Effectiveness and economic impact of screening for colorectal cancer by mass fecal occult blood testing

Economic evaluation of colorectal cancer (CRC) screening

Because of its incidence and mortality colorectal cancer represents a serious public health issue in industrial countries. In order to reduce its social impact a number of screening strategies have been implemented, which allow an early diagnosis and treatment. These basically include faecal tests and studies that directly explore the colon and rectum. No strategy, whether alone or combined, has proven definitively more effective than the rest, but any such strategy is better than no screening at all. Selecting the most efficient strategy for inclusion in a population-wide program is an uncertain choice. Here we review the evidence available on the various economic evaluations, and conclude that no single method has been clearly identified as most cost-effective; further research in this setting is needed once common economic evaluation standards are established in order to alleviate the methodological heterogeneity prevailing in study results.

Review of economic evidence in the prevention and early detection of colorectal cancer

This paper aims to systematically review the cost-effectiveness evidence, and to provide a critical appraisal of the methods used in the model-based economic evaluation of CRC screening and subsequent surveillance. A search strategy was developed to capture relevant evidence published 1999-November 2012. Databases searched were MEDLINE, EMBASE, National Health Service Economic Evaluation (NHS EED), EconLit, and HTA. Full economic evaluations that considered costs and health outcomes of relevant intervention were included. Sixty-eight studies which used either cohort simulation or individual-level simulation were included. Follow-up strategies were mostly embedded in the screening model. Approximately 195 comparisons were made across different modalities; however, strategies modelled were often simplified due to insufficient evidence and comparators chosen insufficiently reflected current practice/recommendations. Studies used up-to-date evidence on the diagnostic test performance combined with outdated information on CRC treatments. Quality of life relating to follow-up surveillance is rare. Quality of life relating to CRC disease states was largely taken from a single study. Some studies omitted to say how identified adenomas or CRC were managed. Besides deterministic sensitivity analysis, probabilistic sensitivity analysis (PSA) was undertaken in some studies, but the distributions used for PSA were rarely reported or justified. The cost-effectiveness of follow-up strategies among people with confirmed adenomas are warranted in aiding evidence-informed decision making in response to the rapidly evolving technologies and rising expectations.

Cost-effectiveness of colorectal cancer screening

Colorectal cancer is an important public health problem. Several screening methods have been shown to be effective in reducing colorectal cancer mortality. The objective of this review was to assess the cost-effectiveness of the different colorectal cancer screening methods and to determine the preferred method from a cost-effectiveness point of view. Five databases (MEDLINE, EMBASE, the Cost-Effectiveness Analysis Registry, the British National Health Service Economic Evaluation Database, and the lists of technology assessments of the Centers for Medicare and Medicaid Services) were searched for cost-effectiveness analyses published in English between January 1993 and December 2009. Fifty-five publications relating to 32 unique cost-effectiveness models were identified. All studies found that colorectal cancer screening was cost-effective or even cost-saving compared with no screening. However, the studies disagreed as to which screening method was most effective or had the best incremental cost-effectiveness ratio for a given willingness to pay per life-year gained. There was agreement among studies that the newly developed screening tests of stool DNA testing, computed tomographic colonography, and capsule endoscopy were not yet cost-effective compared with the established screening options.

Fecal occult blood test in patients on low-dose aspirin, warfarin, clopidogrel, or non-steroidal anti-inflammatory drugs

AIM

To determine the effect of anticoagulants and antiplatelet medications on the positive-predictive-value of fecal occult blood test (FOBT).

METHODS

All patients who underwent a colonoscopy at our institution from 1995 to 2006 for a positive FOBT were identified. Medical records were searched, and patients were stratified into five groups selected a priori: low-dose aspirin, NSAIDs, warfarin, clopidogrel, or controls. The positive-predictive-value of FOBT for advanced colonic neoplasia was computed for each group.

RESULTS

During the study period, 1,126 patients underwent colonoscopy for a positive FOBT and met entry criteria. The average age of study participants was 69 years and most were men. The positive-predictive-value of FOBT for advanced colon neoplasia was significantly higher in the control group (30.5%) when compared to those on low-dose aspirin (20.5%; p = 0.003), NSAIDs (19.7%; p = 0.003), clopidogrel (7.3%; p = 0.002), or warfarin (20%; p = 0.05). The positive-predictive-value of FOBT was significantly lower for those on clopidogrel than those on low-dose aspirin (p = 0.04) and NSAIDs (p = 0.05), but not warfarin (p = 0.08). The positive-predictive-value for FOBT was similar for those on aspirin, NSAIDs, and warfarin. There was a linear trend between the number of number of positive FOBT cards and prevalence of advanced colon neoplasia (p = 0.01).

CONCLUSION

Anticoagulants and antiplatelet medications lower the positive-predictive-value of FOBT for advance colonic neoplasia and should be stopped if clinically feasible prior to stool collection.

The multidisciplinary management of gastrointestinal cancer. Colorectal cancer screening

Colorectal cancer is a worldwide problem having global increases in the number of cases and deaths because of the expanding and aging of the population in both developing and developed countries. Screening methods are available which can reduce the incidence by removal of adenomas and can reduce deaths in diagnosed cancer cases by earlier stage detection. Faecal occult blood testing has the strongest proof of effectiveness based on randomised control trials; sigmoidoscopy has lesser proof based on case control studies, and barium enema the weakest proof of effectiveness. Screening colonoscopy has not been subjected to a randomised trial but there is now considerable evidence of its performance and safety and it has the ability to screen, diagnose, and treat (polypectomy) in one test and it is becoming increasingly offered. Many guidelines are now in place, all with positive a position on the effectiveness of screening. However, screening rates are low and many barriers are present that need to be overcome in order to make a major global impact on colorectal cancer incidence and mortality.

On attitudes about colorectal cancer screening among gastrointestinal specialists and general practitioners in the Netherlands

AIM: To find out whether there are differences in attitudes about colorectal cancer (CRC) screening among gastrointestinal (GI) specialists and general practitioners (GPs) and which method is preferred in a national screening program

METHODS: Four hundred and twenty Dutch GI specialists in the Netherlands and 400 GPs in Amsterdam were questioned in 2004. Questions included demographics, affiliation, attitude towards screening both for the general population and themselves, methods of screening, family history and individual risk.

RESULTS: Eighty-four percent of the GI specialists returned the questionnaire in comparison to 32% of the GPs (P < 0.001). Among the GI specialists, 92% favoured population screening whereas 51% of GPs supported population screening (P < 0.001). Of the GI specialists 95% planned to be screened themselves, while 30% of GPs intended to do so (P < 0.001). Regarding the general population, 72% of the GI specialists preferred colonoscopy as the screening method compared to 27% of the GPs (P < 0.001). The method preferred for personal screening was colonoscopy in 97% of the GI specialists, while 29% of the GPs favoured colonoscopy (P < 0.001).

CONCLUSION: Screening for CRC is strongly supported by Dutch GI specialists and less by GPs. The major health issue is possibly misjudged by GPs. Since GPs play a crucial role in a successful national screening program, CRC awareness should be realized by increasing knowledge about the incidence and mortality, thus increasing awareness of the need for screening among GPs.

Review in depth and meta-analysis of controlled trials on colorectal cancer screening by faecal occult blood test

BACKGROUND

Several randomized studies have shown that colorectal cancer (CRC) screening by faecal occult blood test (FOBT) reduces CRC mortality. These trials have different designs, especially concerning FOBT frequency and duration, as well as the length of follow-up after stopping FOBT campaigns.

AIMS

To review the effectiveness of screening for CRC with FOBT, to consider the reduction in mortality during or after screening or to identify factors associated with a significant mortality reduction.

METHODS

A systematic review of trials of FOBT screening with a meta-analysis of four controlled trials selected for their biennial and population-based design. The main outcome measurements were mortality relative risk (RR) and 95% confidence interval (CI) of biennial FOBT during short (10 years, i.e. five or six rounds) or long-term (six or more rounds) screening periods, as well as after stopping screening and follow-up during 5-7 years. The meta-analysis used the Mantel-Haenszel method with fixed effects when the heterogeneity test was not significant, and used 'intent to screen' results.

RESULTS

Although the quality of the four trials was high, only three were randomized, and one used rehydrated biennial FOBT associated with a high colonoscopy rate (28%). A meta-analysis of mortality results showed that subjects allocated to screening had a reduction of CRC mortality during a 10-year period (RR 0.86; CI 0.79-0.94) although CRC mortality was not decreased during the 5-7 years after the 10-year (six rounds) screening period, nor in the last phase (8-16 years after the onset of screening) of a long-term (16 years or nine rounds) biennial screening. Whatever the design of the period of ongoing FOBT, CRC incidence neither decreased nor increased, although it was reduced for 5-7 years after the 10-year screening period. Neither the design nor the clinical or demographic parameters of these trials were independently associated with CRC mortality reduction.

CONCLUSION

Biennial FOBT decreased CRC mortality by 14% when performed over 10 years, without evidence-based benefit on CRC mortality when performed over a longer period. No independent predictors of CRC mortality reduction have been identified in order to allow a CRC screening programme in any subgroups of subjects at risk.

[Cost-effectiveness of colorectal cancer screening]

Colorectal cancer (CRC) screening in France is based on a faecal occult blood test every two years in average risk subjects 50-74 years of age while other endoscopic or non-endoscopic screening methods are used in Europe and in the USA. Beside the reduced incidence of and mortality from CRC found in available studies, cost-effectiveness data need to be taken into account. Because of the delay between randomized controlled trials and clinical results, transitional probabilistic models of screening programs are useful for public health policy makers. The aim of the present review was to promote the implementation of cost-effectiveness studies, to provide a guide to analyze cost-effectiveness studies on CRC screening and, to propose a French cost effectiveness study comparing CRC screening strategies. Most of these trials were performed by US or UK authors and demonstrate that the incremental cost-effectiveness ratio varies between 5 000 and 15 000 US dollars/one year life gained, with wide variations: these results were highly dependent on the unit costs of the different devices as well as the predictive values of the screening tests. Although CRC screening programs have been implemented in several administrative districts of France since 2002, and the results of these randomized controlled trials using fecal occult blood have been updated, cost-effectiveness criteria need to be integrated; especially since the results of screening campaigns based on other tools such as flexible sigmoidoscopy should be available in 2007.

Colorectal cancer screening in Australia: an economic evaluation of a potential biennial screening program using faecal occult blood tests

OBJECTIVE

To evaluate whether the introduction of a national, co-ordinated screening program using the faecal occult blood test represents 'value-for-money' from the perspective of the Australian Government as third-party funder.

METHODS

The annual equivalent costs and consequences of a biennial screening program in 'steady-state' operation were estimated for the Australian population using 1996 as the reference year. Disability-adjusted life years (DALYs) and the years of life lost (YLLs) averted, and the health service costs were modelled, based on the epidemiology and the costs of colorectal cancer in Australia together with the mortality reduction achieved in randomised controlled trials. Uncertainty in the model was examined using Monte Carlo simulation methods.

RESULTS

We estimate a minimum or 'base program' of screening those aged 55 to 69 years could avert 250 deaths per annum (95% uncertainty interval 99-400), at a gross cost of dollarsA55 million (95% UI dollarsA46 million to dollarsA96 million) and a gross incremental cost-effectiveness ratio of dollarsA17,000/DALY (95% UI dollarsA13,000/DALY to dollarsA52,000/DALY). Extending the program to include 70 to 74-year-olds is a more effective option (cheaper and higher health gain) than including the 50 to 54-year-olds.

CONCLUSIONS

The findings of this study support the case for a national program directed at the 55 to 69-year-old age group with extension to 70 to 74-year-olds if there are sufficient resources. The pilot tests recently announced in Australia provide an important opportunity to consider the age range for screening and the sources of uncertainty, identified in the modelled evaluation, to assist decisions on implementing a full national program.

Cost-effectiveness of an intervention to increase cancer screening in primary care settings

BACKGROUND

The main goal was to conduct a cost-effectiveness analysis of an intervention designed to increase cancer screening rates in primary care settings serving disadvantaged populations. The Cancer Screening Office Systems intervention reminded clinicians whether screening mammography, Pap smears, and/or fecal occult blood tests were up-to-date in eligible patients and then established a division of office responsibilities to ensure that tests were ordered and completed.

METHODS

The cost-effectiveness analysis was predicated on data generated from a cluster-randomized controlled trial of Cancer Screening Office Systems conducted at eight clinics participating in a county-funded health insurance plan in Florida. Cost numerators were computed from estimated time inputs of both clinical personnel and patients valued at nationally representative wages as well as expenses for Cancer Screening Office Systems-related materials and overhead. Effectiveness denominators were constructed from net changes in screening rates observed experimentally over a 12-month follow-up. Two types of incremental cost-effectiveness ratios were computed: the cost per extra screening test by type and the cost per life-year saved without and with Cancer Screening Office Systems.

RESULTS

Cancer Screening Office Systems produced statistically significant increases in screening rates, and these gains more than outweighed the costs of the intervention viewed from either payer or societal perspectives.

CONCLUSIONS

Cancer Screening Office Systems are a cost-effective means of addressing cancer-related health disparities.

Current and evolving strategies for colorectal cancer screening

BACKGROUND

Colorectal cancer is a major cause of cancer mortality and morbidity. Screening can potentially prevent most colorectal cancers by detection and removal of precursor adenomas.

METHODS

The literature and clinical practice guidelines are reviewed, with an emphasis on advances of the last 10 years and evolving screening methods.

RESULTS

Colonoscopy has come to be used for screening in persons at average risk for colorectal cancer because of the comparative ineffectiveness of other methods, although these methods continue to be recommended. Virtual colonoscopy and fecal DNA testing are emerging technologies with promise to be more effective than fecal occult blood testing or sigmoidoscopy in selecting those persons who should undergo colonoscopy. Next to age, family history is the most common risk factor for colorectal cancer and one that warrants more aggressive screening and, in some instances, genetic counseling and testing. Hereditary nonpolyposis colorectal cancer accounts for as many as 1 in 20 colorectal cancers, but to take advantage of recent advances in genetic testing for this disorder, a high level of clinical suspicion must be maintained.

CONCLUSIONS

If we are to reduce mortality and morbidity from colorectal cancer, practicing clinicians need to be aware of current and evolving strategies for colorectal screening, and assertively recommend the appropriate strategy to their patients.

Hereditary colorectal cancer: screening and management

Colorectal cancer (CRC) affects approximately 6% of the US population, with equal distribution between men and women. It is hereditary in a high proportion of cases and is one of the most preventable cancers. Detection and removal of its precursor lesions, the adenomatous polyps, is the foundation of preventive strategies. However, once CRC is diagnosed, surgical resection is the only cure. The likelihood of cure is higher when CRC is diagnosed at an early stage. Dietary and lifestyle modifications have little, if any, impact on CRC. Endoscopy with polypectomy prevents cancer deaths. The most important issues are screening and surveillance by any of the recommended modalities. Remaining concerns include the choice of screening tests, optimal testing intervals, and cost effectiveness. Patients may be stratified by personal and family risk and by the specific strategies used. Newer developments in genetic testing and imaging, including virtual colonoscopy, hold promise for future prevention. Chemoprevention with nonsteroidal anti-inflammatory drugs may have a role in high-risk populations. Colonoscopy is the most effective method of CRC prevention.

Clinicopathological characteristics in large, non-polypoid colorectal adenomas with granule-aggregating appearance

Endoscopically, most large, non-polypoid colorectal adenomas have a granule-aggregating appearance, made up of elevations of small, flat lesions projecting above the surrounding mucosa. In this study we investigated the clinicopathological characteristics in 26 cases of such tumours and proposed the term 'granule-aggregating tumour' (GAT). Patients with GATs (16 men and 10 women) had a mean age of 64.3 years (range, 38-83 years). The mean diameter of the GATs was 28 mm (range, 12-62 mm). Histologically, GATs were diagnosed as tubular (15 cases) or tubulovillous (11 cases) adenomas without submucosal invasion. These tumours had a surface morphology comprised mainly of small, flat elevations or granular structures, measuring 1.2 +/- 0.3 mm in diameter. Of the 26 patients with GATs, 19 (73.1%) were asymptomatic and 11 of these 19 cases (57.9%) were detected by a faecal occult blood test. In nine of the 26 patients (34.6%) GATs were accompanied by colorectal cancers arising at other sites. GATs show typical endoscopic features, often lack symptoms and are frequently accompanied by other cancers in other organs. An awareness of the existence of GATs should assist in the screening, prevention and therapy of colorectal tumours.