Health technology Endoscopic surveillance of Barrett's oesophagus to detect malignancy in an early and curable stage.

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1 Endoscopic surveillance of Barretts esophagus: a cost-effectiveness comparison with mammographic surveillance for breast cancer Streitz J M, Ellis F H, Tilden R L, Erickson R V Record Status This is a critical abstract of an economic evaluation that meets the criteria for inclusion on NHS EED. Each abstract contains a brief summary of the methods, the results and conclusions followed by a detailed critical assessment on the reliability of the study and the conclusions drawn. Health technology Endoscopic surveillance of Barrett's oesophagus to detect malignancy in an early and curable stage. Type of intervention Screening, diagnosis, and treatment. Economic study type Cost-effectiveness analysis. Study population Patients with Barrett's oesophagus. Setting Hospital. The economic study was carried out in the United States. Dates to which data relate Effectiveness and resource use data for breast cancer surveillance were collected during Effectiveness and resource use data for Barrett's oesophagus were collected during the period 1980 to prices were used. Source of effectiveness data The estimate for final outcomes was derived from a single study and from a review of previously published studies. Link between effectiveness and cost data Costing was undertaken retrospectively on the same patient sample as that used in the effectiveness analysis. Study sample For breast cancer, 12,537 mammograms were performed and 267 patients underwent needle-localisation biopsies. For Barrett's oesophagus, 149 patients were seen of whom 13 had adenocarcinoma when first seen. Power calculations were not used to determine the sample size. Study design This was a retrospective case series carried out in a single centre: cancer detection rates for both groups were determined by retrospective record review of patients followed at the authors' hospital. Patients with benign Barrett's oesophagus were followed for 510 patient years. Loss to follow up was not reported. Page: 1 / 5

2 Analysis of effectiveness The analysis of the clinical study was based on intention to treat. The primary health outcome used in the analysis was the number and percentage of cancers detected and 'cured' patients. Effectiveness results For breast cancer 50 of the 267 needle-localisation biopsies proved to be malignant, thus yielding a positive biopsy rate of 19% and a rate of occult malignancy detection of 0.4%. It was calculated that 43 of the 50 patients (86%) would be cured. The 136 patients with benign Barrett's oesophagus underwent 354 endoscopic examinations with biopsy; seven adenocarcinomas were detected during the follow-up period. All seven patients underwent oesophagogastrectomy; five were alive without disease at 1, 2, 4, 6 and 7 years postoperatively, and two had died. From the literature it was assumed that 76% (5/7) were cured. Clinical conclusions The authors' reported that surveillance endoscopy has been shown by this study and others to reliably detect cancer in an early and curable stage, resulting in lives saved. Outcomes assessed in the review Operative mortality, five year survival after surgery for adenocarcinoma in Barrett's oesophagus detected by surveillance endoscopy, and cure rate for screening mammography were assessed via a literature review. Study designs and other criteria for inclusion in the review Sources searched to identify primary studies Criteria used to ensure the validity of primary studies Methods used to judge relevance and validity, and for extracting data Number of primary studies included Six studies. Methods of combining primary studies Mean values were calculated based on the results reported in the studies. Investigation of differences between primary studies Page: 2 / 5

3 Results of the review The mean five year survival after surgery for adenocarcinoma in Barrett's oesophagus was 76% and operative mortality was 0%. Cure rate for screening mammography was 86 %. Measure of benefits used in the economic analysis Cancers detected, cancers cured, and life-years gained were the outcome measures used in the economic analysis. Direct costs Quantities and costs were analysed separately. Costs were not discounted in the baseline analysis, although the time frame of the analysis was more than 2 years. The estimation of quantities was based on actual data and on the authors' assumptions regarding the proportion of patients likely to undergo various forms of therapy. Patient charges for 1995 were used as cost estimates. Only direct costs related to detection and therapy aimed at cure were included. Costs for breast cancer detection included mammography charges for the entire group, and the cost of excisional biopsy for those found to have positive mammograms. The cost of curing a cancer included detection costs and the cost of subsequent cancer therapy. Biopsy costs for patients with positive mammograms but with benign biopsies were included. The cost of therapy, which included adjuvant chemotherapy for both groups, was based on the assumption that half of those found to have cancer would undergo lumpectomy and radiation therapy and that the other half would undergo mastectomy. Surveillance and therapy for adenocarcinoma in Barrett's oesophagus included endoscopy and biopsy charges for the entire screened group and the cost of oesophagogastrectomy for those found to have cancer, which included the diagnosis of high grade dysplasia. No adjuvant therapy was included in the charges. Indirect Costs Not included. Currency US dollars ($). Sensitivity analysis The sensitivity analysis substitutes for the average values used in the initial calculations, the extreme values of the incidence of adenocarcinoma in Barrett's, mammographic cancer detection rates, and cure rates for oesophageal resection. Discount rates were varied from 0 to 7%. Estimated benefits used in the economic analysis For breast cancer, 50 cancers (0.4%) were detected and the cure rate was 86%. Given a relative risk of 0.74 (9.4 cancer deaths in 50 patients compared with the 7 deaths assumed for the surveillance group) and a life expectancy gain of 18 years per patient, the 2.4 cancer deaths averted by a surveillance strategy would yield 43.2 life-years gained. For Barrett's oesophagus, 7 cancers were detected and 76% of them were cured. Assuming that surveillance increased the cures from 1.4 of seven to 5.3 of seven patients (a relative mortality risk of 0.26) then the number of life years gained is The side-effects of treatment were not considered in the economic analysis. Benefits were not discounted. Cost results For breast cancer, at $125 per mammogram and including the surgical biopsy cost of $4,339 each for 267 patients with positive mammograms, a total of $2,725,638 was expended. Assuming that therapy would be divided equally between lumpectomy and radiation ($21,437) and mastectomy ($12,800), a total cost of $3,581,563 would be incurred. The cost of no surveillance was $1,079,125. For Barrett's oesophagus the total cost for 354 endoscopies with biopsy would be $265,500 (at a unit cost of $750), and the cost of resecting seven patients would be $151,200 (unit cost $21,600). This Page: 3 / 5

4 represents a total cost of $416,700. The cost of no surveillance was $156,450. Synthesis of costs and benefits For breast cancer the cost per case detected was $54,513 and the cost per cure would be $83,292. The cost per life year gained would be $57,926. For Barrett's oesophagus assuming that all seven patients underwent resection at a cost of $21,600 per case, and that five patients, or 76% were cured, the total cost per cure would equal $83,340 and the cost per life-year gained would be $4,151. The only assumption in the sensitivity analysis that led to a cost-effectiveness advantage for mammographic surveillance was that treatment of all 50 mammographically detected tumours resulted in cures in women who would otherwise have died within 1 year of breast cancer (cost per life year saved of $3,233 for mammography and $5,490 for endoscopy). Authors' conclusions The cancer incidence of patients with Barrett's oesophagus was 1,370 cases per 100,000 population per year, amounting to a yearly cancer risk of 1.37%. This is substantial, especially for young patients, and warrants surveillance, the cost of which is adequately recovered in years of life saved by early intervention. The cost-effectiveness of Barrett's oesophagus surveillance results from the high cancer incidence, the ease of cancer detection at an early stage, and the marked difference in surgical outcome between surveillance-detected and clinically detected cancers. CRD COMMENTARY - Selection of comparators The reason for the choice of no screening as a comparator is clear. Validity of estimate of measure of benefit The sample size was not determined using power calculations. Some of the effectiveness evidence was derived from the literature, but it is not clear whether the review of the literature was systematic. Additionally, no justification was provided for the use of mean values of the studies' findings included in the review. As a result, the results of this study should be treated with caution. Validity of estimate of costs Resource quantities were reported separately from prices and adequate details of the methods of quantity and cost estimation were given. Costs might not be generalisable to other settings or countries. Other issues Sensitivity analyses were used to account for the uncertainties in the data. Appropriate comparisons were made with other studies. Source of funding None stated. Bibliographic details Streitz J M, Ellis F H, Tilden R L, Erickson R V. Endoscopic surveillance of Barretts esophagus: a cost-effectiveness comparison with mammographic surveillance for breast cancer. American Journal of Gastroenterology 1998; 93(6): PubMedID DOI Page: 4 / 5

5 Powered by TCPDF ( /j x Indexing Status Subject indexing assigned by NLM MeSH Adenocarcinoma /diagnosis /economics; Aged; Barrett Esophagus /complications /economics; Breast Neoplasms /economics /radiography; Cost-Benefit Analysis; Costs and Cost Analysis; Esophageal Neoplasms /diagnosis /economics; Esophagoscopy /economics; Female; Humans; Life Expectancy; Mammography /economics; Middle Aged; Sensitivity and Specificity AccessionNumber Date bibliographic record published 31/10/2000 Date abstract record published 31/10/2000 Page: 5 / 5