Rehydration of guaiac-based faecal occult blood tests in mass screening for colorectal cancer. An economic perspective

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.

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.

Evaluation of new occult blood tests for detection of colorectal neoplasia

BACKGROUND

Hemoccult II, the guaiac-based fecal occult blood test used in most colorectal cancer screening programs, has an unsatisfactory sensitivity for asymptomatic colorectal neoplasms. We evaluated the relative performance of four fecal occult blood tests, directed against various components of the hemoglobin molecule.

METHODS

All tests, Hemoccult II, HemoccultSENSA (a more sensitive guaiac test), HemeSelect (an immunochemical test specific for human hemoglobin), and HemoQuant (the heme-porphyrin assay), were performed by 107 patients with symptomatic colorectal cancer and 81 patients with predominantly asymptomatic adenoma. Hemoccult-SENSA and HemeSelect were performed by 1,355 screenees.

RESULTS

HemeSelect and Hemoccult-SENSA had significantly higher sensitivity for colorectal cancer (97% and 94%, respectively) than the other tests. HemeSelect had the highest sensitivity for adenomas; in 45 patients with large (> or = 10 mm) adenomas, sensitivity was 76% for HemeSelect, 60% for HemoccultSENSA, and 42% for both Hemoccult and HemoQuant. In the screenees, estimated specificity was 97.8% for HemeSelect and 96.1% for Hemoccult-SENSA.

CONCLUSIONS

HemeSelect and Hemoccult-SENSA have the highest levels of sensitivity for detection of colorectal neoplasia, but the immunochemical test HemeSelect provides the best combination of specificity and sensitivity.

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.