Faecal calprotectin in patients with suspected colorectal cancer: a diagnostic accuracy study

Fecal Arachidonic Acid: A Potential Biomarker for Inflammatory Bowel Disease Severity

Arachidonic acid levels are elevated in the colonic mucosa of patients with inflammatory bowel disease (IBD). Fecal metabolites are emerging as valuable diagnostic tools for IBD. This study aimed to investigate associations between 31 fecal fatty acids, including arachidonic acid, to identify potential correlations with disease severity. Among the 31 fatty acids analyzed in feces, dihomo-γ-linolenic acid, arachidonic acid, and adrenic acid were significantly increased in patients with IBD compared to controls. In contrast, levels of linoleic acid and γ-linolenic acid, the precursors of arachidonic acid, were similar between both groups. No significant differences in fatty acid levels were observed between patients with Crohn's disease and ulcerative colitis. Arachidonic acid and adrenic acid levels positively correlated with fecal calprotectin, a clinically established marker of IBD severity, but showed no association with stool consistency or the Gastrointestinal Symptom Rating Scale. This suggests that these fatty acids are linked to disease severity rather than disease-related symptoms. Current IBD-specific medications had no significant impact on the fecal levels of any of the 31 fatty acids. In summary, this study demonstrates elevated fecal levels of dihomo-γ-linolenic acid, arachidonic acid, and adrenic acid in IBD patients. Normal levels of precursor fatty acids suggest that impaired downstream metabolism may contribute to the accumulation of these n-6 polyunsaturated fatty acids.

Review article: Contemporary management of gastrointestinal, pancreatic and hepatic toxicities of immune checkpoint inhibitors

BACKGROUND

Immune checkpoint inhibitors (ICIs) are effective oncologic agents which frequently cause immune-related adverse events (irAEs) which can impact multiple organ systems. Onco-Gastroenterology is a novel and emerging subspecialty within gastroenterology focused on cancer treatment-related complications. Gastroenterologists must be prepared to identify and manage diverse immune-mediated toxicities including enterocolitis, hepatitis, pancreatitis and other ICI-induced toxicities.

AIM

To provide a narrative review of the epidemiology, diagnostic evaluation and management of checkpoint inhibitor-induced gastrointestinal and hepatic toxicities.

METHODS

We searched Cochrane and PubMed databases for articles published through August 2023.

RESULTS

Gastrointestinal and hepatic irAEs include most commonly enterocolitis and hepatitis, but also pancreatitis, oesophagitis, gastritis, motility disorders (gastroparesis) and other rarer toxicities. Guidelines from the National Comprehensive Cancer Network, American Society of Clinical Oncology and European Society for Medical Oncology, in combination with emerging cohort and clinical trial data, offer strategies for management of ICI toxicities. Evaluation of irAEs severity by formal classification and clinical stability, and a thorough workup for alternative etiologies which may clinically mimic irAEs underlie initial management. Treatments include corticosteroids, biologics and other immunosuppressive agents plus supportive care; decisions on dosing, timing and choice of steroid adjuncts and potential for subsequent checkpoint inhibitor dosing are nuanced and toxicity-specific.

CONCLUSIONS

Expanding clinical trial and cohort data have clarified the epidemiology and clinical characteristics of gastrointestinal, pancreatic and hepatic toxicities of ICIs. Guidelines, though valuable, remain based principally on retrospective cohort data. Quality prospective, controlled studies may refine algorithms for treatment and potential immunotherapy rechallenge.

Anti-integrin αvβ6 autoantibodies are a potential biomarker for ulcerative colitis-like immune checkpoint inhibitor-induced colitis

BACKGROUND

No specific biomarker for immune checkpoint inhibitor (ICI)-induced colitis has been established. Previously, we identified anti-integrin αvβ6 autoantibodies in >90% of patients with ulcerative colitis (UC). Given that a subset of ICI-induced colitis is similar to UC, we aimed to clarify the relationship between such autoantibodies and ICI-induced colitis.

METHODS

Serum anti-integrin αvβ6 autoantibody levels were compared between 26 patients with ICI-induced colitis and 157 controls. Endoscopic images of ICI-induced colitis were centrally reviewed. Characteristics of anti-integrin αvβ6 autoantibodies in the ICI-induced colitis patients were compared with those of UC patients.

RESULTS

Anti-integrin αvβ6 autoantibodies were found in 8/26 (30.8%) patients with ICI-induced colitis and 3/157 (1.9%) controls (P < 0.001). Patients with anti-integrin αvβ6 autoantibodies had significantly more typical UC endoscopic features than those without the autoantibodies (P < 0.001). Anti-integrin αvβ6 autoantibodies in ICI-induced colitis patients were associated with grade ≥3 colitis (P = 0.001) and steroid resistance (P = 0.005). Anti-integrin αvβ6 autoantibody titers correlated with ICI-induced colitis disease activity. Anti-integrin αvβ6 autoantibodies of ICI-induced colitis exhibited similar characteristics to those of UC.

CONCLUSIONS

Anti-integrin αvβ6 autoantibodies may serve as potential biomarkers for the diagnosis, classification, risk management, and monitoring the disease activity, of ICI-induced colitis.

Colorectal cancer in symptomatic patients: How to improve the diagnostic pathway

Even in countries with national screening programmes for colorectal cancer, most cancers are identified after the patient has developed symptoms. The patients present these symptoms usually to primary care, or in some countries to specialist care. In either healthcare setting, the clinician has to consider cancer to be a possibility, then to perform triage investigations, followed by definitive investigation, usually by colonoscopy. This apparently simple pathway is not simple: most symptoms of colorectal cancer are more likely to represent benign disease than cancer, and each of these stages represents selection of patients into a higher-risk pool. This article summarises a symptom-based approach to selection and initial investigation of such patients in primary care. Some special groups need particular attention, including the younger patient, those with an inherited predisposition to cancer, and those with co-morbidities.

Fecal Calprotectin in Gastrointestinal Disease

BACKGROUND

Inflammatory bowel disease (IBD) comprises a group of chronic conditions characterized by relapsing and remitting inflammation of the gastrointestinal tract. The incidence is increasing worldwide, and the therapeutic options for management are expanding. Endoscopy is the gold standard investigation for diagnosis of IBD and for assessing mucosal healing, which is increasingly being used as a measure of disease control. However, it is an invasive procedure that is unpleasant for patients and expensive and time-consuming for hospitals. Fecal calprotectin has been shown to be an accurate surrogate marker of gastrointestinal inflammation in IBD.

CONTENT

Fecal calprotectin was initially used for the diagnosis of IBD but is now recognized as having a role in assisting in assessment of disease activity, prediction of relapse, and informing decisions around therapy and may help to minimize requirement for endoscopy. However, there are various preanalytical and analytical factors that can affect interpretation of the results; these need to be understood to optimize clinical care.

SUMMARY

Preanalytical and analytical factors that can potentially influence fecal calprotectin concentrations are examined, and an overview is provided of clinical situations in which fecal calprotectin is commonly measured.

The usefulness of fecal hemoglobin and calprotectin tests in diagnosing significant bowel diseases: a prospective study

OBJECTIVES

Although colonoscopy remains the gold standard for determining bowel diseases, it's invasive and expensive. New non-invasive diagnostic methods are urgently needed as an initial screening modality. We aimed to investigate the value of fecal calprotectin (FC) and fecal immunochemical test (FIT) in differentiation of significant and non- significant bowel diseases.

METHODS

In this prospective study, consecutive individuals were included if they underwent colonoscopy for symptoms of lower gastrointestinal (GI) tract, positive fecal occult blood test, surveillance for IBD or colorectal cancer (CRC) screening. Diagnostic value of FC and FIT in discriminating significant bowel diseases (advanced neoplasia, active inflammatory bowel diseases or bowel inflammation due to other causes) and non-significant bowel diseases (normal, asymptomatic diverticulum, non-adenomatous polyp, or non-advanced neoplasia) were evaluated.

RESULTS

Among 201 individuals included, 107 patients had significant bowel diseases. FC and FIT had an area under the curve (AUC) of 0.722 (95% confidence interval [CI] 0.653-0.792) and 0.797 (95%CI 0.734-0.860), respectively, for determining significant bowel diseases. Combination of FC and FIT predicted significant bowel diseases with an AUC, sensitivity, specificity, and accuracy of 0.832 (95% CI 0.775-0.890), 77.6%, 74.5%, and 76.1%, respectively. Moreover, combination of FC and FIT was more sensitive among patients with lower GI symptoms than asymptomatic individuals (80.8% vs. 74.1%) to identify significant bowel diseases.

CONCLUSIONS

A single measurement of FC or FIT is not sufficiently accurate to identify patients with significant bowel disease. However, combination of FC and FIT can help increase the sensitivity, especially in patients with lower GI symptoms.

A novel blood based triage test for colorectal cancer in primary care: a pilot study

BACKGROUND

The majority of colorectal cancers (CRCs) are detected after symptomatic presentation to primary care. Given the shared symptoms of CRC and benign disorders, it is challenging to manage the risk of missed diagnosis. Colonoscopy resources cannot keep pace with increasing demand. There is a pressing need for access to simple triage tools in primary care to help prioritise patients for referral.

AIM

To evaluate the performance of a novel spectroscopy-based CRC blood test in primary care.

DESIGN & SETTING

Mixed-methods pilot study of test performance and GP focus group discussions in South Wales.

METHOD

Patients on the urgent suspected cancer (USC) pathway were recruited for the Raman spectroscopy (RS) test coupled to machine learning classification ('Raman-CRC') to identify CRC within the referred population. Qualitative focus group work evaluated the acceptability of the test in primary care by thematic analysis of focus group theorising.

RESULTS

A total of 532 patients aged ≥50 years referred on the USC pathway were recruited from 27 GP practices. Twenty-nine patients (5.0%) were diagnosed with CRC. Raman-CRC identified CRC with sensitivity 95.7%, specificity 69.3% with area under curve (AUC) of 0.80 compared with colonoscopy as the reference test (248 patients). Stage I and II cancers were detected with 78.6% sensitivity. Focus group themes underlined the convenience of a blood test for the patient and the test's value as a risk assessment tool in primary care.

CONCLUSION

The findings support this novel, non-invasive, blood-based method to prioritise those patients most likely to have CRC. Raman-CRC may accelerate access to diagnosis with potential to improve cancer outcomes.

A Point-of-Care Faecal Test Combining Four Biomarkers Allows Avoidance of Normal Colonoscopies and Prioritizes Symptomatic Patients with a High Risk of Colorectal Cancer

Most colonoscopies performed to evaluate gastrointestinal symptoms detect only non-relevant pathologies. We aimed to evaluate the diagnostic accuracy of a qualitative point-of-care (POC) test combining four biomarkers (haemoglobin, transferrin, calprotectin, and lactoferrin), a quantitative faecal immunochemical test (FIT) for haemoglobin, and a quantitative faecal calprotectin (FC) test in symptomatic patients prospectively recruited. Colorectal cancer (CRC), adenoma requiring surveillance, inflammatory bowel disease (IBD), microscopic colitis, and angiodysplasia were considered significant pathologies. A total of 571 patients were included. Significant pathology was diagnosed in 118 (20.7%), including 30 CRC cases (5.3%). The POC test yielded the highest negative predictive values: 94.8% for a significant pathology and 100% for CRC or IBD if the four markers turned negative (36.8% of the patients). Negative predictive values of FIT, FC, and its combination for diagnosis of a significant pathology were 88.4%, 87.6%, and 90.8%, respectively. Moreover, the positive predictive value using the POC test was 82.3% for significant pathology when all biomarkers tested positive (6% of the patients), with 70.6% of these patients diagnosed with CRC or IBD. The AUC of the POC test was 0.801 (95%CI 0.754-0.848) for the diagnosis of a significant pathology. Therefore, this POC faecal test allows the avoidance of unnecessary colonoscopies and prioritizes high risk symptomatic patients.

The role of faecal calprotectin in diagnosis and staging of colorectal neoplasia: a systematic review and meta-analysis

Introduction

The presence of inflammation is a key hallmark of cancer and, plays an important role in disease progression and survival in colorectal cancer (CRC). Calprotectin detected in the faeces is a sensitive measure of colonic inflammation. The role of FC as a diagnostic test that may categorise patients by risk of neoplasia is poorly defined. This systematic review and meta-analysis aims to characterise the relationship between elevations of FC and colorectal neoplasia.

Methods

A systematic review was performed using the keywords (MESH terms) and a statistical and meta-analysis was performed.

Results

A total of 35 studies are included in this review. CRC patients are more likely than controls to have an elevated FC OR 5.19, 95% CI 3.12–8.62, p < 0.001 with a heterogeneity (I² = 27%). No tumour characteristics significantly correlated with FC, only stage of CRC shows signs that it may potentially correlate with FC.

Conclusion

FC levels are significantly higher in CRC, with high sensitivity. Its low specificity prevents it from being used to diagnose or screen for CRC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02220-1.

Intramucosal Calprotectin Expression in Inflammatory Bowel Disease (IBD) and Non-IBD Colorectal Inflammation

BACKGROUND: Inflammatory bowel disease (IBD) diagnosis remains a challenge accompanied with high numbers of misdiagnosis causing suboptimal management. Tons of trials have been conducted to improve the diagnostic accuracy, one of which is the use of biomarker such as calprotectin. Calprotectin can be detected in tissue (intramucosal) and is becoming a potential marker of IBD. AIM: This study aims to determine intramucosal calprotectin expression in IBD, non-IBD colitis, and control. METHODS: This analytic retrospective study included consecutively sampled IBD and non-IBD colitis colorectal biopsy specimens, and control group obtained from Cipto Mangunkusumo Hospital registered from 2017 to 2019. Cases were included in the study if specimens were indicative of IBD and non-IBD clinically and histopathologically and no abnormality were found histopathologically in the control group. Specimens with non-adequate data from the hospital medical records or with missing tissue slides were excluded from the study. Calprotectin immunostaining was conducted to evaluate mean intramucosal calprotectin expression (cell/HPF) in each group. RESULTS: Most of the samples from IBD and non-IBD group (45 samples each) showed mild active inflammation. Mucosal calprotectin expression in aforementioned groups was higher than that of control group (p < 0.001). Subjects with active inflammation showed higher calprotectin expression compared to those with inactive inflammation (p < 0.001). Calprotectin expression was also related to activity grade. CONCLUSION: Higher calprotectin expression showed significant association with the presence of inflammation and disease activity. However, the application of intramucosal calprotectin immunohistochemistry test to determine inflammatory etiology (IBD vs. non-IBD) still needs to be further evaluated.

Pre-diagnostic faecal calprotectin levels in patients with colorectal cancer: a retrospective study

BACKGROUND

Faecal calprotectin (FC) is a potential biomarker for colorectal cancer (CRC) screening. There is uncertainty if tumor characteristics are associated with FC levels. We investigated how tumor stage and tumor localization influence the extent of FC levels in patients with CRC in clinical practice.

METHODS

In two cohorts of patients with CRC, we retrospectively analyzed FC tests (CALPRO®) performed within three months prior to diagnosis. One hundred twenty-four patients with CRC were included (mean age 68 years, 44% women).

RESULTS

Ninety-eight patients with CRC (79%) had a FC ≥ 50 µg/g. FC correlated positively with tumor stage (UICC based on WHO TNM classification) (r_s 0.24; p = 0.007) and with CRP levels (r_s 0.31, p = 001), and a negatively with B-haemoglobin (r_s -0.21; p = 0.019). The patients with right-sided CRC had significantly more often a FC ≥ 50 µg/g than patients with left-sided CRC (92% vs 74% p = 0.027). In a binary logistic regression analysis, tumor stage III/IV (adjusted OR 3.47; CI 1.27-9.42) and right-sided tumor localization (adjusted OR 3.80; CI 1.01-14.3) were associated with FC ≥ 50 µg/g. Tumor stage III/IV (adjusted OR 2.30; CI 1.04-5.10) and acetylsalicylic use (adjusted OR 3.54; CI 1.03-12.2) were associated with FC ≥ 100 µg/g. In a cox regression analysis, a FC ≥ 100 µg/g was not associated with survival (Hazard OR 0.61; CI 0.24-1.52).

CONCLUSIONS

Elevated pre-diagnostic FC levels were common in patients with CRC in close proximity to diagnosis. Right-sided localization and tumor stage were significantly associated with a rise in FC levels.

Comparison of faecal protein biomarkers' diagnostic accuracy for colorectal advanced neoplasms: a systematic review and meta-analysis

Early diagnosis of colorectal advanced neoplasms (ANs), including colorectal cancer (CRC) and advanced adenoma (AA), has a positive effect on the survival rate. As a first attempt, the aim of this meta-analysis was to compare the diagnostic accuracy of faecal protein biomarkers for the detection of colorectal neoplasms with consideration of a wide range of covariates. A systematic literature search was performed up to Jun 10, 2021 on Web of Sciences, Scopus and PubMed. The diagnostic accuracies were calculated using the bivariate/hierarchical random effect model. Biomarkers were determined to be clinically applicable (CA) if they had areas under the curve > 0.70 and positive and negative likelihood ratios > 2 and < 0.5, respectively. A total of 47,059 test results were extracted from 16 immunochemical faecal occult blood test (iFOBT), 26 pyruvate kinase-M2 (PK-M2) and 23 faecal calprotectin (FC) studies. Only iFOBT, PK-M2 and FC for CRC plus iFOBT and PK-M2 for AN were CA. iFOBT had significantly superior accuracy (P = 0.02 versus PK-M2 and P < 0.01 versus FC for CRC; P < 0.01 versus PK-M2 for AN). Regarding covariates, the lateral flow method of PK-M2 measurement increased its accuracy for CRC detection compared to the enzyme-linked immunosorbent assay (P < 0.01). iFOBT is recommended as the most accurate faecal biomarker for CRC and AN diagnosis.

The role of faecal calprotectin in the identification of colorectal neoplasia in patients attending for screening colonoscopy

AIM

Although the relationship between colorectal neoplasia and inflammation is well described, the role of faecal calprotectin (FC) in clinical practice to diagnose or screen patients for colorectal neoplasia is less defined. This prospective study characterizes the relationship between FC and colorectal neoplasia in patients within the faecal occult blood testing (FOBT) positive patients in the Scottish Bowel Screening Programme.

METHODS

All FOBT positive patients attending for colonoscopy between February 2016 and July 2017 were invited to participate. Patients provided a stool sample for FC before commencing bowel preparation. All demographics and endoscopic findings were collected prospectively.

RESULTS

In all, 352 patients were included. 210 patients had FC > 50 µg. Colorectal cancer (CRC) patients had a higher median FC (138.5 μg/g, P < 0.05), in comparison to those without CRC, and 13/14 had an FC > 50 µg/g (93%). FC had a high sensitivity (92.8%) and negative predictive value (99.3%) for CRC, but with a low specificity (41.7%) and positive predictive value (6.2%). FC sensitivity increased sequentially as neoplasms progressed from non-advanced to malignant neoplasia (48.6% non-advanced adenoma vs. 92.9% CRC). However, no significant relationship was observed between FC and non-cancer neoplasia.

CONCLUSION

In an FOBT positive screening population, FC was strongly associated with CRC (sensitivity 92.8%, specificity 41.7% for CRC, at 50 µg/g). However, although sensitive for the detection of CRC, FC failed to show sufficient sensitivity or specificity for the detection of non-cancer neoplasia. Based on these results we cannot recommend routine use of FC in a bowel screening population to detect cancer per se, but it is apparent that, with further optimization, faecal assessments including quantification of haemoglobin and inflammation could form part of a risk assessment tool aimed at refining the selection of patients for colonoscopy in both symptomatic and screening populations.

Biomarkers to Detect Early-Stage Colorectal Cancer

Colorectal cancer is a leading cause of mortality worldwide. The high incidence and the acceleration of incidence in younger people reinforces the need for better techniques of early detection. The use of noninvasive biomarkers has potential to more accurately inform how patients are prioritised for clinical investigation, which, in turn, may ultimately translate into improved survival for those subsequently found to have curable-stage CRC. This review surveys a wide range of CRC biomarkers that may (alone or in combination) identify symptomatic patients presenting in primary care who should be progressed for clinical investigation.

Management of Immune-Related Adverse Events in Patients Treated With Immune Checkpoint Inhibitor Therapy: ASCO Guideline Update

PURPOSE

To increase awareness, outline strategies, and offer guidance on the recommended management of immune-related adverse events (irAEs) in patients treated with immune checkpoint inhibitor (ICPi) therapy.

METHODS

A multidisciplinary panel of medical oncology, dermatology, gastroenterology, rheumatology, pulmonology, endocrinology, neurology, hematology, emergency medicine, nursing, trialists, and advocacy experts was convened to update the guideline. Guideline development involved a systematic literature review and an informal consensus process. The systematic review focused on evidence published from 2017 through 2021.

RESULTS

A total of 175 studies met the eligibility criteria of the systematic review and were pertinent to the development of the recommendations. Because of the paucity of high-quality evidence, recommendations are based on expert consensus.

RECOMMENDATIONS

Recommendations for specific organ system-based toxicity diagnosis and management are presented. While management varies according to the organ system affected, in general, ICPi therapy should be continued with close monitoring for grade 1 toxicities, except for some neurologic, hematologic, and cardiac toxicities. ICPi therapy may be suspended for most grade 2 toxicities, with consideration of resuming when symptoms revert ≤ grade 1. Corticosteroids may be administered. Grade 3 toxicities generally warrant suspension of ICPis and the initiation of high-dose corticosteroids. Corticosteroids should be tapered over the course of at least 4-6 weeks. Some refractory cases may require other immunosuppressive therapy. In general, permanent discontinuation of ICPis is recommended with grade 4 toxicities, except for endocrinopathies that have been controlled by hormone replacement. Additional information is available at www.asco.org/supportive-care-guidelines.

Evaluation and management of rectal bleeding in pregnancy

Rectal bleeding occurs in about 40% of pregnant women, and is predominantly attributed to benign perianal pathology (haemorrhoids or anal fissures). More sinister causes of rectal bleeding may be heralded by key red flag clinical and biochemical features. These features should be evaluated in all women with rectal bleeding. Imaging investigations or flexible sigmoidoscopy may be warranted. The latter can be performed safely by experienced operators in pregnant women. Women with evidence of haemodynamic compromise, elevated inflammatory markers, significant anaemia, signs of intestinal obstruction or compromise to the fetus should be evaluated urgently. Providers must be mindful of the changes in normal ranges for common haematological and biochemical parameters in pregnancy compared with the non-pregnant state. Faecal calprotectin is an established tool for identification of intestinal inflammation and is valid in pregnancy. An elevated faecal calprotectin level (≥ 50 µg/g) signifies a need for further diagnostic evaluation. Inflammatory bowel disease may present initially, or with worsening disease activity, in pregnancy. Expedient diagnosis with the use of faecal calprotectin, sigmoidoscopy with or without intestinal ultrasound, exclusion of alternative or compounding infective aetiologies, and institution of appropriate therapy are critical. Medical therapies for management of inflammatory bowel disease can be safely instituted in pregnancy. Colorectal cancer incidence is increasing in younger age groups, but fortunately remains rare. When diagnosed in pregnancy, colorectal cancer can be successfully and safely managed with a collaborative multidisciplinary team approach. Early diagnosis is key to optimising outcomes.

The Fast Track FIT study: diagnostic accuracy of faecal immunochemical test for haemoglobin in patients with suspected colorectal cancer

BACKGROUND

The faecal immunochemical test (FIT) is now available to support clinicians in the assessment of patients at low risk of colorectal cancer (CRC) and within the bowel cancer screening programme.

AIM

To determine the diagnostic accuracy of FIT for CRC and clinically significant disease in patients referred as they were judged by their GP to fulfil National Institute for Health and Care Excellence guideline 12 (NG12) criteria for suspected CRC.

DESIGN AND SETTING

Patients referred from primary care with suspected CRC, meeting NG12 criteria, to 12 secondary care providers in Yorkshire and Humber were asked to complete a FIT before investigation.

METHOD

The diagnostic accuracy of FIT based on final diagnosis was evaluated using receiver operating characteristics analysis. This permitted a statistically optimal cut-off value for FIT to be determined based on the maximisation of sensitivity and specificity. Clinicians and patients were blinded to the FIT results.

RESULTS

In total, 5040 patients were fully evaluated and CRC was detected in 151 (3.0%). An optimal cut-off value of 19 µg Hb/g faeces for CRC was determined, giving a sensitivity of 85.4% (95% confidence interval [CI] = 78.8% to 90.6%) and specificity of 85.2% (95% CI = 84.1% to 86.2%). The negative predictive value at this cut-off value was 99.5% (95% CI = 99.2% to 99.7%) and the positive predictive value 15.1% (95% CI = 12.8% to 17.7%). Sensitivity and specificity of FIT for CRC and significant premalignant polyps at this cut-off value were 62.9% (95% CI = 57.5% to 68.0%) and 86.4% (95% CI = 85.4% to 87.4%), respectively; and when including all organic enteric disease were 35.7% (95% CI = 32.9% to 38.5%) and 88.6% (95% CI = 87.5% to 89.6%), respectively.

CONCLUSION

FIT used in patients fulfilling NG12 criteria should allow for a more personalised CRC risk assessment. FIT should permit effective, patient-centred decision-making to inform the need for, type, and timing of further investigation.

The Addition of Other Fecal Biomarkers Does Not Improve the Diagnostic Accuracy of Immunochemical Fecal Occult Blood Test Alone in a Colorrectal Cancer Screening Cohort

Background: Screening with fecal occult blood test reduces colorectal cancer (CRC) incidence and mortality, and is currently implemented in most countries. However, around 40% of screening colonoscopies are normal. Thus, strategies to avoid these colonoscopies are highly necessary. Adding other fecal biomarkers, such as fecal calprotectin (FC), lactoferrin, and transferrin may be useful, but evidence is scarce.

Aims: To evaluate the diagnostic accuracy of fecal occult blood immunochemical test (FIT), FC, and a one-step combo card test for the simultaneous semi-qualitative detection of human hemoglobin (hHb), transferrin (hTf), calprotectin (hCp) and lactoferrin (hLf) in a CRC screening program population.

Methods: Single-center, prospective observational study, enrolling patients included in a CRC screening program, referred for a colonoscopy due to a positive FIT test. Participants collected a stool sample prior to bowel preparation, and FIT, FC and the combo semi-qualitative tests were performed on the sample. Sensitivity, specificity, positive and negative predictive values and area under receiver operator curve (AUC) for diagnosis of advanced neoplasia, advanced adenoma and CRC were estimated for each biomarker and their combinations. The primary endpoint of the study was to assess whether these biomarkers could improve the diagnostic accuracy of FIT alone.

Results: 336 consecutive patients (64% males) were recruited. Advanced neoplasia was found in 129/336 (38.4%) patients, and of these, 22/336 (6.5%) were diagnosed of CRC. 153/336 (45.5%) colonoscopies were completely normal. The AUC for the diagnosis of advanced neoplasia were 0.725 (95%CI 0.665–0.784) for FIT, 0.477 (95%CI 0.413–0.541) for FC and 0.732 (95%CI 0.674–0.791) for the combination of both (FIT + FC) quantitative tests. The AUCs for the combo test were 0.70 (95%CI 0.641–0.760) for hHb, 0.625 (95%CI 0.562–0.698) for hTf, 0.532 (95%CI 0.469–0.595) for hCp, 0.531 (95%CI 0.466–0.595 ) for hLf and 0.681 (95%CI 0.620–0.741) for the combination of the four biomarkers.

Conclusion: In average-risk population, FIT appears to be the best fecal marker for the diagnosis of CRC and advanced adenoma. None of the other biomarkers explored or their combinations provided a better diagnostic accuracy. Only hTF showed an acceptable diagnostic accuracy. FC and hLF were not useful in this setting.

Diagnostic accuracy of fecal calprotectin in predicting significant gastrointestinal diseases

Background and Aim

It is often unreliable to triage patients for timely endoscopic investigations based on symptoms alone. We need an objective assessment to differentiate between organic gastrointestinal diseases and functional bowel symptoms. We evaluated the diagnostic accuracy of fecal calprotectin (FC) in predicting organic gastrointestinal diseases.

Methods

In a prospective observational study, consecutive patients referred for colonoscopy to the Department of Medicine and Geriatrics at the Kwong Wah Hospital in Hong Kong were recruited. Stool samples were collected within 24 h before colonoscopy. FC was measured by a commercial kit. Upper endoscopy investigations were then proceeded if normal colonoscopy but elevated FC.

Results

Two hundred and seventy out of 429 patients had FC above 50 μg/g. Eighty‐six out of 270 with elevated FC had significant colonoscopy pathological findings. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of FC test for diagnosing a significant organic colonoscopy or upper endoscopy disease were 91.7, 55.6, 57.0, and 91.2%, respectively. The NPV of FC for colorectal cancer, high risk polyp, and colon inflammation were 98.7, 96.2, and 98.1%, respectively. The NPV of FC in the condition of altered bowel habit or abdominal pain in predicting colorectal cancer and inflammation were 93.8 and 100%, respectively.

Conclusions

FC is a reliable marker of ruling out organic bowel diseases. A single negative FC test could be used as a triage tool to prioritize the need and urgency of further investigation, particularly in the setting of altered bowel habits and abdominal pain.

Blood and synovial fluid calprotectin as biomarkers to diagnose chronic hip and knee periprosthetic joint infections

AIMS

Calprotectin (CLP) is produced in neutrophils and monocytes and released into body fluids as a result of inflammation or infection. The aim of this study was to evaluate the utility of blood and synovial CLP in the diagnosis of chronic periprosthetic joint infection (PJI).

METHODS

Blood and synovial fluid samples were collected prospectively from 195 patients undergoing primary or revision hip and knee arthroplasty. Patients were divided into five groups: 1) primary total hip and knee arthroplasty performed due to idiopathic osteoarthritis (OA; n = 60); 2) revision hip and knee arthroplasty performed due to aseptic failure of the implant (AR-TJR; n = 40); 3) patients with a confirmed diagnosis of chronic PJI awaiting surgery (n = 45); 4) patients who have finished the first stage of the PJI treatment with the use of cemented spacer and were qualified for replantation procedure (SR-TJR; n = 25), and 5) patients with rheumatoid arthritis undergoing primary total hip and knee arthroplasty (RA; n = 25). CLP concentrations were measured quantitatively in the blood and synovial fluid using an immunoturbidimetric assay. Additionally, blood and synovial CRP, blood interleukin-6 (IL-6), and ESR were measured, and a leucocyte esterase (LE) strip test was performed.

RESULTS

Patients with PJI had higher CLP concentrations than those undergoing aseptic revision in blood (median PJI 2.14 mg/l (interquartile range (IQR) 1.37 to 3.56) vs AR-TJR 0.66 mg/l (IQR 0.3 to 0.83); p < 0.001) and synovial fluid samples (median PJI 20.46 mg/l (IQR 14.3 to 22.36) vs AR-TJR 0.7 mg/l (IQR 0.41 to 0.95); p < 0.001). With a cut-off value of 1.0 mg/l, blood CLP showed a sensitivity, specificity, positive predictive value, and negative predictive value of 93.3%, 87.5%, 89.4%, and 92.1%, respectively. For synovial fluid with a cut-off value of 1.5 mg/l, these were 95.6%, 95%, 95.5%, and 95%, respectively.

CONCLUSION

This small study suggests that synovial and blood CLP are useful markers in chronic PJI diagnosis with similar or higher sensitivity and specificity than routinely used markers such as CRP, ESR, IL-6, and LE. CLP was not useful to differentiate patients with PJI from those with rheumatoid arthritis. Cite this article: Bone Joint J 2021;103-B(1):46-55.

Tissue mRNA for S100A4, S100A6, S100A8, S100A9, S100A11 and S100P Proteins in Colorectal Neoplasia: A Pilot Study

S100 proteins are involved in the pathogenesis of sporadic colorectal carcinoma through different mechanisms. The aim of our study was to assess tissue mRNA encoding S100 proteins in patients with non-advanced and advanced colorectal adenoma. Mucosal biopsies were taken from the caecum, transverse colon and rectum during diagnostic and/or therapeutic colonoscopy. Another biopsy was obtained from adenomatous tissue in the advanced adenoma group. The tissue mRNA for each S100 protein (S100A4, S100A6, S100A8, S100A9, S100A11 and S100P) was investigated. Eighteen biopsies were obtained from the healthy mucosa in controls and the non-advanced adenoma group (six individuals in each group) and thirty biopsies in the advanced adenoma group (ten patients). Nine biopsies were obtained from advanced adenoma tissue (9/10 patients). Significant differences in mRNA investigated in the healthy mucosa were identified between (1) controls and the advanced adenoma group for S100A6 (p = 0.012), (2) controls and the non-advanced adenoma group for S100A8 (p = 0.033) and (3) controls and the advanced adenoma group for S100A11 (p = 0.005). In the advanced adenoma group, differences between the healthy mucosa and adenomatous tissue were found in S100A6 (p = 0.002), S100A8 (p = 0.002), S100A9 (p = 0.021) and S100A11 (p = 0.029). Abnormal mRNA expression for different S100 proteins was identified in the pathological adenomatous tissue as well as in the morphologically normal large intestinal mucosa.

A Practical Guide for Faecal Calprotectin Measurement: Myths and Realities

BACKGROUND AND AIMS

Faecal calprotectin [FC] is a valid and non-invasive marker of mucosal inflammation. It is widely used both in clinical trials and in daily clinical practice for patients with inflammatory bowel diseases, but currently no accepted standardization for FC testing is available. Our primary aim here was to provide a clinician's guide containing all the practical information on FC measurement in order to avoid any confounding factors, to minimize intra- and inter-individual variability in dosage, and to ensure a better and adequate interpretation of the results.

METHODS

We conducted a detailed search of the scientific literature in the PubMed/MEDLINE, EMBASE and Cochrane databases up to January 2020 to find all relevant and available articles on pre-analytical and analytical phases of FC measurement.

RESULTS

FC testing is a multi-step procedure consisting of a pre-analytical phase aimed to collect and process the stool sample and a subsequent analytical phase of FC measurement. Several factors can influence test results determining false positives or false negatives. Importantly, this faecal marker is mostly used for patient follow-up and as a predictor of treatment response. For this reason, any altered data may affect the physicians' decisions, negatively impacting on patient management.

CONCLUSIONS

This review provides for the first time practical advice to minimize dosage variability, although further dedicated studies are needed to compare commercially available tests and identify the best tools for the most precise and accurate FC measurement.

Proton pump inhibitors and the risk of colorectal cancer: a systematic review and meta-analysis of observational studies

PURPOSE

The increased risk of colorectal cancer (CRC) associated with long-term use of proton pump inhibitors (PPIs) has attracted considerable attention; however, the conclusions of studies evaluating this correlation are inconsistent or even controversial. Therefore, we conducted a systematic review and meta-analysis to determine the association of PPI use with the risk of CRC.

METHODS

A systematic literature search was conducted in PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials to identify relevant studies. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) for the associations between PPI use and the risk of CRC were estimated with a fixed-effects or random-effects model.

RESULTS

We identified and included 9 observational studies (3 cohort studies and 6 case-control studies) comprising 1,036,438 participants. Overall, there was no statistically significant association between PPI use and the risk of CRC (pooled OR 1.26, 95% CI: 0.90-1.73; p = 0.166) when PPI exposure was assessed as a binary variable. However, a weak association between long-term use of PPIs and CRC was demonstrated (pooled OR 1.19, 95% CI: 1.09-1.31; p < 0.001) when the cumulative duration of PPI exposure was confined to > 5 years.

CONCLUSIONS

Although the present meta-analysis suggests a weak association between long-term use (> 5 years) of PPIs and CRC, there is not enough statistical power to refute or confirm an association between the use of PPIs and CRC. More high-quality prospective cohort studies are needed to assess this correlation.

Calcium Binding to the Innate Immune Protein Human Calprotectin Revealed by Integrated Mass Spectrometry

Although knowledge of the coordination chemistry and metal-withholding function of the innate immune protein human calprotectin (hCP) has broadened in recent years, understanding of its Ca²⁺-binding properties in solution remains incomplete. In particular, the molecular basis by which Ca²⁺ binding affects structure and enhances the functional properties of this remarkable transition-metal-sequestering protein has remained enigmatic. To achieve a molecular picture of how Ca²⁺ binding triggers hCP oligomerization, increases protease stability, and enhances antimicrobial activity, we implemented a new integrated mass spectrometry (MS)-based approach that can be readily generalized to study other protein-metal and protein-ligand interactions. Three MS-based methods (hydrogen/deuterium exchange MS kinetics; protein-ligand interactions in solution by MS, titration, and H/D exchange (PLIMSTEX); and native MS) provided a comprehensive analysis of Ca²⁺ binding and oligomerization to hCP without modifying the protein in any way. Integration of these methods allowed us to (i) observe the four regions of hCP that serve as Ca²⁺-binding sites, (ii) determine the binding stoichiometry to be four Ca²⁺ per CP heterodimer and eight Ca²⁺ per CP heterotetramer, (iii) establish the protein-to-Ca²⁺ molar ratio that causes the dimer-to-tetramer transition, and (iv) calculate the binding affinities associated with the four Ca²⁺-binding sites per heterodimer. These quantitative results support a model in which hCP exists in its heterodimeric form and is at most half-bound to Ca²⁺ in the cytoplasm of resting cells. With release into the extracellular space, hCP encounters elevated Ca²⁺ concentrations and binds more Ca²⁺ ions, forming a heterotetramer that is poised to compete with microbial pathogens for essential metal nutrients.

The combination of quantitative faecal occult blood test and faecal calprotectin is a cost-effective strategy to avoid colonoscopies in symptomatic patients without relevant pathology

BACKGROUND

Faecal occult blood test (FOBT) has demonstrated effectiveness in colorectal cancer (CRC) screening. Faecal calprotectin (FC) has proven efficient for evaluating activity in inflammatory bowel disease (IBD), but its value in CRC detection is less established. Most symptomatic patients have benign pathologies, but still undergo colonoscopy in many settings.

AIMS

To evaluate the diagnostic accuracy and cost-effectiveness of the combination of FOBT plus FC in symptomatic patients.

METHODS

Patients who completed colonic investigations and returned stool samples, on which FOBT and FC were performed, were recruited prospectively. CRC, advanced adenoma, IBD and angiodysplasia were considered as relevant pathologies.

RESULTS

A total of 404 patients were included, of whom 87 (21.5%) had relevant pathologies. Sensitivity and specificity were 50.6% and 69.6% for FOBT, 78.2% and 54.4% for FC. Negative predictive value (NPV) was 90.1% for FC and 86.9% for FOBT. NPV for the combination of FOBT and FC was 94.1%, with a sensitivity and specificity of 88.5% and 50.3%. The area under ROC (receiver operator curve) (AUC) was 0.741 for FOBT, 0.736 for FC and 0.816 for the combination. The total cost for visits and procedures was €233,016 (€577/patient). Using a combination of FOBT and FC as pre-endoscopic tool allows colonoscopies to be reduced by 39.4%, reducing total costs by 20.5%.

CONCLUSION

The combination of FOBT and FC has a better diagnostic accuracy compared with each test alone. Performing both tests before colonoscopy is a less costly and more effective strategy, reducing unnecessary procedures and complications.

Limitations of the determination of faecal calprotectin in patients with ulcerative colitis and inflammatory polyps

INTRODUCTION

Faecal calprotectin is a useful technique for detecting activity in patients with ulcerative colitis. However, there may be high levels due to factors other than the activity of ulcerative colitis. Our aim was to analyse possible false positive results of calprotectin for the activity of ulcerative colitis owing to the presence of inflammatory polyps.

PATIENTS AND METHODS

Retrospective, observational, descriptive study. Data was collected from patients monitored for 2 years in whom a colonoscopy had been requested within 3 months after detecting high calprotectin values (>150μg/g) and before modifying the treatment.

RESULTS

We reviewed 39 patients and in 5 of them, with previous diagnosis of extensive ulcerative colitis, inflammatory polyps were detected. Three patients were on treatment with mesalazine, one with azathioprine and other with infliximab. All of them were asymptomatic and the endoscopy did not show macroscopic activity (endoscopic Mayo score=0) or histological activity. The median values of calprotectin were 422μg/g (IQR: 298-2,408) and they remained elevated in a second measurement. In 4 of the patients the inflammatory polyps were multiple and small in size. The other patient had a polyp measuring 4cm.

DISCUSSION

In clinical practice we can find high faecal calprotectin levels not due to the presence of ulcerative colitis activity, but due to other lesions such as inflammatory polyps. This fact must be taken into account before carrying out relevant changes such as step-up therapy to immunosuppressive drugs or biological drugs in patients with confirmed high calprotectin levels.

British Society of Gastroenterology consensus guidelines on the management of inflammatory bowel disease in adults

Ulcerative colitis and Crohn's disease are the principal forms of inflammatory bowel disease. Both represent chronic inflammation of the gastrointestinal tract, which displays heterogeneity in inflammatory and symptomatic burden between patients and within individuals over time. Optimal management relies on understanding and tailoring evidence-based interventions by clinicians in partnership with patients. This guideline for management of inflammatory bowel disease in adults over 16 years of age was developed by Stakeholders representing UK physicians (British Society of Gastroenterology), surgeons (Association of Coloproctology of Great Britain and Ireland), specialist nurses (Royal College of Nursing), paediatricians (British Society of Paediatric Gastroenterology, Hepatology and Nutrition), dietitians (British Dietetic Association), radiologists (British Society of Gastrointestinal and Abdominal Radiology), general practitioners (Primary Care Society for Gastroenterology) and patients (Crohn's and Colitis UK). A systematic review of 88 247 publications and a Delphi consensus process involving 81 multidisciplinary clinicians and patients was undertaken to develop 168 evidence- and expert opinion-based recommendations for pharmacological, non-pharmacological and surgical interventions, as well as optimal service delivery in the management of both ulcerative colitis and Crohn's disease. Comprehensive up-to-date guidance is provided regarding indications for, initiation and monitoring of immunosuppressive therapies, nutrition interventions, pre-, peri- and postoperative management, as well as structure and function of the multidisciplinary team and integration between primary and secondary care. Twenty research priorities to inform future clinical management are presented, alongside objective measurement of priority importance, determined by 2379 electronic survey responses from individuals living with ulcerative colitis and Crohn's disease, including patients, their families and friends.

British Society of Gastroenterology consensus guidelines on the management of inflammatory bowel disease in adults

Ulcerative colitis and Crohn's disease are the principal forms of inflammatory bowel disease. Both represent chronic inflammation of the gastrointestinal tract, which displays heterogeneity in inflammatory and symptomatic burden between patients and within individuals over time. Optimal management relies on understanding and tailoring evidence-based interventions by clinicians in partnership with patients. This guideline for management of inflammatory bowel disease in adults over 16 years of age was developed by Stakeholders representing UK physicians (British Society of Gastroenterology), surgeons (Association of Coloproctology of Great Britain and Ireland), specialist nurses (Royal College of Nursing), paediatricians (British Society of Paediatric Gastroenterology, Hepatology and Nutrition), dietitians (British Dietetic Association), radiologists (British Society of Gastrointestinal and Abdominal Radiology), general practitioners (Primary Care Society for Gastroenterology) and patients (Crohn's and Colitis UK). A systematic review of 88 247 publications and a Delphi consensus process involving 81 multidisciplinary clinicians and patients was undertaken to develop 168 evidence- and expert opinion-based recommendations for pharmacological, non-pharmacological and surgical interventions, as well as optimal service delivery in the management of both ulcerative colitis and Crohn's disease. Comprehensive up-to-date guidance is provided regarding indications for, initiation and monitoring of immunosuppressive therapies, nutrition interventions, pre-, peri- and postoperative management, as well as structure and function of the multidisciplinary team and integration between primary and secondary care. Twenty research priorities to inform future clinical management are presented, alongside objective measurement of priority importance, determined by 2379 electronic survey responses from individuals living with ulcerative colitis and Crohn's disease, including patients, their families and friends.

Colorectal cancer detection by biomarker quantification in noninvasively collected colorectal mucus: preliminary comparison of 24 protein biomarkers

OBJECTIVES

Noninvasive colorectal cancer detection and screening remain global diagnostic challenges because the existing stool tests either lack sensitivity or are complex and expensive. Moreover, colorectal cancer screening uptake is low due to stool sampling inconvenience. We have developed a simple and patient-friendly noninvasive technique for collecting highly informative colorectal mucus. In this study, we aimed to comparatively assess a range of candidate biomarkers in colorectal mucus samples for colorectal cancer detection.

METHODS

The study included 17 patients with colorectal cancer and 35 healthy controls, who provided noninvasively collected colorectal mucus samples. Protein biomarker quantification in these samples by enzyme-linked immunosorbent assays allowed comparing diagnostic performances of 24 candidate biomarkers that comprised haemoglobin, D-dimer, M2-pyruvate kinase, carcinoembryonic antigen, C-reactive protein, calprotectin, eosinophil-derived neurotoxin, protein S100A12, tumour necrosis factor α, clusterin, soluble cytokeratin 18, caspase-cleaved cytokeratin 18, citrullinated histone H3, peptidyl arginine deiminase 4, epidermal growth factor, epidermal growth factor receptor, matrix metalloproteinase 9, tissue inhibitor of metalloproteinase 1, periostin, vascular endothelial growth factor A, vascular endothelial growth factor receptor 1, vascular cell adhesion molecule 1, intercellular adhesion molecule 1 and mucin 2. Tested biomarkers were ranked for colorectal cancer detection efficiency using receiver operating characteristic curve analysis.

RESULTS

High area under the curve values between 0.943 and 0.768 were observed for haemoglobin, tissue inhibitor of metalloproteinase 1, M2-pyruvate kinase, peptidyl arginine deiminase 4, C-reactive protein, matrix metalloproteinase 9, epidermal growth factor receptor, eosinophil-derived neurotoxin and calprotectin.

CONCLUSION

Quantification of protein biomarkers in noninvasively collected samples of colorectal mucus certainly allows detecting colorectal cancer. Further clinical evaluation of the optimal biomarkers identified by this study is needed.

Ca2+-Binding Proteins of the EF-Hand Superfamily: Diagnostic and Prognostic Biomarkers and Novel Therapeutic Targets

A multitude of Ca²⁺-sensor proteins containing the specific Ca²⁺-binding motif (helix-loop-helix, called EF-hand) are of major clinical relevance in a many human diseases. Measurements of troponin, the first intracellular Ca-sensor protein to be discovered, is nowadays the "gold standard" in the diagnosis of patients with acute coronary syndrome (ACS). Mutations have been identified in calmodulin and linked to inherited ventricular tachycardia and in patients affected by severe cardiac arrhythmias. Parvalbumin, when introduced into the diseased heart by gene therapy to increase contraction and relaxation speed, is considered to be a novel therapeutic strategy to combat heart failure. S100 proteins, the largest subgroup with the EF-hand protein family, are closely associated with cardiovascular diseases, various types of cancer, inflammation, and autoimmune pathologies. The intention of this review is to summarize the clinical importance of this protein family and their use as biomarkers and potential drug targets, which could help to improve the diagnosis of human diseases and identification of more selective therapeutic interventions.

Diagnostic accuracy of fecal calprotectin for screening patients with colorectal cancer: A meta-analysis

BACKGROUND/AIMS

Fecal calprotectin (FC) is reported to have a broad diagnostic accuracy for colorectal cancer (CRC). Therefore, we explored the diagnostic value of FC for CRC using meta-analytical techniques to substantiate the assertion.

MATERIALS AND METHODS

An electronic search of the MEDLINE and Embase databases was conducted to identify studies that assessed the diagnostic accuracy of FC for CRC. The sensitivities and specificities of the eligible studies were summarized using a bivariable random-effects model.

RESULTS

In total, 20 studies were included in the final analysis. The pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of FC for CRC detection were 0.83 (95% confidence interval CI, 0.77-0.88), 0.61 (95% CI, 0.54-0.68), 2.15 (95% CI, 1.82-2.55), and 0.28 (95% CI, 0.21-0.37), respectively. The overall diagnostic odds ratio of FC for CRC was 7.76 (95% CI, 5.41-11.12) with an area under the curve of 0.81 (95% CI, 0.77-0.84), whereas the diagnostic value of FC for colorectal adenoma was relatively inferior (area under the curve, 0.55; 95% CI, 0.51-0.59; diagnostic odds ratio, 1.27; 95% CI, 0.91-1.78).

CONCLUSION

The results imply that the FC test, as currently implemented, cannot be recommended for CRC detection.

Diagnostic accuracy of one or two faecal haemoglobin and calprotectin measurements in patients with suspected colorectal cancer

BACKGROUND

The role of faecal biomarkers in patients at 'high risk' of colorectal cancer (CRC) is not yet defined. Pre-analytical factors, such as heterogeneity of biomarker distribution within faeces, may influence their optimisation in clinical practice. We undertook to determine whether repeat or combined biomarker testing improves diagnostic accuracy for CRC or clinically significant disease.

METHODS

Patients referred with suspected CRC provided two separate faecal samples each for faecal immunochemical testing (FIT) and faecal calprotectin (FC) prior to investigation. Diagnostic accuracy of FIT and FC were evaluated based on final diagnoses.

RESULTS

Five hundred fifteen patients completed a full colorectal evaluation. The optimal cut-off for CRC using a single FIT was ≥12 µgHb/g faeces (84.6% sensitivity, 88.5% specificity). For two FIT, the cut-off was ≥43 µgHb/g faeces if either and ≥2 µgHb/g faeces if both were positive. There was no advantage in their diagnostic accuracy compared with a single FIT. FC had a lower diagnostic accuracy for CRC than FIT, which was not improved by repeat FC. No benefit was identified with FIT-FC combined. For CRC, significant adenomatous polyps and organic enteric disease combined, FIT and FC performed similarly to each other but were poorer predictors (AUC 0.677 and 0.660). There was no uplift in diagnostic accuracy when the tests were repeated or combined.

CONCLUSION

This study supports using a single FIT at a cut-off close to that recommended by NICE DG30 to improve diagnostic accuracy for 'two-week wait' patients referred with suspected CRC.

Faecal calprotectin effectively excludes inflammatory bowel disease in 789 symptomatic young adults with/without alarm symptoms: a prospective UK primary care cohort study

BACKGROUND

Primary care faecal calprotectin testing distinguishes inflammatory bowel disease (IBD) from functional gut disorder in young patients presenting with abdominal symptoms; however, previous evaluations have excluded patients with alarm symptoms.

AIMS

We sought to evaluate the diagnostic accuracy of calprotectin to distinguish IBD from functional gut disorder in young adults in whom general practitioners (GPs) suspected IBD; including patients reporting gastrointestinal alarm symptoms. We hypothesised that calprotectin would reduce secondary care referrals and healthcare costs.

METHODS

We undertook a prospective cohort study of 789 young adults (18-46 years old) presenting with gastrointestinal symptoms to 49 local general practices that had undergone calprotectin testing (1053 tests: between Jan 2014 and May 2016) because of suspected IBD. We considered calprotectin levels of ≥100 μg/g positive. Primary and secondary care records over 12 months from the point of calprotectin testing were used as the reference standard.

RESULTS

Overall, 39% (308/789) patients reported gastrointestinal alarm symptoms and 6% (50/789) tested patients were diagnosed with IBD. The positive and negative predictive values of calprotectin testing for distinguishing IBD from functional gut disorder in patients with gastrointestinal alarm symptoms were 50% (95% CI 36%-64%) and 98% (96%-100%): and in patients without gastrointestinal alarm symptoms were 27% (16%-41%) and 99% (98%-100%), respectively. We estimate savings of 279 referrals and £160 per patient.

CONCLUSIONS

Calprotectin testing of young adults with suspected IBD in primary care accurately distinguishes IBD from functional gut disorder, even in patients with gastrointestinal alarm symptoms and reduces secondary care referrals and diagnostic healthcare costs.

Fecal Calprotectin

Calprotectin is a 36kDa member of the S100 family of proteins. It is derived predominantly from neutrophils and has direct antimicrobial effects and a role within the innate immune response. Calprotectin is found in various body fluids in proportion to the degree of any existing inflammation and its concentration in feces is about six times that of plasma. Measurement of fecal calprotectin is a useful surrogate marker of gastrointestinal inflammation. It has a high negative predictive value in ruling out inflammatory bowel disease (IBD) in undiagnosed, symptomatic patients and a high sensitivity for diagnosing the disease making it useful as a tool for prioritising endoscopy. In patients with known IBD, fecal calprotectin can be a useful tool to assist management, providing evidence of relapse or mucosal healing to enable therapy to be intensified or reduced. There are a number of commercial calprotectin assays with marked difference in performance as judged by external quality assessment and at present no standardised reference material exists. Various factors may affect results including age, medication and day to day variation. Laboratories should therefore be mindful of the characteristics of their own assay and factors that may affect results.

Clinical features of bowel disease in patients aged <50 years in primary care: a large case-control study

Background

Incidences of colorectal cancer (CRC) and inflammatory bowel disease (IBD) are increasing in those aged <50 years.

Aim

To identify and quantify clinical features in primary care of CRC/IBD in those aged <50 years. This study considered the two conditions together and aimed to determine which younger patients, presenting in primary care with symptoms, would benefit from investigation for potentially serious colorectal disease.

Design and setting

Matched case-control study using primary care records from the Clinical Practice Research Datalink, UK.

Method

Incident cases (aged <50 years) of CRC (n = 1661) and IBD (n = 9578) diagnosed between 2000 and 2013 were each matched with up to three controls (n = 3979 CRC; n = 22 947 IBD). Odds ratios (OR) and positive predictive values (PPV) were estimated for features of CRC/IBD in the year before diagnosis.

Results

Ten features were independently associated with CRC/IBD (all P<0.001): rectal bleeding, change in bowel habit, diarrhoea, raised inflammatory markers, thrombocytosis, abdominal pain, low mean cell volume (MCV), low haemoglobin, raised white cell count, and raised hepatic enzymes. PPVs were >3% for rectal bleeding with diarrhoea, thrombocytosis, low MCV, low haemoglobin or raised inflammatory markers; for change in bowel habit with low MCV, thrombocytosis or low haemoglobin; and for diarrhoea with thrombocytosis.

Conclusion

This study quantified the risk of serious bowel disease in symptomatic patients aged <50 years in primary care. Rectal bleeding and change in bowel habit are strongly predictive of CRC/IBD when combined with abnormal haematology. The present findings help prioritise patients for colonoscopy where the diagnosis is not immediately apparent.

The fecal occult blood test as a tool for improved outpatient qualification for colonoscopy. A single-center experience and 10-year follow-up survey

PURPOSE

Colonoscopy is not widely and easily available in all countries, even for symptomatic patients. This is one of the causes of tumors not being diagnosed until an advanced stage. The aim of this study was to estimate the efficacy of the fecal occult blood test (FOBT) in the diagnostic work-up of outpatients referred to a colorectal unit due to indistinct abdominal symptoms.

PATIENTS/METHODS

Among 10418 consecutive symptomatic individuals referred to the outpatient clinic, an immunochemical FOBT (Hem-Check 1^®) was recommended for 9432 patients with indistinct symptoms as a tool for qualifying them for colonoscopy. All the subjects were treated according to their diagnosis and followed-up for the next 10 years.

RESULTS

Colorectal cancer (CRC) was diagnosed in 535 individuals: 393/986 (39.9%) among patients with red-flag symptoms, and 142/951 (14.9%) of individuals with indistinct symptoms and a positive FOBT. In the latter group, less-advanced tumors, classed as such using Dukes' classification, were twice as common and more advanced CRC occurred twice as seldom than in the former. Cancer recurrence-free and overall survival periods after surgical treatment for CRC were significantly longer in patients with indistinct symptoms who qualified for diagnostic procedures on the basis of a positive FOBT.

CONCLUSIONS

Patients with symptoms suggesting organic colon disease had a worse prognosis compared to individuals with non-specific symptoms. If bowel endoscopy is not widely and easily available, qualification for colonoscopy on the basis of alarm symptoms and a positive FOBT seems to be an effective strategy in early CRC diagnosis.

Poor predictive value of lower gastrointestinal alarm features in the diagnosis of colorectal cancer in 1981 patients in secondary care

BACKGROUND

Clinicians are advised to refer patients with lower gastrointestinal (GI) alarm features for urgent colonoscopy to exclude colorectal cancer (CRC). However, the utility of alarm features is debated.

AIM

To assess whether performance of alarm features is improved by using a symptom frequency threshold to trigger referral, or by combining them into composite variables, including minimum age thresholds, as recommended by the National Institute for Health and Care Excellence (NICE).

METHODS

We collected data prospectively from 1981 consecutive adults with lower GI symptoms. Assessors were blinded to symptom status. The reference standard to define CRC was histopathological confirmation of adenocarcinoma in biopsy specimens from a malignant-looking colorectal lesion. Controls were patients without CRC. Sensitivity, specificity, positive predictive values (PPVs) and negative predictive values were calculated for individual alarm features, as well as combinations of these.

RESULTS

In identifying 47 (2.4%) patients with CRC, individual alarm features had sensitivities ranging from 11.1% (family history of CRC) to 66.0% (loose stools), and specificities from 30.5% (loose stools) to 75.6% (family history of CRC). Using higher symptom frequency thresholds improved specificity, but to the detriment of sensitivity. NICE referral criteria also had higher specificities and lower sensitivity, with PPVs above 4.8%. More than 80% of those with CRC met at least one of the NICE referral criteria.

CONCLUSIONS

Using higher symptom frequency thresholds for alarm features improved specificity, but sensitivity was low. NICE referral criteria had PPVs above 4.8%, but sensitivities ranged from 2.2% to 32.6%, meaning many cancers would be missed.

Diagnosing colorectal cancer and inflammatory bowel disease in primary care: The usefulness of tests for faecal haemoglobin, faecal calprotectin, anaemia and iron deficiency. A prospective study

OBJECTIVE

Abdominal complaints are common reasons to consult primary care but they are seldom caused by colorectal cancer (CRC), high-risk adenomas (HRAs), or inflammatory bowel disease (IBD). Reliable diagnostic aids would be helpful in deciding which patients to refer for bowel imaging. Our aim was to assess the value of a faecal immunochemical test (FIT) and a faecal calprotectin (FC) test in detecting CRC, HRAs and IBD in primary care, and the value of combining these tests with anaemia and iron-deficiency tests.

MATERIALS AND METHODS

This prospective study included 373 consecutive patients that received a FIT or a FC test ordered by a primary care physician. We collected samples for FITs, FC tests, full blood counts and iron-deficiency tests. Physicians were instructed to refer patients with a positive FIT or FC test (cut-off ≥100μg/g) for bowel imaging. The patients' presenting symptoms were recorded. Patients were followed for 2 years.

RESULTS

The best test for detecting CRC and IBD was the combination of the FIT and haemoglobin concentration. This test had a sensitivity, specificity, positive predictive value and negative predictive value of 100%, 61.7%, 11.7% and 100%, respectively. The FIT detected a significantly larger proportion of CRC, HRAs and IBD than the FC test (0.92 versus 0.46, 95% confidence interval 0.22-0.67).

CONCLUSION

A negative FIT combined with a normal haemoglobin concentration could rule out CRC and IBD with a high degree of safety. This could be useful in prioritising referrals for bowel imaging from primary care.