Is it worthwhile to perform capsule endoscopy for asymptomatic patients with positive immunochemical faecal occult blood test?

Risk of Oral and Upper Gastrointestinal Cancers in Persons With Positive Results From a Fecal Immunochemical Test in a Colorectal Cancer Screening Program

BACKGROUND & AIMS

European guidelines recommend screening for colorectal cancer (CRC) using the fecal immunochemical test (FIT), with follow-up colonoscopies for individuals with positive test results. However, more than half of participants with positive results from the FIT are not found to have advanced neoplasia in the colonoscopy examination. Fecal occult blood might also come from the upper gastrointestinal (GI) tract, so perhaps we should consider esophagogastroduodenoscopy (EGD), to detect upper GI cancers. We aimed to determine how many individuals are found to have oral or upper GI cancers (oral cavity, throat, esophageal, gastric, or small bowel cancer) within 3 years after a positive or negative result from a FIT in a CRC screening program.

METHODS

We performed a retrospective analysis of data from a pilot study of 3 rounds of biennial FIT-based screening for CRC in 2 regions in the west of the Netherlands, from 2006 through October 2012. Participants who developed oral or upper GI cancers were identified through linkage with the National Cancer Registry. We classified these cancers into 3 groups: those that developed in individuals with a positive result from a FIT but negative findings from colonoscopy (no advanced neoplasia), those that developed in individuals with a positive result from a FIT and a positive finding from colonoscopy (advanced neoplasia), and those that developed in individuals with negative results from a FIT. We compared oral and upper GI cancer incidence among groups.

RESULTS

Among 16,165 screening participants, linkage identified 52 persons who developed an oral or upper GI cancer within 3 years after a FIT. We found no significant difference in incidence values between individuals with a positive vs a negative FIT result: 8 cancers developed in individuals with a positive result from a FIT (0.37%; 95% CI, 0.19-0.76) and 44 developed in individuals with a negative result from a FIT (0.31%; 95% CI, 0.23-0.42) (P = .65). Of the 8 individuals with a positive result from a FIT and an oral or upper GI cancer, 6 were diagnosed after negative findings from colonoscopy and 2 after positive findings from colonoscopy. We found that only 0.14% of all persons with a positive result from a FIT were diagnosed with a gastric or esophageal cancer within 3 years.

CONCLUSION

In a study of individuals in the Netherlands undergoing screening for CRC by FIT, we found fewer than 1% of patients with a positive result from the FIT to receive a diagnosis of upper GI cancers within 3 years. Routine EGD investigation of individuals with positive results from a FIT and negative findings from colonoscopy is therefore not recommended. TrialRegister.nl, Number: NTR5385.

Luminally expressed gastrointestinal biomarkers

A biomarker is a measurable indicator of normal biologic processes, pathogenic processes or pharmacological responses. The identification of a useful biomarker is challenging, with several hurdles to overcome before clinical adoption. This review gives a general overview of a range of biomarkers associated with inflammatory bowel disease or colorectal cancer along the gastrointestinal tract. Areas covered: These markers include those that are already clinically accepted, such as inflammatory markers such as faecal calprotectin, S100A12 (Calgranulin C), Fatty Acid Binding Proteins (FABP), malignancy markers such as Faecal Occult Blood, Mucins, Stool DNA, Faecal microRNA (miRNA), other markers such as Faecal Elastase, Faecal alpha-1-antitrypsin, Alpha2-macroglobulin and possible future markers such as microbiota, volatile organic compounds and pH. Expert commentary: There are currently a few biomarkers that have been sufficiently validated for routine clinical use at present such as FC. However, many of these biomarkers continue to be limited in sensitivity and specificity for various GI diseases. Emerging biomarkers have the potential to improve diagnosis and monitoring but further study is required to determine efficacy and validate clinical utility.

Is a fecal occult blood test a useful tool for judging whether to perform capsule endoscopy in low-dose aspirin users with negative colonoscopy and esophagogastroduodenoscopy?

BACKGROUND

Aspirin use is reportedly not to be associated with fecal immunochemical occult blood test (FIT) false-positive results for the detection of colorectal cancer. The need for additional small bowel exploration in FIT-positive, low-dose aspirin users with a negative colonoscopy is controversial. The aim of this study was to assess the ability of FIT to judge whether capsule endoscopy (CE) should be performed in low-dose aspirin users with negative colonoscopy and esophagogastroduodenoscopy findings by comparing FIT results with CE findings.

METHODS

A total of 264 consecutive low-dose aspirin users with negative colonoscopy and esophagogastroduodenoscopy who were scheduled to undergo CE at five hospitals in Japan were enrolled. Patients had been offered FIT prior to the CE. The association between the FIT results and the CE findings was then assessed.

RESULTS

One hundred and fifty-seven patients were included in the final analysis. Eighty-four patients (53.5 %) had positive FIT results. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of positive FIT results for small bowel ulcers were 0.56, 0.47, 0.30, and 0.73, respectively. Furthermore, the NPV of positive FIT results for severe small bowel injury (Lewis score ≥790) was markedly high (0.90). When the analysis was performed only in low-dose aspirin users with anemia, the sensitivity of the positive FIT results was notably improved (0.72).

CONCLUSIONS

Small bowel evaluation using CE is not recommended for FIT-negative, low-dose aspirin users. However, small bowel evaluation using CE should be considered in both FIT-positive and anemic low-dose aspirin users.

Fecal occult blood testing for the prediction of small-bowel pathology detected by capsule endoscopy: a systematic review and meta-analysis

Background

Fecal occult blood testing (FOBT) has been suggested as a potential screening tool for small-bowel capsule endoscopy (CE). We conducted a meta-analysis of studies correlating FOBT and CE findings to examine the predictive value of positive FOBT for CE findings.

Methods

PubMed and Embase search. Sensitivity, specificity and diagnostic odds ratios (DORs) were calculated.

Results

Six studies were identified. Four used fecal immunochemical testing (FIT), one used FIT and guaiac FOBT, one used hemoglobin/haptoglobin complex testing (Hb/Hpt). Five of the 6 studies were suitable for statistical analysis. For all positive FOBT, sensitivity for small-bowel findings was 0.60 (95%CI 0.50-0.69), specificity was 0.72 (95%CI 0.52-0.86), and DOR was 3.96 (95%CI 1.50-10.4). For the 4 studies using only FIT, sensitivity was 0.48 (95%CI 0.36-0.61), specificity was 0.60 (95%CI 0.42-0.76), and DOR was 1.41 (95%CI 0.72-2.75).

Conclusions

Although a number of modalities have been suggested for screening small-bowel CE referrals, none of them, including FOBT, offer a comprehensive solution. Further work is required to refine screening methods for small-bowel CE referrals.

[Capsule endoscopy and obscure gastrointestinal bleeding: does the form of presentation matter?]

INTRODUCTION

Obscure gastrointestinal bleeding (OGIB) is defined as bleeding from the gastrointestinal tract with no obvious cause after assessment with upper and lower gastrointestinal endoscopy. In these cases, the source is suspected to be in the small bowel. Obscure bleeding can be occult or overt. The aim of this study was to analyze the clinical and analytical characteristics and findings on capsule endoscopy in patients with OGIB and to determine the factors related to the detection of lesions in both forms of presentation.

METHODS

We performed a retrospective study of capsule endoscopies carried out between November 2009 and November 2012 for OGIB.

RESULTS

We analyzed 284 capsule endoscopies in 272 patients. Initially, 12 procedures could not be evaluated and were repeated. A total of 272 procedures were finally included in the analysis. The results of 114 (41.9%) capsule endoscopies were normal. Compared with patients with occult OGIB, those with overt OGIB were significantly older (70.2 vs. 67.5 years; p = 0.04), consumed more NSAID (24.2% vs. 11.9%; p = 0.01), had higher hemoglobin levels (9.3 vs. 10.4; p < 0,001) and more frequently required transfusion (64.5% vs 32.2%; p < 0.001). No differences were found between the two forms of presentation in the detection of canker sores-ulcers and polyps-masses. Vascular lesions were more frequently detected in overt than in occult OGIB (40.3% vs. 25.7%, respectively), (p < 0.05). When the total number of diagnoses carried out by capsule endoscopy was analyzed, no differences were found in diagnostic yield between overt OGIB (57%) and occult OGIB (54%), (p = 0.6). In overt OGIB, multivariate analysis showed that the variables that significantly predicted the detection of lesions on capsule endoscopy were consumption of medication NSAID (OR 2.75; p = 0.01), antiplatelets and anticoagulants (OR 2.64; p = 0.03) and analytical data hemoglobin (OR 3.23; p < 0.001) and INR (OR 1.8; p = 0.02). In occult OGIB, multivariate analysis showed that the factors significantly related to the detection of lesions on endoscopy were age (OR 1.9; p = 0.04) and NSAID consumption (OR 2.1; p = 0.01).

CONCLUSIONS

Capsule endoscopy is essential in the assessment of OGIB. Although the diagnostic yield was similar in both forms of presentation, vascular lesions were more frequently detected in overt OGIB. The diagnostic yield of capsule endoscopy could be optimized by taking into account the form of presentation (overt vs. occult) and certain clinical and analytic data (age, drug consumption, hemoglobin).

Impact of fecal occult blood on obscure gastrointestinal bleeding: Observational study

AIM: To elucidate the association between small bowel diseases (SBDs) and positive fecal occult blood test (FOBT) in patients with obscure gastrointestinal bleeding (OGIB).

METHODS: Between February 2008 and August 2013, 202 patients with OGIB who performed both capsule endoscopy (CE) and FOBT were enrolled (mean age; 63.6 ± 14.0 years, 118 males, 96 previous overt bleeding, 106 with occult bleeding). All patients underwent immunochemical FOBTs twice prior to CE. Three experienced endoscopists independently reviewed CE videos. All reviews and consensus meeting were conducted without any information on FOBT results. The prevalence of SBDs was compared between patients with positive and negative FOBT.

RESULTS: CE revealed SBDs in 72 patients (36%). FOBT was positive in 100 patients (50%) and negative in 102 (50%). The prevalence of SBDs was significantly higher in patients with positive FOBT than those with negative FOBT (46% vs 25%, P = 0.002). In particular, among patients with occult OGIB, the prevalence of SBDs was higher in positive FOBT group than negative FOBT group (45% vs 18%, P = 0.002). On the other hand, among patients with previous overt OGIB, there was no significant difference in the prevalence of SBDs between positive and negative FOBT group (47% vs 33%, P = 0.18). In disease specific analysis among patients with occult OGIB, the prevalence of ulcer and tumor were higher in positive FOBT group than negative FOBT group. In multivariate analysis, only positive FOBT was a predictive factors of SBDs in patients with OGIB (OR = 2.5, 95%CI: 1.4-4.6, P = 0.003). Furthermore, the trend was evident among patients with occult OGIB who underwent FOBT on the same day or a day before CE. The prevalence of SBDs in positive vs negative FOBT group were 54% vs 13% in patients with occult OGIB who underwent FOBT on the same day or the day before CE (P = 0.001), while there was no significant difference between positive and negative FOBT group in those who underwent FOBT two or more days before CE (43% vs 25%, P = 0.20).

CONCLUSION: The present study suggests that positive FOBT may be useful for predicting SBDs in patients with occult OGIB. Positive FOBT indicates higher likelihood of ulcers or tumors in patients with occult OGIB. Undergoing CE within a day after FOBT achieved a higher diagnostic yield for patients with occult OGIB.

Application of fecal hemoglobin-haptoglobin complex testing for small bowel lesions

OBJECTIVE

Fecal hemoglobin-haptoglobin (Hb-Hpt) complex testing is theoretically superior to immunochemical fecal occult blood test detecting human hemoglobin (Hb), as Hb-Hpt is more stable compared to Hb during passage through the gastrointestinal (GI) tract. The aim was to examine the role of fecal Hb-Hpt complex testing in predicting small bowel lesions detected by video capsule endoscopy (VCE).

MATERIALS AND METHODS

Stools from patients undergoing small bowel VCE for obscure GI bleeding (OGIB) without ongoing overt bleeding were included. Two stool specimens were obtained on different days just before VCE to measure Hb-Hpt complex by ELISA and Hb by latex agglutination turbidimetric immunoassay.

RESULTS

Seventy-six patients (39 men and 37 women, average age 66 years) with suspected small bowel lesions entered. Median Hb-Hpt complex and Hb levels were significantly higher (p<0.001) in those with small bowel lesions compared to those without. Using the suitable cutoff points (Hb>0 ng/ml and Hb-Hpt complex>5 ng/ml), the sensitivity and specificity of the Hb-Hpt complex test to predict small bowel lesions were 71.4% and 73.3%, and those of the Hb test were 61.2% and 89.3%. Small bowel lesions were found in 58.3% with only Hb-Hpt complex positive results (15.8% of total subjects) compared to 83.3% when both were positive (55.3% of total).

CONCLUSIONS

Measuring fecal Hb-Hpt complex in addition to Hb may be useful to predict the presence of small bowel lesions in patients with OGIB.

Colorectal cancer screening--optimizing current strategies and new directions

The first evidence that screening for colorectal cancer (CRC) could effectively reduce mortality dates back 20 years. However, actual population screening has, in many countries, halted at the level of individual testing and discussions on differences between screening tests. With a wealth of new evidence from various community-based studies looking at test uptake, screening-programme organization and the importance of quality assurance, population screening for CRC is now moving into a new realm, promising better results in terms of reducing CRC-specific morbidity and mortality. Such a shift in the paradigm requires a change from opportunistic, individual testing towards organized population screening with comprehensive monitoring and full-programme quality assurance. To achieve this, a combination of factors--including test characteristics, uptake, screenee autonomy, costs and capacity--must be considered. Thus, evidence from randomized trials comparing different tests must be supplemented by studies of acceptance and uptake to obtain the full picture of the effectiveness (in terms of morbidity, mortality and cost) the different strategies have. In this Review, we discuss a range of screening modalities and describe the factors to be considered to achieve a truly effective population CRC screening programme.