refer if timely referral was not made.

RESULTS

Between December 2019 and October 2020, 5672 patients presented to primary care with high and/or low risk symptoms warranting investigations. Of these, 622 (11%) patients were referred without a FIT, of whom 36 (5.8%) had CRC. The remaining 5050 patients had a FIT, of which 4187 (83%) were processed to produce a quantitative result. Of these, 1085 patients (25.9%) had an f-Hb ≥9.5 μg/g and of those, 982 patients (90.5%) were referred and 56 (5.7%) had CRC. A total of 3102 patients (74.1%) had an f-Hb <9.5 μg/g, of which 456 (14.7%) were referred and three (0.7%) had CRC. A total of 97 cancers were diagnosed with a cancer prevalence of 1.7%.

CONCLUSION

A 2-week wait pathway incorporating FIT as a triage tool can be implemented successfully in primary care to identify symptomatic patients at highest risk of CRC.

The impact of COVID-19 pandemic in the diagnosis and management of colorectal cancer patients

The novel coronavirus disease 2019 (COVID-19) pandemic has posed an unprecedented challenge to healthcare systems worldwide, causing downscaling of almost all other activities, especially in its early stages. Currently, the availability of vaccines along with the spread of new viral variants has modified the epidemiology of the disease, and the previous activity is being gradually resumed in most healthcare facilities. In this review, we have summarized the influence of the COVID-19 pandemic in the diagnosis and management of colorectal cancer (CRC) patients. Population-based screening with either colonoscopy or fecal occult blood tests has proven to reduce CRC incidence and mortality, so screening programs have been implemented in most western countries. However, during the first COVID-19 wave, most of these programs had to be disrupted temporarily. In this review, we have thoroughly analyzed the consequences of these disruptions of screening programs as well as of the forced delays in diagnostic and therapeutic services on CRC prognosis, although its exact impact cannot be exactly measured yet. In any way, strategies to minimize its effect, such as catch-up strategies expanding the colonoscopy capacity or using fecal occult blood concentration and other risk factors to prioritize patients, are urgently needed. The COVID-19 pandemic has also led to a change in CRC patient presentation, with an overall temporary decreased incidence due to postponed diagnoses, but with more patients presenting in need of an emergency admission or with symptoms. Finally, changes in treatment approaches in CRC patients have been reported during the pandemic, namely a drop in the proportion of laparoscopic surgeries or a rise in short-term radiotherapy courses. We have therefore aimed to summarize the available evidence to guide the healthcare professionals treating CRC patients to choose the best treatment options in the current pandemic situation.

A cohort study of duplicate faecal immunochemical testing in patients at risk of colorectal cancer from North-West England

OBJECTIVES

We sought to investigate if duplicate faecal immunochemical testing (FIT) sampling improves the negative and positive predictive value of patients thought to be at risk of colorectal cancer (CRC). Specifically, we aimed to investigate whether the proportion of FIT-negative CRC missed by a single FIT test in symptomatic patients could be reduced by duplicate FIT testing.

DESIGN

A retrospective service evaluation cohort study of the diagnostic accuracy of duplicate FIT testing.

SETTING

Patients referred from primary care with suspected CRC to four secondary care trusts in North-West England.

PARTICIPANTS

28 622 patients over 18-years-old with lower gastrointestinal symptoms suggestive of CRC who completed two FIT samples.

PRIMARY AND SECONDARY OUTCOME MEASURES

The performance of duplicate FIT for detecting CRC at a threshold of 10 µgHb/g.

RESULTS

The sensitivity if either test was >10 µgHb/g was 0.978 (0.955-0.989), specificity was 0.662 (0.657-0.668), positive predictive value 0.031 (0.028-0.035) and negative predictive value 1.00 (0.999-1.00). Despite two-thirds of patients (18952) being negative following two tests, at this threshold only seven CRC were missed over a 26-month period. All seven patients had other high-risk features which should have prompted investigation.

CONCLUSIONS

This study suggests that in routine NHS practice, a duplicate FIT sample strategy together with clinical evaluation for evidence of anaemia and weight loss is superior to a single FIT sample alone and would allow symptomatic patients to be managed in primary care without the need for urgent referral to secondary care for urgent colonic imaging.