Negative Fecal Occult Blood Test Research Articles

A Colorectal Cancer Screening Program in an Underserved, Ethnically Diverse Population in Chicago, IL

The purpose of this project was to describe the structure and outcomes of a colorectal cancer screening program at CommunityHealth, the largest free health clinic in Illinois. We conducted a retrospective observational study using administrative clinical data from 2006 to 2011. A total of 4,026 patients were eligible for colorectal cancer screening of which 2,418 (60.0%) completed fecal occult blood testing (FOBT). Subsequently, 1,657 patients had negative FOBT results and 1,365 patients underwent on-site flexible sigmoidoscopy. Over 90% of patients had never had a prior screening examination. A majority of patients were female (61.7%) and self-identified as Mexican (37.5%) or Polish (28.2%). A total of 203 biopsies were performed resulting in the detection of 69 adenomas (5.0%) and 1 adenocarcinoma (0.1%). A comprehensive colorectal cancer screening program was successfully implemented in a large community health center serving a population of diverse racial and ethnic backgrounds without prior access to screening. This program could serve as model for colorectal cancer screening in diverse, low resource communities.

Putting an End to the Misuse of the Fecal Occult Blood Test in Diagnostic Medicine

Putting an End to the Misuse of the Fecal Occult Blood Test in Diagnostic Medicine

A Case of Video Capsule Retention in a Rare Epiphrenic Diverticulum

Purpose: Video capsule endoscopy (VCE) is a minimally invasive method of visualizing the small bowel. Capsule retention is the most common complication of VCE. While VCE retention has been described in various anatomical locations, there are no known reports of retention in an epiphrenic esophageal diverticulum. A 73-year old African-American female, with a long history of iron deficiency anemia, presented for evaluation of obscure gastrointestinal bleeding with VCE. She denied melena, hematochezia, abdominal pain, or dizziness. Her physical exam was unremarkable, with a negative in-office fecal occult blood test. On presentation to our clinic the patient was noted to have hemoglobin and hematocrit values of 9.9g/dL and 29.9%, respectively. VCE was performed using a PillCam SB (Given Imaging, Yoqneam, Israel). After 8 hours of recording, the capsule was noted to be halted in the esophagus. Further evaluation with an esophagram showed a large epiphenic esophageal diverticulum and diffuse esophageal spasms with poor peristalsis. The retained capsule was not observed in this study. The patient remained completely asymptomatic during this time. She underwent a second VCE study, this time with endoscopic deployment of the video capsule. The EGD confirmed a large epiphrenic diverticulum just above the gastroesophageal (GE) junction and a small hiatal hernia. The initial retained capsule, however, was not seen during the EGD and was presumed to have spontaneously passed. To our knowledge, this is the first case of video capsule retention in an epiphrenic esophageal diverticulum, likely due to their rarity. Our case suggests that esophageal diverticula may be a relative contraindication for VCE. In patients with hyper or hypomotility disorders, which are commonly associated with other anatomical problems within the GI tract, endoscopic deployment of the VCE beyond the diverticulum is a much safer alternative. Moreover, symptomatic patients may benefit from diagnostic work-up of esophageal and other GI tract diverticula as a preventative measure of capsule retention.Figure: Esophagram showing distal esophageal diverticulum (epiphrenic diverticulum).

A population-based audit of the clinical use of faecal occult blood testing in primary care for colorectal cancer

Symptoms related to colorectal cancer (CRC) are common. We investigated the value of the faecal occult blood test (FOBT), when administered in primary care, in the diagnosis of CRC. All patients who underwent a FOBT (Hemoccult II) at 20 public primary care centres in Sörmland County, Sweden, during 2000-2005, were included (n=9048). Linkage to the Swedish Cancer Registry identified all cases of CRC. Symptoms recorded at the time of the FOBT were retrieved from the patient records. The outcome from the FOBT to diagnosis and subsequent survival was compared between patients who were FOBT negative and patients who were FOBT positive. One-hundred and sixty-one patients were diagnosed with CRC within 2 years after undergoing a FOBT in primary care. These comprised 18% of all 917 patients diagnosed with CRC in the county during the study period. In 41 (25.4%) of the 161 patients the test was negative. Symptoms related to CRC were documented for 158 (98%) patients at the time the FOBT was administered. The median investigation time from the FOBT test to the diagnosis of CRC was 91 days: 80 days for FOBT-positive patients and 188 days for FOBT-negative patients (P<0.001). This difference was significant independent of age, sex and site of tumour. The hazard ratio for FOBT negativity, 3 years after the FOBT, when adjusted for age and sex, was 1.47 (95% CI, 0.81-2.68). Despite having suggestive symptoms, 41 (4.5%) of 917 CRC patients had a negative FOBT result in primary care. This was associated with diagnostic delay and, potentially, a worse outcome.

Colonoscopy core curriculum

Colonoscopy core curriculum

Comparison of screen-detected and interval colorectal cancers in the Bowel Cancer Screening Programme

Background:The NHS Bowel Cancer Screening Programme (BCSP) offers biennial faecal occult blood testing (FOBt) followed by colonoscopy after positive results. Colorectal cancers (CRCs) registered with the Northern Colorectal Cancer Audit Group database were cross-referenced with the BCSP database to analyse their screening history.Methods:The CRCs in the screening population between April 2007 and March 2010 were identified and classified into four groups: control (diagnosed before first screening invite), screen-detected, interval (diagnosed between screening rounds after a negative FOBt), and non-uptake (declined screening). Patient demographics, tumour characteristics and survival were compared between groups.Results:In all, 511 out of 1336 (38.2%) CRCs were controls; 825 (61.8%) were in individuals invited for screening of which 322 (39.0%) were screen detected, 311 (37.7%) were in the non-uptake group, and 192 (23.3%) were interval cancers. Compared with the control and interval cancer group, the screen-detected group had a higher proportion of men (P=0.002, P=0.003 respectively), left colon tumours (P=0.007, P=0.003), and superior survival (both P<0.001). There was no difference in demographics, tumour location/stage, or survival between control and interval groups.Conclusion:The FOBt is better at detecting cancers in the left colon and in men. The significant numbers of interval cancers weren’t found to have an improved outcome compared with the non-screened population.

Slipping through the bowel cancer screening programme

Colorectal cancer is common and a leading cause of cancer death. Faecal occult blood screening has been shown to reduce mortality. The aim of this study was to identify patients in Gloucestershire with a new diagnosis of colorectal cancer who had previously been screened via the Bowel Cancer Screening Programme (BCSP). Between 2006 and 2009, 1030 patients were diagnosed with colorectal cancer. Of these 237 (23%) had been invited to be screened via the BCSP. Their clinical notes were analysed. Fifty-seven (24%) of the 237 patients had previously had a negative faecal occult blood result. Thirty-three (14%) had their cancer discovered as part of the BCSP. Seventy (30%) had already been diagnosed with colorectal cancer prior to invitation, 62 (26%) did not respond to the invitation, nine (4%) were registered outside Gloucestershire and had therefore not been invited, and three (3%) had died before the invitation. Of the 57 patients with a negative faecal occult blood test, 47 (83%) had colorectal cancer staged Dukes B or C, and 34 (60%) had a rectal or sigmoid cancer. Patients will present with colorectal cancer despite having been invited to participate in the BCSP, with many having received a negative faecal occult blood test. This could be considered a high false negative rate.

OC-115 Comparison of screen detected and interval colorectal cancers in the bowel cancer screening programme: experience from the North East of England

IntroductionThe NHS Bowel Cancer Screening Programme (BCSP) commenced screening in North East England in February 2007. It offers biennial faecal occult blood testing (FOBt) followed by colonoscopy for those with...

Can False Reassurance Caused by a Negative Fecal Occult Blood Test Increase Mortality?

Can False Reassurance Caused by a Negative Fecal Occult Blood Test Increase Mortality?

Preference for Colonoscopy in a Program of Annual Fecal Occult Blood Testing

Purpose: American College of Gastroenterology guidelines suggest that colonoscopy is the preferred screening strategy with fecal immunochemical test as the first alternative to colonoscopy. We assessed the cross-over rate to colonoscopy among study participants randomized to annual fecal occult blood test (FOBT) in a randomized controlled trial (RCT) comparing colonoscopy and annual (sensitive) FOBT. High cross-over rates would indicate that additional colonoscopy capacity will be required in a screening program of FOBT beyond that required for evaluating positive FOBTs if annual FOBT is not readily accepted as the screening modality. Methods: The National Colonoscopy Study is a feasibility study comparing screening colonoscopy to a program of annual FOBT conducted at 3 clinical centers: University of Minnesota (predominantly private insurance setting dominated by managed care organizations), Group Health Cooperative (integrated health plan setting), and Louisiana State University at Shreveport (minority-serving institution). Use of colonoscopy in the study period among those assigned to FOBT who had only negative or uncompleted FOBTs during the study period was the endpoint of this analysis. Subjects submitting a positive FOBT were censored at the time of their test. The cumulative percent crossing over to colonoscopy up to 4 years after randomization, overall and by center, was estimated using Kaplan-Meier curves. Results: Of 1765 randomized to a program of annual FOBT, the cross-over rate varied by clinical site with the highest cross-over rate in the private-insurance site (29% over 4 years) and with lower rates for the managed care plan (16%) and the minority serving institution (5%) (Figure). Conclusion: Colonoscopy use was observed for a substantial subset of subjects assigned to annual FOBT screening. This happened more frequently in patient populations with some fee-for-service insurance compared to the settings of an integrated health plan or a minority-serving institution. This phenomenon should be recognized in planning for a screening FOBT program and in clinical practice using FOBT.Figure

Influence of the Pre-Analytical Specimen Storage Conditions on the Fecal Occult Blood Test Results

Korean national cancer screening program selected fecal occult blood test (FOBT) as a primary screening method of colorectal carcinoma in adult > or =50 yr old irrespective of symptom. Notice to pre-analytical errors is especially important for the FOBT because examinees collect and submit their specimens to laboratories by themselves. We examined the influences of the fecal storage temperatures, durations and with or without buffer on the FOBT results. Thirty FOBT-positive specimens above 100 ng/mL were used for the study from July to August 2008. Quantitative FOBT was performed with OC-sensors II (Eiken Chemical Co., Japan). Each specimen was divided into 4 groups. Two groups in plastic buffer-free containers were kept either at 4 degrees C or room temperature (25-28 degrees C), respectively. Another two groups in buffer-tubes were also kept either at 4 degrees C or room temperature. Each group was repeatedly examined with same method every 24 hr up to 120 hr. Eleven specimens (36.7%) in buffer-free containers converted to negative results (below the 100 ng/mL) after 24 hr and 17 specimens (56.7%) did after 48 hr at room temperature. Ten specimens (33.3%) in buffer-free containers converted to negative after 48 hr at 4 degrees C. Specimens contained in buffer-tubes showed little change; 3 specimens (10.0%) at room temperature and no specimen at 4 degrees C showed negative conversions after 48 hr. Buffer-tube minimizes false negative FOBT results during pre-analytical delay of specimen. The examinees using buffer-free containers need to be educated to hand in their specimens to laboratories as soon as possible.

False negative fecal occult blood tests due to delayed sample return in colorectal cancer screening

Delayed return of immunochemical fecal occult blood test (iFOBT) samples to a laboratory might cause false negatives because of hemoglobin degradation. Quantitative iFOBT's became increasingly more accepted in colorectal cancer screening. Therefore, we studied the effects of delay between sampling and laboratory delivery on iFOBT performance. IFOBT positivity (>or=50 ng/ml hemoglobin) in colorectal cancer screening participants without delay between sampling and laboratory delivery (<5 days), was compared with positivity in participants with >or=5 and >or=7 days delay. Additionally, positive tests were stored at room temperature and retested 5 times within 10-14 days. The sampling date was reported by 61% (n = 3,767) of the participants: in 19% delay was >or=5 days and in 5% >or=7 days. Compared with no-delay, the adenoma detection rate was already significantly decreased after >or=5 days delay (OR 0.6; 95%CI 0.4-0.9). We retested iFOBT samples of 170 positives of which 139 (82%) had a colonoscopy: 45 (32%) had advanced adenomas (not colorectal cancer) and 8 (6%) had colorectal cancer. Mean daily fecal hemoglobin decrease was 29 ng/ml (S.D. 38 and median 11 ng/ml). In patients with advanced adenomas, hemoglobin in the sample was <50 ng/ml in 5 (11%) 2-3 days after the initial test and in 16 (36%) after 10-14 days. Seven days after the initial test, 2 (25%) colorectal cancer patients became false negative. Both had stage I colorectal cancer and initial values below 100 ng/ml, where the average for stage I is 532 ng/ml. Delay in sample return increased false negative immunochemical FOBT's. Mainly precursor lesions, but also colorectal cancer, will be missed due to delayed sample return.

FL-DNA approach for noninvasive early diagnosis of colorectal cancer in FOBT-screened patients

11062 Background: A promising approach for the early diagnosis of colorectal cancer (CRC) is the evaluation of genomic DNA integrity (FL-DNA) extracted from stool. Pilot and confirmatory studies carried out by our group have shown that, thanks to its diagnostic accuracy, this molecular assay could be a useful tool for the non-invasive, early diagnosis of CRC. The aim of the present study was to verify whether the FL-DNA method could represent a valid alternative to the fecal occult blood test (FOBT) or whether it could be used alongside FOBT in screening programs to unmask false FOBT positives and spare patients from unnecessary colonoscopy. For this purpose, stool samples were collected from all individuals participating in the FOBT (OC-Sensor, Alpha Wassermann) Regional Screening Program run by the Cancer Prevention Unit of Morgagni-Pierantoni Hospital in Forli. Methods: The program recruited subjects of either sex aged 50 to 69 years. Of the 560 individuals with FOBT-positive stool subjected to colonoscopy, 26 were diagnosed with adenocarcinoma, 264 with high-grade adenoma and 54 with low-grade adenoma. More than one third (216) of the group had only benign disease (hemorrhoids, diverticulitis, inflammation, etc), hyperplastic polyps or nothing. The integrity of fecal DNA was analyzed blindly by the FL-DNA test on the same specimen used for the occult blood determination. Results: Using a cut-off of 10 ng, the molecular analysis detected over 90% of the colorectal cancers and about 50% of the high- and low-grade adenomas. In particular, diagnostic accuracy was similar for lesions of any localization, level of dysplasia and histopathological characteristic, and higher for lesions &gt; 2 cm and multiple lesions. The test also confirmed its capacity to identify colorectal cancer in asymptomatic individuals. Conclusions: FL-DNA represents a valid alternative to or support for approaches currently used in screening programs. A more in depth DNA stool evaluation in negative FOBT individuals could reveal the test's usefulness in unmasking colorectal tumors and adenomas missed by FOBT. No significant financial relationships to disclose.

The Appropriateness of Colonoscopy in the Screening Programme of Colorectal Cancer Based On Fecal Occult Blood Test (FOBT): The Outcomes Expected and Surprising

Introduction: The incidence of colorectal cancer in the Czech Republic is continuously increasing. A national screening programme based on the biennial FOBT and colonoscopy, in the event of FOBT positivity, was launched in 2000. The total number of colonoscopies increased by 50%, reaching approximately 130,000 (3.5% of the eligible population) per year. The number of FOBT has multiplied. The aim of this prospective multicenter study was to assess the potential role of colonoscopy in the diagnosis and screening of colorectal cancer in the conditions of the screening programme. Results: A total of 3827 colonoscopic records were analyzed. The mean rate of caecum intubation was 87.6%. The most frequent indication for colonoscopy was enterorrhage (32.4%) followed by pain (27.5%) and changes in stool habits (21.3%). Overall, 542 (14.1%) colonoscopies were performed as an official screening method following either positive (395) or negative (147) FOBT. A total of 385 (10.1%) colonoscopies were performed as a primary screening procedure without previous FOBT (altogether 927 - 24.2% - screening procedures). 2251 polyps in 1172 patients (30.5%), 334 advanced adenomas in 269 patients (7,0%), and 143 (3.7%) carcinomas were found. In 479 patients reporting a positive family history, carcinoma was detected in 7 (1.5%) and advanced adenoma in 19 (4.0%) of them, which was lower than in 3348 patients without a positive family history (136 cancers: 4.1%, 315 advanced adenomas: 9.4%), but 212 procedures were done as part of the screening (44.2% vs. 21.3% in patients without positive family history). Among 1395 patients reporting blood in the stool, 141 patients underwent FOBT (106 positive, 35 negative). In patients with enterorrhage, carcinomas were found in 75 (5.4%) patients, which is higher than their occurrence in 2432 other patients (69 cancers: 2.8%). Altogether, ninety four (37.1%) of advanced adenomas and 51 (36.7%) carcinomas were detected by screening. Conclusions: We proved yield of the screening programme based on FOBT and colonoscopy, since a relatively high proportion of all colonoscopies was indicated either after FOBT or as primary screening procedures, and a relatively high proportion of advanced lesions was detected by screening. Surprisingly, in patients with a positive family history, the detection rate of significant lesions was rather low, which could be explained by the relatively high rate of screening procedures in this group. The consequences of the screening process have to be analyzed with caution.

Getting adequate information across to colorectal cancer screening subjects can be difficult

Participation in screening should be the outcome of an informed decision. We evaluated whether invitees in the first Dutch colorectal cancer (CRC) screening programme were adequately informed after having received a detailed information leaflet. A total of 20,623 subjects aged 50-75 years were invited to the fecal occult blood test (FOBT) screening programme. All received a detailed information leaflet by mail between May 2006 and January 2007. After two weeks, a reminder letter was sent to all invitees, accompanied by a survey on CRC and screening. The survey was completed by 9594 invitees (47%). Almost all responders (99%) found the leaflet clear and readable. Almost all indicated that CRC can be treated better if found early (99%). Only 20% of the responders answered all knowledge-related answers correctly. Almost half of the responders (47%) believed that a negative FOBT excludes the presence of CRC. Older age and having a positive family member for CRC were correctly identified as risk factors by 80%. This study demonstrates that although an information leaflet was reported as being clear and readable, the information provided in it was not always understood well. This suggests that other educational options should be investigated in order to improve general knowledge of CRC in screening invitees.

Digital Fecal Occult Blood Testing in the Ambulatory Urology Clinic

This study was designed to evaluate the use and yield of fecal occult blood testing (FOBT) in an ambulatory urology clinic. Patients seen in the ambulatory urology clinic were prospectively evaluated with FOBT. The test was performed only on patients when a rectal examination was indicated as part of their urologic evaluation. Patients who were found to have a positive FOBT were then referred for additional gastrointestinal evaluation. One hundred eight patients were evaluated, including 57 men and 51 women. Eight patients (7%), including six men and two women, were found to be positive for fecal occult blood. Two patients were found to have upper gastrointestinal sources of bleeding (one gastritis with Barrett's esophagitis and one with a duodenal ulcer). Two patients had benign lower gastrointestinal sources of bleeding, including one with hyperplastic polyps and one with a tubular adenoma. One patient was diagnosed with a moderately differentiated adenocarcinoma of the sigmoid colon. One had negative followup fecal occult blood test, and two were lost to followup. Addition of FOBT to routine digital rectal examination performed in the ambulatory urology clinic is an inexpensive and simple test that can detect otherwise asymptomatic underlying gastrointestinal pathology. Although the six-sample test is a preferred test for colorectal cancer screening, a digital FOBT during routine urologic evaluation can detect a clinically significant upper or lower gastrointestinal lesion, at the same time increase compliance with FOBT. Larger, prospective studies are needed to confirm the benefit of digital FOBT during a routine urologic visit.

The clinical histopathological examination of advanced colorectal cancer through false negative fecal occult blood testing.

The clinical histopathological examination of advanced colorectal cancer through false negative fecal occult blood testing.

Gastrointestinal Bleeding of Obscure Origin Undetected by Multiple Tests for Fecal Occult Blood and Diagnosed Only by Capsule Endoscopy: A Case Report

The term gastrointestinal bleeding of obscure origin is used to describe bleeding of unknown origin that persists or recurs after a negative initial esophagogastroduodenoscopy and colonoscopy. We report the case of a middle-aged woman with gastrointestinal bleeding of obscure origin who had 9 stool specimens that tested negative for occult blood but was found to have adenocarcinoma of the distal duodenum on capsule endoscopy. This case illustrates that, in the presence of unexplained iron-deficiency anemia, multiple negative fecal occult blood tests do not exclude the presence of GI blood loss, and that capsule endoscopy is a valuable diagnostic study in this context.

Detection and prognosis of advanced colorectal cancer through negative fecal occult blood testing.

Detection and prognosis of advanced colorectal cancer through negative fecal occult blood testing.

Colonoscopic Screening of Average-Risk Women for Colorectal Neoplasia

Veterans Affairs (VA) Cooperative Study 380 showed that some advanced colorectal neoplasias (i.e., adenomas at least 1 cm in diameter, villous adenomas, adenomas with high-grade dysplasia, or cancer) in men would be missed with the use of flexible sigmoidoscopy but detected by colonoscopy. In a tandem study, we examined the yield of screening colonoscopy in women. To determine the prevalence and location of advanced neoplasia, we offered colonoscopy to consecutive asymptomatic women referred for colon-cancer screening. The diagnostic yield of flexible sigmoidoscopy was calculated by estimating the proportion of patients with advanced neoplasia whose lesions would have been identified if they had undergone flexible sigmoidoscopy alone. Lesions were considered detectable by flexible sigmoidoscopy if they were in the distal colon or if they were in the proximal colon in patients who had concurrent small adenomas in the distal colon, a finding that would have led to colonoscopy. The results were compared with the results from VA Cooperative Study 380 for age-matched men and women with negative fecal occult-blood tests and no family history of colon cancer. Colonoscopy was complete in 1463 women, 230 of whom (15.7 percent) had a family history of colon cancer. Colonoscopy revealed advanced neoplasia in 72 women (4.9 percent). If flexible sigmoidoscopy alone had been performed, advanced neoplasia would have been detected in 1.7 percent of these women (25 of 1463) and missed in 3.2 percent (47 of 1463). Only 35.2 percent of women with advanced neoplasia would have had their lesions identified if they had undergone flexible sigmoidoscopy alone, as compared with 66.3 percent of matched men from VA Cooperative Study 380 (P<0.001). Colonoscopy may be the preferred method of screening for colorectal cancer in women.