Guaiac versus immunochemical tests: faecal occult blood test screening for colorectal cancer in a rural community

Interventions to improve primary healthcare in rural settings: A scoping review

BACKGROUND

Residents of rural areas have poorer health status, less healthy behaviours and higher mortality than urban dwellers, issues which are commonly addressed in primary care. Strengthening primary care may be an important tool to improve the health status of rural populations.

OBJECTIVE

Synthesize and categorize studies that examine interventions to improve rural primary care.

ELIGIBILITY CRITERIA

Experimental or observational studies published between January 1, 1996 and December 2022 that include an historical or concurrent control comparison.

SOURCES OF EVIDENCE

Pubmed, CINAHL, Cochrane Library, Embase.

CHARTING METHODS

We extracted and charted data by broad category (quality, access and efficiency), study design, country of origin, publication year, aim, health condition and type of intervention studied. We assigned multiple categories to a study where relevant.

RESULTS

372 papers met our inclusion criteria, divided among quality (82%), access (20%) and efficiency (13%) categories. A majority of papers were completed in the USA (40%), Australia (15%), China (7%) or Canada (6%). 35 (9%) papers came from countries in Africa. The most common study design was an uncontrolled before-and-after comparison (32%) and only 24% of studies used randomized designs. The number of publications each year has increased markedly over the study period from 1-2/year in 1997-99 to a peak of 49 papers in 2017.

CONCLUSIONS

Despite substantial inequity in health outcomes associated with rural living, very little attention is paid to rural primary care in the scientific literature. Very few studies of rural primary care use randomized designs.

Determinants of cancer screenings participation in Queensland: a scoping review

Introduction Cancer screening programmes for cervical, breast, and colorectal cancer have successfully reduced mortality rates among target groups. However, a large proportion of women and men are unscreened. Aim This review aims to provide an overview of the literature regarding the determinants of cancer screening participation among target groups in Queensland. Methods Electronic databases were searched for studies on determinants of cancer screening participation in Queensland. Retrieved studies were screened, and eligible articles were selected for data extraction. Both peer-reviewed and grey literature studies were included. The determinants of cancer screening participation were classified according to the I-Change model. Results Sixteen out of 75 articles were selected and analysed. Information factors, such as the lack of tailored strategies, determined cancer screening participation. Age, gender, cultural beliefs, fear and past experiences were the most reported predisposing factors to cancer screening participation. Lack of knowledge, misconceptions, low awareness, timely access to service, privacy and confidentiality were mainly reported awareness and motivation factors. Encouragement from health professionals, providing more information and interactions with communities would result in different effects on cancer screening participation among the target groups. Discussion The I-Change model is a valuable tool in mapping the current determinants of cancer screening participation programs. Further research may be needed to fully understand the barriers and facilitators of cancer screening programs.

The impact of 6 years of the National Colorectal Cancer Screening Program on colorectal cancer incidence and 5-year survival

We aimed to assess the impact of the first three rounds of the National Colorectal Cancer Screening Program (NCCSP) on CRC incidence and mortality in Slovenia. In NCCSP, we use two fecal immune tests (FITs) and if test is positive patient is referred to colonoscopy. From 2009, we invite Slovenian residents aged 50-69 years, one screening round takes 2 years. The response rate was from 56.9 to 59.9%. FIT was positive in 6.0-6.2% (more in older patients and in men; P < 0.05). The adenoma detection rate was >51.3% (more in men; P < 0.01). In NCCSP, 70.3% of all cancers diagnosed were in stages I and II, while 20.7% of all CRC were found in polyps resected during colonoscopies. Patients with positive first FIT have odds ratio 2.19 [95% confidence interval (CI), 2.06-2.32] for advanced neoplasia and cancer compared to patients with two negative FITs. The incidence rate for CRC has dropped significantly after 6 years in population and in men (P < 0.01) but not in women. Five-year CRC survival was 31.3% higher if cancer was diagnosed in NCCSP (P < 0.05). After 6 years of NCCSP, the incidence rate for CRC has dropped significantly (P < 0.01). Hazard ratio for death from CRC was 3.84 higher (95% CI, 3.36-4.40; P < 0.001) in patients with cancer detected outside the program.

Implementation Strategies for Interventions Aiming to Increase Participation in Mail-Out Bowel Cancer Screening Programs: A Realist Review

Background: Bowel cancer is the third most commonly diagnosed cancer and the third most common cause of cancer-related death, with 1,849,518 new cases of bowel diagnosed and 880,792 deaths reported globally in 2018 alone. Survival can be improved through early detection via national mail-out bowel cancer screening programs; however, participation remains low in many countries. Behavior change is therefore required to increase participation. This realist review aims to (a) identify the behavior change techniques (BCTs) used in each intervention, (b) understand the mechanisms of action (MoAs) responsible for the BCT effectiveness, and (c) apply a behavior change model to inform how MoAs can be combined to increase screening participation.

Methods: We systematically reviewed the literature for interventions aiming to increase participation in mail-out bowel cancer screening. We used a four-stage realist synthesis approach whereby (1) interventions were extracted from each study; (2) BCTs applied in each intervention were identified and coded using the BCT Taxonomy-v1; (3) the Theory and Techniques Tool was used to link BCTs to their MoA; and (4) BCTs and MoAs were categorized according to their effectiveness and what Health Action Process Approach (HAPA) stage of change they would affect.

Results: We identified 68 intervention trials using 26 unique BCTs and 13 MoAs to increase participation. Sixteen BCTs and 10 MoAs were identified within the interventions that successfully increased participation rates. Interventions targeting both stages of the HAPA model had a higher success rate (80%) than those targeting one stage of change (51%). When targeting only one stage, interventions targeting the volitional stage had a higher success rate (71%) than interventions targeting only the motivational stage of change (26%).

Conclusion: Importantly, this review identified a suite of BCTs and MoAs effective for increasing participation in mail-out bowel cancer screening programs. With increased participation in bowel cancer screening leading to improved survival, our findings are key to informing the improvement of policy and interventions that aim to increase screening using specific strategies at key stages of health decision-making.

Strategies for increasing participation in mail-out colorectal cancer screening programs: a systematic review and meta-analysis

BACKGROUND

Population mail-out bowel screening programs are a convenient, cost-effective and sensitive method of detecting colorectal cancer (CRC). Despite the increased survival rates associated with early detection of CRC, in many countries, 50% or more of eligible individuals do not participate in such programs. The current study systematically reviews interventions applied to increase fecal occult blood test (FOBT) kit return, specifically in population mail-out programs.

METHODS

Five electronic databases (PubMed, PsycINFO, Scopus, CINAHL, and ProQuest Dissertations and Theses) were searched for articles published before the 10th of March 2018. Studies were included if they reported the results of an intervention designed to increase the return rate of FOBT kits that had been mailed to individuals' homes. PRISMA systematic review reporting methods were applied and each study was assessed using Cochrane's Risk of Bias tool. Pooled effect sizes were calculated for each intervention type and the risk of bias was tested as a moderator for sensitivity analysis.

RESULTS

The review identified 53 interventions from 30 published studies from which nine distinct intervention strategy types emerged. Sensitivity analysis showed that the risk of bias marginally moderated the overall effect size. Pooled risk ratios and confidence intervals for each intervention type revealed that telephone contact RR = 1.23, 95% CI (1.08-1.40), GP endorsement RR = 1.19, 95% CI (1.10-1.29), simplified test procedures RR = 1.17, 95% CI (1.09-1.25), and advance notifications RR = 1.09, 95% CI (1.07-1.11) were effective intervention strategies with small to moderate effect sizes. Studies with a high risk of bias were removed and pooled effects remained relatively unchanged.

CONCLUSIONS

Interventions that combine program-level changes incorporating the issue of advance notification and alternative screening tools with the involvement of primary health professionals through endorsement letters and telephone contact should lead to increases in kit return in mail-out CRC screening programs.

SYSTEMATIC REVIEW REGISTRATION

This review is registered with PROSPERO; registration number CRD42017064652.

The Impact of Transitioning From Guaiac-Fecal Occult Blood Testing to Fecal Immunochemical Testing in a Canadian Colon Cancer Screening Program

Objectives

To determine the impact of transitioning from guaiac-based fecal occult blood testing (gFOBT) to fecal immunochemical testing (FIT) on the detection rate of adenomas, advanced adenomas (AA) and colorectal cancer (CRC).

Background

Recently, the health region in Edmonton, Alberta switched from gFOBT to FIT for CRC screening.

Study

A retrospective analysis of all patients, aged 50 to 74 years, referred for colonoscopy from January 1, 2013 to December 31, 2014 due to a positive gFOBT (at least one of three samples positively using the guaiac-based Hemoccult II SENSA in 2013) or FIT (≥75 µg/g of stool, using the Polymedco OC FIT-CHEK in 2014). The primary outcomes were the number of colon cancers, AA and adenomas detected in 2013 and 2014. A comparison between the two tests was also made for the composite outcome of detection of either AA or CRC.

Results

Six hundred and forty-nine patients underwent colonoscopy due to a positive gFOBT in 2013, and 2167 patients for a positive FIT in 2014. FIT compared with gFOBT detected more CRC (67 compared with 34), AA (770 compared with 147) and adenomas (1575 versus 320). By multivariable regression analysis adjusted for different demographics and endoscopic metrics, positive FIT was independently associated with higher adenoma detection rate (odds ratio [OR] 2.62; 95% confidence interval [CI] 2.13 to 3.21, P < 0.001), AA detection rate (OR 1.83, 95% CI 1.43 to 2.33, P < 0.001), and the composite outcome of AA and CRC (OR 2.04, 95% CI 1.60 to 2.59, P < 0.001).

Conclusions

Adoption of FIT compared with gFOBT led to higher detection of colon cancer, AA and adenomas.

Effect of Physician Notification Regarding Nonadherence to Colorectal Cancer Screening on Patient Participation in Fecal Immunochemical Test Cancer Screening: A Randomized Clinical Trial

IMPORTANCE

Increasing participation in fecal screening tests is a major challenge in countries that have implemented colorectal cancer (CRC) screening programs.

OBJECTIVE

To determine whether providing general practitioners (GPs) a list of patients who are nonadherent to CRC screening enhances patient participation in fecal immunochemical testing (FIT).

DESIGN, SETTING, AND PARTICIPANTS

A 3-group, cluster-randomized study was conducted from July 14, 2015, to July 14, 2016, on the west coast of France, with GPs in 801 practices participating and involving adult patients (50-74 years) who were at average risk of CRC and not up-to-date with CRC screening. The final follow-up date was July 14, 2016.

INTERVENTIONS

General practitioners were randomly assigned to 1 of 3 groups: 496 received a list of patients who had not undergone CRC screening (patient-specific reminders group, 10 476 patients), 495 received a letter describing region-specific CRC screening adherence rates (generic reminders group, 10 606 patients), and 455 did not receive any reminders (usual care group, 10 147 patients).

MAIN OUTCOMES AND MEASURES

The primary end point was patient participation in CRC screening 1 year after the intervention.

RESULTS

Among 1482 randomized GPs (mean age, 53.4 years; 576 women [38.9%]), 1446 participated; of the 33 044 patients of these GPs (mean age, 59.7 years; 17 949 women [54.3%]), follow-up at 1 year was available for 31 229 (94.5%). At 1 year, 24.8% (95% CI, 23.4%-26.2%) of patients in the specific reminders group, 21.7% (95% CI, 20.5%-22.8%) in the generic reminders group, and 20.6% (95% CI, 19.3%-21.8%) in the usual care group participated in the FIT screening. The between-group differences were 3.1% (95% CI, 1.3%-5.0%) for the patient-specific reminders group vs the generic reminders group, 4.2% (95% CI, 2.3%-6.2%) for the patient-specific reminders group vs the usual care group, and 1.1% (95% CI, -0.6% to 2.8%) for generic reminders group vs the usual care group.

CONCLUSIONS AND RELEVANCE

Providing French GPs caring for adults at average risk of CRC with a list of their patients who were not up-to-date with their CRC screening resulted in a small but significant increase in patient participation in FIT screening at 1 year compared with patients who received usual care. Providing GPs with generic reminders about regional rates of CRC screening did not increase screening rates compared with usual care.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT02515344.

Results of the FIT-based National Colorectal Cancer Screening Program in Slovenia

BACKGROUND

Colorectal cancer (CRC) is one of the most common malignancies in the western world.

OBJECTIVE

We aimed to assess the first round of fecal immunochemical test (FIT)-based National CRC screening program (NCSP).

METHODS

In the NCSP conducted in Slovenia, a FIT and colonoscopy for those tested positive was used. The NCSP central unit sent 536,709 invitations to Slovenian residents age 50 to 69 years old between 2009 and 2011. The adherence rate was 56.9% (303,343 participants). FIT was positive in 6.2% (15,310) of the participants (men, 7.8%; women, 5.0%; P<0.01). A total of 13,919 unsedated colonoscopies were performed with the cecal intubation rate of 97.8%.

RESULTS

The overall adenoma detection rate was 51.3% [95% confidence interval (CI), 50.5%-52.1%] of which 61.0% (95% CI, 59.9%-62.1%) was in men, and 39.1% (95% CI, 37.8%-40.3%) in women (P<0.01). The mean number of adenoma per positive colonoscopy was 1.94 (95% CI, 1.90-1.97). Adenoma, advanced adenoma, or cancer were found in 7732 (55.5%) colonoscopies. A total of 862 (6.2%) CRC cases were found. Only 161 (18.7%) carcinomas were situated in the right colon. A total of 597 (70.2%) patients with cancer were in the early clinical stages (N, negative; 194 22.8%) of all cancers were cured with only endoscopic resection.

CONCLUSIONS

In the NCSP, CRC was found in 6.2% of those participants attending colonoscopy, with 81.3% of carcinomas found in the left colon. A localized clinical stage was found in 70.2% participants. In 22.8% of CRC patients, cancer was cured with endoscopic resection only.

Screening for Colorectal Cancer: A Systematic Review and Meta-Analysis

To evaluate the effectiveness of colorectal cancer (CRC) screening in asymptomatic adults. A search was conducted of the Medline, Embase, and the Cochrane Library databases. A targeted search of PubMed was conducted for on-topic randomized controlled trials (RCTs). Meta-analysis across 4 RCTs for guaiac fecal occult blood testing (gFOBT) and flexible sigmoidoscopy (FS) screening showed a reduction of 18% (risk ratio [RR], 0.82; 95% CI [CI], 0.73-0.92) and 26% (RR, 0.74; 95% CI, 0.67-0.83) in CRC mortality for the screening group compared to controls, respectively. The number needed to screen (NNS) were 377 (95% CI, 249-887) and 864 (95% CI, 672-1266) for gFOBT and FS screening, respectively. A reduction of 8% and 27% in incidence of late-stage CRC was also observed for gFOBT and FS screening, respectively, but both had no significant effect on all-cause mortality. A single RCT found that screening with immunochemical fecal occult blood test (iFOBT) had no significant impact on CRC mortality (RR, 0.88; 95% CI, 0.72-1.07). Screening with FS has potential harms such as perforation, major and minor bleeding, and death from the procedure or from follow-up colonoscopy. gFOBT and FS screening reduce CRC mortality and incidence of late-stage disease. The absolute effect and NNS were much more favorable for older adults (≥ 60 years), suggesting that a targeted screening approach may avoid exposing younger adults to the harms of CRC screening, from which they are unlikely to derive any significant benefit. Although there is insufficient RCT evidence on the impact of iFOBT on mortality outcomes. compared to gFOBT, this test showed higher sensitivity and comparable specificity, indicating the need to update and reevaluate the evidence in light of future high-quality research. The protocol for this systematic review have been published with PROSPERO 2014: CRD42014009777.

European Code against Cancer, 4th Edition: Cancer screening

In order to update the previous version of the European Code against Cancer and formulate evidence-based recommendations, a systematic search of the literature was performed according to the methodology agreed by the Code Working Groups. Based on the review, the 4th edition of the European Code against Cancer recommends: "Take part in organized cancer screening programmes for: Bowel cancer (men and women); Breast cancer (women); Cervical cancer (women)." Organized screening programs are preferable because they provide better conditions to ensure that the Guidelines for Quality Assurance in Screening are followed in order to achieve the greatest benefit with the least harm. Screening is recommended only for those cancers where a demonstrated life-saving effect substantially outweighs the potential harm of examining very large numbers of people who may otherwise never have, or suffer from, these cancers, and when an adequate quality of the screening is achieved. EU citizens are recommended to participate in cancer screening each time an invitation from the national or regional screening program is received and after having read the information materials provided and carefully considered the potential benefits and harms of screening. Screening programs in the European Union vary with respect to the age groups invited and to the interval between invitations, depending on each country's cancer burden, local resources, and the type of screening test used For colorectal cancer, most programs in the EU invite men and women starting at the age of 50-60 years, and from then on every 2 years if the screening test is the guaiac-based fecal occult blood test or fecal immunochemical test, or every 10 years or more if the screening test is flexible sigmoidoscopy or total colonoscopy. Most programs continue sending invitations to screening up to the age of 70-75 years. For breast cancer, most programs in the EU invite women starting at the age of 50 years, and not before the age of 40 years, and from then on every 2 years until the age of 70-75 years. For cervical cancer, if cytology (Pap) testing is used for screening, most programs in the EU invite women starting at the age of 25-30 years and from then on every 3 or 5 years. If human papillomavirus testing is used for screening, most women are invited starting at the age of 35 years (usually not before age 30 years) and from then on every 5 years or more. Irrespective of the test used, women continue participating in screening until the age of 60 or 65 years, and continue beyond this age unless the most recent test results are normal.

Colorectal cancer screening in a low-incidence area: general invitation versus family risk targeting: a comparative study from Montenegro

OBJECTIVES

Colorectal cancer (CRC) is one of the most common malignancies worldwide. The aim of this study was to compare the outcomes of two different screening approaches in a small country (Montenegro, 650,000 inhabitants) with a CRC incidence lower than the European average.

METHODS

Two structured invitation programs were compared with respect to compliance and neoplasia yield: (i) program A focused on first-degree relatives of CRC patients diagnosed in two hospitals (n=206), inviting them for colonoscopy; (ii) program B was an invitation program for fecal occult blood testing, followed by colonoscopy if positive, conducted in University Hospital, Podgorica, Montenegro, on 2760 randomly selected average-risk persons, age 50-74 years, living in a single municipality.

RESULTS

Of 710 first-degree relatives of 206 CRC patients approached, 540 presented for colonoscopy (76.05% uptake). Overall, 31 were diagnosed with a cancer, 58 with advanced adenoma, and 151 with adenoma in general. In the general screening program, of 2760 individuals invited, 920 underwent fecal immunochemical test (33.3% uptake) and colonoscopy was performed in all 95 positive cases (10.3%); six cancers was found in five patients (one patient had two cancers), 19 patients were diagnosed with advanced adenoma, and 26 with any adenomas. The risk-targeted screening program had a significantly higher yield for cancers in both per invited (31/710 vs. 5/2760, P<0.001) and per eligible person analysis (31/540 vs. 5/920, P<0.001).

CONCLUSION

In a low-incidence country with limited resources, it may be advisable to start with CRC screening targeted to risk groups.

Tests and investigations for colorectal cancer screening

Worldwide, colorectal (CRC) is the third most common form of cancer, after lung and breast cancer, and the fourth most common cause of cancer death, although in developed countries CRC incidence is higher and it accounts for an even higher proportion of cancer deaths. Successful treatment of early-stage CRC confers substantial survival advantage, and there is now overwhelming evidence that screening average-risk individuals for CRC reduces the incidence and disease-specific mortality. In spite of considerable research for new biomarkers for CRC, the detection of blood in faeces remains the most effective screening tool. The best evidence to date for population-based CRC screening comes from randomised-controlled trials that used a guaiac-based faecal occult blood test (gFOBt) as the first-line screening modality, whereby test-positive individuals are referred for follow-up investigations, usually colonoscopy. A major innovation in the last ten years or so has been the development of other more analytically sensitive and specific screening techniques for blood in faeces. The faecal immunochemical test for haemoglobin (FIT) confers substantial benefits over gFOBt in terms of analytical sensitivity, specificity and practicality and FIT are now recommended for CRC screening by the European guidelines for quality assurance in colorectal cancer screening and diagnosis. The challenge internationally is to develop high quality CRC screening programmes for which uptake is high. This is especially important for developing countries witnessing an increase in the incidence of CRC as populations adopt more westernised lifestyles. This review describes the tests available for CRC screening and how they are being used worldwide. The reader will gain an understanding of developments in CRC screening and issues that arise in choosing the most appropriate screening test (or tests) for organised population-based screening internationally and optimising the performance of the chosen test (or tests). Whilst a wide range of literature has been cited, this is not a systematic review. The authors provide FOBT CRC screening for a population of 14.6 million in the south of England and the senior author (SPH) was the lead author of the European guidelines for quality assurance in colorectal cancer screening and diagnosis and leads the World Endoscopy Organization Colorectal Cancer Committee's Expert Working Group on 'FIT for Screening'.

Uptake and positive predictive value of fecal occult blood tests: A randomized controlled trial

OBJECTIVE

The aim of this study is to compare the uptake of three mailed high-sensitivity fecal occult blood tests (FOBTs).

METHODS

We conducted a parallel 3-arm randomized controlled trial in an integrated healthcare delivery system in Washington State. From January 2010 through February 2011, automated data were used to identify potentially eligible patients aged 50-74 due for colorectal cancer screening. Participants were mailed one of three FOBT kits (1-sample OC-Auto® fecal immunochemical test [FIT], 2-sample InSure® FIT, or 3-sample guaiac Hemoccult SENSA®), instructions, and a postage-paid return envelope. We performed a modified intent-to-treat analysis with return of any FOBT within 6 months of randomization as the primary outcome.

RESULTS

Of the 9922 people invited, 2873 returned surveys, 2263 were randomized, and 2234 were analyzed. FOBTs were returned by 1431 participants. At 6 months post-randomization, the proportions screened by any FOBT were 0.69 (95% confidence interval [CI] 0.66-0.72) for the OC-Auto arm, 0.64 (95% CI: 0.61-0.68) for the InSure arm, and 0.61 (95% CI: 0.58-0.65) for the Hemoccult SENSA arm (P<0.001 for any difference). Pairwise comparisons showed significant differences between the OC-Auto group and each of the other groups after correction for multiple comparisons.

CONCLUSION

Uptake of mailed FOBT kits varies by kit type.

The sensitivity and specificity of guaiac and immunochemical fecal occult blood tests for the detection of advanced colonic adenomas and cancer

PURPOSE

Fecal immunochemical tests (FITs) have been developed to address analytical problems inherent in the older guaiac-based fecal occult blood tests (g-FOBTs). Our aim was to compare the performance characteristics of one g-FOBT (Hemoccult II) and two FITs (the Hemoccult ICT and MagStream HemSp) relative to colonoscopy for the detection of colorectal cancer and significant precursor lesions. We also examined whether a 1-day collection strategy would negatively impact test diagnostic performance.

METHODS

We used a prospective observational cohort design in a Canadian population eligible for screening. All participants received colonoscopy after performing the occult blood tests.

RESULTS

One thousand seventy-five individuals were enrolled (mean age 56.3 years, 53.8 % females). Using colonoscopy as the gold standard, the sensitivity for screen-relevant neoplasm was determined for Hemoccult II (7.2, 95 % CI: 1.1-13.4), Hemoccult ICT (23.2 %: 13.2-33.1), and MagStream HemSp using 67 μg/gram stool as the cut-off (23.2 %: 13.2-33.1). The Magstream HemSp, using a cut-off threshold of 30 μg/gram stool, had the lowest specificity at 87.6 % (85.4-89.6), while the Hemoccult II had the highest at 98.8 % (98.1-99.5). Single-day stool testing reduced the false-positive rates of all tests without significantly reducing the sensitivity.

CONCLUSION

We found that FITs have a significantly increased sensitivity but reduced specificity for screen-relevant neoplasm compared to g-FOBT using colonoscopy as the gold standard. Optimal threshold levels for hemoglobin detection depend on the desired trade off between sensitivity and false-positive rate. Single-day testing with an FIT may be an option to enhance population compliance with screening.

Comparing participation rates between immunochemical and guaiac faecal occult blood tests: a systematic review and meta-analysis

BACKGROUND

Biennial screening with faecal occult blood tests (FOBts) has been found to reduce colorectal cancer mortality. Faecal immunochemical tests (FITs) are superior to guaiac faecal occult blood tests (G-FOBts) due to their improved sensitivity and specificity. However the effectiveness of a screening programme depends highly on participation rates. The aim of this study was to review studies comparing guaiac faecal occult blood tests and faecal immunochemical tests, in terms of participation rates.

METHODS

We searched PubMed and the Cochrane Library (2000-September 2011) to identify randomised control trials comparing guaiac faecal occult blood test with faecal immunochemical test participation rates. One author screened the titles and abstracts, and performed data extraction which was then checked by the other authors. Risk of bias in the included studies was also assessed.

RESULTS

Seven studies met the eligibility criteria and were entered into a meta-analysis. Participation rates were significantly higher for individuals offered faecal immunochemical tests compared to those offered a guaiac faecal occult blood test (RR 1.21; 95% CI 1.09-1.33). Potential factors that could have influenced participation were discussed.

CONCLUSIONS

Colorectal cancer screening programmes currently using guaiac faecal occult blood tests could improve participation rates by converting to faecal immunochemical tests. More research examining the acceptability of faecal immunochemical tests, from a patient perspective, is warranted.

Population-based screening for colorectal cancer using an immunochemical faecal occult blood test: a comparison of two invitation strategies

BACKGROUND

To date, there is no screening programme for colorectal cancer (CRC) in Flanders, Belgium. However, The European Code Against Cancer (2003) recommends a population-based approach for CRC screening. This study aimed to obtain information about potential participation rates for a population-based screening programme for CRC in Flanders, and to compare two invitation strategies.

METHODS

In 2009, a trial programme for CRC screening was set up in three Flemish areas for all average-risk people aged 50-74 years, using an immunochemical faecal occult blood test (iFOBT) with a cut-off value set at 75 ng/ml of haemoglobin. The faecal sampling set was sent at random by post (mail group) or provided by the general practitioner (GP group).

RESULTS

In total, 19,542 people were invited to participate. Of these, 8229 provided a faecal sample, resulting in an overall participation rate of 42.1%. Participation by mail and through the GP was 52.3% (95% CI, 51.3-53.2) and 27.7% (95% CI, 26.7-28.6), respectively. The difference of 24.6% was statistically significant (95% CI, 23.3-25.9, p<0.001). Before the reminder letter was sent and the other invitation strategy was offered, the overall participation rate was 26.5% (n=5176); 36.4% (95% CI, 35.5-37.4) for the mail group and 16.6% (95% CI, 15.8-17.3) for the GP group. The odds of participating in CRC screening was almost three times higher for people invited by mail as opposed to people invited through a GP (OR=2.96, 95% CI, 2.78-3.14, p<0.001). Women were more likely to participate in CRC screening than men (OR=1.22, 95% CI, 1.15-1.30, p<0.001). In addition, we found that inhabitants from residential (OR=1.98, 95% CI, 1.85-2.11) and rural (OR=2.90, 95% CI, 2.66-3.16) areas were more likely to participate than those in urban areas. Of the 8229 people who submitted a faecal sample, 435 (5.3%) had a positive iFOBT, and of those, CRC was diagnosed in 18 (5.7%) individuals. Compliance for follow-up colonoscopy was 72.9%, and did not differ between the mail (72.4%, 95% CI, 67.5-77.3) and GP groups (74.3, 95% CI, 66.2-82.5).

CONCLUSION

Inviting people for CRC screening by means of a direct-mail invitation, and including a faecal sampling set (iFOBT), results in much higher participation rates than inviting people through the GP.

Does CT colonography have a role for population-based colorectal cancer screening?

Colorectal cancer (CRC) is the second most common cancer and second most common cause of cancer-related deaths in Europe. CRC screening has been proven to reduce disease-specific mortality and several European countries employ national screening programmes. These almost exclusively rely on stool tests, with endoscopy used as an adjunct in some countries. Computed tomographic colonography (CTC) is a potential screening test, with an estimated sensitivity of 88 % for advanced neoplasia ≥10 mm. Recent randomised studies have shown that CTC and colonoscopy have similar yields of advanced neoplasia per screened invitee, indicating that CTC is potentially viable as a primary screening test. However, the evidence is not fully elaborated. It is unclear whether CTC screening is cost-effective and the impact of extracolonic findings, both medical and economic, remains unknown. Furthermore, the effect of CTC screening on CRC-related mortality is unknown, as it is also unknown for colonoscopy. It is plausible that both techniques could lead to decreased mortality, as for sigmoidoscopy and gFOBT. Although radiation exposure is a drawback, this disadvantage may be over-emphasised. In conclusion, the detection characteristics and acceptability of CTC suggest it is a viable screening investigation. Implementation will depend on detection of extracolonic disease and health-economic impact. Key Points • Meta-analysis of CT colonographic screening showed high sensitivity for advanced neoplasia ≥10mm. • CTC, colonoscopy and sigmoidoscopy screening all have similar yields for advanced neoplasia. • Good quality information regarding the cost-effectiveness of CTC screening is lacking. • There is little good quality data regarding the impact of extracolonic findings. • CTC triage is not clinically effective in first round gFOBT/FIT positives.

Factors affecting compliance in faecal occult blood testing: a cluster randomized study of the faecal immunochemical test versus the guaiac faecal occult test

OBJECTIVE

To compare the uptake of faecal immunochemical occult blood test (FIT) with guaiac faecal occult blood test (gFOBT) in a screening programme, with specific attention to the demographic and socioeconomic factors that might affect test uptake.

SETTING

The Clalit Health Service screening programme, Israel.

METHODS

Average-risk individuals aged 50-75 years were randomized into a FIT arm or gFOBT arm using a programme based on the socioeconomic status (SES) of their primary care clinics. G-FOBT was performed with Hemoccult SENSA™ (3 evacuations) and FIT with the OC- MICRO(TM) (3 evacuations, refrigerating mandated). The GLIMMIX model was used.

RESULTS

There were 5,464 and 10,668 eligible participants in the FIT and gFOBT arms respectively. Compliance in taking the kits was better (but not statistically significantly better) with gFOBT (37.8% vs. 29.3%; odds ratio [OR] 1.43 [95% CI 0.73-2.80]; P = 0.227). Kit return was higher in the FIT arm (65.0% vs. 78.9%; OR 0.45 [95% CI 0.24-0.83], P = 0.021). Overall test uptake was affected by age, gender, being immigrant and SES (determined by whether or not the participant paid national insurance tax, and the SES of the primary care clinic). The overall uptake of gFOBT and FIT was comparable (OR 0.996 [95% CI 0.46-2.17], P = 0.99).

CONCLUSIONS

Overall compliance for test uptake was comparable between the two methods despite the more demanding procedure in the FIT arm. Sociodemographic parameters were the major determinants of compliance. An educational programme, with emphasis on the sociodemographic characteristics of the target population, should be instigated.

A higher detection rate for colorectal cancer and advanced adenomatous polyp for screening with immunochemical fecal occult blood test than guaiac fecal occult blood test, despite lower compliance rate. A prospective, controlled, feasibility study

Immunochemical fecal occult blood test (FIT) is a new colorectal cancer (CRC) screening method already recommended by the American screening guidelines. We aimed to test the feasibility of FIT as compared to guaiac fecal occult blood test (G-FOBT) in a large urban population of Tel Aviv. Average-risk persons, aged 50-75 years, were offered FIT or G-FOBT after randomization according to the socioeconomic status of their clinics. Participants with positive tests underwent colonoscopy. Participants were followed through the Cancer Registry 2 years after the study. Hemoccult SENSA™ and OC-MICRO™ (three samples, 70 ng/ml threshold) were used. FIT was offered to 4,657 persons (Group A) and G-FOBT to 7,880 persons (Group B). Participation rate was 25.9% and 28.8% in Group A and B, respectively (p < 0.001). Positivity rate in Group A and B was 12.7% and 3.9%, respectively (p < 0.001). Cancer found in six (0.49%) and eight (0.35%) patients of Group A and B, respectively (NS). Cancer registry follow-up found missed cancer in five (0.22%) cases of Group B and none in Group A (NS). The sensitivity, specificity, negative and positive predictive value for cancer in Group A and B were 100%, 85.9%, 100%, 3.9% and 61.5%, 96.4%, 99.8%, 9.1%, respectively. There was increased detection of advanced adenomatous polyp (AAP) by FIT, irrespective of age, gender, and socioeconomic status (Per Protocol: odds ratio 2.69, 95% confidence interval 1.6-4.5; Intention to Screen: odds ratio 3.16, 95% confidence interval 1.8-5.4). FIT is feasible in urban, average-risk population, which significantly improved performance for detection of AAP and CRC, despite reduced participation.

Cluster randomized trials of cancer screening interventions: are appropriate statistical methods being used?

The design and analysis of cluster randomized trials can require more sophistication than individually randomized trials. However, the need for statistical methods that account for the clustered design has not always been appreciated, and past reviews have found widespread deficiencies in methodology and reporting. We reviewed cluster randomized trials of cancer screening interventions published in 1995-2010 to determine whether the use of appropriate statistical methods had increased over time. Literature searches yielded 50 articles reporting outcome analyses of cluster randomized trials of breast, cervix and colorectal cancer screening interventions. Of studies published in 1995-1999, 2000-2002, 2003-2006 and 2007-2010, 55% (6/11), 82% (9/11), 92% (12/13) and 60% (9/15) used appropriate analytic methods, respectively. Results were suggestive of a peak in 2003-2006 (p =.06) followed by a decline in 2007-2010 (p =.08). While the sample of studies was small, these results indicate that many cluster randomized trials of cancer screening interventions have had deficiencies in the application of correct statistical procedures for the outcome analysis, and that increased adoption of appropriate methods in the early and mid-2000's may not have been sustained.

Repeat participation in colorectal cancer screening utilizing fecal occult blood testing: a community-based project in a rural setting

BACKGROUND AND AIM

To investigate participation in a second round of colorectal cancer screening using a fecal occult blood test (FOBT) in an Australian rural community, and to assess the demographic characteristics and individual perspectives associated with repeat screening.

METHODS

Potential participants from round 1 (50-74 years of age) were sent an intervention package and asked to return a completed FOBT (n = 3406). Doctors of participants testing positive referred to colonoscopy as appropriate. Following screening, 119 participants completed qualitative telephone interviews. Multivariable logistic regression models evaluated the association between round-2 participation and other variables.

RESULTS

Round-2 participation was 34.7%; the strongest predictor was participation in round 1. Repeat participants were more likely to be female; inconsistent screeners were more likely to be younger (aged 50-59 years). The proportion of positive FOBT was 12.7%, that of colonoscopy compliance was 98.6%, and the positive predictive value for cancer or adenoma of advanced pathology was 23.9%. Reasons for participation included testing as a precautionary measure or having family history/friends with colorectal cancer; reasons for non-participation included apathy or doctors' advice against screening.

CONCLUSION

Participation was relatively low and consistent across rounds. Unless suitable strategies are identified to overcome behavioral trends and/or to screen out ineligible participants, little change in overall participation rates can be expected across rounds.

Cost-effectiveness of colorectal cancer screening - an overview

There are several modalities available for a colorectal cancer (CRC) screening program. When determining which CRC screening program to implement, the costs of such programs should be considered in comparison to the health benefits they are expected to provide. Cost-effectiveness analysis provides a tool to do this. In this paper we review the evidence on the cost-effectiveness of CRC screening. Published studies universally indicate that when compared with no CRC screening, all screening modalities provide additional years of life at a cost that is deemed acceptable by most industrialized nations. Many recent studies even find CRC screening to be cost-saving. However, when the alternative CRC screening strategies are compared against each other in an incremental cost-effectiveness analysis, no single optimal strategy emerges across the studies. There is consensus that the new technologies of stool DNA testing, computed tomographic colonography and capsule endoscopy are not yet cost-effective compared with the established CRC screening tests.

Comparison of immunochemical and guaiac-based fecal occult blood test in screening and surveillance for advanced colorectal neoplasms: a meta-analysis

OBJECTIVE

To systematically evaluate whether immunochemical fecal occult blood tests (iFOBT) could improve clinical performance and test accuracy in screening and surveillance for advanced colorectal neoplasms.

METHODS

Eligible articles were identified by searches of electronic databases. All randomized trials and diagnostic cohort trials directly comparing iFOBT with guaiac-based FOBT (gFOBT) were included. A statistical analysis was performed using RevMan 4.2.8. A sensitivity, specificity and summary receiver operating characteristic curve was performed using Meta Disc.

RESULTS

We identified five randomized trials and 11 diagnostic cohort trials. In the randomized trials, the detection rates of advanced colorectal neoplasms with iFOBT or gFOBT were 2.23 percent and 1.24 percent, respectively. The pooled odds ratio (OR) was 1.50 (95% CI 0.94-2.39). In cohort trials, the advanced neoplasm detection rates of iFOBT or gFOBT were 1.44 percent and 0.50 percent (OR 1.99, 95% CI 1.24-3.19) in the average-risk screened population, and were 8.8 percent and 7.1 percent (OR 1.27, 95% CI 1.01-1.60) in diagnosed patients scheduled for colonoscopy. The sensitivity of iFOBT (0.67, 95% CI 0.61-0.73) was superior to that of gFOBT (0.54, 95% CI 0.48-0.60), as well as the specificities (0.85, 95% CI 0.83-0.87 vs 0.80, 95% CI 0.78-0.82) and positive predictive values (0.41 vs 0.29) in cohort trials of diagnosed patients.

CONCLUSION

Our review suggests that iFOBT could perform better in increasing the detection rate of advanced colorectal neoplasm than gFOBT and possesses higher sensitivity and specificity in the surveillance of advanced colorectal neoplasm for patients.

Perspectives of colorectal cancer screening in Germany 2009

Adequate screening methods can decrease colorectal cancer (CRC) mortality. The guaiac test for fecal occult-blood (FOBT) is part of the German CRC Screening Program since 1970 and has evidence level Ia. In randomized multicenter-studies FOBT has an average sensitivity of 24% and decreases CRC mortality up to 30%. Immunological tests for human haemoglobin (iFOBT) show better performance characteristics than guaiac FOBT, with augmented sensitivity and specificity. However, the single tests show wide differences in diagnostic performance and iFOBT is not yet covered by insurance companies although it should replace the guaiac test for CRC screening. Visual colonoscopy, which was introduced to the German National Cancer Screening Program in 2002, is the gold standard for the diagnosis of colorectal neoplasia. From 2003 to 2007 more than 2.8 million examinations have been documented in Germany. The prevalence of adenomas is around 20% and of CRC about 0.7% to 1.0% of the screenings. Seventy percent of the carcinomas detected during screening are in an early stage (UICC I and II). Furthermore, screening colonoscopy is a cost saving procedure with a low complication rate (0.25% overall). Insurance companies save 216€ for each screening colonoscopy mainly by prevention of neoplasia due to polypectomy. In Germany, virtual colonography by computed tomography (CT) or magnetic resonance imaging still lacks standardization of the hard and software. In experienced centres the sensitivity for CRC and large polyps of CT colonography is comparable to colonoscopy but in meta-analyses the ranking is lower. New technologies like computer-aided colonoscopies with sheath or double balloon techniques are coming up as well as capsule colonoscopy, which sensitivity for large polyps is about 70%. Advised by his physician, the patient can choose his most acceptable examination method from this whole set of screening tools.

Random comparison of guaiac and immunochemical fecal occult blood tests for colorectal cancer in a screening population

BACKGROUND & AIMS

Despite poor performance, guaiac-based fecal occult blood tests (G-FOBT) are most frequently implemented for colorectal cancer screening. Immunochemical fecal occult blood tests (I-FOBT) are claimed to perform better, without randomized comparison in screening populations. Our aim was to randomly compare G-FOBT with I-FOBT in a screening population.

METHODS

We conducted a population-based study on a random sample of 20,623 individuals 50-75 years of age, randomized to either G-FOBT (Hemoccult-II) or I-FOBT (OC-Sensor). Tests and invitations were sent together. For I-FOBT, the standard cutoff of 100 ng/ml was used. Positive FOBTs were verified with colonoscopy. Advanced adenomas were defined as >or=10 mm, high-grade dysplasia, or >or=20% villous component.

RESULTS

There were 10,993 tests returned: 4836 (46.9%) G-FOBTs and 6157 (59.6%) I-FOBTs. The participation rate difference was 12.7% (P < .01). Of G-FOBTs, 117 (2.4%) were positive versus 339 (5.5%) of I-FOBTs. The positivity rate difference was 3.1% (P < .01). Cancer and advanced adenomas were found, respectively, in 11 and 48 of G-FOBTs and in 24 and 121 of I-FOBTs. Differences in positive predictive value for cancer and advanced adenomas and cancer were, respectively, 2.1% (P = .4) and -3.6% (P = .5). Differences in specificities favor G-FOBT and were, respectively, 2.3% (P < .01) and -1.3% (P < .01). Differences in intention-to-screen detection rates favor I-FOBT and were, respectively, 0.1% (P < .05) and 0.9% (P < .01).

CONCLUSIONS

The number-to-scope to find 1 cancer was comparable between the tests. However, participation and detection rates for advanced adenomas and cancer were significantly higher for I-FOBT. G-FOBT significantly underestimates the prevalence of advanced adenomas and cancer in the screening population compared with I-FOBT.

Comparison of a guaiac based and an immunochemical faecal occult blood test in screening for colorectal cancer in a general average risk population

BACKGROUND

The guaiac faecal occult blood test (G-FOBT) is recommended as a screening test for colorectal cancer but its low sensitivity has prevented its use throughout the world.

METHODS

We compared the performances of the reference G-FOBT (non-rehydrated Hemoccult II test) and the immunochemical faecal occult blood test (I-FOBT) using different positivity cut-off values in an average risk population sample of 10,673 patients who completed the two tests. Patients with at least one test positive were asked to undergo colonoscopy.

RESULTS

Using the usual cut-off point of 20 ng/ml haemoglobin, the gain in sensitivity associated with the use of I-FOBT (50% increase for cancer and 256% increase for high risk adenoma) was balanced by a decrease in specificity. The number of extra false positive results associated with the detection of one extra advanced neoplasia (cancer or high risk adenoma) was 2.17 (95% confidence interval 1.65-2.85). With a threshold of 50 ng/ml, I-FOBT detected more than twice as many advanced neoplasias as the G-FOBT (ratio of sensitivity = 2.33) without any loss in specificity (ratio of false positive rate = 0.99). With a threshold of 75 ng/ml, associated with a similar positivity rate to G-FOBT (2.4%), the use of I-FOBT allowed a gain in sensitivity of 90% and a decrease in the false positive rate of 33% for advanced neoplasia.

CONCLUSIONS

Evidence in favour of the substitution of G-FOBT by I-FOBT is increasing, the gain being more important for high risk adenomas than for cancers. The automated reading technology allows choice of the positivity rate associated with an ideal balance between sensitivity and specificity.