The cost of screening for colorectal cancer

Non-medical costs of colonoscopy

Colorectal cancer is one of the most common malignancies in Europe and North America. Colonoscopy done every 10 years beginning at age 50 is the preferred method of screening. In Poland and some other countries examinations are offered to subjects free of charge. However, as well as direct medical costs there are direct non-medical costs, which include the cost of transportation and costs related to caregivers’ time, and indirect costs, which are costs related to patients’ time. These costs essentially augment the total societal costs of colonoscopy.

Systematic review of economic evidence for the detection, diagnosis, treatment, and follow-up of colorectal cancer in the United Kingdom

Objectives: The aim of this study was to examine the availability and consistency of economic evidence for the detection, diagnosis, treatment, and follow-up of colorectal cancer.

Methods: A systematic review of UK economic evaluations of colorectal cancer interventions was undertaken. Searches were undertaken across ten electronic databases. Studies were critically appraised through reference to a conceptual model of UK colorectal cancer services.

Results: Forty-seven studies met the inclusion criteria. There is a substantial economic evidence base surrounding population-level colorectal screening, surgical procedures, and cytotoxic therapies for the adjuvant and palliative treatment of colorectal cancer. There is limited evidence concerning the diagnosis of suspected colorectal cancer, curative treatments for metastatic disease and follow-up regimens for nonmetastatic disease. No studies were identified relating to the economics of radiotherapy, surveillance of increased-risk groups, end-of-life care, or the management of hereditary colorectal cancer. Where evidence is available, studies are subject to important differences concerning treatment options, decision criteria, and incongruent assumptions concerning the disease and its management.

Conclusions: Across many aspects of the colorectal cancer service, current practice appears to have emerged without the consideration or support of economic evidence. There is a need to develop a common understanding how colorectal cancer models should be structured and implemented.

Cost-effectiveness of screening for colorectal cancer: evidence from the Nottingham faecal occult blood trial

OBJECTIVES

To estimate the cost-effectiveness of faecal occult blood (FOB) screening for colorectal cancer within the Nottingham trial.

SETTING

A randomised controlled trial (1981-present) of 153,000 subjects, of whom approximately half were offered biennial FOB testing over up to five screening rounds.

METHODS

The additional costs of participation in screening relative to symptomatic presentation were calculated by combining the results of (i) a comprehensive audit of resource use on the part of subjects within the trial, (ii) previously-established unit costs for each of the procedures involved. Life expectancy gains were estimated from a survival analysis of those trial subjects who had been diagnosed with cancer (screening participants vs controls).

RESULTS

The cost of screening under the Nottingham trial protocol was pound 5290 per cancer detected (at 2002 prices). Under conservative assumptions, the incremental cost per life year gained as a result of screening was pound 1584 (Confidence Interval [CI]:717 to 8612).

Willingness-to-pay for colorectal cancer screening

Willingness-to-pay (WTP) techniques are increasingly being used in economic evaluation, as a means of assessing the value of new health care technologies. This paper presents the results of a WTP investigation of two types of screening for colorectal cancer. A questionnaire was issued to a general population via general practitioners (GPs), yielding a sample of approximately 2000 cases for analysis. Regression models demonstrated that WTP was significantly influenced by factors such as gender, income, age, risk perceptions, illness experiences and health beliefs. The median WTP for screening emerged as being pound30 or pound50, depending on the method used to elicit WTP, but independent of the screening protocol. Combining the results with those from related research, it emerged, first, that WTP subjects offered higher values for flexible sigmoidoscopy screening than the costs actually incurred by revealed preference studies and, second, they offered WTP values similar to the likely resource costs of the screening procedures.

Randomised controlled trial of faecal-occult-blood screening for colorectal cancer

BACKGROUND

There is growing evidence that faecal-occult-blood (FOB) screening may reduce colorectal cancer (CRC) mortality, but this reduction in CRC mortality has not been shown in an unselected population-based randomised controlled trial. The aim of this study was to assess the effect of FOB screening on CRC mortality in such a setting.

METHODS

Between February, 1981, and January, 1991, 152,850 people aged 45-74 years who lived in the Nottingham area of the UK were recruited to our study. Participants were randomly allocated FOB screening (76,466) or no screening (controls; 76,384). Controls were not told about the study and received no intervention. Screening-group participants were sent a Haemoccult FOB test kit with instructions from their family doctor. FOB tests were not rehydrated and dietary restrictions were imposed only for retesting borderline results. Individuals with negative FOB tests at the first screening, together with those who tested positive but in whom no neoplasia was found on colonoscopy, were invited to take part in further screening every 2 years. Screening was stopped in February, 1995, by which time screening-group participants had been offered FOB tests between three and six times. Screening-group participants who had a positive test were offered full colonoscopy. All participants were followed up until June, 1995. The primary outcome measure was CRC mortality.

FINDINGS

Of the 152,850 individuals recruited to the study, 2599 could not be traced or had emigrated and were excluded from the analysis. Thus, there were 75,253 participants in the screening group and 74,998 controls. 44,838 (59.6%) screening-group participants completed at least one screening. 28,720 (38.2%) of these individuals completed all the FOB tests they were offered and 16,118 (21.4%) completed at least one screening but not all the tests they were offered. 30,415 (40.4%) did not complete any test. Of 893 cancers (20% stage A) diagnosed in screening-group participants (CRC incidence of 1.49 per 1000 person-years), 236 (26.4%) were detected by FOB screening, 249 (27.9%) presented after a negative FOB test or investigation, and 400 (44.8%) presented in non-responders. The incidence of cancer in the control group (856 cases, 11% stage A) was 1.44 per 1000 person-years. Median follow-up was 7.8 years (range 4.5-14.5). 360 people died from CRC in the screening group compared with 420 in the control group-a 15% reduction in cumulative CRC mortality in the screening group (odds ratio=0.85 [95%; CI 0.74-0.98], p = 0.026).

INTERPRETATION

Our findings together with evidence from other trials suggest that consideration should be given to a national programme of FOB screening to reduce CRC mortality in the general population.

Colorectal cancer screening in asymptomatic populations

Colorectal cancer is the second commonest cause of cancer death in the UK. An effective national screening programme is urgently required to reduce the substantial morbidity and mortality from the disease. The success of any screening programme will depend on the screening test detecting early Dukes's A carcinomas and adenomatous polyps. Prognosis is directly related to tumour staging and a proportion of carcinomas are thought to arise from polyps. Two screening methods exist--faecal occult blood testing and sigmoidoscopy. Large trials of faecal occult blood testing show that it detects more early lesions than in patients presenting with symptoms, but whether this reduces mortality is not yet confirmed and lack of sensitivity for cancers and polyps may ultimately limits its usefulness. The role of sigmoidoscopy in screening, particularly flexible sigmoidoscopy, has not been fully investigated. Flexible sigmoidoscopy has a greater sensitivity for distal lesions than stool testing and a randomised controlled trial of its efficacy is planned in Britain. Compliance with screening is essential to ensure its cost effectiveness in both health and economic terms. Large trials of faecal occult blood testing conducted over several years achieved compliance rates in excess of 60%, although in smaller studies these are often much less. Women frequently participate more than men. There are many reasons for non-compliance including lack of appreciation of the concept of asymptomatic illness and fear of the screening tests and cancer itself. Colorectal cancer screening is relatively cheap compared with breast and cervical cancer screening. Provisional cost estimates suggest that the amount spent to detect or prevent cancer by screening is similar to the amount required to treat a symptomatic patient.

Faecal occult blood testing and colonoscopy in the surveillance of subjects at high risk of colorectal neoplasia

Colonoscopy is the established method of surveillance of subjects at high risk of developing colorectal neoplasia but the procedure is expensive, time consuming and occasionally hazardous. Faecal occult blood tests can be prepared at home and are cheap, simple and safe. Hemeselect is an immunological faecal occult blood test that is more sensitive for colorectal cancer than Haemoccult. The aim of this study was to determine the sensitivity of the Hemeselect test for asymptomatic colorectal neoplasia in subjects at high risk of the disease who were undergoing colonoscopy, thus assessing its suitability as an alternative means of screening high-risk groups. A total of 919 asymptomatic subjects were asked to complete Hemeselect tests. These were completed satisfactorily by 808 individuals (compliance rate 88 per cent) and were positive in 164 patients (20 per cent). At colonoscopy 11 cancers were detected in ten patients (seven Hemeselect positive) and 36 (16 Hemeselect positive) had at least one adenoma 1 cm or more in diameter. The test sensitivites of Hemeselect for carcinoma and large (1 cm or more) adenomas were 70 and 44 per cent respectively. In a subset of 417 subjects who also completed Haemoccult tests, the sensitivities were 33 and 18 per cent. Hemeselect specificity is 88 per cent compared with 98 per cent for Haemoccult. While the sensitivity of Hemeselect is higher than that of Haemoccult, it is still insufficient to replace colonoscopy in high-risk groups.

Effect of retesting with dietary restriction in Haemoccult screening for colorectal cancer

OBJECTIVES

To determine the detection rate, false positive and false negative rates associated with a policy of retesting with dietary restriction after an initial positive Haemoccult screening test for colorectal cancer, in order to compare the cost effectiveness of such a policy with the alternative, in which all subjects with a positive test would proceed directly to diagnostic colonoscopy.

METHODS

Over four years in a large randomised control trial in Nottingham 35,260 subjects had a mean of 1.5 screening rounds each at two-yearly intervals, and were followed up for a minimum of 27 months. During this period subjects with positive screening tests were asked to repeat the test with dietary restrictions. Estimates of costs of the initial screening and of diagnostic colonoscopy were used to estimate the cost for each cancer detected by the different policies.

RESULTS

1209 subjects had a positive initial screening test and 1033 (85.4%) completed the retests. Four hundred and ninety nine subjects were investigated and 89 cancers detected. In the 710 subjects with negative retests six interval cancers were diagnosed in the two years after screening. If these had been detected by screening under a policy of immediate colonoscopy, test sensitivity would have been improved from 53.6% to 57.2% (P = 0.02), but the cost for each cancer detected would have increased from pound 773 to pound 1509.

CONCLUSION

Retesting with dietary restrictions reduces costs and maximises the benefit of limited colonoscopy resources, but results in a small but significant reduction in test sensitivity compared with a policy for immediate colonoscopy.

Screening for colorectal cancer: what are the costs?

We examined a screening program for colorectal cancer in South Australia in terms of its overall direct costs to society and costs to participants. The best estimate of the cost per cancer detected was $18,924 (Australian dollars). Potential improvements in health outcome through screening are discussed in light of these costs.

Colorectal cancer screening and quality of life

To evaluate the quality of life of patients following surgery for colorectal cancer, and to compare the quality of life between patients whose cancer was detected as a result of faecal occult blood screening with that of patients whose cancer presented symptomatically, an analysis was conducted within the context of the randomized controlled trial of colorectal cancer screening, University Hospital, Nottingham, UK. A total of 418 survivors of the trial's test and control groups and 33 randomly selected cancer patients completed quality of life questionnaires (Nottingham Health Profile and Health Measurement Questionnaire). The mode of entry to diagnosis and treatment (screening vs. non-screening) appeared to exert no major impact on post-intervention quality of life. The stage of cancer progression was not closely related to outcome life quality. A quality of life coefficient for surviving patients based on the Rosser classification was estimated to lie within the range 0.948-0.981. This figure accords well with the estimates of other studies of interventions in populations of similar age. Overall, there are no grounds for believing that faecal occult blood screening for colorectal cancer per se significantly influences patients' post-intervention quality of life.

Population screening for colorectal cancer: comparison between guaiac and immunological faecal occult blood tests

There is concern about the low sensitivity of the guaiac-based Haemoccult test in mass population faecal occult blood (FOB) screening for the early detection of colorectal carcinoma. Hemeselect, an immunological FOB test, has been shown to be more sensitive for symptomatic colorectal cancer and may prove to be a more reliable screening method. In Brighton and Guildford, 4018 asymptomatic subjects aged 50-75 years were offered screening with Haemoccult and Hemeselect. A total of 1489 (37.7 per cent) completed both tests, of which 17 (1.1 per cent) were positive for Haemoccult and 145 (9.7 per cent) positive for Hemeselect (a total of 148 subjects had positive tests). Seven subjects (4.7 per cent) refused to be investigated. Colonic investigation in the remainder revealed nine cancers and 49 patients with 67 adenomas (32 tumours 1 cm or more in size). All cancers (Dukes A, six; B, one; C, two) were detected by Hemeselect (positive predictive value 6.2 per cent) but only one patient was Haemoccult positive (positive predictive value 5.9 per cent). Hemeselect detected 65 adenomas (31 of 1 cm or more) in 48 patients (positive predictive value 33.1 per cent) compared with 11 adenomas (seven of 1 cm or more) in eight patients who were positive for Haemoccult (positive predictive value 47.1 per cent). The test specificity for neoplasia was respectively 94.9 and 99.6 per cent. The Hemeselect positive rate is high but its substantial positive predictive value for cancer warrants continuing evaluation.

Increased risk of colorectal cancer associated with congenital anomalies of the urinary tract

Two young mothers of children presenting with congenital anomalies of the urinary tract underwent colectomy for carcinoma or adenomatosis of the colon. In another family with urinary anomalies, the maternal grandmother had died from carcinoma of the colon at 36 years of age. This previously unreported associated led to two reviews. In the first, of 14 patients with colorectal cancer presenting under 45 years of age, three had known congenital urinary tract anomalies. In the second, which included the first three families, a detailed family history was obtained from children receiving treatment for congenital anomalies of the urinary tract. Seven of 116 grandparents and two mothers among 58 parents had colorectal carcinoma or adenomatosis of the colon; this was significantly greater than the expected incidence. A family history of congenital anomalies of the urinary tract may be a useful marker in screening for colorectal cancer.

Effect of subject age on costs of screening for colorectal cancer

STUDY OBJECTIVE

The aim was to estimate costs and yields of faecal occult blood screening and rescreening for colorectal cancer, for differing age cohorts.

DESIGN

Cost and clinical data were used as the basis for modelling the expected costs, and cost savings, resulting from the treatment of screen detected cancers, as compared with cancers detected by symptomatic presentation.

SETTING

Data were derived from the MRC screening trial currently in progress in Nottingham.

PARTICIPANTS

Approximately 140,000 subjects, age 50-79 years, were randomly allocated to a test (screened) and a control (unscreened) group.

MAIN RESULTS

The net costs of detecting and treating a cancer following colorectal screening fall as the age of the target population increases, owing principally to the increasing incidence of the disease with age. Generally, the marginal detection and treatment costs falls for all age groups with the first screening round, but rises considerably with the second. If allowance is made for cancers prevented as a result of early detection and excision of adenomas, the costs of screening are substantially reduced for all age groups.

CONCLUSIONS

Assuming a cost per QALY (quality adjusted life year gained) equivalent to that derived for the breast cancer screening programme, and a QALY gain from colorectal screening of one year, three screens, each separated by two years, appear economically justified for populations aged 60 years and above. Expected gains from cancer prevention make two screens justifiable for those between 45 and 59 years of age.