Quantitative estimates of the impact of sensitivity and specificity in mammographic screening in Germany

Improvement in risk prediction, early detection and prevention of breast cancer in the NHS Breast Screening Programme and family history clinics: a dual cohort study

Background

In the UK, women are invited for 3-yearly mammography screening, through the NHS Breast Screening Programme (NHSBSP), from the ages of 47–50 years to the ages of 69–73 years. Women with family histories of breast cancer can, from the age of 40 years, obtain enhanced surveillance and, in exceptionally high-risk cases, magnetic resonance imaging. However, no NHSBSP risk assessment is undertaken. Risk prediction models are able to categorise women by risk using known risk factors, although accurate individual risk prediction remains elusive. The identification of mammographic breast density (MD) and common genetic risk variants [single nucleotide polymorphisms (SNPs)] has presaged the improved precision of risk models.

Objectives

To (1) identify the best performing model to assess breast cancer risk in family history clinic (FHC) and population settings; (2) use information from MD/SNPs to improve risk prediction; (3) assess the acceptability and feasibility of offering risk assessment in the NHSBSP; and (4) identify the incremental costs and benefits of risk stratified screening in a preliminary cost-effectiveness analysis.

Design

Two cohort studies assessing breast cancer incidence.

Setting

High-risk FHC and the NHSBSP Greater Manchester, UK.

Participants

A total of 10,000 women aged 20–79 years [Family History Risk Study (FH-Risk); UK Clinical Research Network identification number (UKCRN-ID) 8611] and 53,000 women from the NHSBSP [aged 46–73 years; Predicting the Risk of Cancer At Screening (PROCAS) study; UKCRN-ID 8080].

Interventions

Questionnaires collected standard risk information, and mammograms were assessed for breast density by a number of techniques. All FH-Risk and 10,000 PROCAS participants participated in deoxyribonucleic acid (DNA) studies. The risk prediction models Manual method, Tyrer–Cuzick (TC), BOADICEA (Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm) and Gail were used to assess risk, with modelling based on MD and SNPs. A preliminary model-based cost-effectiveness analysis of risk stratified screening was conducted.

Main outcome measures

Breast cancer incidence.

Data sources

The NHSBSP; cancer registration.

Results

A total of 446 women developed incident breast cancers in FH-Risk in 97,958 years of follow-up. All risk models accurately stratified women into risk categories. TC had better risk precision than Gail, and BOADICEA accurately predicted risk in the 6268 single probands. The Manual model was also accurate in the whole cohort. In PROCAS, TC had better risk precision than Gail [area under the curve (AUC) 0.58 vs. 0.54], identifying 547 prospective breast cancers. The addition of SNPs in the FH-Risk case–control study improved risk precision but was not useful inBRCA1(breast cancer 1 gene) families. Risk modelling of SNPs in PROCAS showed an incremental improvement from using SNP18 used in PROCAS to SNP67. MD measured by visual assessment score provided better risk stratification than automatic measures, despite wide intra- and inter-reader variability. Using a MD-adjusted TC model in PROCAS improved risk stratification (AUC = 0.6) and identified significantly higher rates (4.7 per 10,000 vs. 1.3 per 10,000;p < 0.001) of high-stage cancers in women with above-average breast cancer risks. It is not possible to provide estimates of the incremental costs and benefits of risk stratified screening because of lack of data inputs for key parameters in the model-based cost-effectiveness analysis.

Conclusions

Risk precision can be improved by using DNA and MD, and can potentially be used to stratify NHSBSP screening. It may also identify those at greater risk of high-stage cancers for enhanced screening. The cost-effectiveness of risk stratified screening is currently associated with extensive uncertainty. Additional research is needed to identify data needed for key inputs into model-based cost-effectiveness analyses to identify the impact on health-care resource use and patient benefits.

Future work

A pilot of real-time NHSBSP risk prediction to identify women for chemoprevention and enhanced screening is required.

Funding

The National Institute for Health Research Programme Grants for Applied Research programme. The DNA saliva collection for SNP analysis for PROCAS was funded by the Genesis Breast Cancer Prevention Appeal.

Screening for breast cancer with Breast-CT in a ProHTA simulation

Aims: The potential of dedicated Breast-CT is evaluated by simulating its impact onto the performance of the German breast cancer screening program. Attendance rates, cancer detection and economic implications are quantified. Methods: Based on a prospective health technology assessment approach, we simulated screening in different scenarios. Results: In the simulation, attendance rates increase from 54 to up to 72% due to reduced pain. Breast cancers will be detected earlier while nodal positives and distant recurrences decrease. Assuming no additional cost, cost savings of up to €55 million in one screening period are computed. Conclusion: The simulation indicates that earlier cancer detection, fewer unnecessary biopsies and less pain are potential benefits of Breast-CT resulting in cost savings and higher attendance.

Simulation models in population breast cancer screening: A systematic review

The aim of this review was to critically evaluate published simulation models for breast cancer screening of the general population and provide a direction for future modeling. A systematic literature search was performed to identify simulation models with more than one application. A framework for qualitative assessment which incorporated model type; input parameters; modeling approach, transparency of input data sources/assumptions, sensitivity analyses and risk of bias; validation, and outcomes was developed. Predicted mortality reduction (MR) and cost-effectiveness (CE) were compared to estimates from meta-analyses of randomized control trials (RCTs) and acceptability thresholds. Seven original simulation models were distinguished, all sharing common input parameters. The modeling approach was based on tumor progression (except one model) with internal and cross validation of the resulting models, but without any external validation. Differences in lead times for invasive or non-invasive tumors, and the option for cancers not to progress were not explicitly modeled. The models tended to overestimate the MR (11-24%) due to screening as compared to optimal RCTs 10% (95% CI - 2-21%) MR. Only recently, potential harms due to regular breast cancer screening were reported. Most scenarios resulted in acceptable cost-effectiveness estimates given current thresholds. The selected models have been repeatedly applied in various settings to inform decision making and the critical analysis revealed high risk of bias in their outcomes. Given the importance of the models, there is a need for externally validated models which use systematical evidence for input data to allow for more critical evaluation of breast cancer screening.

A cross-national comparative study on the influence of individual life course factors on mammography screening

OBJECTIVES

Drawing on insights from the life course perspective, the aim of this paper is to gain a better understanding of persistent socioeconomic inequalities related to the uptake of mammography screening in 13 European countries. We examine whether these inequalities originate in childhood and relate them to the history and progression of each country's screening programs.

METHODS

Retrospective data from the third wave of the Survey of Health, Ageing and Retirement (SHARELIFE) is analyzed by means of event-history analyses to examine the role of childhood preventive health behavior on mammography screening initiation. The results are framed within the context of policy developments concerning mammography screening in each of the separate European countries.

RESULTS

Childhood preventive health care behavior predicts mammography screening in 9 of the 13 countries after conventional measurements of socioeconomic position in childhood and adulthood are accounted for. Net effects of education and income are still found for respectively 6 and 7 countries, but in about half of these countries national screening programs are able to reduce the social gradient. Very strong cohort and period effects are found for every country.

CONCLUSIONS

In a substantial number of the European countries, socioeconomic inequalities in preventive health behavior originate in childhood, which point to the deeply rooted nature of these inequalities. A long-term perspective is essential to further unravel how health policies can reduce or eliminate these persistent inequalities.

Cost-effectiveness of opportunistic versus organised mammography screening in Switzerland

BACKGROUND

Various centralised mammography screening programmes have shown to reduce breast cancer mortality at reasonable costs. However, mammography screening is not necessarily cost-effective in every situation. Opportunistic screening, the predominant screening modality in several European countries, may under certain circumstances be a cost-effective alternative. In this study, we compared the cost-effectiveness of both screening modalities in Switzerland.

METHODS

Using micro-simulation modelling, we predicted the effects and costs of biennial mammography screening for 50-69 years old women between 1999 and 2020, in the Swiss female population aged 30-70 in 1999. A sensitivity analysis on the test sensitivity of opportunistic screening was performed.

RESULTS

Organised mammography screening with an 80% participation rate yielded a breast cancer mortality reduction of 13%. Twenty years after the start of screening, the predicted annual breast cancer mortality was 25% lower than in a situation without screening. The 3% discounted cost-effectiveness ratio of organised mammography screening was euro11,512 per life year gained. Opportunistic screening with a similar participation rate was comparably effective, but at twice the costs: euro22,671-24,707 per life year gained. This was mainly related to the high costs of opportunistic mammography and frequent use of imaging diagnostics in combination with an opportunistic mammogram.

CONCLUSION

Although data on the performance of opportunistic screening are limited, both opportunistic and organised mammography screening seem effective in reducing breast cancer mortality in Switzerland. However, for opportunistic screening to become equally cost-effective as organised screening, costs and use of additional diagnostics should be reduced.

Cost-effectiveness of drotrecogin alfa (activated) for the treatment of severe sepsis in Germany

Drotrecogin alfa (activated) (Xigris; Eli Lilly and Company, Indianapolis, IN) significantly reduced mortality in severe sepsis in the PROWESS trial. We evaluate the cost-effectiveness of drotrecogin alfa (activated) as an adjunct to standard therapy from the German healthcare payer's perspective with respect to patients with 1) severe sepsis and 2) severe sepsis and multiple organ failure the approved European indication. Hospital resource use based on PROWESS was valued using German unit costs. German life-tables and long-term survival assumptions determined life-years gained. European and German healthcare resource use data are examined in the sensitivity analysis. We assumed a unit price of euro;237.50 for drotrecogin alfa (activated). Per patient treated, drotrecogin alfa (activated) increased costs by euro;7,500, and hospital costs by euro;900 for all patients (euro;7,400 and euro;1,500 respectively for the approved indication) and survival by 0.59 life years (0.87 life years respectively for the approved indication). Thus drotrecogin alfa (activated) cost euro;14,100 (euro;17,700 discounting life years at 3%) per life year gained for all patients (euro;10,200 and euro;12,900, respectively, for the approved indication). Testing the unit cost of drotrecogin alfa (activated), pattern of resource use, and survival benefit, demonstrated that cost-effectiveness lies well within the range of other life saving interventions in Germany representing good economic value.

The limited incorporation of economic analyses in clinical practice guidelines

BACKGROUND

Because there is increasing concern that economic data are not used in the clinical guideline development process, our objective was to evaluate the extent to which economic analyses are incorporated in guideline development.

METHODS

We searched medline and HealthSTAR databases to identify English-language clinical practice guidelines (1996-1999) and economic analyses (1990-1998). Additional guidelines were obtained from The National Guidelines Clearinghouse Internet site available at http://www.guideline.gov. Eligible guidelines met the Institute of Medicine definition and addressed a topic included in an economic analysis. Eligible economic analyses assessed interventions addressed in a guideline and predated the guideline by 1 or more years. Economic analyses were defined as incorporated in guideline development if 1) the economic analysis or the results were mentioned in the text or 2) listed as a reference. The quality of economic analyses was assessed using a structured scoring system.

RESULTS

Using guidelines as the unit of analysis, 9 of 35 (26%) incorporated at least 1 economic analysis of above-average quality in the text and 11 of 35 (31%) incorporated at least 1 in the references. Using economic analyses as the unit of analysis, 63 economic analyses of above-average quality had opportunities for incorporation in 198 instances across the 35 guidelines. Economic analyses were incorporated in the text in 13 of 198 instances (7%) and in the references in 18 of 198 instances (9%).

CONCLUSIONS

Rigorous economic analyses may be infrequently incorporated in the development of clinical practice guidelines. A systematic approach to guideline development should be used to ensure the consideration of economic analyses so that recommendations from guidelines may impact both the quality of care and the efficient allocation of resources.

Surgical pathology-based outcomes assessment of breast cancer early diagnosis: a College of American Pathologists Q-Probes study in 199 institutions

OBJECTIVE

To develop breast cancer outcomes data relating pathologic tumor variables at diagnosis with clinical method of detection.

DESIGN

Anatomic pathologists assessed 30 consecutive breast cancers at each institution, resulting in an aggregate database of 4232 breast cancers.

SETTING

Hospital-based laboratories from the United States (98%), Canada, Australia, and Belgium.

PARTICIPANTS

One hundred ninety-nine laboratories in the 1999 College of American Pathologists Q-Probes voluntary quality improvement program.

MAIN OUTCOME MEASURES

Pathologic variables indicative of favorable outcomes included percentage of carcinomas detected at the in situ stage, tumors < or = 1 cm in diameter, and invasive cancers with lymph nodes negative for metastases.

RESULTS

All outcomes measures, including percent in situ carcinomas (26.9% vs 13.8%), tumor size < or = 1 cm (57.8% vs 36.5%), and lymph node-negative status (77.8% vs 64%), were more favorable when tumors were detected by screening mammography (P <.001) compared to all other detection methods.

CONCLUSIONS

This study demonstrates an opportunity for pathologists to develop outcomes information of interest to health care organizations, providers, patients, and payers by integrating routine oncologic surgical pathology and clinical breast cancer detection data. Such readily obtained interim outcomes data trended and benchmarked over time can demonstrate the relative clinical efficacy of preventive breast care provided by health care systems long before mortality data are available.