Gastroscopy following a positive fecal occult blood test and negative colonoscopy: systematic review and guideline. Can J Gastroenterol. 2010;24:113-120. [PMID: 20151070 DOI: 10.1155/2010/516363]

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%.

Gastroscopy after positive screening for faecal immunochemical tests and colonoscopy: A systematic review

BACKGROUND

Colorectal cancer (CRC) screening using the faecal immunochemical test (FIT) kits based on the detection of occult blood in stool is widely advocated in numerous screening programs worldwide. However, CRC is not commonly diagnosed in positive cases. We undertook this review to determine if there is evidence to suggest the use of opportunistic oesophago-gastro-duodenoscopy (OGD) in patients without CRC.

METHODS

A systematic review encompassing three electronic databases was performed. All peer-reviewed studies of FIT-positive patients who underwent either OGD and colonoscopy concurrently or OGD post-colonoscopy were included. Only studies from 2008 to 2022 using FIT kits were included to ensure studies not previously included in an earlier review were being analysed. A forward citation search of the included articles was also conducted to ensure no relevant articles were missed.

RESULTS

A total of 2409 records were extracted. Only four studies fulfilled the selection criteria and were included. Although the rates of abnormal OGD results were relatively high in the four studies, only 3 of 605 (0.50%) patients had gastric cancer in the entire review sample. No other malignancies were identified in all four studies. Other notable pathologies such as gastric polyps and gastritis were also reported.

CONCLUSIONS

There is little overall evidence to recommend UGI screening for all FIT-positive patients following a colonoscopy. However, there may be a role for clinicians to consider opportunistic OGD in this group of patients. Future research should examine patient populations from other sociocultural contexts including cost-effective analysis when considering changes in health guidelines on UGI screening.

Comparison of Findings From Fecal Occult Blood Test and Esophagogastroduodenoscopy With Histopathology Among Symptomatic Saudi Adults: A Retrospective Study

Background A fecal occult blood test is an established way to detect blood in stool samples. However, this diagnostic test is prone to false positives and false negatives, not to mention misuse and misinterpretation of results. In this study, we aimed to compare relevant findings among three diagnostic tests: a fecal occult blood test, an esophagogastroduodenoscopy, and histopathology. Methods This study used a retrospective analysis of 74 patients' electronic medical records from September 2021 to September 2022 at the Human Clinic and Gastroenterology Specialized Clinic in Riyadh, Saudi Arabia. Symptomatic adult Saudi patients who underwent a fecal occult blood test, esophagogastroduodenoscopy, and histopathology were included in the study. Results A total of 74 patients with a mean age of 43.76 ± 15.1 years were analyzed. More than half of the patients were men (63.5%). Eighteen (18) individuals tested positive through a fecal occult blood test, and 49 individuals showed a positive finding under esophagogastroduodenoscopy. Furthermore, statistical analyses revealed a significant correlation between fecal occult blood test outcomes and histopathological outcomes (p = 0.001). Conclusion A significant proportion of the sample population presented a false negative result under the fecal occult blood test. This emphasizes the importance of confirmatory endoscopic procedures and subsequent histopathology in the diagnosis of abnormalities in the upper gastrointestinal tract.

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.

Introducing the Sanguis-Filum for Detection of Gastric Mucosal Lesions Prior to Endoscopy: A Study Protocol

Early diagnosis of gastric cancer (GC) is compromised by a lack of specific signs to enable identification of affected individuals. We designed the Sanguis-filum (S-filum) as a simple bedside tool that could be used to detect the presence of gastric mucosal lesions prior to endoscopy. We previously published evidence that at a sensitivity of 91%, the presence of free blood in the stomach was associated with mucosal lesions. The S-filum is made of an inert but absorbent string coiled up in a gelatin capsule (Capsuline, FL, USA), which can be swallowed and the string retrieved to test for free blood. Preliminary testing of the S-filum was successfully conducted on healthy volunteers. We now intend to test it on actual patients, comparing the results to oesophagogastroduodenoscopy (OGD) findings. This will enable us to determine the diagnostic accuracy of the S-filum at detecting GC and other mucosal lesions. The S-filum as a bedside tool has the potential to assist healthcare providers to identify individuals likely to have early gastric mucosal lesions and requiring OGD examination. The S-filum could, in the long run, facilitate population-wide screening for early GC prior to endoscopy.

Colorectal cancer screening programme: is the French faecal immunological test (FIT) threshold optimal?

BACKGROUND

In France, the colorectal cancer organised screening programme uses the faecal immunological test. A positive test ⩾30 μg Hb/g of stool leads to a colonoscopy for identification of potential colorectal lesions. Cut-off values vary from 20 to 47 μg Hb/g of stool in Western countries. We herein question this threshold's relevance in a French population and perform a retrospective observational study using the Parisian database between 1 April 2015 and 31 December 2018.

METHODS

Rates of participation, numbers of positive faecal immunological test (FIT), detection rates and positive predictive values for advanced adenomas and/or colorectal cancer were determined. Mean positivity values for colorectal lesions were calculated.

RESULTS

In our population, there were 4.1% positive tests and 67.6% colonoscopy results available with final reports. Positive predictive value for advanced adenomas and colorectal cancer were 30% [95% confidence interval (CI) 29.8-30.3] and 7.4% (95% CI 7.35-7.52), respectively. The mean positivity value for all positive tests in our population was 101.7 µg Hb/g of stool (95% CI 85-118.3). There were 1136 normal colonoscopies (21.4%) with a mean positivity value of 88.6 μg Hb/g of stool. Following a negative test in a first screening campaign, 40.8% of patients in our population performed a second test with a positivity rate of 1.3% and with the encounter of 81 colorectal cancers. The risk of having a positive test during the second screening campaign and finding advanced colorectal lesions significantly increased (all p < 0.001) when comparing negative FIT results ranging between 15 and 29 μg Hb/g of stool to 0 and 14 μg Hb/g of stool from the previous campaign.

CONCLUSION

Using the current positivity threshold, some patients were considered negative with a delay in colorectal cancer diagnosis, suggesting the threshold could be lowered. Also, the mean positivity value for normal colonoscopies was high, raising the question of upper gastrointestinal bleeding.

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.

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.

Stool-Based Tests for Colorectal Cancer Screening: Performance Benchmarks Lead to High Expected Efficacy

PURPOSE OF REVIEW

Participation goals for colorectal cancer (CRC) screening in the USA have not been met. Non-invasive screening strategies may improve CRC screening participation. We highlight recent literature on stool-based screening performance and expectations for emerging non-invasive screening tests.

RECENT FINDINGS

Stool-based CRC screening detects screen-relevant colorectal neoplasia and outperforms a currently available plasma assay. Though modestly sensitive for CRC, adherence to annual fecal immunochemical testing (FIT) is sub-optimal. Multi-target stool DNA (MT-sDNA) has greater adherence, superior sensitivity for screen-relevant lesions (including those in the proximal colon and sessile serrated architecture), and equivalent specificity to FIT over a 3-year period. Stool-based CRC screening tests are anticipated to reduce the incidence and mortality of CRC through detection of early-stage cancers and high-risk polyps. These endpoints in performance will need to be met by emerging blood sample-based tests in order have meaningful impact in clinical practice.

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.

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.

Association of ten gastrointestinal and other medical conditions with positivity to faecal occult blood testing in routine screening: a large prospective study of women in England

BACKGROUND

In 2006, the Bowel Cancer Screening Programme (BCSP) in England began offering biennial faecal occult blood testing (FOBt) at ages 60-69 years. Although FOBt is aimed at detecting colorectal neoplasms, other conditions can affect the result. In a large UK prospective study, we examined associations, both before and after screening, between FOBt positivity and 10 conditions that are often associated with gastrointestinal bleeding.

METHODS

By electronically linking BCSP and Million Women Study records, we identified 604 495 women without previous colorectal cancer who participated in their first routine FOBt screening between 2006 and 2012. Regression models, using linked national hospital admission records, yielded adjusted relative risks (RRs) in FOBt-positive versus FOBt-negative women for colorectal cancer, adenoma, diverticular disease, inflammatory bowel disease, haemorrhoids, upper gastrointestinal cancer, oesophagitis, peptic ulcer, anaemia and other haematological disorders.

RESULTS

RRs in FOBt-positive versus FOBt-negative women were 201.3 (95% CI 173.8-233.2) for colorectal cancer and 197.9 (95% CI 180.6-216.8) for adenoma within 12 months after screening and 3.49 (95% CI 2.31-5.26) and 4.88 (95% CI 3.80-6.26), respectively, 12-24 months after screening; P < 0.001 for all RRs. In the 12 months after screening, the RR for inflammatory bowel disease was 26.3 (95% CI 19.9-34.7), and ranged between 2 and 5 for the upper gastrointestinal or haematological disorders. The RRs of being diagnosed with any of the eight conditions other than colorectal neoplasms before screening, and in the 12-24 months after screening, were 1.81 (95% CI 1.81-2.01) and 1.92 (95% CI 1.66-2.13), respectively.

CONCLUSIONS

Whereas FOBt positivity is associated with a substantially increased risk of colorectal neoplasms after screening, eight other gastrointestinal and haematological conditions are also associated with FOBt positivity, both before and after screening.

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.

Is gastroscopy for fecal immunochemical test positive patients worthwhile?

BACKGROUND

The use of fecal immunochemical test (FIT) in the screening for colorectal cancer is long established. However, more than 50 % of patients with positive FITs have a negative colonoscopy. The role of a subsequent oesophago-gastro-duodenoscopy (OGD) is debatable. The aim of this study is to evaluate the yield of OGD in patients with positive FITs.

METHODOLOGY

A retrospective review of patients who underwent colonoscopy for a positive FIT between Jan. 2008 and Dec. 2012 was identified from a prospectively collected endoscopy database at the National University Hospital, Singapore. Patients who underwent concurrent or subsequent OGDs for positive FIT formed the study group. We considered any new cancer or significant upper gastrointestinal pathology such as peptic ulcer disease or gastritis requiring treatment as a positive examination.

RESULTS

A total of 202 patients underwent both a colonoscopy and an OGD for a positive FIT and formed the study group. One hundred and six (52.5 %) of them had a positive examination with gastritis and duodenitis representing the most common UGI pathology in 89 (44.1 %) patients. Twenty-nine (14.4 %) patients tested positive for helicobacter pylori infection and another 16 (7.9 %) patients had peptic ulcer disease. There were no UGI cancers detected. One patient had an esophageal leiomyoma that was treated conservatively.

CONCLUSION

Routine gastroscopy for FIT positivity has a high diagnostic yield for benign upper gastrointestinal pathology. Well-designed prospective studies to further evaluate the cost-effectiveness of routine gastroscopy in the work up of FIT positivity are warranted to make better clinical practice guidelines.

Long-term Follow-up of Patients Having False-Positive Multitarget Stool DNA Tests after Negative Screening Colonoscopy: The LONG-HAUL Cohort Study

Background: Studies of colorectal cancer screening by multitarget stool DNA (MT-sDNA) show false-positive (FP) rates of 7% to 13%. It is unclear whether FP patients are at increased long-term risk of adverse outcomes.Methods: We compared subsequent clinical events among patients with apparent FP MT-sDNA with those in patients reported as true negative (TN). This was a retrospective cohort study of participants in pre-FDA approval MT-sDNA studies having nonadvanced or negative baseline colonoscopy findings from a single referral center. Per-protocol and calibrated cutoffs defined FP and TN groups. From the time of stool collection, we measured differences between FP and TN groups in time to death, subsequent cancer diagnosis, and onset of alarm symptoms.Results: Of 1,050 eligible patients, only 6 were lost to follow-up. Median age was 65.6 years [interquartile range (IQR), 56.8-72.3]; 54% were female. Median follow-up time was 4 years (IQR, 3.5-5.3). Eight aerodigestive (lung and gastrointestinal tract) cancers occurred. FP status by calibrated, but not per-protocol, cutoffs was associated with subsequent aerodigestive cancer; however, cumulative incidence did not exceed SEER expectations from the general population. By any cutoff method, FP status was not associated with mortality or alarm symptoms.Conclusions: Although FP status was associated with long-term aerodigestive cancers, new cases were not temporally related and did not exceed incidence estimates from general population.Impact: These observations do not justify aggressive follow-up evaluation for patients with FP MT-sDNA at this time. Larger studies are needed to confirm these early findings. Cancer Epidemiol Biomarkers Prev; 26(4); 614-21. ©2016 AACR.

Sensitivity and Specificity of Community Fecal Immunotesting Screening for Colorectal Carcinoma in a High-Risk Canadian Population

CONTEXT

Community-based programs are a common way of promoting colorectal cancer screening by primary care physicians. Fecal immunochemical testing (FIT) is a screening method commonly used in such programs. Fecal immunochemical testing has advantages to the patient as well as to clinical laboratories.

OBJECTIVE

To assess the operational test characteristics of a FIT pilot program in Calgary, Alberta, Canada, between April 2011 and May 2012.

DESIGN

Four hundred fifty-seven high-risk patients undergoing both FIT and colonoscopy were included. Areas under the curve and positive predictive values were derived for FIT values and biopsy-proven neoplasia. Subgroup analysis was also performed on men and women and for ages older and younger than the mean age of 62 years.

RESULTS

For colorectal carcinoma and colonic adenomas the areas under the curve were 0.79 (95% confidence interval 0.71-0.87) and 0.60 (95% confidence interval 0.54-0.65), respectively. The positive predictive value of a positive FIT result for any neoplasia was 53%. The overall performance of the test for all neoplasia was better for men and better for older individuals.

CONCLUSIONS

The performance of FIT in this clinical setting was very good for detecting carcinoma, but marginal for detection of colonic adenomas.

Do we have to perform a renal biopsy? Clinical dilemmas in a case with nephrotic syndrome

Renal biopsy is one of the pivotal diagnostic tools used in the field of nephrology. A morphological analysis of the kidney may also be of value for the overall management of patients with diabetic nephropathy. However, the indications for renal biopsy differ considerably among nephrologists, and no global consensus regarding performing this procedure among diabetic patients with various renal manifestations has yet been achieved. In this report, we would like to describe our serendipitous experience with a male type 2 diabetic patient presenting with nephrotic syndrome complicated by concurrent gastric carcinoma. We also discuss several conundrums that arose in the current case, which had an impact on our diagnostic and therapeutic decisions.

Accuracy of faecal occult blood test and Helicobacter pylori stool antigen test for detection of upper gastrointestinal lesions

OBJECTIVE

Highly sensitive guaiac-based faecal occult blood (Hemoccult SENSA) and Helicobacter pylori stool antigen testing might help detect upper gastrointestinal lesions when appended to a colorectal cancer screening programme with faecal immunochemical testing. We evaluated the diagnostic accuracies of two stool tests in detecting upper gastrointestinal lesions.

DESIGN

Cross-sectional design.

SETTING

Hospital-based and community-based screening settings.

PARTICIPANTS

A hospital-based deviation cohort of 3172 participants to evaluate test performance and a community-based validation cohort of 3621 to verify the findings.

INTERVENTIONS

Three types of stool tests with bidirectional endoscopy as the reference standard.

OUTCOMES

Sensitivity, specificity and positive and negative likelihood ratios.

RESULTS

For detecting upper gastrointestinal lesions in cases with negative immunochemical tests, the sensitivity, specificity, and positive and negative likelihood ratios of the guaiac-based and H pylori antigen tests were 16.3% (95% CI 13.3% to 19.8%), 90.1% (88.9% to 91.2%), 1.64 (1.31 to 2.07), and 0.93 (0.89 to 0.97), respectively, and 52.5% (48.1% to 56.9%), 80.6% (79.0% to 82.1%), 2.71 (2.41 to 3.04) and 0.59 (0.54 to 0.65), respectively. For detecting upper gastrointestinal lesions in cases with normal colonoscopy, the results of the guaiac-based and H pylori antigen tests were 17.9% (14.8% to 21.5%), 90.1% (88.9% to 91.2%), 1.81 (1.45 to 2.26) and 0.91 (0.87 to 0.95), respectively, and 53.1% (48.6% to 57.4%), 80.7% (79.1% to 82.2%), 2.75 (2.45 to 3.08) and 0.58 (0.53 to 0.64), respectively. Within the community, positive predictive values of the immunochemical and H pylori antigen tests were 36.0% (26.0% to 46.0%) and 31.9% (28.3% to 35.5%), respectively, for detecting lower and upper gastrointestinal lesions, which were similar to expected values.

CONCLUSIONS

The H pylori stool antigen test is more accurate than the guaiac-based test in the screening of upper gastrointestinal lesions in a population with high prevalence of H pylori infection and upper gastrointestinal lesions. It is applicable to add the H pylori antigen test to the immunochemical test for pan detection.

TRIAL REGISTRATION

NCT01341197 (ClinicalTrial.gov).

The impact of age, sex and socioeconomic deprivation on outcomes in a colorectal cancer screening programme

Background

Population-based colorectal cancer screening has been shown to reduce cancer specific mortality and is used across the UK. Despite evidence that older age, male sex and deprivation are associated with an increased incidence of colorectal cancer, uptake of bowel cancer screening varies across demographic groups. The aim of this study was to assess the impact of age, sex and deprivation on outcomes throughout the screening process.

Methods

A prospectively maintained database, encompassing the first screening round of a faecal occult blood test screening programme in a single geographical area, was analysed.

Results

Overall, 395 096 individuals were invited to screening, 204 139 (52%) participated and 6 079 (3%) tested positive. Of the positive tests, 4 625 (76%) attended for colonoscopy and cancer was detected in 396 individuals (9%). Lower uptake of screening was associated with younger age, male sex and deprivation (all p<0.001). Only deprivation was associated with failure to proceed to colonoscopy following a positive test (p<0.001). Despite higher positivity rates in those that were more deprived (p<0.001), the likelihood of detecting cancer in those attending for colonoscopy was lower (8% most deprived vs 10% least deprived, p = 0.003).

Conclusion

Individuals who are deprived are less likely to participate in screening, less likely to undergo colonoscopy and less likely to have cancer identified as a result of a positive test. Therefore, this study suggests that strategies aimed at improving participation of deprived individuals in colorectal cancer screening should be directed at all stages of the screening process and not just uptake of the test.

Is esophagogastroduodenoscopy necessary in patients with positive fecal occult blood tests and negative colonoscopy?

BACKGROUND

False positives of fecal occult blood tests (FOBT) regarding colorectal cancer detection are common. The aim was to investigate the upper gastrointestinal (GI) condition confirmed by endoscopy in positive FOBT patients without advanced colorectal neoplasia, hemorrhoid, or colitis.

METHODS

The authors reviewed the collective data of 340 positive FOBT patients who underwent both esophagogastroduodenoscopy (EGD) and colonoscopy from January 2005 to October 2011. Demographic data, effects of medications, including antiplatelet agents, nonsteroidal anti-inflammatory drugs, or warfarin on the results of FOBT, presence or absence of GI mucosal lesions confirmed by EGD and colonoscopy, and FOBT titer in 552 positive FOBT patients were analyzed.

RESULTS

On colonoscopy, colorectal cancer was detected in 35 patients (10.3%), advanced adenoma in 22 patients (6.4%). "Negative colonoscopy" included no significant lesions and non-advanced adenomas. In 243 patients with "negative colonoscopy", EGD findings included 3 (1.2%) gastric cancers and 39 (16%) peptic ulcer diseases. Gastric cancers were all found in patients who had no experience of EGD within 2 years; however, the incidence of peptic ulcer disease was not different in patients with or without previous EGD within 2 years. Two or more antiplatelet agents increased false positive rates of FOBT.

CONCLUSIONS

Upper GI evaluation is mandatory in patients with positive FOBTs and negative colonoscopy especially in patients without experience of EGD within 2 years.

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.

How should individuals with a false-positive fecal occult blood test for colorectal cancer be managed? A decision analysis

Several industrialized nations recommend fecal occult blood testing (FOBT) to screen for colorectal cancer (CRC), but corresponding screening guidelines do not specify how individuals with a prior false-positive FOBT result (fpFOBT) should be managed in terms of subsequent CRC screening. Accordingly, we conducted a decision analysis to compare different strategies for managing such individuals. We used a previously developed CRC microsimulation model, SimCRC, to calculate life-years and the lifetime number of colonoscopies (as a measure of required resources) for a cohort of 50-year-olds to whom FOBT-based CRC screening is offered annually from 50 to 75 years. We compared three management strategies for individuals with a prior fpFOBT: (i) resume screening in 10 years with 10-yearly colonoscopy (SwitchCol_long); (ii) resume screening in 1 year with annual FOBT (ContinueFOBT_Short) and (iii) resume screening in 10 years (i.e., the recommended interval following a negative colonoscopy) with annual FOBT (ContinueFOBT_long). We performed sensitivity analyses on various parameters and assumptions. When using different management strategies for individuals with a prior fpFOBT, the variation in the number of life-years gained relative to no screening was <2%, whereas the variation in the lifetime number of colonoscopies was 23% (percentages are calculated as the maximum difference across strategies divided by the lowest number across strategies). The ContinueFOBT_long strategy showed the lowest lifetime number of colonoscopies per life-year gained even when key assumptions were varied. In conclusion, the ContinueFOBT_long strategy was advantageous regarding both clinical benefit and required resources. Specifying an appropriate management strategy for individuals with a prior fpFOBT may substantially reduce required resources within a FOBT-based CRC screening program without limiting its effectiveness.

A future for faecal haemoglobin measurements in the medical laboratory

Guaiac-based faecal occult blood tests (gFOBT) are still used in asymptomatic population bowel screening programmes but are being replaced by faecal immunochemical tests (FIT) for haemoglobin. gFOBT have many well-documented disadvantages and there is little evidence for their use in assessment of the symptomatic. Many laboratories have eliminated gFOBT from their approved repertoires by invoking the authoritative published guidelines. Data continue to accumulate that gFOBT are obsolete. FIT are available in two formats, qualitative and quantitative, the latter having advantages that the faecal haemoglobin concentrations are measured and cut-off concentrations that stimulate further investigation can be user-defined. There is growing evidence that FIT would be useful in a spectrum of clinical settings in addition to screening. All laboratories should have FIT in their existing repertoire. For some uses, qualitative FIT would be adequate. However, much evidence has accumulated that measurements of faecal haemoglobin concentrations are beneficial for the assessment of both disease severity and the future risk of colorectal neoplasia. Interpretation requires appreciation that faecal haemoglobin concentrations are higher in men than women and rise with age. It might well be that risk scoring systems that take gender and age into account, possibly with other factors including symptoms, will benefit individuals. Laboratories should consider how quantitative faecal haemoglobin measurements could be brought into routine practice and included in their forward planning. External quality assessment is needed. Specialists in laboratory medicine are urged to play a significant role in the research and development still required to make this a truly mature investigation.

Negative screening colonoscopy after a positive guaiac faecal occult blood test: not a contraindication to continued screening

AIM

In guaiac faecal occult blood test (gFOBT) screening at least 50% of positive individuals will have a colonoscopy negative for colorectal neoplasia. The question of continuing screening in this group has not been addressed.

METHOD

Data on participants aged 50-69 years with a positive gFOBT result and a negative colonoscopy were followed through the biennial screening pilot conducted between 2000 and 2007 in Scotland.

RESULTS

In the first screening round, 1527 colonoscopies were negative for neoplasia. 1300 were re-invited in the second round, 905 accepted, and 157 had a positive gFOBT result, giving a positivity rate of 17.4%. Colonoscopy revealed 20 subjects with adenoma and six with invasive cancer. In the third screening round 1031 were invited for a third time and 730 accepted: 55 had a positive gFOBT test, giving a positivity rate of 7.5%. In this group, six colonoscopies revealed adenomas but there were no cancers diagnosed. In the third screening round, 108 individuals had had two positive gFOBT results and two subsequent negative colonoscopies. Eighty-four were invited for a third gFOBT, 66 accepted and 19 (25.6%) had a positive result none of whom had an adenoma or carcinoma.

CONCLUSION

These data indicate that a negative colonoscopy following a positive gFOBT is not a contraindication for further screening, although this is likely to have a low yield of neoplastic pathology after two negative colonoscopies.

Canadian Association of Gastroenterology position statement on screening individuals at average risk for developing colorectal cancer: 2010

The Canadian Association of Gastroenterology and the Canadian Digestive Health Foundation published guidelines on colon cancer screening in 2004. Subsequent to the publication of these guidelines, many advances have occurred, thereby necessitating a review of the existing guidelines in the context of new technologies and clinical knowledge. The assembled guideline panel recognized three recent American sets of guidelines and identified seven issues that required comment from a Canadian perspective. These issues included, among others, the role of program-based screening, flexible sigmoidoscopy, computed tomography colonography, barium enema and quality improvement. The panel also provided context for the selection of the fecal immunochemical test as the fecal occult blood test of choice, and the relative role of colonoscopy as a primary screening tool. Recommendations were also provided for an upper age limit for colon cancer screening, whether upper endoscopy should be performed following a negative colonoscopy for a positive fecal occult blood test and when colon cancer screening should resume following negative colonoscopy.

Use of faecal markers in screening for colorectal neoplasia: a European group on tumor markers position paper

Several randomized controlled trials have shown that population-based screening using faecal occult blood testing (FOBT) can reduce mortality from colorectal neoplasia. Based on this evidence, a number of countries have introduced screening for colorectal cancer (CRC) and high-risk adenoma and many others are considering its introduction. The aim of this article is to critically review the current status of faecal markers as population-based screening tests for these neoplasia. Most of the available faecal tests involve the measurement of either occult blood or a panel of DNA markers. Occult blood may be measured using either the guaiac faecal occult blood test (gFOBT) or a faecal immunochemical test (iFOBT). Although iFOBT may require a greater initial investment, they have several advantages over gFOBT, including greater analytical sensitivity and specificity. Their use results in improved clinical performance and higher uptake rates. Importantly for population screening, some of the iFOBTs can be automated and provide an adjustable cutoff for faecal haemoglobin concentration. However, samples for iFOBT, may be less stable after collection than for gFOBT. For new centres undertaking FOBT for colorectal neoplasia, the European Group on Tumour Markers recommends use of a quantitative iFOBT with an adjustable cutoff point and high throughput analysis. All participants with positive FOBT results should be offered colonoscopy. The panel recommends further research into increasing the stability of iFOBT and the development of improved and affordable DNA and proteomic-based tests, which reduce current false negative rates, simplify sample transport and enable automated analysis.