Is there an added value of faecal calprotectin and haemoglobin in the diagnostic work-up for primary care patients suspected of significant colorectal disease? A cross-sectional diagnostic study

Possible Value of Faecal Immunochemical Test (FIT) When Added in Symptomatic Patients Referred for Colonoscopy: A Systematic Review

If Colorectal cancer (CRC) is detected and treated early, the survival rate is high. This is one of the reasons that population-based screening programs for the early detection of CRC using the faecal immunochemical test (FIT) started worldwide. These programs compete with regular colonoscopy programs and increase the waiting time for symptomatic patients. However, the literature has shown that the correlation between intestinal complaints and the gain of colonoscopy is poor. The aim of this study is to assess the diagnostic utility of symptoms for the yield (CRC) of colonoscopy and to compare this with the diagnostic utility of FIT when offered to symptomatic patients. Methods: We performed a systematic review search for CRC as an outcome of colonoscopy in referred symptomatic patients and separately for CRC as an outcome in symptomatic patients with a positive FIT. We searched systematically for clinical trials or observational studies in databases, followed by hand-searching of reference lists. We used random Meta-Disc to evaluate the diagnostic performance, using the exploration of heterogeneity with a variety of test statistics and by computing the pooled estimates. Results: We included 35 studies, with almost 5 million symptomatic patients. In addition, we included nine prospective studies with a positive FIT in symptomatic patients, with more than 5000 patients. Significant heterogeneity was found for every symptom and the outcome of colonoscopy in the effect size of sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and diagnostic odds ratio. In a random effect model, the pooled sensitivity of colonoscopy in symptomatic patients was very low (25%). However, the pooled sensitivity in symptomatic patients with a positive FIT was 83% and the pooled specificity 77%. A total of 75 symptomatic patients (1.4%) had a false-negative FIT. Conclusion: Adding FIT in symptomatic patients seems useful for predicting CRC as an outcome of colonoscopy. FIT seems a potential tool for an improved triage of colonoscopy in symptomatic patients.

Mental Health Morbidities and Time to Cancer Diagnosis Among Adults With Colon Cancer in England

Importance

Mental health morbidity (MHM) in patients presenting with possible cancer symptoms may be associated with prediagnostic care and time to cancer diagnosis.

Objective

To compare the length of intervals to cancer diagnosis by preexisting MHM status in patients who presented with symptoms of as-yet-undiagnosed colon cancer and evaluate their risk of emergency cancer diagnosis.

Design, Setting, and Participants

This cohort study was conducted using linked primary care data obtained from the population-based Clinical Practice Research Datalink, which includes primary care practices in England, linked to cancer registry and hospital data. Included participants were 3766 patients diagnosed with colon cancer between 2011 and 2015 presenting with cancer-relevant symptoms up to 24 months before their diagnosis. Data analysis was performed in January 2021 to April 2022.

Exposures

Mental health conditions recorded in primary care before cancer diagnosis, including anxiety, depression, schizophrenia, bipolar disorder, alcohol addiction, anorexia, and bulimia.

Main Outcomes and Measures

Fast-track (also termed 2-week wait) specialist referral for investigations, time to colonoscopy and cancer diagnosis, and risk of emergency cancer diagnosis.

Results

Among 3766 patients with colon cancer (median [IQR] age, 75 [65-82] years; 1911 [50.7%] women ), 623 patients [16.5%] had preexisting MHM recorded in primary care the year before cancer diagnosis, including 562 patients (14.9%) with preexisting anxiety or depression (accounting for 90.2% of patients with preexisting MHM) and 61 patients (1.6%) with other MHM; 3143 patients (83.5%) did not have MHM. Patients with MHM had records of red-flag symptoms or signs (ie, rectal bleeding, change in bowel habit, or anemia) in the 24 months before cancer diagnosis in a smaller proportion compared with patients without MHM (308 patients [49.4%] vs 1807 patients [57.5%]; P < .001). Even when red-flag symptoms were recorded, patients with MHM had lower odds of fast-track specialist referral (adjusted odds ratio [OR] = 0.72; 95% CI, 0.55-0.94; P = .01). Among 2115 patients with red-flag symptoms or signs, 308 patients with MHM experienced a more than 2-fold longer median (IQR) time to cancer diagnosis (326 [75-552] days vs 133 [47-422] days) and higher odds of emergency diagnosis (90 patients [29.2%] vs 327 patients [18.1%]; adjusted OR = 1.63; 95% CI, 1.23-2.24; P < .001) compared with 1807 patients without MHM.

Conclusions and Relevance

This study found that patients with MHM experienced large and prognostically consequential disparities in diagnostic care before a colon cancer diagnosis. These findings suggest that appropriate pathways and follow-up strategies after symptomatic presentation are needed for earlier cancer diagnoses and improved health outcomes in this large patient group.

Faecal immunochemical tests safely enhance rational use of resources during the assessment of suspected symptomatic colorectal cancer in primary care: systematic review and meta-analysis

OBJECTIVE

Implementation of faecal immunochemical tests (FIT) as a triage test in primary healthcare may improve the efficiency of referrals without missing cases of colorectal cancer (CRC). We aim to summarise the performance characteristics of FITs for CRC in symptomatic patients presenting to primary healthcare.

DESIGN

We performed a systematic literature review of Medline and EMBASE databases from May 2018 to November 2020. Previous related systematic searches were also adapted to this aim and completed with reference screening. We identified studies performed on adult patients consulting for abdominal symptoms in primary care which reported data such that the FIT diagnostic performance parameters for CRC could be obtained. Bivariate models were used to synthesise available evidence. Meta-regression analysis was performed to evaluate the causes of heterogeneity.

RESULTS

Twenty-three studies (69 536 participants) were included (CRC prevalence 0.3%-6.2%). Six studies (n=34 691) assessed FIT as rule in test (threshold of ≥150 µg Hb/g faeces) showing a sensitivity of 64.1% (95% CI 57.8% to 69.9%) and a specificity of 95.0% (95% CI 91.2% to 97.2%). A threshold of 10 µg/g (15 studies; n=48 872) resulted in a sensitivity of 87.2% (95% CI 81.0% to 91.6%) and a specificity of 84.4% (95% CI 79.4% to 88.3%) for CRC. At a 20 µg Hb/g faeces threshold (five studies; n=24 187) less than one additional CRC would be missed per 1000 patients investigated compared with 10 µg Hb/g faeces threshold (CRC prevalence 2%).

CONCLUSION

FIT is the test of choice to evaluate patients with new-onset lower gastrointestinal symptoms in primary healthcare.

Do presenting symptoms, use of pre-diagnostic endoscopy and risk of emergency cancer diagnosis vary by comorbidity burden and type in patients with colorectal cancer?

BACKGROUND

Cancer patients often have pre-existing comorbidities, which can influence timeliness of cancer diagnosis. We examined symptoms, investigations and emergency presentation (EP) risk among colorectal cancer (CRC) patients by comorbidity status.

METHODS

Using linked cancer registration, primary care and hospital records of 4836 CRC patients (2011-2015), and multivariate quantile and logistic regression, we examined variations in specialist investigations, diagnostic intervals and EP risk.

RESULTS

Among colon cancer patients, 46% had at least one pre-existing hospital-recorded comorbidity, most frequently cardiovascular disease (CVD, 18%). Comorbid versus non-comorbid cancer patients more frequently had records of anaemia (43% vs 38%), less frequently rectal bleeding/change in bowel habit (20% vs 27%), and longer intervals from symptom-to-first relevant test (median 136 vs 74 days). Comorbid patients were less likely investigated with colonoscopy/sigmoidoscopy, independently of symptoms (adjusted OR = 0.7[0.6, 0.9] for Charlson comorbidity score 1-2 and OR = 0.5 [0.4-0.7] for score 3+ versus 0. EP risk increased with comorbidity score 0, 1, 2, 3+: 23%, 35%, 33%, 47%; adjusted OR = 1.8 [1.4, 2.2]; 1.7 [1.3, 2.3]; 3.0 [2.3, 4.0]) and for patients with CVD (adjusted OR = 2.0 [1.5, 2.5]).

CONCLUSIONS

Comorbid individuals with as-yet-undiagnosed CRC often present with general rather than localising symptoms and are less likely promptly investigated with colonoscopy/sigmoidoscopy. Comorbidity is a risk factor for diagnostic delay and has potential, additionally to symptoms, as risk-stratifier for prioritising patients needing prompt assessment to reduce EP.

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.

Association of Serum Neuron-Specific Enolase and C-Reactive Protein With Disease Location and Endoscopic Inflammation Degree in Patients With Crohn's Disease

Objective: The objective of this study was to explore the association between serum markers neuron-specific enolase (NSE) and C-reactive protein (CRP) with intestinal lesion location and degree of inflammation in patients with Crohn's disease (CD).

Design: The levels of serum NSE, CRP, and fecal calprotectin (FC) in patients with CD were analyzed retrospectively. The severity of inflammatory lesions in the intestinal wall was accessed using the Simple Endoscopic Score for Crohn's disease (SES-CD).

Results: The levels of NSE in patients with CD were higher than those of healthy individuals (14.87 vs. 12.68 ng/ml, P < 0.001). The levels of CRP in patients with CD were higher than those of healthy individuals (12.30 vs. 3.40 mg/l, P < 0.001). The FC levels in patients with CD were higher than those of patients with non-inflammatory bowel disease (1,143.90 vs. 114.21 μg/g, P < 0.05). The levels of NSE in CD with ileal lesions and simultaneous ileal and colon lesions were significantly higher than those in patients with CD with colonic lesions. However, the CRP was higher in patients with colonic lesions than those with ileal lesions. The levels of NSE in patients with severe inflammation were higher than those in patients with moderate inflammation (15.95 vs. 13.89 ng/ml, P < 0.05). Similarly, the NSE levels in patients with CD with severe inflammation were higher than those in patients with CD with mild inflammation (15.95 vs. 13.53 ng/mL, P < 0.05). The levels of CRP in severe inflammation were higher than those in moderate inflammation (29.80 vs. 19.60 mg/l, P < 0.05). In addition, the CRP levels in severe inflammation were higher than those in mild inflammation (29.80 vs. 5.86 mg/l, P < 0.05). ROC curve analysis showed that when NSE was combined with CRP for distinguishing between patients with CD and those without CD, sensitivity increased to 80.41%, specificity increased to 74.66%, and a highest AUC was equal to 0.843.

Conclusion: Our study shows that serum NSE and CRP can be used to assess the severity of CD as well as the location of intestinal involvement. Therefore, NSE and CRP could be used as the non-invasive tests in detecting the location and severity of disease in patients with CD in daily routine practice.

Recognising Colorectal Cancer in Primary Care

Colorectal cancer (CRC) is the third most common cancer worldwide. Primary care professionals can play an important role in both prevention and early detection of CRC. Most CRCs are attributed to modifiable lifestyle factors, which can be addressed within primary care, and promotion of population-based screening programmes can aid early cancer detection in asymptomatic patients. Primary care professionals have a vital role in clinically assessing patients presenting with symptoms that may indicate cancer, as most patients with CRC first present with symptoms. These assessments are often challenging—many of the symptoms of CRC are non-specific and commonly occur in patients presenting with non-malignant disease. The range of options for investigating symptomatic patients in primary care is rapidly growing. Simple tests, such as faecal immunochemical testing (FIT), are now being used to guide decisions around referral for more invasive tests, such as colonoscopy, while direct access to specialist investigations is also becoming more common. Clinical decision support tools (CDSTs) which calculate cancer risk based on symptomatology, patient characteristics and test results can provide an additional resource to guide decisions on further investigation. This article explores the challenges of CRC prevention and detection from the primary care perspective, discusses current evidence-based approaches for CRC detection used in primary care (with examples from UK guidelines), and highlights emerging research which may likely alter practice in the future.

Use of faecal immunochemical testing as an alternative to faecal calprotectin in children

BACKGROUND

Faecal calprotectin has been widely used as a non-invasive marker of intestinal inflammation in children. Measurement of faecal haemoglobin using faecal immunochemical test is well established in adults for detection of colorectal cancer. In adults, faecal haemoglobin has been recommended as a reliable tool to aid identification of those at low risk of significant bowel disease and has also been used in inflammatory bowel disease to assess mucosal healing.

AIMS

We aimed to evaluate the performance of faecal haemoglobin in the paediatric population and compare it with faecal calprotectin.

METHODS

Children being assessed in the paediatric gastroenterology clinic for bowel symptoms had a sample sent for both faecal calprotectin and faecal haemoglobin. Samples were collected over a 10-month period from November 2018 to September 2019. Faecal haemoglobin was measured using an OC-Sensor. Faecal calprotectin was measured using Liason®Calprotectin.

RESULTS

One hundred forty three samples were returned for faecal haemoglobin and in 107 a paired faecal calprotectin was also available. Faecal haemoglobin correlated with faecal calprotectin, Spearman's rank coefficient 0.656 (P < 0.0001). There were 35 patients with faecal haemoglobin >20 μg/g and in 32 of these patients faecal calprotectin was >200 μg/g; 74 patients with faecal haemoglobin and 38 patients with faecal calprotectin underwent colonoscopy. Patients with normal histology had faecal haemoglobin <4 μg/g; faecal haemoglobin >20 µg/g was associated with signification inflammation.

CONCLUSION

Our study is the first to compare faecal haemoglobin and faecal calprotectin in a paediatric population. Results suggest that faecal haemoglobin correlates with faecal calprotectin and, as in adults, may be useful to rule out significant bowel disease. A faecal haemoglobin >20 μg/g was consistent with significant histological inflammation.

Intestinal ultrasound as first-line investigation in low-risk gastrointestinal symptoms: a new model of care

BACKGROUND

Functional gut disorders (FGD) are common. Diagnosis is symptom based, although symptoms may be indistinguishable from inflammatory bowel disease. As a result of this, investigations are common, diagnostic yield is low. A streamlined novel model of care may reduce costly investigations.

AIM

To compare a new model of care for patients with low-risk gastrointestinal symptoms to a matched historical cohort.

METHODS

Data were prospectively collected over 12 months. General practitioner referrals for low-risk abdominal symptoms were triaged to a new multidisciplinary clinic structure utilising intestinal ultrasound. Outcomes were compared to the historical model in the preceding 12 months. Duration of care (time from referral to discharge), number of contact episodes and investigations ordered were reviewed.

RESULTS

Thirty-seven patients meeting strict inclusion criteria completed their care. Compared with the historical cohort, colonoscopies reduced from 0.7 to 0.05 per patient (P < 0.0001). Gastroenterology consults reduced from 1.5 to 1.2 (P = 0.303) and dietitian review increased from 0.8 to 1.5 (P < 0.0001). Total contact episodes reduced from 3.2 to 1.8 (P < 0.0001). Duration of care reduced from a median of 252 days to 130 days (interquartile ranges (IQR) 287 and 69, respectively; P < 0.0001). Time from first consultation to discharge reduced from 125 to 42 days (IQR 188 and 63; P < 0.0001).

CONCLUSION

This multidisciplinary approach to care of low-risk abdominal symptoms significantly reduced contact episodes, time in care and invasive investigations. It decreased costly gastroenterology consultation and increased allied health exposure. It demonstrates improved health service outcomes.

Faecal immunochemical testing for adults with symptoms of colorectal cancer attending English primary care: a retrospective cohort study of 14 487 consecutive test requests

BACKGROUND

Faecal immunochemical testing (FIT) is recommended by the National Institute for Health and Care Excellence (NICE) to triage symptomatic primary care patients for further investigation of colorectal cancer.

AIM

To ascertain the diagnostic performance of FIT in symptomatic adult primary care patients.

METHODS

Faecal samples from routine primary care practice in Oxfordshire, UK were analysed using the HM-JACKarc FIT method between March 2017 and March 2020. Clinical details were recorded. Patients were followed for up to 36 months in linked hospital records for evidence of benign and serious (colorectal cancer, high-risk adenomas and bowel inflammation) colorectal disease. The diagnostic accuracy of FIT is reported by gender, age group and FIT threshold.

RESULTS

In 9896 adult patients with at least 6-month follow-up, a FIT result ≥10 µg Hb/g faeces had a sensitivity for colorectal cancer of 90.5% (95% CI 84.9%-96.1%), specificity 91.3% (90.8%-91.9%), positive predictive value (PPV) 10.1% (8.15%-12.0%) and negative predictive value (NPV) 99.9% (99.8%-100.0%). The PPV and specificity for serious colorectal disease were higher and the sensitivity and NPV lower than for colorectal cancer alone. The area under the curve for all adults did not change substantially by gender or by increasing the minimum age of testing. Using ≥10 µg Hb/g faeces, 10% of adults would be investigated to detect 91% of cancers, a number needed to scope of ten to detect one cancer. Using ≥7, ≥50 and ≥150 µg Hb/g faeces, 11%, 4% and 3% of adults would be investigated, and 91%, 74% and 54% cancers detected, respectively.

CONCLUSION

A FIT threshold of ≥10 µg Hb/g faeces would be appropriate to triage adult patients presenting to primary care with symptoms of serious colorectal disease. FIT may be used to reprioritise patients referred with colorectal cancer symptoms whose investigations have been delayed by the COVID-19 pandemic.

Impact of the faecal immunochemical test on colorectal cancer survival

Background

There is already evidence that the faecal immunochemical test (FIT) is a useful tool for the diagnosis of colorectal cancer (CRC) that helps to identify symptomatic patients requiring early colonoscopy. Although the recommendation to use FIT is widely accepted, there are no data concerning whether this strategy improves patient survival.The objective was to assess whether the survival is higher if CRC patients have been first diagnosed by FIT (as compared with the rest of patients with CRC).

Methods

We identified all cases of CRC diagnosed between 2009 and 2016 in Donostialdea (Spain), excluding all the CRC detected in population screening. We focused on symptomatic patients. One thousand five hundred twenty-seven cases of CRC were divided into two groups based on the route to diagnosis: group 1: individuals who tested positive in a FIT during the year before diagnosis, and group 2: others.Survival was assessed by Kaplan-Meier estimation, and with the log-rank test. A Cox regression model was used to adjust for differences between groups due to other variables associated with survival.

Results

One thousand nine hundred sixty-seven cases of invasive CRC were identified, of which 22.4% were detected in population screening. Of the 1527 cases diagnosed in symptomatic patients, 317 patients had undergone a FIT in the year before the diagnosis of CRC. In 279 cases(18.3%), the result had been positive and this was the first step towards their CRC diagnosis (group 1). Group 2 was composed of the 1248 cases of CRC (81.7%). Considering these cases, 1210 patients with CRC did not undergo any FIT while 38 patients presented a negative result in the year before the diagnosis. The rate of early-stage disease (stage I or II) was higher in group 1 (51.3% vs 45.5% in group 2) (p = 0.04). Furthermore, the 3-year survival was longer in group 1 (72% vs 59% in group 2) (HR 1.50; 95% CI 1.22–1.84).The variables independently associated with worse survival were: group 2, age > 70 years and stage at the moment of diagnosis.

Conclusions

The use of FIT as a diagnostic strategy in symptomatic patients may improve survival in CRC. Nonetheless,FIT is still not widely used in our region.

Patient-reported and doctor-reported symptoms when faecal immunochemical tests are requested in primary care in the diagnosis of colorectal cancer and inflammatory bowel disease: a prospective study

BACKGROUND

Rectal bleeding and a change in bowel habits are considered to be alarm symptoms for colorectal cancer and they are also common symptoms for inflammatory bowel disease. However, most patients with these symptoms do not have any of these diseases. Faecal immunochemical tests (FITs) for haemoglobin are used as triage tests in Sweden and other countries but little is known about the symptoms patients have when FITs are requested.

OBJECTIVE

Firstly, to determine patients' symptoms when FITs are used as triage tests in primary care and whether doctors record the symptoms that patients report, and secondly to evaluate the association between symptoms, FIT results and possible prediction of colorectal cancer or inflammatory bowel disease.

METHODS AND MATERIALS

This prospective study included 364 consecutive patients for whom primary care doctors requested a FIT. Questionnaires including gastrointestinal symptoms were completed by patients and doctors.

RESULTS

Concordance between symptoms reported from patients and doctors was low. Rectal bleeding was recorded by 43.5% of patients versus 25.6% of doctors, FITs were negative in 58.3 and 52.7% of these cases respectively. The positive predictive value (PPV) of rectal bleeding recorded by patients for colorectal cancer or inflammatory bowel disease was 9.9% (95% confidence interval [CI] 5.2-14.7); for rectal bleeding combined with a FIT the PPV was 22.6% (95% CI 12.2-33.0) and the negative predictive value (NPV) was 98.9% (95% CI 96.7-100). For patient-recorded change in bowel habits the PPV was 6.1% (95% CI 2.4-9.8); for change in bowel habits combined with a FIT the PPV was 18.2% (95% CI 9.1-30.9) and the NPV 100% (95% CI 90.3-100).

CONCLUSIONS

Doctors should be aware that, during consultations, they do not record all symptoms experienced by patients. FITs requested in primary care, when found positive, may potentially be of help in prioritising referrals, also when patients present with rectal bleeding or change in bowel habits.

Fecal calprotectin and colorectal cancer

Fecal calprotectin (FC) is a bioactive protein secreted by inflammatory cells in the intestine, having anti-microbial and anti-infection activities. The content of FC reflects the inflammatory state of the intestine, and its role in inflammatory bowel disease has been translated into clinical practice. In recent years, the application of FC in colorectal cancer (CRC) has been increasing. Previous research results show that FC can be used to screen colorectal cancer and differentiate it from other intestinal diseases, and the concentration of FC may be related to the stage, location, and resectability of CRC. However, its role still needs to be further clarified through high-quality, large-sample research. This paper reviews the application of FC in colorectal cancer.

Experience of adopting faecal immunochemical testing to meet the NICE colorectal cancer referral criteria for low-risk symptomatic primary care patients in Oxfordshire, UK

OBJECTIVE

To compare the diagnostic performance of guaiac faecal occult blood (gFOB) testing with faecal immunochemical test (FIT) in a low-risk symptomatic primary care population to provide objective data on which to base local referral guidelines.

DESIGN

Stool samples from routine primary care practice sent for faecal occult blood testing were analysed by a standard gFOB method and the HM-JACKarc FIT between January and March 2016. Symptoms described on the test request were recorded. Patients were followed up over 21 months for evidence of serious gastrointestinal pathology including colorectal adenocarcinoma.

RESULTS

In 238 patients, the sensitivity and specificity for colorectal adenocarcinoma detection using gFOB were 85.7% and 65.8%, respectively, compared with 85.7% and 89.2% for FIT. The positive predictive value (PPV) for gFOB was 7.1% and negative predictive value (NPV) was 99.3%. Comparatively, the PPV for FIT was 19.4% and NPV 99.5%. The improved performance of FIT over gFOB was due to a lower false positive rate (10.8 vs 34.2, p≤0.01) with no increase in the false negatives rate. For any significant colorectal disease, the PPV for FIT increased to 35.5% with a reduction in NPV to 95.7%.

CONCLUSION

In this low-risk symptomatic patient group, the proportion of samples considered positive by FIT was considerably lower than gFOB with the same rate of colorectal adenocarcinoma detection. One in three of those with positive FIT had a significant colorectal disease. This supports National Institute of Health and Care Excellence recommendation that FIT can be reliably used as a triage test in primary care without overburdening endoscopy resources.

Potential for Reducing Time to Referral for Colorectal Cancer Patients in Primary Care

PURPOSE

An optimal diagnostic process in primary care is pivotal for reducing cancer-related disease burden. This study aims to explore reasons for long times to referral for Dutch colorectal cancer (CRC) patients in primary care.

METHODS

A retrospective cohort study of anonymized free-text primary care records from the Julius General Practitioners' Network database, linked to the Netherlands Cancer Registry. Patients with a confirmed CRC diagnosis from 2007 through 2011 that symptomatically presented in primary care were included. Median time and interquartile ranges from presentation in primary care to referral were calculated for multiple patient and presentation characteristics. Associations of these characteristics with long time to referral (75th percentile was ≥59 days) were examined with log-binomial regression analyses. Routes to referral of patients with the longest times to referral were explored using thematic free-text analyses (90th percentile at ≥219 days).

RESULTS

Among the 309 people with CRC, patients who were female, did not have a registered family history, had a history of malignancy, lacked alarm symptoms at presentation, or had hemorrhoids at physical examination were at risk for longer time to referral in univariable analyses (longer median durations and/or univariable association with the 75th percentile). Only presentation without alarm symptoms showed a statistically significant association with long duration (75th percentile) in multivariable analysis (relative risk = 1.7; 95% CI, 1.1-2.6). Thematic exploration of the diagnostic routes to referral of patients with the longest durations (90th percentile) showed 2 dominating themes: "alternative working diagnosis" and "suboptimal diagnostic strategies," and included the sub-themes "omitting to reconsider an initial diagnosis" and "lacking follow-up."

CONCLUSIONS

Long time to referral for CRC in primary care is mainly related to low cancer suspicion. There is potential for reducing the longest times to referral for patients with CRC in primary care, with earlier reconsideration of the initial hypothesis and implementation of strict follow-up consultations.

Impact of introducing a faecal immunochemical test (FIT) for haemoglobin into primary care on the outcome of patients with new bowel symptoms: a prospective cohort study

Objective

To determine whether a faecal immunochemical test (FIT) for faecal haemoglobin concentration (f-Hb) can be safely implemented in primary care as a rule-out test for significant bowel disease (SBD) (colorectal cancer (CRC), higher risk adenoma (HRA) and inflammatory bowel disease (IBD)) when used as an adjunct to the clinical assessment of new bowel symptoms.

Design

Single-centre prospective cohort study of all patients who attended primary care and submitted a FIT in the first calendar year of the service beginning December 2015. f-Hb was estimated using HM-JACKarc (Kyowa Medex) with a clinical cut-off of ≥10 µg Hb/g faeces. Incident cases of CRC were verified via anonymised record linkage to the Scottish Cancer Registry.

Results

5422 patients submitted 5660 FIT specimens, of which 5372 were analysed (positivity: 21.9%). 2848 patients were referred immediately to secondary care and three with f-Hb <10 µg/g presented acutely within days with obstructing CRC. 1447 completed colonoscopy in whom overall prevalence of SBD was 20.5% (95 CRC (6.6%), 133 HRA (9.2%) and 68 IBD (4.7%)); 6.6% in patients with f-Hb <10 µg/g vs 32.3% in patients with f-Hb ≥10 µg/g. One CRC was detected at CT colonoscopy. 2521 patients were not immediately referred (95.3% had f-Hb <10 µg/g) of which four (0.2%) later developed CRC. Record linkage identified no additional CRC cases within a follow-up period of 23–35 months.

Conclusion

In primary care, measurement of f-Hb, in conjunction with clinical assessment, can safely and objectively determine a patient’s risk of SBD.

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 immunochemical tests for haemoglobin (FIT) in the assessment of patients with lower abdominal symptoms: current controversies

Faecal immunochemical tests for haemoglobin (FIT), as an adjunct to clinical information, assist in the triage of patients presenting in primary care with lower abdominal symptoms. Controversy remains regarding whether and which qualitative and quantitative FIT can be used, which groups of patients would benefit most from FIT, whether FIT should be done in primary and/or secondary care, and how FIT should be incorporated into diagnostic pathways. Controversy also exists as to the optimum cut-off used for referral for colonoscopy. A single sample of faeces may be sufficient. Reporting of results requires consideration. FIT provide a good rule in test for colorectal cancer and a good rule out test for significant bowel disease, but robust safety-netting is required for patients with negative results and ongoing symptoms. Risk scoring models have been developed, but their value is unclear as yet. Further evaluation of these topics is required to inform good practice.

Attitudes towards faecal immunochemical testing in patients at increased risk of colorectal cancer: an online survey of GPs in England

BACKGROUND

There is increasing interest in using a quantitative faecal immunochemical test (FIT) to rule out colorectal cancer (CRC) in patients with high-risk symptoms in primary care.

AIM

This study aimed to investigate GPs' attitudes and willingness to use a FIT over an urgent 2-week wait (2WW) referral.

DESIGN AND SETTING

A cross-sectional online survey involving 1024 GPs working across England.

METHOD

Logistic regression models were used to explore the likelihood of GPs using a FIT instead of a 2WW referral, and reported using odds ratios (ORs) and 95% confidence intervals (95% CIs).

RESULTS

Just over one-third of GPs (n = 365) preferred to use a FIT as a rule-out test over a 2WW referral. GPs were more willing if they were: aged 36-45 years (OR 1.59 [95% CI = 1.04 to 2.44]); 46-55 years (OR 1.99 [95% CI = 1.14 to 3.47]); thought a FIT was highly accurate (OR 1.63 [95% CI = 1.16 to 2.29]); thought patients would benefit compared with having a colonoscopy (OR 2.02 [95% CI = 1.46 to 2.79]); and were highly confident about discussing the benefits of a FIT (OR 2.14 [95% CI = 1.46 to 3.16]). GPs were less willing if they had had >10 urgent referrals in the past year (OR 0.62 [95% CI = 0.40 to 0.94]) and thought that longer consultations would be needed (OR 0.61 [95% CI = 0.44 to 0.83]).

CONCLUSION

The study findings suggest that the acceptability of using a FIT as a rule-out test in primary care is currently low, with less than half of GPs who perceived the test to be accurate preferring it over colonoscopy. Any potential guideline changes recommending a FIT in patients with high-risk symptoms, instead of urgent referral to rule out CRC, are likely to require intensive supporting educational outreach to increase GP confidence in the accuracy and application of a FIT in this context.

The value of using the faecal immunochemical test in general practice on patients presenting with non-alarm symptoms of colorectal cancer

Background

Around 50% of individuals with colorectal cancer (CRC) initially present with non-alarm symptoms.

Methods

We investigated the value of using the faecal immunochemical test (FIT) in the diagnostic process of CRC and other serious bowel disease in individuals presenting with non-alarm symptoms in general practice. The study was conducted in the Central Denmark Region from 1 September 2015 to 30 August 2016. The FIT was used as a rule-in test on patients aged ≥30 years with non-alarm symptoms of CRC. The cut-off value was set to 10 µg Hb/g faeces.

Results

A total of 3462 valid FITs were performed. Of these, 540 (15.6%) were positive. Three months after FIT performance, 51 (PPV: 9.4% (95% CI: 7.0;11.9)) individuals with a positive FIT were diagnosed with CRC and 73 (PPV: 13.5% (95%CI: 10.6;16.4)) with other serious bowel disease. Of CRCs, 66.7% were diagnosed in UICC stage I & II and 19.6% in stage IV. The false negative rate for CRC was <0.1% for the initial 3 months after FIT performance.

Conclusion

The FIT may be used as a supplementary diagnostic test in the diagnostic process of CRC and other serious bowel disease in individuals with non-alarm symptoms of CRC in general practice.

Evaluation of sample stability for a quantitative faecal immunochemical test and comparison of two sample collection approaches

Background

Faecal immunochemical testing is increasingly being used to triage symptomatic patients for suspected colorectal cancer. However, there are limited data on the effect of preanalytical factors on faecal haemoglobin when measured by faecal immunochemical testing. The aim of this work was to evaluate the stability of faecal haemoglobin in faeces and to compare two methods of faecal haemoglobin sampling for faecal immunochemical testing.

Methods

Six patients provided faeces for faecal haemoglobin measurement which were transferred into specialized collection devices at baseline and at 1, 2, 3 and 7 days after storage at either room temperature or 4°C. A total of 137 patients returned both faeces transferred into the specialized collection device and faeces in a standard collection pot. A quantitative immunoturbidometric method was used to measure faecal haemoglobin and results were compared categorically. Discrepant results were assessed against diagnosis.

Results

Faecal haemoglobin concentration declined rapidly within a day of storage at room temperature but results remained ≥10 μg Hb/g faeces in 5/6 patients after two days. A faecal haemoglobin result ≥10 μg Hb/g faeces was obtained in 4/6 patients after storage for seven days at 4°C. Results obtained when patients used specialized collection devices were significantly different from results obtained when faeces was transferred into the specialized collection device in the laboratory.

Conclusion

There is considerable heterogeneity in the sample stability of faecal haemoglobin; therefore, samples should be transferred rapidly into specialized collection devices to prevent false-negative results. Use of collection devices by patients can lead to false-positive results compared with their use in a laboratory.

Reimagining the diagnostic pathway for gastrointestinal cancer

A crisis is looming for the diagnosis of gastrointestinal cancers, one grounded only partly in the steady increase in their overall incidence. Public demand for diagnostic tests to be undertaken early and at lower levels of risk is reflected in early diagnosis being a widely held policy objective for reasons of both clinical outcome and patient experience. In the UK, urgent referrals for suspected lower gastrointestinal cancer have increased by 78% in the past 6 years, with parallel increases in endoscopy and imaging activity. Such growth in demand is unsustainable with current models of care. If gastrointestinal cancer diagnosis is to be affordable, the roles of professionals and their interactions with each other will need to be reframed while retaining public confidence in the process. In this Perspective, we consider how the relationship between medical specialists and generalists could be redefined to make better use of the skills of each while delivering optimal clinical outcomes and a good patient experience.

Discovery and validation of a colorectal cancer classifier in a new blood test with improved performance for high-risk subjects

BACKGROUND

The aim was to improve upon an existing blood-based colorectal cancer (CRC) test directed to high-risk symptomatic patients, by developing a new CRC classifier to be used with a new test embodiment. The new test uses a robust assay format-electrochemiluminescence immunoassays-to quantify protein concentrations. The aim was achieved by building and validating a CRC classifier using concentration measures from a large sample set representing a true intent-to-test (ITT) symptomatic population.

METHODS

4435 patient samples were drawn from the Endoscopy II sample set. Samples were collected at seven hospitals across Denmark between 2010 and 2012 from subjects with symptoms of colorectal neoplasia. Colonoscopies revealed the presence or absence of CRC. 27 blood plasma proteins were selected as candidate biomarkers based on previous studies. Multiplexed electrochemiluminescence assays were used to measure the concentrations of these 27 proteins in all 4435 samples. 3066 patients were randomly assigned to the Discovery set, in which machine learning was used to build candidate classifiers. Some classifiers were refined by allowing up to a 25% indeterminate score range. The classifier with the best Discovery set performance was successfully validated in the separate Validation set, consisting of 1336 samples.

RESULTS

The final classifier was a logistic regression using ten predictors: eight proteins (A1AG, CEA, CO9, DPPIV, MIF, PKM2, SAA, TFRC), age, and gender. In validation, the indeterminate rate of the new panel was 23.2%, sensitivity/specificity was 0.80/0.83, PPV was 36.5%, and NPV was 97.1%.

CONCLUSIONS

The validated classifier serves as the basis of a new blood-based CRC test for symptomatic patients. The improved performance, resulting from robust concentration measures across a large sample set mirroring the ITT population, renders the new test the best available for this population. Results from a test using this classifier can help assess symptomatic patients' CRC risk, increase their colonoscopy compliance, and manage next steps in their care.

Diagnostic work-up of patients presenting in primary care with lower abdominal symptoms: which faecal test and triage strategy should be used?

Bowel endoscopy referrals from primary care have increased steadily over recent years. However, most patients do not have significant colorectal disease (SCD). Therefore, strategies to select those who would benefit most from endoscopy are of current interest. A recent study developed a multivariable diagnostic model for SCD with routine clinical information, extended with quantitative faecal calprotectin (f-C) point-of-care (POC) testing and/or qualitative POC faecal immunochemical test (FIT) for haemoglobin (f-Hb) results. This study used POC tests for both f-C and f-Hb; however, POC tests have many disadvantages and there are several reasons why quantitative measurements of f-Hb are advantageous. Quantitative faecal immunochemical tests have been used very successfully in triage of patients presenting in primary care as a rule-out test. Studies have compared f-C and f-Hb in this clinical context and consider that f-C is not required in diagnosis. A single quantitative f-Hb result, without any clinical information, could be sufficient to decide whom to refer for endoscopy and, because of the significant overlap of symptoms in those with and without SCD, could be the primary investigation performed.Please see related article: http://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-016-0684-5 .