Cost-effectiveness of high-sensitivity faecal immunochemical test and colonoscopy screening for colorectal cancer

Colorectal cancer screening with fecal immunochemical testing or primary colonoscopy: inequities in diagnostic yield

BACKGROUND

Socioeconomic inequalities in the uptake of colorectal cancer screening are well documented, but the implications on inequities in health gain remain unclear.

METHODS

Sixty-year-olds were randomly recruited from the Swedish population between March 2014 and March 2020 and invited to undergo either 2 rounds of fecal immunochemical testing (FIT) 2 years apart (n = 60 137) or primary colonoscopy just once (n = 30 400). By linkage to Statistics Sweden's registries, we obtained socioeconomic data. In each defined socioeconomic group, we estimated the cumulative yield of advanced neoplasia in each screening arm (intention-to-screen analysis). In the biennial FIT arm, we predicted the probability of exceeding the yield in the primary colonoscopy arm by linear extrapolation of the cumulative yield to (hypothetical) additional rounds of FIT.

RESULTS

In the lowest income group, the yield of advanced neoplasia was 1.63% (95% confidence interval [CI] = 1.35% to 1.93%) after 2 rounds of FIT vs 1.93% (95% CI = 1.49% to 2.40%) in the primary colonoscopy arm. Extrapolation to a third round of FIT implied a 86% probability of exceeding the yield in the primary colonoscopy arm. In the highest income group, we found a more pronounced yield gap between the 2 screening strategies-2.32% (95% CI = 2.15% to 2.49%) vs 3.71% (95% CI = 3.41% to 4.02%)- implying a low (2%) predicted probability of exceeding yield after a third round of FIT.

CONCLUSIONS

Yield of advanced neoplasia from 2 rounds of FIT 2 years apart was poorer as compared with primary colonoscopy, but the difference was less in lower socioeconomic groups.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT02078804.

A Systematic Review of Cost-Effectiveness Analyses of Colorectal Cancer Screening in Europe: Have Studies Included Optimal Screening Intensities?

OBJECTIVE

To assess the range of strategies analysed in European cost-effectiveness analyses (CEAs) of colorectal cancer (CRC) screening with respect to the screening intervals, age ranges and test cut-offs used to define positivity, to examine how this might influence what strategies are found to be optimal, and compare them with the current screening policies with a focus on the screening interval.

METHODS

We searched PubMed, Web of Science and Scopus for peer-reviewed, model-based CEAs of CRC screening. We included studies on average-risk European populations using the guaiac faecal occult blood test (gFOBT) or faecal immunochemical test (FIT). We adapted Drummond's ten-point checklist to appraise study quality.

RESULTS

We included 39 studies that met the inclusion criteria. Biennial screening was the most frequently used interval which was analysed in 37 studies. Annual screening was assessed in 13 studies, all of which found it optimally cost-effective. Despite this, 25 of 26 European stool-based programmes use biennial screening. Many CEAs did not vary the age range, but the 14 that did generally found broader ranges optimal. Only 11 studies considered alternative FIT cut-offs, 9 of which found lower cut-offs superior. Conflicts between current policy and CEA evidence are less clear regarding age ranges and cut-offs.

CONCLUSIONS

The existing CEA evidence indicates that the widely adopted biennial frequency of stool-based testing in Europe is suboptimal. It is likely that many more lives could be saved throughout Europe if programmes could be offered with more intensive annual screening.

Head-to-Head Diagnostic Test Accuracy Meta-analysis of Colonoscopy and Fecal Immunochemical Test in Detecting Advanced Colon Neoplasia

Background: Studies on the use of fecal immunochemical test (FIT) in colorectal screening have long assumed perfect accuracy for colonoscopy. No study to date has directly compared the diagnostic accuracy of colonoscopy and FIT to detect advanced neoplasia (AN) in a head-to-head diagnostic accuracy meta-analysis. Methods: A comprehensive electronic search was performed for a head-to-head comparison of FIT and colonoscopy using a third acceptable reference standard in asymptomatic adults. Cochrane methodology was used to perform a head-to-head diagnostic test accuracy (DTA) meta-analysis. Quality assessment tool for diagnostic accuracy studies-2 (QUADAS-2) was used to assess the risk of bias in included studies. Results: Two studies met the eligibility criteria. Overall sensitivity and specificity were 98.5 (95% CI 96.3-100%) and 100% (99.9-100%) for colonoscopy and 16.4% (10.3-22.6%) and 95.4% (94.3-96.4%) for FIT. Colonoscopy was significantly better than FIT (P < 0.0001). The positive and negative likelihood ratios (LRs) were 1.75 (1.57-1.96) and 0.03 (0.01-0.08) for colonoscopy and 3.02 (2.01-4.55) and 0.88 (0.82-0.95) for FIT, respectively. Conclusion: Colonoscopy provides significantly better diagnostic accuracy to detect AN compared with FIT (GRADE: ⨁⨁◯◯). Our study provided precise sensitivity and specificity of both colonoscopy and FIT and a revision in screening policies based on an updated cost-effectiveness analysis considering the results of the head-to-head analysis.

Potential Modifiers and Different Cut-offs in Diagnostic Accuracy of Fecal Immunochemical Test in Detecting Advanced Colon Neoplasia: A Diagnostic Test Accuracy Meta-analysis

Background: Fecal immunoglobulin test (FIT) has been advocated as the first line of screening for colorectal cancer (CRC) in several jurisdictions. Most studies have focused on CRC as the outcome of interest. Our goal was to quantify the diagnostic accuracy of different thresholds of FIT as compared with colonoscopy for detection of advanced colonic neoplasia and potential modifiers using proper Cochrane methodology. Methods: A comprehensive electronic search was performed for studies on FIT using colonoscopy as the reference standard to detect advanced neoplasia. Cochrane methodology was used to perform a diagnostic test accuracy (DTA) meta-analysis. Diagnostic accuracy of different cut-offs of FIT, including 25, 50, 75, 100, 150, and 200 ng/mL, were calculated separately. Meta-regression analysis was also performed to detect potential a priori modifiers, including age, location of the tumor, and time from FIT to colonoscopy. Results: Twenty-four studies were included with no evidence of publication bias. The sensitivity of FIT did not decrease with lowering the cut-off, although specificity increased in higher cut-offs. Commonly used cut-offs of 50 ng/mL, 75 ng/mL, and 100 ng/mL for FIT provided sensitivity of 39%, 36%, 27% and specificity of 92%, 94%, 96%, respectively. Diagnostic accuracy of FIT did not significantly differ in proximal versus distal lesions or in individuals below or over the age of 50 years. The results remained robust in a meta-regression of the location of the study, time from FIT to colonoscopy, and methodological quality. Conclusion: The sensitivity of FIT might have been overestimated in previous studies focusing on CRC, and it seems to be independent of age, location of neoplasia, or cut-offs, contrary to some previous studies. Lowering the cut-off will reduce the diagnostic odds ratio (DOR) by increasing specificity but without any effect on sensitivity.

Cost-effectiveness analysis of colonoscopy and fecal immunochemical testing for colorectal cancer screening in China

Objective

This study aimed to evaluate the cost-effectiveness of the colorectal cancer screening in China, and that when the screening was implemented in a specific region.

Methods

A 13-state Markov model was established to compare four screening protocols, including annual fecal immunochemical testing (FIT1), biennial fecal immunochemical testing (FIT2), electronic colonoscopy every 10 years (e-CSPY10), and electronic colonoscopy every 5 years (e-CSPY5), with no screening from the perspective of Chinese healthcare system. The model simulated the health states of a cohort of 100,000 average-risk individuals aging from 50 to 75. Additionally, scenarios including the implementation in a specific region, starting from 40, and incompletely successful treatment of cancer were also analyzed.

Results

Annual and biennial FIT could save 8.13USD (US Dollar) and 44.96USD per person, and increase 0.0705QALYs (Quality-Adjusted Life Years) and 0.2341 QALYs compared with no screening, respectively. Annual FIT could decrease costs by 36.81USD per person and increase 0.1637 QALYs in comparison to biennial FIT. The results showed that both annual and biennial FIT for screening were dominant over no screening, and annual FIT was dominant over biennial FIT. The ICER (Incremental Cost-Effectiveness Ratio) for e-CSPY10 were 1183.51USD/QALY and 536.66USD/QALY compared with FIT1 and FIT2. The ICER for e-CSPY5 were 1158.16USD/QALY and 770.85USD/QALY compared with FIT1 and FIT2. And the ICER for e-CSPY5 relative to e-CSPY10 was 358.71USD/QALY. All the ICER values were lower than the economic threshold of 2021 Chinese GDP (Gross Domestic Product) per capita in 2021(12554.42USD).

Conclusions

It is worthwhile to popularize CRC screening in mainland China, as FIT always saving costs and colonoscopy is cost-effective. Regions with high income can take electronic colonoscopy every 10 years, or even every 5 years into consideration when determining the specific strategies.

Colorectal cancer screening with fecal immunochemical testing or primary colonoscopy: An analysis of health equity based on a randomised trial

BACKGROUND

We have addressed health equity attained by fecal immunochemical testing (FIT) and primary colonoscopy (PCOL), respectively, in the randomised controlled screening trial SCREESCO conducted in Sweden.

METHODS

We analysed data on the individuals recruited between March 2014, and March 2020, within the study registered with ClinicalTrials.gov, NCT02078804. Swedish population registry data on educational level, household income, country of birth, and marital status were linked to each 60-year-old man and woman who had been randomised to two rounds of FIT 2 years apart (n = 60,123) or once-only PCOL (n = 30,390). Furthermore, we geo-coded each study individual to his/her residential area and assessed neighbourhood-level data on deprivation, proportion of non-Western immigrants, population density, and average distance to healthcare center for colonoscopy. We estimated adjusted associations of each covariate with the colonoscopy attendance proportion out of all invited to respective arms; ie, the preferred outcome for addressing health equity. In the FIT arm, the test uptake and the colonoscopy uptake among the test positives were considered as the secondary outcomes.

FINDINGS

We found a marked socioeconomic gradient in the colonoscopy attendance proportion in the PCOL arm (adjusted odds ratio [95% credibility interval] between the groups categorised in the highest vs. lowest national quartile for household income: 2·20 [2·01-2·42]) in parallel with the gradient in the test uptake of the FIT × 2 screening (2·08 [1·96-2·20]). The corresponding gradient in the colonoscopy attendance proportion out of all invited to FIT was less pronounced (1·29 [1·16-1·42]), due to higher proportions of FIT positives in socioeconomically disadvantaged groups.

INTERPRETATION

The unintended risk of exacerbating inequalities in health by organised colorectal cancer screening may be higher with a PCOL strategy than a FIT strategy, despite parallel socioeconomic gradients in uptake.

FUNDING

This work was supported by the Swedish Cancer Society under Grant 20 0719. CB and US provided economic support from the Swedish Research Council for Health, Working life, and Welfare under Grant 2020-00962.

Optimizing screening with faecal immunochemical test for both sexes - Cost-effectiveness analysis from Finland

A faecal immunochemical test (FIT) screening pilot was introduced in Finland in 2019 with sex-specific screening strategies. This study aims to model cost-effectiveness of sex-specific strategies for the whole population, and to assess whether the current strategies are optimal. We developed separate MISCAN-Colon models, including different FIT performances, for the Finnish men and women using the first-year data of the FIT screening pilot. We evaluated 180 FIT strategies varying in FIT cut-off, screening interval, age to start, and age to stop screening, and compared them to no-screening by sex. We used incremental cost-effectiveness ratios (ICERs) to identify the optimal strategy after combining all male and female strategies and restricting the analysis by costs and referral rate to diagnostic colonoscopies. Offering annual FIT screening with a cut-off of 25 μg/g at 50-79 years in men and with a cut-off of 10 μg/g at 55-69 years in women was optimal. This combined strategy prevented 28% of colorectal cancer (CRC) cases and 55% of CRC deaths with acceptable costs (ICER = 9000€/life-years gained). Screening at the current target age of 60-74 years was suboptimal for both sexes. Among strategies with the same target age and interval for both sexes, expected benefits from optimal screening were lower but still reasonable. Our results support a wider age range of screening in men, and a lower cut-off for a positive test in women when restrictions on colonoscopy capacity and costs are in place. National FIT screening program should start at younger age.

Optimal cut-off value for detecting colorectal cancer with fecal immunochemical tests according to age and sex

In the fecal immunological test, a suitable cut-off value may be selected to classify results as either positive or negative. Our aim is to estimate the optimal cut-off value for detecting colorectal cancer in different age and sex groups. This is a multicentric retrospective cohort study of participants in CRC screening programs with FIT between 2006 and 2012. A total of 545,505 participations were analyzed. Cancers diagnosed outside of the program were identified after a negative test result (IC_test) up until 2014. The Wilcoxon test was used to compare fecal hemoglobin levels. ROC curves were used to identify the optimal cut-off value for each age and sex group. Screening program results were estimated for different cut-off values. The results show that the Hb concentration was higher in colorectal cancer (average = 179.6μg/g) vs. false positives (average = 55.2μg/g), in IC_test (average = 3.1μg/g) vs. true negatives (average = 0μg/g), and in men (average = 166.2μg/g) vs. women (average = 140.2μg/g) with colorectal cancer. The optimal cut-off values for women were 18.3μg/g (50-59y) and 14.6μg/g (60-69y), and 16.8μg/g (50-59y) and 19.9μg/g (60-69y) for men. Using different cut-off values for each age and sex group lead to a decrease in the IC_test rate compared to the 20μg/g cut-off value (from 0.40‰ to 0.37‰) and an increase in the false positive rate (from 6.45% to 6.99%). Moreover, test sensitivity improved (90.7%), especially in men and women aged 50-59y (89.4%; 90%) and women aged 60-69y (90.2%). In conclusion, the optimal cut-off value varies for different sex and age groups and the use of an optimal cut-off value for each group improves sensitivity and leads to a small decrease in IC_tests, but also to a larger increase in false positives.

Gender-specific cut-off levels in colorectal cancer screening with fecal immunochemical test: A population-based study of colonoscopy findings and costs

OBJECTIVE

In the population-based Swedish regional colorectal cancer (CRC) screening program of Stockholm-Gotland using the fecal immunochemical test (FIT), gender-specific cut-off levels of fecal hemoglobin are applied, since previous studies have indicated a lower sensitivity of FIT for CRC in women. The aim was to evaluate the diagnostic yield and the screening costs overall and per detected CRC of this strategy.

METHODS

All individuals aged 60-69 invited to screening in 2015-2017 were included. Cut-off level for positive FIT was 40 µg/g in women and 80 µg/g in men. Those with a positive FIT were referred to colonoscopy. The yield of CRC and screening cost for the study period were assessed and compared to cut-off levels of 80 µg/g in both genders.

RESULTS

Approximately 230,000 individuals were invited. Overall participation rates were 72% in women and 65% in men (p < 0.05). FIT was positive in 4256 individuals (2.7% in both genders). In 3758 colonoscopies, 258 (6.9%) CRCs were detected. The positive predictive value for CRC was significantly higher in men (8.3% vs. 5.8%). In 120 women with CRC, 28 (23%) had FIT < 80 µg/g. Negative colonoscopies were more common in women (24% vs. 17%, p < 0.05). Total costs for the study period were 52,000,000SEK (≈5,200,000€), i.e. 16% higher compared to using cut-off levels of 80 µg/g in both genders, and corresponding to a 3% increment in cost per detected CRC.

CONCLUSION

The high rate of CRC detected in women in the lowest FIT category outweighs the minor reduction in screening costs if the same cut-off level was used as for men.

Adherence to follow-up examination after positive fecal occult blood test results affects colorectal cancer mortality: A Korea population-based cohort study

BACKGROUND

The impact of adherence to follow-up examination after a fecal occult blood test (FOBT) remains ill-defined.

AIM

To evaluate the impact of adherence to the follow-up examination on clinical outcomes in individuals with positive FOBT results.

METHODS

This was a retrospective cohort study involving Korean individuals aged 50 years or older who participated in the National Cancer Screening Program for CRC from 2009 to 2010. Individuals who underwent a confirmative examination within a year after positive FOBT results were included in compliant group, and those who did not were included in non-compliant group. The incidence and stage of CRC, and 5-year survival were compared between two groups.

RESULTS

5,914 were diagnosed with CRC in the compliant group and 2,973 in the non-compliant group. The proportion of advanced-stage CRC was significantly higher in the non-compliant group (localized CRC 44.6% vs. 36.7% and distant CRC 8.7% vs. 12.5%, p< 0.0001). The survival probability within 5 years was 71.0% in the non-compliant group and 85.9% in the compliant group (hazard ratio 1.70, 95% CI, 1.52-1.90, p< 0.001).

CONCLUSION

Individuals who underwent follow-up examination 1 year or more after positive FOBT had a lower survival rate compared with that in those who underwent examination within 1 year.

Aspects of colorectal cancer screening, methods, age and gender

Colorectal cancer (CRC) is, besides breast, prostate, lung and skin cancers, the most common cancer worldwide and is suitable for screening. The incidence of CRC varies considerably in different parts of the world: in well-developed countries, the incidence is between 30 and 70 per 100 000 inhabitants, whereas in less-developed countries such as sub-Saharan Africa, it is 10-20/100 000 inhabitants. Women have a lower incidence of CRC, which is usually one-third of total incidence. Several studies have shown that it is possible to decrease mortality from CRC with about 20%, which is evidenced through the data from countries with screening programmes. Though the method of choice to identify blood samples in faecal matter is under debate, the most feasible way is to perform colonoscopy. Other methods include more advanced faecal analyses, testing for mutations from CRC, sigmoidoscopy, CT colonoscopy or optical colonoscopy. Colonoscopy is in most countries not available in sufficient amount and has to be carried out with great accuracy; otherwise, lesions will be missed to identify, thus leading to complications. Gender is an issue in CRC screening, as women have about 20% fewer colorectal adenomas and CRCs, but they also have more right-sided lesions, which are more difficult to detect with tests for faecal blood since they create less blood in faeces. Thus, other strategies may have to be developed for women in order for screening to have the same effect. It is essential to introduce colorectal cancer screening in all countries together with other clinical pieces of advice such as information on smoking, obesity and exercise in order to reduce one of the most dangerous cancers.

Individual feedback and monitoring of endoscopist performance improves the adenoma detection rate in screening colonoscopy: a prospective case-control study

BACKGROUND AND PURPOSE

Previous reports have suggested that a longer withdrawal time (WT) during colonoscopy led to an improved adenoma detection rate (ADR); however, there are few controlled studies that substantiated monitoring WT as an educational method. We aimed to validate a feedback and monitoring system to improve the ADR in screening colonoscopy in a prospective case-control setting.

METHODS

After collecting data in the pre-feedback period (3.5 months), the individual performance and the average ADR and WT values of the facility were provided to 6 endoscopists in the intervention group, while 3 endoscopists were isolated as the control group during the feedback period (2 weeks). The intervention group consisted of two subgroups, the Fast and Slow WT groups, according to the results from the pre-feedback period. The endoscopists in the intervention group were instructed to be aware of their own WT in each examination during the post-feedback period (4 months). The performances of all endoscopists in the post-feedback period were analyzed and compared with those in the pre-feedback period.

RESULTS

Among the initial analyses, the correlation analysis and multivariate analysis revealed that WT was an independent predictor for the ADR (P = 0.0101). After providing individual performance feedback and instruction regarding real-time WT monitoring, the WT was significantly prolonged in the Fast WT group (P = 0.0346) but did not change in the Slow WT and control groups. In addition, the ADR of the Fast WT group significantly improved after the intervention (P = 0.024), whereas the ADR of the Slow WT and control groups did not change.

CONCLUSION

Providing individual feedback on ADR and WT and monitoring WT helped improve the endoscopists' ADRs.

Diagnostic Yield of One-Time Colonoscopy vs One-Time Flexible Sigmoidoscopy vs Multiple Rounds of Mailed Fecal Immunohistochemical Tests in Colorectal Cancer Screening

BACKGROUND & AIMS

We compared the diagnostic yields of colonoscopy, flexible sigmoidoscopy, and fecal immunochemical tests (FITs) in colorectal cancer (CRC) screening.

METHODS

A total of 30,007 asymptomatic persons, 50-74 years old, were invited for CRC screening in the Netherlands. Participants were assigned to groups that received 4 rounds of FIT (mailed to 15,046 participants), once-only flexible sigmoidoscopy (n = 8407), or once-only colonoscopy (n = 6600). Patients with positive results from the FIT (≥10 μg Hb/g feces) were referred for colonoscopy. Patients who underwent flexible sigmoidoscopy were referred for colonoscopy if they had a polyp of ≥10 mm; adenoma with ≥25% villous histology or high-grade dysplasia; sessile serrated adenoma; ≥3 adenomas; ≥20 hyperplastic polyps; or invasive CRC. The primary outcome was number of advanced neoplasia detected (diagnostic yield) by each test. Secondary outcomes were number of colonoscopies needed to detect advanced neoplasia and number of interval CRCs found during each primary screening test. Patients with interval CRCs were found through linkage with Netherlands Cancer Registry. Advanced neoplasia were defined as CRC, adenomas ≥ 10 mm, adenomas with high-grade dysplasia, or adenomas with a villous component of at least 25%.

RESULTS

The cumulative participation rate was significantly higher for FIT screening (73%) than for flexible sigmoidoscopy (31%; P < .001) or colonoscopy (24%; P < .001). The percentage of colonoscopies among invitees was higher for colonoscopy (24%) compared to FIT (13%; P < .001) or flexible sigmoidoscopy (3%; P < .001). In the intention to screen analysis, the cumulative diagnostic yield of advanced neoplasia was higher with FIT screening (4.5%; 95% CI 4.2-4.9) than with colonoscopy (2.2%; 95% CI, 1.8-2.6) or flexible sigmoidoscopy (2.3%; 95% CI, 2.0-2.7). In the as-screened analysis, the cumulative yield of advanced neoplasia was higher for endoscopic screening with colonoscopy (9.1%; 95% CI, 7.7-10.7) or flexible sigmoidoscopy (7.4%; 95% CI, 6.5-8.5) than with the FIT (6.1%; 95% CI, 5.7-6.6). All 3 screening strategies detected a similar proportion of patients with CRC. Follow-up times differed for each test (median 8.3 years for FIT and flexible sigmoidoscopy and 5.8 years for colonoscopy). Proportions of patients that developed interval CRC were 0.13% for persons with a negative result from FIT, 0.09% for persons with a negative result from flexible sigmoidoscopy, and 0.01% for persons with a negative result from colonoscopy.

CONCLUSIONS

Mailed multiple-round FITs detect significantly more advanced neoplasia, on a population level, compared with once-only flexible sigmoidoscopy or colonoscopy screening. Significantly fewer colonoscopies are required by individuals screened by multiple FITs. Trialregister.nl numbers: first round, NTR1096; second round and additional invitees, NTR1512; fourth round, NTR5874; COCOS trial NTR1829.

Efficacy and cost-effectiveness of fecal immunochemical test versus colonoscopy in colorectal cancer screening: a systematic review and meta-analysis

BACKGROUND AND AIMS

The fecal immunochemical test (FIT) and colonoscopy are the most commonly used strategies for colorectal cancer (CRC) screening worldwide. We aimed to compare their efficacy and cost-effectiveness in CRC screening in an average-risk population.

METHODS

PubMed, Embase, and National Health Services Economic Evaluation Database were searched. Risk ratio (RR) was used to evaluate the differences in detection rates of colorectal neoplasia between FIT and colonoscopy groups. A random-effects model was used to pool RRs. Incremental cost-effectiveness ratios (ICERs) were calculated to evaluate the cost-effectiveness of FIT versus colonoscopy.

RESULTS

Six randomized controlled trials and 17 cost-effectiveness studies were included. The participation rate in the FIT group was higher than that in the colonoscopy group (41.6% vs 21.9%). In the intention-to-treat analysis, FIT had a detection rate of CRC comparable with colonoscopy (RR, .73; 95% confidence interval, .37-1.42) and lower detection rates of any adenoma and advanced adenoma than 1-time colonoscopy. Most included cost-effectiveness studies showed that annual (13/15) or biennial (5/6) FIT was cost-saving (ICER < $0) or very cost-effective ($0 < ICER ≤ $25000/quality-adjusted life-year) compared with colonoscopy every 10 years.

CONCLUSIONS

FIT may be similar to 1-time colonoscopy in the detection rate of CRC, although it has lower detection rates of any adenoma and advanced adenoma than 1-time colonoscopy. Furthermore, annual or biennial FIT appears to be very cost-effective or cost-saving compared with colonoscopy every 10 years. These findings indicate, at least partly, that FIT is noninferior to colonoscopy in CRC screening in an average-risk population. Our findings should be treated with caution and need to be further confirmed.

Qualitative faecal immunochemical tests (FITs) for diagnosing colorectal cancer in patients with histories of rectal bleeding in primary care: a cohort study

BACKGROUND

Rectal bleeding is considered an alarm symptom for colorectal cancer (CRC) but it is common and mostly caused by benign conditions. Qualitative faecal immunochemical tests (FITs) for occult blood have been used as diagnostic aids for many years in Sweden when CRC is suspected. The study aimed to evaluate the usefulness of FITs requested by primary care physicians for patients with and without histories of rectal bleeding, in the diagnosis of CRC.

METHODS

Results of all FITs requested in primary care for symptomatic patients in the Örebro region during 2015 were retrieved. Data on each patient's history of rectal bleeding was gathered from electronic health records. Patients diagnosed with CRC within 2 years were identified from the Swedish Cancer Register. The analysis focused on three-sample FITs, the customary FIT in Sweden.

RESULTS

A total of 4232 patients provided three-sample FITs. Information about the presence/absence of rectal bleeding was available for 2027 patients, of which 59 were diagnosed with CRC. For 606 patients with the presence of rectal bleeding, the FIT showed sensitivity 96.2%, specificity 60.2%, positive predictive value 9.8% (95% CI 6.1-13.4) and negative predictive value 99.7% (95% CI 99.2-100) for CRC. For 1421 patients without rectal bleeding, the corresponding figures were 100%, 73.6%, 8.3% (95% CI 5.6-10.9) and 100% (95% CI 99.6-100).

CONCLUSION

The diagnostic performance of a qualitative three-sample FIT provided by symptomatic patients in primary care was similar for those with and without a history of rectal bleeding. FITs seem useful for prioritising patients also with rectal bleeding for further investigation.

Economic evaluations of screening strategies for the early detection of colorectal cancer in the average-risk population: A systematic literature review

Background

Colorectal cancer (CRC) screening has proven effective in reducing CRC mortality. This study aimed to systematically review, and evaluate the reporting quality, of the economic evidence regarding CRC screening in average-risk individuals.

Methods

Databases searched included Medline, EMBASE, National Health Service Economic Evaluation, Database of Abstracts of Reviews of Effects, Cost-Effectiveness Analysis registry, EconLit, and Health Technology Assessment database. Eligible studies were cost-effectiveness and cost-utility analyses comparing CRC screening strategies in average-risk individuals, published in English or Spanish, between January 2012 and November 2018. Reporting quality was assessed using the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) checklist.

Results

Of 1,993 publications initially retrieved, 477 were excluded by duplicate review, 1,449 by title/abstract review, and 34 by full-text review. Finally, 33 publications were included in the qualitative synthesis. Most studies were conducted in Europe (36,4%), followed by United States (24,2%) and Asia (24,2%). The main screening modalities considered were fecal immunochemical tests (70%), colonoscopy (67%), guaiac fecal occult blood test (42%) and flexible sigmoidoscopy (30%). In most studies, CRC screening was deemed cost-effective compared to no screening. Sensitivity analyses indicated that cost of CRC screening tests, adherence to screening, screening test sensitivity, and cost of CRC treatment had the greatest impact on cost-effectiveness results across studies. The majority of studies (73%) adequately reported at least 50% of the items included in the CHEERS checklist. Least well reported items included setting, study perspective, discount rate, model choice, and methods to identify effectiveness data or to estimate resource use and costs.

Conclusions

CRC screening is an efficient alternative to no screening. Nevertheless, it is not possible to conclude which strategy should be preferred for population-based screening programs. Although we observed an overall good adherence to CHEERS recommendations, there is still room for improvement in economic evaluations reporting in this field.

Cost-utility analysis of genetic polymorphism universal screening in colorectal cancer prevention by detection of high-risk individuals

BACKGROUND

In the past 15 years numerous studies have been published on the involvement of low-penetrance susceptibility genes on the risk for developing colorectal cancer (CRC).

AIM

To perform an economic analysis of blood genetic testing in CRC screening in a population-based nationwide setting using polymorphisms in prostaglandin E₂ pathway genes as proof of concept.

METHODS

A cost-utility analysis was performed from a societal perspective in Portugal comparing two strategies: blood genetic testing by the age of 40 versus no genetic screening under different assumptions of the cost of genetic testing (€10 and €30) and expected risk (1.5 to 5-fold). The adopted threshold was set at €44,870 (USD 50,000). The primary outcome was the incremental cost-effectiveness ratio (ICER) for a base case scenario.

RESULTS

Polymorphism genotyping provided cost-utility only under the assumption of a 5-fold increased risk in the general population, providing ICERs of €44,356 and €30,389 for €30 and €10 tests, respectively.

CONCLUSION

Blood genetic screening for colorectal cancer has cost-utility only under specific assumptions of increased CRC risk and conservative cost estimates. Future studies should focus on defining genetic profiles because single-gene approaches are very unlikely to be cost-effective considering their modest predictive value.

Cost-Effectiveness of Colorectal Cancer Screening Strategies-A Systematic Review

BACKGROUND & AIMS

Widespread screening for colorectal cancer (CRC) has reduced its incidence and mortality. Previous studies investigated the economic effects of CRC screening. We performed a systematic review to provide up-to-date evidence of the cost effectiveness of CRC screening strategies by answering 3 research questions.

METHODS

We searched PubMed, National Institute for Health Research Economic Evaluation Database, Social Sciences Citation Index (via the Web of Science), EconLit (American Economic Association) and 3 supplemental databases for original articles published in English from January 2010 through December 2017. All monetary values were converted to US dollars (year 2016). For all research questions, we extracted, or calculated (if necessary), per-person costs and life years (LYs) and/or quality-adjusted LYs, as well as the incremental costs per LY gained or quality-adjusted LY gained compared with the baseline strategy. A cost-saving strategy was defined as one that was less costly and equally or more effective than the baseline strategy. The net monetary benefit approach was used to answer research question 2.

RESULTS

Our review comprised 33 studies (17 from Europe, 11 from North America, 4 from Asia, and 1 from Australia). Annual and biennial guaiac-based fecal occult blood tests, annual and biennial fecal immunochemical tests, colonoscopy every 10 years, and flexible sigmoidoscopy every 5 years were cost effective (even cost saving in most US models) compared to no screening. In addition, colonoscopy every 10 years was less costly and/or more effective than other common strategies in the United States. Newer strategies such as computed tomographic colonography, every 5 or 10 years, was cost effective compared with no screening.

CONCLUSIONS

In an updated review, we found that common CRC screening strategies and computed tomographic colonography continued to be cost effective compared to no screening. There were discrepancies among studies from different regions, which could be associated with the model types or model assumptions.

Surgical treatment and survival from colorectal cancer in Denmark, England, Norway, and Sweden: a population-based study

BACKGROUND

Survival from colorectal cancer has been shown to be lower in Denmark and England than in comparable high-income countries. We used data from national colorectal cancer registries to assess whether differences in the proportion of patients receiving resectional surgery could contribute to international differences in colorectal cancer survival.

METHODS

In this population-based study, we collected data from all patients aged 18-99 years diagnosed with primary, invasive, colorectal adenocarcinoma from Jan 1, 2010, to Dec 31, 2012, in Denmark, England, Norway, and Sweden, from national colorectal cancer registries. We estimated age-standardised net survival using multivariable modelling, and we compared the proportion of patients receiving resectional surgery by stage and age. We used logistic regression to predict the resectional surgery status patients would have had if they had been treated as in the best performing country, given their individual characteristics.

FINDINGS

We extracted registry data for 139 457 adult patients with invasive colorectal adenocarcinoma: 12 958 patients in Denmark, 97 466 in England, 11 450 in Norway, and 17 583 in Sweden. 3-year colon cancer survival was lower in England (63·9%, 95% CI 63·5-64·3) and Denmark (65·7%, 64·7-66·8) than in Norway (69·5%, 68·4-70·5) and Sweden (72·1%, 71·2-73·0). Rectal cancer survival was lower in England (69·7%, 69·1-70·3) than in the other three countries (Denmark 72·5%, 71·1-74·0; Sweden 74·1%, 72·7-75·4; and Norway 75·0%, 73·1-76·8). We found no significant differences in survival for patients with stage I disease in any of the four countries. 3-year survival after stage II or III rectal cancer and stage IV colon cancer was consistently lower in England (stage II rectal cancer 86·4%, 95% CI 85·0-87·6; stage III rectal cancer 75·5%, 74·2-76·7; and stage IV colon cancer 20·5%, 19·9-21·1) than in Norway (94·1%, 91·5-96·0; 83·4%, 80·1-86·1; and 33·0%, 31·0-35·1) and Sweden (92·9%, 90·8-94·6; 80·6%, 78·2-82·7; and 23·7%, 22·0-25·3). 3-year survival after stage II rectal cancer and stage IV colon cancer was also lower in England than in Denmark (stage II rectal cancer 91·2%, 88·8-93·1; and stage IV colon cancer 23·5%, 21·9-25·1). The total proportion of patients treated with resectional surgery ranged from 47 803 (68·4%) of 69 867 patients in England to 9582 (81·3%) of 11 786 in Sweden for colon cancer, and from 16 544 (59·9%) of 27 599 in England to 4106 (70·8%) of 5797 in Sweden for rectal cancer. This range was widest for patients older than 75 years (colon cancer 19 078 [59·7%] of 31 946 patients in England to 4429 [80·9%] of 5474 in Sweden; rectal cancer 4663 [45·7%] of 10 195 in England to 1342 [61·9%] of 2169 in Sweden), and the proportion of patients treated with resectional surgery was consistently lowest in England. The age gradient of the decline in the proportion of patients treated with resectional surgery was steeper in England than in the other three countries in all stage categories. In the hypothetical scenario where all patients were treated as in Sweden, given their age, sex, and disease stage, the largest increase in resectional surgery would be for patients with stage III rectal cancer in England (increasing from 70·3% to 88·2%).

INTERPRETATION

Survival from colon cancer and rectal cancer in England and colon cancer in Denmark was lower than in Norway and Sweden. Survival paralleled the relative provision of resectional surgery in these countries. Differences in patient selection for surgery, especially in patients older than 75 years or individuals with advanced disease, might partly explain these differences in international colorectal cancer survival.

FUNDING

Early Diagnosis Policy Research Grant from Cancer Research UK (C7923/A18348).

Association between nonalcoholic fatty liver disease and colorectal tumours in asymptomatic adults undergoing screening colonoscopy: a systematic review and meta-analysis

BACKGROUND

It is currently uncertain whether non-alcoholic fatty liver disease (NAFLD) is associated with an increased risk of colorectal tumours. We performed a meta-analysis of relevant observational studies to quantify the magnitude of the association between NAFLD and risk of colorectal adenomas and cancer.

METHODS

We searched PubMed, Scopus and Web of Science from January 2000 to November 2017 using pre-defined keywords to identify observational studies of asymptomatic adults undergoing screening colonoscopy, in which NAFLD was diagnosed by imaging or histology. Data from selected studies were extracted and meta-analysis was performed using random-effects modelling.

RESULTS

Eleven observational studies (8 cross-sectional and 3 longitudinal) with aggregate data on 91,124 asymptomatic adults (32.1% with NAFLD) of predominantly Asian descent accounting for a total of 14,911 colorectal adenomas and 1684 cancers were included in the final analysis. NAFLD was associated with an increased risk of prevalent colorectal adenomas (n = 7 studies using liver imaging techniques; random-effects odds ratio [OR] 1.28, 95% CI 1.11-1.48; I² = 82.9% or n = 1 study using liver biopsy; random-effects OR 1.61, 95% CI 0.90-2.89) and cancer (n = 4 studies using liver imaging techniques; random-effects OR 1.56, 95% CI 1.25-1.94; I² = 65.6% or n = 1 study using liver biopsy; random-effects OR 3.04, 95% CI 1.29-7.18). NAFLD was also associated with an increased risk of incident colorectal adenomas (n = 3 studies; random-effects hazard ratio [HR] 1.42, 95% CI 1.18-1.72; I² = 0%) and cancer (n = 1 study; random-effects HR 3.08, 95% CI 1.02-9.03). These risks were independent of age, sex, smoking, body mass index and diabetes (or metabolic syndrome). Sensitivity analyses did not alter these findings. Funnel plot and Egger's test did not reveal significant publication bias.

CONCLUSIONS

This meta-analysis of observational studies (involving asymptomatic individuals of predominantly Asian descent undergoing screening colonoscopy) suggests that NAFLD (detected by imaging or biopsy) is independently associated with a moderately increased prevalence and incidence of colorectal adenomas and cancer. However, the observational design of the studies does not allow for proving causality, and the possibility of residual confounding by some unmeasured factors cannot be ruled out. More prospective studies, particularly in European and American individuals, and mechanistic studies are required to better understand the association between NAFLD and colonic carcinogenesis.

Cost-utility analysis of colonoscopy or faecal immunochemical test for population-based organised colorectal cancer screening

Background

Organised programmes for colorectal cancer screening demand a high burden of medical and economic resources. The preferred methods are the faecal immunochemical test and primary colonoscopy.

Objective

The purpose of this study was to perform an economic analysis and comparison between these tests in Europe.

Methods

We used a Markov cost-utility analysis from a societal perspective comparing biennial faecal immunochemical test or colonoscopy every 10 years screening versus non-screening in Portugal. The population was screened, aged from 50-74 years, and efficacy was evaluated in quality-adjusted life years. For the base-case scenario, the faecal immunochemical test cost was €3 with 50% acceptance and colonoscopy cost was €397 with 38% acceptance. The threshold was set at €39,760/quality-adjusted life years and the primary outcome was the incremental cost-effectiveness ratio.

Results

Screening by biennial faecal immunochemical test and primary colonoscopy every 10 years resulted in incremental utilities of 0.00151 quality-adjusted life years and 0.00185 quality-adjusted life years at additional costs of €4 and €191, respectively. The faecal immunochemical test was the most cost-effective option providing an incremental cost-effectiveness ratio of €2694/quality-adjusted life years versus €103,633/quality-adjusted life years for colonoscopy. Colonoscopy capacity would have to increase 1.3% for a faecal immunochemical test programme or 31% for colonoscopy.

Conclusion

Biennial faecal immunochemical test screening is better than colonoscopy as it is cost-effective, allows more individuals to get screened, and provides a more rational use of the endoscopic capacity available.

Positive predictive values of fecal immunochemical tests used in the STOP CRC pragmatic trial

Annual fecal immunochemical testing (FIT) is cost-effective for colorectal cancer (CRC) screening. However, FIT positivity rates and positive predictive value (PPV) can vary substantially, with false-positive (FP) results adding to colonoscopy burden without improving cancer detection. Our objective was to describe FIT PPV and the factors associated with FP results among patients undergoing CRC screening. In an ongoing pragmatic clinical trial of mailed-FIT outreach, clinics delivered one of three FIT brands (InSure, OC-Micro, and Hemosure). Patients who had a positive FIT result and a follow-up colonoscopy were included in this analysis (N = 1130). Patients' demographic and medical histories were abstracted from electronic health records (EHR). Associations with a FP result (ie, a positive FIT result with no evidence of advanced neoplasia during follow-up colonoscopy) were evaluated for FIT brand and patient factors using mixed-effects multivariable logistic regression. The mean proportion of FIT-positive results ranged from 8% in centers using the OC-Micro test to 21% for Hemosure. PPVs for advanced neoplasia were 0.30 to 0.17, respectively (P for χ2  = 0.08). In multivariable-adjusted models, use of Hemosure was associated with greater odds of a FP result than OC-Micro (OR = 2.00, 95% CI: 0.47-8.56) or InSure (OR = 1.72, 95% CI: 0.44-6.68). However, only female sex (OR = 1.58, 95% CI: 1.19-2.10) and history of a colorectal condition (OR = 2.17, 95% CI: 1.13-4.15) were significantly associated with FP. In conclusion, FIT positivity varied by brand, and FP results differed by patient factors available through the EHR. These results can be used to minimize the frequency of FP results, reducing patient distress and colonoscopy burden.

Assessing the value of screening tools: reviewing the challenges and opportunities of cost-effectiveness analysis

Background

Screening is an important part of preventive medicine. Ideally, screening tools identify patients early enough to provide treatment and avoid or reduce symptoms and other consequences, improving health outcomes of the population at a reasonable cost. Cost-effectiveness analyses combine the expected benefits and costs of interventions and can be used to assess the value of screening tools.

Objective

This review seeks to evaluate the latest cost-effectiveness analyses on screening tools to identify the current challenges encountered and potential methods to overcome them.

Methods

A systematic literature search of EMBASE and MEDLINE identified cost-effectiveness analyses of screening tools published in 2017. Data extracted included the population, disease, screening tools, comparators, perspective, time horizon, discounting, and outcomes. Challenges and methodological suggestions were narratively synthesized.

Results

Four key categories were identified: screening pathways, pre-symptomatic disease, treatment outcomes, and non-health benefits. Not all studies included treatment outcomes; 15 studies (22%) did not include treatment following diagnosis. Quality-adjusted life years were used by 35 (51.4%) as the main outcome. Studies that undertook a societal perspective did not report non-health benefits and costs consistently. Two important challenges identified were (i) estimating the sojourn time, i.e., the time between when a patient can be identified by screening tests and when they would have been identified due to symptoms, and (ii) estimating the treatment effect and progression rates of patients identified early.

Conclusions

To capture all important costs and outcomes of a screening tool, screening pathways should be modeled including patient treatment. Also, false positive and false negative patients are likely to have important costs and consequences and should be included in the analysis. As these patients are difficult to identify in regular data sources, common treatment patterns should be used to determine how these patients are likely to be treated. It is important that assumptions are clearly indicated and that the consequences of these assumptions are tested in sensitivity analyses, particularly the assumptions of independence of consecutive tests and the level of patient and provider compliance to guidelines and sojourn times. As data is rarely available regarding the progression of undiagnosed patients, extrapolation from diagnosed patients may be necessary.

Colorectal cancer surveillance in Portuguese families with lynch syndrome: a cohort study

PURPOSE

Lynch syndrome (LS) is associated with a high risk of colorectal cancer (CRC). The aim of this study was to assess the cumulative risk for the development of colorectal adenomas or carcinomas in a LS CRC surveillance program and to audit the quality of the endoscopic procedures.

METHODS

We evaluated 147 asymptomatic LS mutation carriers, without previous CRC, in a surveillance program with colonoscopy every 12-18 months, between 2005 and 2016. Data was obtained by retrospective review of colonoscopy reports and hospital clinical files. The main outcome was assessed using Kaplan-Meier curves. Logistic regression was used to study the risk of developing adenomas.

RESULTS

Patients were under surveillance for 1092 observation years (mean, 7.7 years/patient). Most exams presented adequate bowel preparation (83.5%) and 99.2% achieved cecal intubation. The estimated risk for adenomas at age 60 was 75.6% in men (95%CI, 60.5-88.3) and 65.5% in women (95%CI, 50.8-79.7). Male gender (OR 2.4; 95%CI, 1.2-4.9; p = 0.018) and age at start of surveillance > 40 years (OR 3.7; 95%CI, 1.8-7.7; p < 0.001) were independent risk factors for adenoma detection. CRC was diagnosed in 11 patients with an estimated cumulative risk at age 60 of 18.4% (95%CI, 9.2-34.8%); 72.7% of CRC were classified as stage I; no patient died from CRC.

CONCLUSION

A colonoscopic surveillance program in LS patients allowed the detection of adenomas in a large group of mutation carriers and diagnosis of early-stage carcinomas. Our findings may help other teams to adopt similar strategies or to refer patients early to specialized centers.