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

Post-colonoscopy upper gastrointestinal malignancies in positive immunochemical fecal occult blood test patients: An Australian data linkage study

BACKGROUND AND AIM

In immunochemical fecal occult blood test (iFOBT) positive subjects, colonoscopy screening can detect colorectal cancers and advanced adenomas, yet most iFOBT-positive subjects find no relevant lower gastrointestinal lesions. Limited data are available on upper gastrointestinal (UGI) cancer risk in iFOBT-positive patients. This study investigated the incidence of UGI malignancies diagnosed within 3 years post-colonoscopy after a positive iFOBT.

METHODS

Retrospective analysis of iFOBT-positive patients aged 50-75 years who underwent a colonoscopy at a single institution. All patients with a diagnosis of UGI cancer within 3 years post-colonoscopy were identified by linking with the Queensland Cancer Register. This was used to compare to the geographical population aged 50-74 years based on the Australian Bureau of Statistics and Queensland Cancer Council data.

RESULTS

From 1748 eligible participants, 0.23% (95% confidence interval [CI] 0.06-0.58) were diagnosed with UGI cancer within 3 years post-colonoscopy. This indicates an esophageal cancers rate of 114.42 per 100 000 (95% CI 100.56-298.28) and gastric cancer rate of 57.21 per 100 000 (95% CI 55.76-261.12). Of the patients with a UGI cancer, 75% would have had an unexplained iFOBT. Annual incidence for the same geographic region, ages, and period for the combined esophageal and gastric cancer was 36.08 per 100 000 (95% CI 32.87-39.52).

CONCLUSIONS

Among individuals with a positive iFOBT in a bowel cancer screening program, the rates of gastric and esophageal cancers were 2.7 and 7.5 times higher than the general population. Adding gastroscopy to a colonoscopy for iFOBT-positive patients in cancer surveillance programs may be justifiable.

Risk of Cancers Proximal to the Colon in Fecal Immunochemical Test Positive Screenees in a Colorectal Cancer Screening Program

BACKGROUND & AIMS

In more than half of the colorectal cancer screening participants with a positive fecal immunochemical test (FIT) result, no advanced neoplasia (AN) is detected at colonoscopy. The positive FIT result could also be generated by cancers located proximal to the colon: upper gastrointestinal, oral cavity, nose, and throat cancers. We evaluated screenees' risk of being diagnosed with a cancer proximal to the colon within the 3 years and compared risks between those with a positive vs those with a negative FIT.

METHODS

Data of Dutch colorectal cancer screening participants who underwent biennial FIT-based screening 2014-2018 were collected from the national screening database and linked to the National Cancer Registry. Screenees were classified into 3 groups: FIT-positives with AN (FIT+/AN+), FIT-positives without AN (FIT+/AN-), and FIT-negatives (FIT-). We compared the cumulative incidence of cancers proximal to the colon in each group 3 years after FIT. A Cox regression analysis with left truncation and right censoring, using FIT positivity as time-dependent variable and stratified for sex, was performed to compare the hazard of cancers proximal to the colon in participants who were FIT-positive vs FIT-negative.

RESULTS

Three-year cumulative incidence of cancers proximal to the colon in FIT+/AN+ (n = 65,767), FIT+/AN- (n = 50,661), and FIT- (n = 1,831,647) screenees was 0.7%, 0.6%, and 0.4%, respectively (P < .001). FIT-positives were older and more frequently male than FIT-negatives (P < .001). Significantly more cancers proximal to the colon were detected among FIT-positives (P < .001; hazard ratio, 1.55; 95% CI, 1.44-1.67).

CONCLUSION

FIT-positive screenees were at significantly increased risk of being diagnosed with a cancer proximal to the colon within 3 years after FIT, although the 3-year cumulative incidence was still less than 1%.

Understanding the Utility of Fecal Occult Blood Testing in Hospitalized Patients With Suspected GI Bleeding

Colorectal cancer (CRC) is one of the leading causes of cancer-related mortality worldwide. There have been increasing efforts to reduce its incidence and mortality. Screening plays a crucial role, with various tests such as the fecal occult blood test (FOBT), colonoscopy, and flexible sigmoidoscopy commonly used for investigation. FOBT is a Food and Drug Administration (FDA) approved screening tool commonly used in acute healthcare settings for early detection of CRC. We report a 50-year-old man presenting with shortness of breath, chills, and malaise with findings positive for pneumonia. Laboratory tests revealed anemia as an incidental finding. A subsequent FOBT came back positive, and the patient was admitted for further gastrointestinal testing. Esophagogastroduodenoscopy (EGD) and colonoscopy were performed, but no significant findings were observed. This case report focuses on the overuse of FOBT testing during hospital admission, despite its limited impact on patient care in acute settings. Key takeaways include being aware of the potential for false positive and false negative results from a FOBT. Using the test carefully can help reduce both direct and indirect healthcare costs for hospitalized patients, as well as minimize the use of hospital resources. The test should primarily be used for CRC screening in the outpatient setting.

Esophageal cancer: Treatment advances and need for screening

ABSTRACT

Esophageal cancer is a challenging malignancy that often is diagnosed in advanced stages, resulting in a poor prognosis. This article provides a comprehensive review of the two main types of esophageal cancer, esophageal squamous cell carcinoma and esophageal adenocarcinoma, and reviews epidemiology, risk factors, pathogenesis, diagnostic modalities, staging systems, and established and emerging treatments. Recent advancements in treatment for resectable and unresectable esophageal cancer also are explored. These include immunotherapy, targeted therapy, sentinel lymph node mapping, radiogenomics, palliative measures, and screening measures.

Uncovering a dose-response relationship between positive fecal immunochemical test (FIT) and all-cause, cardiovascular and cancer-related mortality

BACKGROUND

Fecal immunochemical test (FIT) is for colorectal cancer (CRC) screening. Its association with non-CRC mortality has been overlooked. Given the quantitative FIT values, its dose-response relationships with different causes of deaths and years of life shortened were assessed.

METHODS

This retrospective study included 546,214 adults aged ≥ 20 who attended a health surveillance program from 1994 to 2017 and were followed up until the end of 2020. FIT ≥ 20 μg Hb/g was defined as positive. The Cox model was used to assess adjusted hazard ratios (aHR).

RESULTS

Positive FIT was associated with increased all-cause mortality (aHR: 1.34, 95 % CI: 1.25-1.44) and all-cancer mortality (aHR: 1.71, 95 % CI: 1.55-1.89), with a reduction of life expectancy by 4 years. The association remained even with CRC excluded. With each 10 μg Hb/g increase in FIT above 20 μg Hb/g, life expectancy was reduced by one year, and mortality increased by 4 %. About 18.6 % of deaths with positive FIT were attributed to cardiovascular disease (CVD), followed by CRC (13.5 %) and upper gastrointestinal (GI) cancers (4.5 %). The all-cause mortality rate after excluding CRC for positive FIT was 3.56/1,000 person-year, comparable to the all-cause mortality rate of 3.69/1,000 person-year for hypertension.

CONCLUSION

Positive FIT was associated with increased mortality in a dose-response manner and shortened life expectancy by 4 years, an overlooked risk comparable to hypertension, even with CRC excluded. After a negative colonoscopy, subjects with positive FIT should undergo a workup on CVD risk factors and look for other upper GI cancers.

Incidental findings in the bowel cancer population screening program: other polyps and malignancies - A nationwide study

The introduction of bowel cancer population screening programs has had a profound impact on gastrointestinal pathology. While the focus is mainly on quality assurance of diagnoses relevant for the outcome of these programs (colorectal cancer and its precursors), incidental findings are increasingly diagnosed. The incidence of such findings is largely unknown. Therefore, we investigated the incidence of incidental findings within the national screening program of the Netherlands. From the Dutch nationwide pathology databank (PALGA), we retrieved all histological diagnoses of patients participating in the national bowel cancer screening program from the start in 2014 until 1/1/2021. Descriptive statistics were used. During these 7 years, in total 9407 other polyps and malignancies (262 per 10,000 colonoscopies) were diagnosed. The majority (65%) were classified as inflammatory polyps. The most common malignancies were neuroendocrine tumours (n = 198, 6 per 10,000 colonoscopies); less common were lymphomas (n = 64) and metastases (n = 33). Mesenchymal polyps, such as leiomyomas and lipomas, were relatively common (27 and 16 per 10,000 colonoscopies, respectively), in comparison with neural polyps such as perineuriomas, ganglioneuromas, and neurofibromas (respectively 3, 2, and 1 per 10,000 colonoscopies). This is the largest study into the incidence of nonconventional colorectal polyps and malignancies in a homogeneous cohort of asymptomatic patients. Several of these diagnoses may have consequences for treatment and follow-up, in particular the malignancies and detection of patients with hereditary cancer syndromes.

Feasibility of Support by Family Practitioners in Reducing Colorectal Cancer-Related Death among Outpatients Who Have Not Undergone Colorectal Cancer Screening

We aimed to clarify the effectiveness of interventions in outpatients who did not undergo colorectal cancer (CRC) screening. From September 2012 to August 2013, we conducted a project, which showed that the immunological fecal occult blood test (FOBT) was actively recommended for outpatients who were ≥40 years of age, attended the Marumori Hospital regularly, and were not screened for CRC in the previous two years. We evaluated the detection rate of CRC and the disease specific survival ratio in February 2021 among patients with positive FOBT results during the retrospective cohort study. Overall, 388 (91%) out of the 425 outpatients submitted their stool samples. Among 388 outpatients, 66 tested positive for FOBT. While both the positive rate of FOBT and the detection rate of CRC (17% and 0.77%, respectively) were significantly higher than those in the nationwide administrative examination (5.7% and 0.13%, respectively) (p < 0.05), there was no statistically significant difference in the detection rate, compared with the group aged 65 years and older in the nationwide administrative examination. The 7-year CRC-specific survival ratio was 98.5%. Active promotion of FOBT at primary care institutions for outpatients who did not undergo CRC screening may contribute to reducing the frequency of CRC-related deaths.

Not FIT for Use: Fecal Immunochemical Testing in the Inpatient and Emergency Settings

BACKGROUND

Fecal immunochemical testing (FIT) is widely used for colorectal cancer screening, its only indication. Its effect on clinical decision-making beyond screening is unknown. We studied the use of FIT in emergency and inpatient settings and its impact on patient care.

METHODS

Using electronic medical records, we reviewed all non-ambulatory FITs performed from November 2017 to October 2019 at a tertiary care community hospital. We collected data on demographics, indications, gastroenterology consultations, and endoscopic procedures. Multivariate logistic regression was performed to determine the effect of FIT on gastroenterology consultation and endoscopy.

RESULTS

We identified 550 patients with at least 1 FIT test. Only 3 FITs (0.5%) were performed for colorectal cancer screening. FITs were primarily ordered from the emergency department (45.3%) or inpatient hospital floor (42.2%). Anemia (44.0%), followed by gastrointestinal bleeding (40.9%), were the most common indications. FIT was positive in 253 patients (46.0%), and gastroenterology consultation was obtained for 47.4% (n = 120), compared with 14.5% (n = 43) of the 297 FIT-negative patients (odds ratio 3.28; 95% confidence interval, 2.23-4.82, P < .0001). A potential bleeding source was identified in 80% of patients with reported or witnessed overt gastrointestinal bleeding, a similar proportion (80.7%; P = .92) to patients who were FIT positive with overt gastrointestinal bleeding. Multivariate analysis showed that melena, hematemesis, and a positive FIT were associated with gastroenterology consultation (all P < .05), while only melena (odds ratio 3.34; 95% confidence interval, 1.48-7.54) was associated with endoscopy.

CONCLUSIONS

Nearly all emergency department and inpatient FIT use was inappropriate. FIT resulted in more gastroenterology consultation but was not independently associated with inpatient endoscopy.

The Value of Quantitative Faecal Immunochemical Testing as a Prioritisation Tool for the Endoscopic Investigation of Patients With Iron Deficiency

Difficulty in providing endoscopy for patients with iron deficiency anaemia (IDA) during the COVID-19 pandemic has highlighted the requirement for a prioritisation tool. We aimed to test the validity of qFIT as a prioritisation tool in patients with iron deficiency and its ability to identify patients with advanced neoplastic lesions (ANLs). Data collected from patients referred with biochemically proven iron deficiency (ferritin ≤ 15 μg/L) and synchronous qFIT who underwent full gastrointestinal investigation within NHS Greater Glasgow and Clyde was analysed retrospectively. Patients who did not undergo full investigation, defined as gastroscopy and colonoscopy or CT colonography, were excluded. ANLs were defined as defined as upper GI cancer, colorectal adenoma ≥ 1 cm or colorectal cancer. Area under the curve (AUC) analysis was performed on qFIT results and outcome, defined as the presence of an ANL. AUC analysis guided cut-off scores for qFIT. Patients with a qFIT of <10, 10-200, >200, were allocated a score of 1, 2, and 3, respectively. A total of 575 patients met criteria for inclusion into the study. Overall, qFIT results strongly predicted the presence of ANLs (AUC 0.87, CI 0.81-0.92; P < 0.001). The prevalence of ANLs in patients with scores 1-3 was 1.2, 13.5, and 38.9% respectfully. When controlled for other significant variables, patients with a higher qFIT score were statistically more likely to have an ANL (qFIT score = 2; OR 12.8; P < 0.001, qFIT score = 3, OR 50.0; P < 0.001). A negative qFIT had a high NPV for the presence of ANLs (98.8%, CI 97.0-99.5%). These results strongly suggest that qFIT has validity as a prioritisation tool in patients with iron deficiency; both allowing for a more informed decision of investigation of patients with very low risk of malignancy, and in identifying higher risk patients who may benefit from more urgent endoscopy.

High Rate of Inappropriate Fecal Immunochemical Testing at a Large Veterans Affairs Health Care System

INTRODUCTION

Colonoscopies and fecal immunochemical tests (FITs) are the preferred modalities for colorectal cancer (CRC) screening. In addition to proper patient selection, appropriate fecal immunochemical testing requires that negative tests be repeated annually, positive tests lead to a diagnostic colonoscopy, and FIT not be performed within 5 years of a colonoscopy with adequate bowel preparation. We sought to study the frequency of inappropriate FITs at the Veterans Affairs Pittsburgh Health Care System in Pennsylvania.

METHODS

A retrospective quality assurance study was undertaken of veterans undergoing FIT in a 3-year period (2015-2017). We calculated the rate of a negative initial FIT in 2015/2016 followed by a second FIT in 2016/2017 in a random selection of veterans (3% SE, 95% CI). Demographics were compared in an equal random number of veterans that did and did not have a follow-up FIT (5% SE, 95% CI of all negative FIT). We also calculated the rate of completing colonoscopy following a positive FIT in a random selection of veterans (3% SE, 95% CI). Finally, we investigated use of FIT following a colonoscopy for all veterans in the study period.

RESULTS

A total of 6,766 FITs were performed; 4,391 unique veterans had at least 1 negative FIT, and 709 unique veterans had a positive FIT. Of 1,742 veterans with at least 1 negative FIT, 870 were eligible for repeat testing during the study period, and only 543 (62.4%) underwent at least 2 FITs. There was no significant demographic difference in veterans that had only 1 or at least 2 FITs. Of 410 veterans with a positive FIT, 113 (27.5%) did not undergo a subsequent colonoscopy within 1 year due to patient refusal, or failure to schedule or keep a colonoscopy appointment. Of 832 veterans who had both a FIT and colonoscopy in the interval, 108 veterans underwent colonoscopy with a subsequent FIT (1.6% of total FITs performed). Of these, 95 (88%) were judged to be inappropriate. Thirteen instances of FIT following colonoscopy were appropriate based on patient preference to undergo fecal immunochemical testing for CRC screening modality after undergoing colonoscopy with an inadequate bowel preparation.

CONCLUSIONS

Veterans underwent inappropriate testing due to failure to undergo serial FIT after a negative result (37.6%), failure to complete colonoscopy following a positive FIT (27.5%), and undergoing inappropriate FIT following a recent colonoscopy (88%). Efforts are still required to improve both patient and provider education and adherence to appropriate fecal immunochemical testing and CRC screening guidelines.

Systematic upper endoscopy concomitant with colonoscopy performed within the colorectal cancer screening program: Impact on the patients' management

BACKGROUND AND AIMS

The French colorectal cancer screening program is based on a fecal immunochemical test, followed by colonoscopy in case of positivity. The benefit of adding a concomitant upper endoscopy to detect upper digestive lesions (precancerous or others) is still debated. Our aim was to evaluate the frequency of upper digestive lesions detected by upper endoscopy performed concomitantly with colonoscopy following a positive fecal immunochemical test, and their impact on the patients' management (i.e., surveillance, medical treatment, endoscopic or surgical procedure).

METHODS

Data of all the patients who consulted for a positive test between May 2016 and May 2019 in our center, and for whom concomitant upper endoscopy and colonoscopy were performed, were analyzed retrospectively. Patients with significant history of upper gastrointestinal diseases or with current gastrointestinal symptoms were excluded.

RESULTS

One hundred patients were included [median age (min-max): 62 (50-75), men 64%]. Macroscopic and/or microscopic upper digestive lesions were found in 58 of them (58%): Helicobacter pylori infection in 17 patients, gastric precancerous lesions in 9 patients (chronic atrophic gastritis with intestinal metaplasia, n=8, low grade dysplasia, n=1), Barrett's esophagus requiring surveillance in 4 patients, and 1 duodenal adenoma with low-grade dysplasia. In 44 patients (44%), the upper endoscopy findings had an impact on patients' management, with no significant difference between the groups with positive (CRC or advanced adenoma)- or negative (any other lesions or normal) colonoscopy.

CONCLUSION

A systematic upper endoscopy combined with colonoscopy for positive fecal immunochemical test could represent an efficient strategy for upper digestive lesions screening in France. Further studies are necessary to confirm these results and to evaluate cost-effectiveness of this approach.

A Novel Insight Into Fecal Occult Blood Test for the Management of Gastric Cancer: Complication, Survival, and Chemotherapy Benefit After R0 Resection

BACKGROUND

Previous studies have shown that the all-cause mortality and non-colorectal cancer mortality of patients with fecal occult blood test (FOBT) positivity are significantly increased, implying that FOBT results may have more prognostic value.

METHODS

Retrospective analysis was performed for gastric cancer (GC) patients who underwent R0 gastrectomy from July 2007 to July 2014 at our hospital. Propensity score matching (PSM) was used to reduce confounding bias and a computerized technique for the nearest available score matching without replacement was applied. The cumulative survival rate was calculated using the Kaplan-Meier method and a log-rank test. Cox proportional hazards regression and logistic regression was used to determine the independent prognostic factors associated with survival and postoperative complications, respectively. The expression level of tumor-associated macrophages (TAMs) and proinflammatory cytokines (TNF-α, IL-6) were evaluated by immunohistochemical (IHC).

RESULTS

A total of 3,003 patients were included and 246 patients (8.2%) were in preoperative FOBT positive status. There was no significant difference in demographic data between preoperative FOBT positive and negative group after a 1:4 PSM. The overall postoperative complications, major complications, and anastomotic leakage were significantly higher in the preoperative FOBT-positive group than in the preoperative FOBT-negative group. Moreover, preoperative FOBT-positivity was an independent risk factor for 5-year overall survival (OS) (HR: 1.32, p = 0.005). For stage II/III patients, the postoperative adjuvant chemotherapy (PAC) benefit was found in preoperative FOBT-negative group (5-year OS: 49.9 vs. 36.8%, p = 0.001), whereas the PAC benefit was lost in preoperative FOBT-positive groups (5-year OS: 40.8 vs. 37.7% p = 0.896). Finally, IHC found that preoperative FOBT-positivity in patients was significantly associated with higher TAMs infiltration and higher expression of IL-6 and TNF-α in tumor tissues than in the preoperative FOBT-negative group.

CONCLUSION

As a simple and low-cost method, preoperative FOBT results can predict both complications and survival after R0 gastrectomy for GC. More importantly, stage II/III GC patients with FOBT-positive seem not benefit from PAC alone. Further exploration is warranted.

Occult Blood in Feces Is Associated With an Increased Risk of Ischemic Stroke and Myocardial Infarction: A Nationwide Population Study

Background

Although occult hemoglobin in feces is universally valued as a screening tool for colorectal cancer (CRC), only few studies investigated the clinical meaning of fecal immunochemical test (FIT) in other diseases. We evaluated the clinical utility of FIT in patients with cardiovascular diseases (namely, ischemic stroke and myocardial infarction [MI]).

Methods and Results

Using the National Health Insurance database, participants (aged >50 years) with CRC screening records from 2009 to 2012 were screened and followed up. Subjects with a history of cardiovascular diseases and CRC were excluded. Ischemic stroke, MI, and other comorbidities were defined by International Classification of Diseases, Tenth Revision (ICD‐10), codes. Age, sex, smoking, alcohol consumption, regular exercise, diabetes mellitus, hypertension, dyslipidemia, and body mass index were adjusted in a multivariate analysis. A total of 6 277 446 subjects were eligible for analysis. During the mean 6.79 years of follow‐up, 168 570 participants developed ischemic stroke, 105 983 developed MI, and 11 253 deaths were observed. A multivariate‐adjusted model revealed that the risk of ischemic stroke was higher in the FIT‐positive population (adjusted hazard ratio [HR], 1.09; 95% CI, 1.07–1.11). Similarly, FIT‐positive subjects were at an increased risk of MI (adjusted HR, 1.09; 95% CI, 1.06–1.12). Moreover, increased all‐cause mortality was observed in the FIT‐positive population (adjusted HR, 1.15; 95% CI, 1.07–1.23). The increased risk remained consistent in the stratified analysis on anemia and CRC status.

Conclusions

Positive FIT findings were associated with ischemic stroke, MI, and mortality. Occult blood in feces may offer more clinical information than its well‐known conventional role in CRC screening.

Positive Fecal Immunochemical Test Results Are Associated with Increased Risks of Esophageal, Stomach, and Small Intestine Cancers

Background: The current guideline does not recommend upper gastrointestinal evaluation for patients with a positive fecal immunochemical test (FIT) and negative colonoscopy results. However, this indication was based on low-quality evidence as data on this issue are very limited. We assessed the risk of proximal cancers (oral or throat, esophageal, stomach, and small intestine cancers) after negative or positive FIT results in the Korean National Cancer Screening Program (NCSP). Methods: Using the NCSP databases, we collected data on participants who underwent FIT between 2009 and 2011. Participants were classified based on FIT results and colorectal cancer (CRC) diagnosed within 1 year after FIT as FIT− (n = 5,551,755), FIT+/CRC− (n = 368,553), and FIT+/CRC+ (n = 12,236). Results: The incidence rates of overall proximal cancers in FIT−, FIT+/CRC−, and FIT+/CRC+ patients within 1, 2, and 3 years after FIT were 0.38%, 0.68%, and 2.26%; 0.57%, 0.93%, and 2.74%; and 0.79%, 1.21%, and 3.15%, respectively. After adjusting confounding variables, the risks of esophageal, stomach, and small intestine cancers as well as overall proximal cancers within 1, 2, and 3 years after FIT were higher in FIT+/CRC− patients than those in FIT− patients. However, the risk of oral or throat cancer did not differ between FIT− and FIT+/CRC− patients. The risks for oral or throat cancer and small intestine cancer were higher in FIT+/CRC+ patients than those in FIT+/CRC− patients. Conclusions: In this population-based study, FIT+/CRC− patients were at higher risk for esophageal, stomach, and small intestine cancers than were FIT− patients, suggesting that positive FIT results were associated with these cancers.

A Case for Abandoning Inpatient Fecal Occult Blood Testing

Fecal occult blood testing (FOBT) is currently Food and Drug Administration (FDA) approved only for colorectal cancer (CRC) screening. There is now widespread off-label use of FOBT in the hospital setting as a diagnostic test. Here we present a brief case and a more detailed review of the literature arguing against inpatient FOBT. Inpatient use of FOBT is problematic for several reasons including failure to account for false positives or negatives, delays in appropriate consultations or endoscopy, increased costs, increase length of stays, unnecessary procedures, and test results that do not change management. Inappropriate use of FOBT can lead to both overuse and underuse of endoscopy. Many retrospective audit studies and more recently a meta-analysis have shown that FOBTs have poor test performance and are unable rule out the need for endoscopy in patients with iron deficiency anemia. For these reasons we argue that inpatient FOBT should be abandoned. 

Use of Fecal Occult Blood Testing as a Diagnostic Tool for Clinical Indications: A Systematic Review and Meta-Analysis

INTRODUCTION

Fecal occult blood tests (FOBTs) are validated only for colorectal cancer (CRC) screening, but are commonly used as a diagnostic test in other clinical settings. We performed a systematic review to assess performance characteristics of FOBT as a diagnostic test for clinical indications.

METHODS

Bibliographic databases were searched to identify studies in adult patients with a specific gastrointestinal symptom or condition who underwent FOBT and a reference test and provided data on diagnoses. Our primary end point was sensitivity. Risk of bias was assessed with the QUADAS-2 tool.

RESULTS

Twenty-two studies met the inclusion criteria: 12 in iron deficiency anemia (IDA) (5 fecal immunochemical (FIT) and 7 guaiac based), 8 in ulcerative colitis (FIT), and 2 in acute diarrhea (guaiac based). Only 2 studies had low risk of bias on all domains of the QUADAS-2. On meta-analysis, FOBT had a sensitivity of 0.58 (95% confidence interval [CI] 0.53-0.63) and a specificity of 0.84 (95% CI 0.75-0.89) in predicting presumptive causes of IDA at endoscopy, with comparable results for guaiac-based tests and FIT. Sensitivity was higher for CRC (0.83) than non-CRC lesions (0.54). FIT had a sensitivity of 0.72 (95% CI 0.57-0.84) and a specificity of 0.80 (95% CI 0.67-0.89) in predicting endoscopic activity in UC. Sensitivities of FOBT for positive stool culture in acute diarrhea were 0.38 and 0.87.

DISCUSSION

Sensitivity of FOBT is poor for IDA: 42% of patients with identifiable causes of IDA had false-negative FOBT. Our results did not show acceptable performance characteristics for FOBT to guide decisions regarding endoscopic evaluation and do not support its use in IDA.

Risk of gastrointestinal cancer in a symptomatic cohort after a complete colonoscopy: Role of faecal immunochemical test

BACKGROUND

Faecal immunochemical test (FIT) has been recommended to assess symptomatic patients for colorectal cancer (CRC) detection. Nevertheless, some conditions could theoretically favour blood originating in proximal areas of the gastrointestinal tract passing through the colon unmetabolized. A positive FIT result could be related to other gastrointestinal cancers (GIC).

AIM

To assess the risk of GIC detection and related death in FIT-positive symptomatic patients (threshold 10 μg Hb/g faeces) without CRC.

METHODS

Post hoc cohort analysis performed within two prospective diagnostic test studies evaluating the diagnostic accuracy of different FIT analytical systems for CRC and significant colonic lesion detection. Ambulatory patients with gastrointestinal symptoms referred consecutively for colonoscopy from primary and secondary healthcare, underwent a quantitative FIT before undergoing a complete colonoscopy. Patients without CRC were divided into two groups (positive and negative FIT) using the threshold of 10 μg Hb/g of faeces and data from follow-up were retrieved from electronic medical records of the public hospitals involved in the research. We determined the cumulative risk of GIC, CRC and upper GIC. Hazard rate (HR) was calculated adjusted by age, sex and presence of significant colonic lesion.

RESULTS

We included 2709 patients without CRC and a complete baseline colonoscopy, 730 (26.9%) with FIT ≥ 10 µgr Hb/gr. During a mean time of 45.5 ± 20.0 mo, a GIC was detected in 57 (2.1%) patients: An upper GIC in 35 (1.3%) and a CRC in 14 (0.5%). Thirty-six patients (1.3%) died due to GIC: 22 (0.8%) due to an upper GIC and 9 (0.3%) due to CRC. FIT-positive subjects showed a higher CRC risk (HR 3.8, 95%CI: 1.2-11.9) with no differences in GIC (HR 1.5, 95%CI: 0.8-2.7) or upper GIC risk (HR 1.0, 95%CI: 0.5-2.2). Patients with a positive FIT had only an increased risk of CRC-related death (HR 10.8, 95%CI: 2.1-57.1) and GIC-related death (HR 2.2, 95%CI: 1.1-4.3), with no differences in upper GIC-related death (HR 1.4, 95%CI: 0.6-3.3). An upper GIC was detected in 22 (0.8%) patients during the first year. Two variables were independently associated: anaemia (OR 5.6, 95%CI: 2.2-13.9) and age ≥ 70 years (OR 2.7, 95%CI: 1.1-7.0).

CONCLUSION

Symptomatic patients without CRC have a moderate risk increase in upper GIC, regardless of the FIT result. Patients with a positive FIT have an increased risk of post-colonoscopy CRC.

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.

False-Positive Results in a Population-Based Colorectal Screening Program: Cumulative Risk from 2000 to 2017 with Biennial Screening

BACKGROUND

The aim of this study was to estimate the cumulative risk of a false-positive (FP) result in a fecal occult blood test (FOBT) through 7 screening rounds and to identify its associated factors in a population-based colorectal cancer screening program.

METHODS

Retrospective cohort study, which included participants ages 50 to 69 years of a colorectal cancer screening program in Catalonia, Spain. During this period, 2 FOBTs were used (guaiac and immunochemical). A discrete-time survival model was performed to identify risk factors of receiving a positive FOBT with no high-risk adenoma or colorectal cancer in the follow-up colonoscopy. We estimated the probability of having at least 1 FP over 7 screening rounds.

RESULTS

During the period of 2000 to 2017, the cumulative FP risk was 16.3% (IC_95%: 14.6%-18.3%), adjusted by age, sex, and type of test. The median number of screens was 2. Participants who began screening at age 50 years had a 7.3% [95% confidence interval (CI), 6.35-8.51] and a 12.4% (95% CI, 11.00-13.94) probability of an FP with 4 screening rounds of guaiac-based test and immunochemical test, respectively. Age, the fecal immunochemical test, first screening, and number of personal screens were factors associated with an FP result among screenees.

CONCLUSIONS

The cumulative risk of an FP in colorectal screening using FOBT seems acceptable as the colonoscopy, with its high accuracy, lengthens the time until additional colorectal screening is required, while complication rates remain low.

IMPACT

It is useful to determine the cumulative FP risk in cancer screening for both advising individuals and for health resources planning.