Computed tomographic colonography in subjects with positive faecal occult blood test refusing optical colonoscopy

Colorectal Cancer Screening with Computed Tomography Colonography: Single Region Experience in Kazakhstan

Background/Aims

The aim of our study was to determine the efficacy of computed tomography colonography (CTC) in screening for colorectal cancer (CRC).

Methods

A total of 612 females and 588 males aged 45 to 75 years were enrolled in CTC screening. CTC was performed following standard bowel preparation and colonic insufflation with carbon dioxide. The main outcomes were the detection rate of CRC and advanced adenoma (AA), prevalence of colorectal lesions in relation to socio-demographic and health factors, and overall diagnostic performance of CTC.

Results

Overall, 56.5% of the 1,200 invited subjects underwent CTC screening. The sensitivity for CRC and AA was 0.89 and 0.97, respectively, while the specificity was 0.71 and 0.99, respectively. The prevalence of CRC and AA was 3.0% (18/593) and 7.1% (42/593), respectively, with the highest CRC prevalence in the 66-75 age group (≥12 times; odds ratio [OR], 12.11; 95% confidence interval [CI], 4.45-32.92). CRC and AA prevalence were inversely correlated with Asian descent, physical activity, and negative fecal immunochemical test results (OR=0.43; 95% CI, 0.22-0.83; OR=0.16; 95% CI, 0.04-0.68; OR=0.5; 95% CI, 0.07-3.85, respectively).

Conclusions

Our study revealed high accuracy of CTC in diagnosing colonic neoplasms, good compliance with CTC screening, and high detection rate of CRC.

Barriers to completing colonoscopy after a positive fecal occult blood test

Background

Colorectal cancer leads to significant morbidity and mortality. Early detection and treatment are essential. Screening using fecal occult blood tests has increased significantly, but adherence to colonoscopy follow-up is suboptimal, increasing CRC mortality risk.

The aim of this study was to identify barriers to colonoscopy following a positive FOBT at the level of the patient, physician, organization and policymakers.

Methods

This mixed methods study was conducted at two health care organizations in Israel. The study included retrospective analyses of 45,281 50–74 year-old members with positive fecal immunochemical tests from 2010 to 2014, and a survey of 772 patients with a positive test during 2015, with and without follow-up. The qualitative part of the study included focus groups with primary physicians and gastroenterologists and in-depth interviews with opinion leaders in healthcare.

Results

Patient lack of comprehension regarding the test was the strongest predictor of non-adherence to follow-up. Older age, Arab ethnicity, and lower socio economic status significantly reduced adherence. We found no correlation with gender, marital status, patient activation, waiting time for appointments or distance from gastroenterology clinics. Primary care physicians underestimate non-adherence rates. They feel responsible for patient follow-up, but express lack of time and skills that will allow them to ensure adherence among their patients. Gastroenterologists do not consider fecal occult blood an effective tool for CRC detection, and believe that all patients should undergo colonoscopy. Opinion leaders in the healthcare field do not prioritize the issue of follow-up after a positive screening test for colorectal cancer, although they understand the importance.

Conclusions

We identified important barriers that need to be addressed to improve the effectiveness of the screening program. Targeted interventions for populations at risk for non-adherence, specifically for those with low literacy levels, and better explanation of the need for follow-up as a routine need to be set in place. Lack of agreement between screening recommendations and gastroenterologist opinion, and lack of awareness among healthcare authority figures negatively impact the screening program need to be addressed at the organizational and national level.

Trial registration

This study was approved by the IRB in both participating organizations (Meuhedet Health Care Institutional Review Board #02–2–5-15, Maccabi Healthcare Institutional Review Board BBI-0025-16). Participant consent was waived by both IRB’s.

Imaging alternatives to colonoscopy: CT colonography and colon capsule. European Society of Gastrointestinal Endoscopy (ESGE) and European Society of Gastrointestinal and Abdominal Radiology (ESGAR) Guideline - Update 2020

1: ESGE/ESGAR recommend computed tomographic colonography (CTC) as the radiological examination of choice for the diagnosis of colorectal neoplasia.Strong recommendation, high quality evidence.ESGE/ESGAR do not recommend barium enema in this setting.Strong recommendation, high quality evidence. 2: ESGE/ESGAR recommend CTC, preferably the same or next day, if colonoscopy is incomplete. The timing depends on an interdisciplinary decision including endoscopic and radiological factors.Strong recommendation, low quality evidence.ESGE/ESGAR suggests that, in centers with expertise in and availability of colon capsule endoscopy (CCE), CCE preferably the same or the next day may be considered if colonoscopy is incomplete.Weak recommendation, low quality evidence. 3: When colonoscopy is contraindicated or not possible, ESGE/ESGAR recommend CTC as an acceptable and equally sensitive alternative for patients with alarm symptoms.Strong recommendation, high quality evidence.Because of lack of direct evidence, ESGE/ESGAR do not recommend CCE in this situation.Very low quality evidence.ESGE/ESGAR recommend CTC as an acceptable alternative to colonoscopy for patients with non-alarm symptoms.Strong recommendation, high quality evidence.In centers with availability, ESGE/ESGAR suggests that CCE may be considered in patients with non-alarm symptoms.Weak recommendation, low quality evidence. 4: Where there is no organized fecal immunochemical test (FIT)-based population colorectal screening program, ESGE/ESGAR recommend CTC as an option for colorectal cancer screening, providing the screenee is adequately informed about test characteristics, benefits, and risks, and depending on local service- and patient-related factors.Strong recommendation, high quality evidence.ESGE/ESGAR do not suggest CCE as a first-line screening test for colorectal cancer.Weak recommendation, low quality evidence. 5: ESGE/ESGAR recommend CTC in the case of a positive fecal occult blood test (FOBT) or FIT with incomplete or unfeasible colonoscopy, within organized population screening programs.Strong recommendation, moderate quality evidence.ESGE/ESGAR also suggest the use of CCE in this setting based on availability.Weak recommendation, moderate quality evidence. 6: ESGE/ESGAR suggest CTC with intravenous contrast medium injection for surveillance after curative-intent resection of colorectal cancer only in patients in whom colonoscopy is contraindicated or unfeasibleWeak recommendation, low quality evidence.There is insufficient evidence to recommend CCE in this setting.Very low quality evidence. 7: ESGE/ESGAR suggest CTC in patients with high risk polyps undergoing surveillance after polypectomy only when colonoscopy is unfeasible.Weak recommendation, low quality evidence.There is insufficient evidence to recommend CCE in post-polypectomy surveillance.Very low quality evidence. 8: ESGE/ESGAR recommend against CTC in patients with acute colonic inflammation and in those who have recently undergone colorectal surgery, pending a multidisciplinary evaluation.Strong recommendation, low quality evidence. 9: ESGE/ESGAR recommend referral for endoscopic polypectomy in patients with at least one polyp ≥ 6 mm detected at CTC or CCE.Follow-up CTC may be clinically considered for 6 - 9-mm CTC-detected lesions if patients do not undergo polypectomy because of patient choice, comorbidity, and/or low risk profile for advanced neoplasia.Strong recommendation, moderate quality evidence.

Preferences for different diagnostic modalities to follow up abnormal colorectal cancer screening results: a hypothetical vignette study

OBJECTIVES

In England, a significant proportion of people who take part in the national bowel cancer screening programme (BCSP) and have a positive faecal occult blood test (FOBt) result, do not attend follow-up colonoscopy (CC). The aim of this study was to investigate differences in intended participation in a follow-up investigation by diagnostic modality offered including CC, CT colonography (CTC) or capsule endoscopy (CE).

SETTING

We performed a randomised online experiment with individuals who had previously completed an FOBt as part of the English BCSP.

METHODS

Participants (n=953) were randomly allocated to receive one of three online vignettes asking participants to imagine they had received an abnormal FOBt result, and that they had been invited for a follow-up test. The follow-up test offered was either: CC (n=346), CTC (n=302) or CE (n=305). Participants were then asked how likely they were to have their allocated test or if they refused, either of the other tests. Respondents were also asked to cite possible emotional and practical barriers to follow up testing. Multivariable logistic regression models were used to investigate intentions.

RESULTS

Intention to have the test was higher in the CTC group (96.7%) compared with the CC group (91.8%; OR 2.64; 95% CI 1.22 to 5.73). CTC was considered less 'off-putting' (OR 0.66, 95% CI 0.47 to 0.94) and less uncomfortable compared with CC (OR 0.51, 95% CI 0.34 to 0.77). For those who did not intend to have the test they were offered, CE (39.7%) or no investigation (34.5%) was preferable to CC (8.6%) or CTC (17.2%).

CONCLUSIONS

Alternative tests have the potential to increase attendance at diagnostic follow-up appointments.

Colorectal Cancer Screening: The Role of Psychological, Social and Background Factors in Decision-making Process

Since ColoRectal Cancer (CRC) remains the third cause of cancer death in the world, a better understanding of the reasons underlying poor adherence to and delay in undergoing CRC screening programs is important. CRC screening decision-making process can be conceptualized as the relationship between intention and behavior and needs to be investigated including the impact on patients' decision of a broad range of psychological factors and personal predisposition as fear of a positive screening test, poor understanding of the procedure, psychological distress, anxiety, anticipation of pain, feelings of embarrassment and vulnerability. Also socioeconomic, ethnic and sociological influences, and organizational barriers have been identified as factors influencing CRC screening adherence. Decision-making process can finally be influenced by the healthcare background in which the intervention is promoted and screening programs are carried out. However, there is still a gap on the scientific knowledge about the influences of diverse elements on screening adherence and this deserves further investigations in order to carry out more focused and effective prevention programs.

CT colonography: role in FOBT-based screening programs for colorectal cancer

Computed tomographic colonography (CTC) is a minimally invasive imaging examination for the colon, and is safe, well tolerated and accurate for the detection of colorectal cancer (CRC) and advanced adenoma. While the role of CTC as a primary test for population screening of CRC is under investigation, the fecal occult blood test (FOBT) has been recommended for population screening of CRC in Europe. Subjects with positive FOBT are invited to undergo total colonoscopy, which has some critical issues, such as suboptimal compliance, contraindications and the possibility of an incomplete exploration of the colon. Based on available data, the integration of CTC in FOBT-based population screening programs for CRC may fall into three scenarios. First, CTC is recommended in FOBT-positive subjects when colonoscopy is refused, incomplete or contraindicated. For these indications CTC should replace double-contrast barium enema. Second, conversely, CTC is not currently recommended as a second-level examination prior to colonoscopy in all FOBT-positive subjects, as this strategy is most probably not cost-effective. Finally, CTC may be considered instead of colonoscopy for surveillance after adenoma removal, but specific studies are needed.

Patient factors associated with non-attendance at colonoscopy after a positive screening faecal occult blood test

Background Screening participants with abnormal faecal occult blood test results who do not attend further testing are at high risk of colorectal cancer, yet little is known about their reasons for non-attendance. Methods We conducted a medical record review of 170 patients from two English Bowel Cancer Screening Programme centres who had abnormal guaiac faecal occult blood test screening tests between November 2011 and April 2013 but did not undergo colonoscopy. Using information from patient records, we coded and categorized reasons for non-attendance. Results Of the 170 patients, 82 were eligible for review, of whom 66 had at least one recorded reason for lack of colonoscopy follow-up. Reasons fell into seven main categories: (i) other commitments, (ii) unwillingness to have the test, (iii) a feeling that the faecal occult blood test result was a false positive, (iv) another health issue taking priority, (v) failing to complete bowel preparation, (vi) practical barriers (e.g. lack of transport), and (vii) having had or planning colonoscopy elsewhere. The most common single reasons were unwillingness to have a colonoscopy and being away. Conclusions We identify a range of apparent reasons for colonoscopy non-attendance after a positive faecal occult blood test screening. Education regarding the interpretation of guaiac faecal occult blood test findings, offer of alternative confirmatory test options, and flexibility in the timing or location of subsequent testing might decrease non-attendance of diagnostic testing following positive faecal occult blood test.

CT colonography for population screening of colorectal cancer: hints from European trials

CT colonography (CTC) is a minimally invasive radiological investigation of the colon. Robust evidence indicates that CTC is safe, well tolerated and highly accurate for the detection of colorectal cancer (CRC) and large polyps, which are the targets of screening. Randomized controlled trials were carried out in Europe to evaluate CTC as the primary test for population screening of CRC in comparison with faecal immunochemical test (FIT), sigmoidoscopy and colonoscopy. Main outcomes were participation rate and detection rate. Participation rate for screening CTC was in the range of 25-34%, whereas the detection rate of CTC for CRC and advanced adenoma was in the range of 5.1-6.1%. Participation for CTC screening was lower than that for FIT, similar to that for sigmoidoscopy and higher than that for colonoscopy. The detection rate of CTC was higher than that of one FIT round, similar to that of sigmoidoscopy and lower than that of colonoscopy. However, owing to the higher participation rate in CTC screening with respect to colonoscopy screening, the detection rates per invitee of CTC and colonoscopy would be comparable. These results justify consideration of CTC in organized screening programmes for CRC. However, assessment of other factors such as polyp size threshold for colonoscopy referral, management of extracolonic findings and, most importantly, the forthcoming results of cost-effectiveness analyses are crucial to define the role of CTC in primary screening.

CT Colonography: an update on current and future indications

Computed tomographic colonography (CTC) is a minimally invasive, patient-friendly, safe and robust colonic imaging modality. The technique is standardized and consolidated evidence from the literature shows that the diagnostic performances for the detection of colorectal cancer and large polyps are similar to colonoscopy (CS) and largely superior to alternative radiological exams, like barium enema. A clear understanding of the exact role of CTC will be beneficial to maximize the benefits and minimize the potential sources of frustration or disappointment for both referring clinicians and patients. Incomplete, failed, or unfeasible CS; investigation of elderly, and frail patients and assessment of diverticular disease are major indications supported by evidence-based data and agreed by the endoscopists. The use of CTC for symptomatic patients, colorectal cancer screening and colonic surveillance is still under debate and, thus, recommended only if CS is unfeasible or refused by patients.

Effect of faecal occult blood positivity on detection rates and positive predictive value of CT colonography when screening for colorectal neoplasia

AIM

To determine the detection rates and positive predictive value (PPV) of computed tomography (CT) colonography (CTC) according to the magnitude of faecal occult blood test (FOBt) positivity.

MATERIALS AND METHODS

Anonymised data from individuals undergoing CTC after a positive FOBt in the English Bowel Cancer Screening Programme were analysed. The detection of colorectal cancer (CRC), advanced neoplasia, and ≥ 6 mm polyps were stratified by the number of positive FOBt windows. The PPV was calculated by reference to subsequent endoscopy results. The influence of the FOBt result on detection rates was estimated with multilevel logistic regression. PPV, CRC stage, and location were compared across groups according to FOBt positivity.

RESULTS

Four thousand, six hundred and one individuals were included (mean = 66.7 years, 54.2% men). Detection rates of CRC and advanced neoplasia increased with greater numbers of positive FOBt windows (odds ratio [OR] for CRC = 1.41; 95% confidence interval [CI]: 1.31-1.52; OR for advanced neoplasia = 1.17; 95%CI: 1.12-1.23; both p < 0.0001). The PPV was significantly greater at higher FOBt levels (p = 0.020). The number of positive FOBt windows had no significant effect on stage (p = 0.30) or location (p = 0.20) of confirmed CRC.

CONCLUSIONS

The magnitude of FOBt positivity influences the PPV and detection rates when screening for colorectal neoplasia. CTC may be particularly useful for FOBt patients with few positive test windows.

Computed tomography colonography in 2014: an update on technique and indications

Twenty years after its introduction, computed tomographic colonography (CTC) has reached its maturity, and it can reasonably be considered the best radiological diagnostic test for imaging colorectal cancer (CRC) and polyps. This examination technique is less invasive than colonoscopy (CS), easy to perform, and standardized. Reduced bowel preparation and colonic distention using carbon dioxide favor patient compliance. Widespread implementation of a new image reconstruction algorithm has minimized radiation exposure, and the use of dedicated software with enhanced views has enabled easier image interpretation. Integration in the routine workflow of a computer-aided detection algorithm reduces perceptual errors, particularly for small polyps. Consolidated evidence from the literature shows that the diagnostic performances for the detection of CRC and large polyps in symptomatic and asymptomatic individuals are similar to CS and are largely superior to barium enema, the latter of which should be strongly discouraged. Favorable data regarding CTC performance open the possibility for many different indications, some of which are already supported by evidence-based data: incomplete, failed, or unfeasible CS; symptomatic, elderly, and frail patients; and investigation of diverticular disease. Other indications are still being debated and, thus, are recommended only if CS is unfeasible: the use of CTC in CRC screening and in surveillance after surgery for CRC or polypectomy. In order for CTC to be used appropriately, contraindications such as acute abdominal conditions (diverticulitis or the acute phase of inflammatory bowel diseases) and surveillance in patients with a long-standing history of ulcerative colitis or Crohn's disease and in those with hereditary colonic syndromes should not be overlooked. This will maximize the benefits of the technique and minimize potential sources of frustration or disappointment for both referring clinicians and patients.

A comparison of different strategies used to invite subjects with a positive faecal occult blood test to a colonoscopy assessment. A randomised controlled trial in population-based screening programmes

OBJECTIVE

The purpose of this parallel randomised controlled trial was to compare compliance with different modalities used to invite patients with a positive immunochemical faecal occult blood test (FIT+) for a total colonoscopy (TC).

METHOD

FIT+ patients from nine Italian colorectal cancer screening programmes were randomised to be invited for a TC initially by mail or by phone and, for non-compliers, to be recalled by mail, for counselling with a general practitioner, or to meet with a specialist screening practitioner (nurse or healthcare assistant).

RESULTS

In all, 3777 patients were randomised to different invitation strategies. Compliance with an initial invitation by mail and by phone was similar (86.0% vs. 84.0%, relative risk - RR: 1.02; 95%CI 0.97-1.08). Among non-responders to the initial invitation, compliance with a recall by appointment with a specialist practitioner was 50.4%, significantly higher than with a mail recall (38.1%; RR:1.33; 95%CI 1.01-1.76) or with a face-to-face counselling with the GP (30.8%; RR:1.45;95%CI 1.14-1.87).

CONCLUSION

Compliance with an initial invitation for a TC by mail and by phone was similar. A personal meeting with a specialist screening practitioner was associated with the highest compliance among non-compliers with initial invitations, while the involvement of GPs in this particular activity seemed less effective.

CT colonography: clinical evaluation of a method for automatic coregistration of polyps at follow-up surveillance studies

PURPOSE

To evaluate the accuracy of a method of automatic coregistration of the endoluminal surfaces at computed tomographic (CT) colonography performed on separate occasions to facilitate identification of polyps in patients undergoing polyp surveillance.

MATERIALS AND METHODS

Institutional review board and HIPAA approval were obtained. A registration algorithm that was designed to coregister the coordinates of endoluminal colonic surfaces on images from prone and supine CT colonographic acquisitions was used to match polyps in sequential studies in patients undergoing polyp surveillance. Initial and follow-up CT colonographic examinations in 26 patients (35 polyps) were selected and the algorithm was tested by means of two methods, the longitudinal method (polyp coordinates from the initial prone and supine acquisitions were used to identify the expected polyp location automatically at follow-up CT colonography) and the consistency method (polyp coordinates from the initial supine acquisition were used to identify polyp location on images from the initial prone acquisition, then on those for follow-up prone and follow-up supine acquisitions). Two observers measured the Euclidean distance between true and expected polyp locations, and mean per-patient registration accuracy was calculated. Segments with and without collapse were compared by using the Kruskal-Wallace test, and the relationship between registration error and temporal separation was investigated by using the Pearson correlation.

RESULTS

Coregistration was achieved for all 35 polyps by using both longitudinal and consistency methods. Mean ± standard deviation Euclidean registration error for the longitudinal method was 17.4 mm ± 12.1 and for the consistency method, 26.9 mm ± 20.8. There was no significant difference between these results and the registration error when prone and supine acquisitions in the same study were compared (16.9 mm ± 17.6; P = .451).

CONCLUSION

Automatic endoluminal coregistration by using an algorithm at initial CT colonography allowed prediction of endoluminal polyp location at subsequent CT colonography, thereby facilitating detection of known polyps in patients undergoing CT colonographic surveillance.

Role of preoperative CT colonography in patients with colorectal cancer

In patients with colorectal cancer (CRC), accurate preoperative evaluation is essential for a correct therapeutic plan. Colonoscopy and intravenous contrast-enhanced computed tomography (CT) are currently recommended in the preoperative work-up for CRC. Preoperative colonoscopy has some limitations such as misdiagnosis of synchronous cancers in cases of incomplete exploration of the colon and inaccurate tumor localization. Intravenous contrast-enhanced CT successfully documents distant metastases although it sometimes enables unsatisfactory locoregional staging. Computed tomography colonography (CTC) is obtained after gas insufflation of the colon and offers a comprehensive preoperative evaluation in patients with CRC, including a definition of the segmental location of the tumor, presence of synchronous lesions or lack thereof, and fairly accurate locoregional staging. CTC has some limitations, including a lack of biopsy capability, suboptimal sensitivity for synchronous small polyps, and unsatisfactory nodal staging. Bearing in mind these limitations, CTC could be employed as a “one-stop-shop” examination for preoperative assessment in patients with CRC.

Colorectal cancer screening: 20 years of development and recent progress

Colorectal cancer (CRC) is the second most common cancer in Europe and its incidence is steadily increasing. This trend could be reversed through timely secondary prevention (screening). In the last twenty years, CRC screening programs across Europe have experienced considerable improvements (fecal occult blood testing; transition from opportunistic to population based program settings). The Czech Republic is a typical example of a country with a long history of nationwide CRC screening programs in the face of very high CRC incidence and mortality rates. Each year, approximately 8000 people are diagnosed with CRC and some 4000 die from this malignancy. Twenty years ago, the first pilot studies on CRC screening led to the introduction of the opportunistic Czech National Colorectal Cancer Screening Program in 2000. Originally, this program was based on the guaiac fecal occult blood test (FOBT) offered by general practitioners, followed by colonoscopy in cases of FOBT positivity. The program has continuously evolved, namely with the implementation of immunochemical FOBTs and screening colonoscopy, as well as the involvement of gynecologists. Since the establishment of the Czech CRC Screening Registry in 2006, 2405850 FOBTs have been performed and 104565 preventive colonoscopies recorded within the screening program. The overall program expanded to cover 25.0% of the target population by 2011. However, stagnation in the annual number of performed FOBTs lately has led to switching to the option of a population-based program with personal invitation, which is currently being prepared.