Assessment of lifetime gained as a result of mammographic breast cancer screening using a computer model

Health benefits and harms of mammography screening in older women (75+ years)-a systematic review

BACKGROUND

There is little evidence on the balance between potential benefits and harms of mammography screening in women 75 years and older. The aim of this systematic review was to synthesise the evidence on the outcomes of mammography screening in women aged 75 years and older.

METHODS

A systematic review of mammography screening studies in women aged 75 years and over.

RESULTS

Thirty-six studies were included in this review: 27 observational studies and 9 modelling studies. Many of the included studies used no or uninformative comparison groups resulting in a potential bias towards the benefits of screening. Despite this, there was mixed evidence about the benefits and harms of continuing mammography screening beyond the age of 75 years. Some studies showed a beneficial effect on breast cancer mortality, and other studies showed no effect on mortality. Some studies showed some harms (false positive tests and recalls) being comparable to those in younger age-groups, with other studies showing increase in false positive screens and biopsies in older age-group. Although reported in fewer studies, there was consistent evidence of increased overdiagnosis in older age-groups.

CONCLUSION

There is limited evidence available to make a recommendation for/against continuing breast screening beyond the age of 75 years. Future studies should use more informative comparisons and should estimate overdiagnosis given potentially substantial harm in this age-group due to competing causes of death. This review was prospectively registered with PROSPERO (CRD42020203131).

Overuse of mammography during the first round of an organized breast cancer screening programme

OBJECTIVES

We examined the frequency of mammography screening among women who had had a screening mammogram recently and therefore generally did not need to repeat the examination.

METHODS

A population-based sample of 50- to 69-year-old women were surveyed immediately before and 8 months after they received an invitation to participate in the first round of screening of the newly organized mammography screening programme in Geneva, Switzerland. These women also received a booklet that included the recommendation to have screening mammograms at 2-year intervals.

RESULTS

The baseline survey identified 660 women who had had a mammogram within the previous 12 months. Of these, 23.2% [95% confidence interval (CI), 20.0-26.6] had an opportunistic mammogram and 4.1% (95% CI, 2.7-5.9) had an organized mammogram during follow-up. Women who had had their last mammogram 6-12 months prior to baseline (vs. more recently), intended to have a mammogram within the next 6 months, wished to receive more information on mammography screening, and had a history of surgical breast biopsy were more likely to have an unnecessary screening mammogram (either organized or opportunistic) during follow-up. Compared with women who had an opportunistic mammogram, women who had an organized mammogram were more likely to be of lower socioeconomic status, to have made their own screening decision and to have anticipated the date of their next mammogram by no more than a few months.

CONCLUSIONS

Opportunistic mammography screening in excess of recommendation is common, and persists despite explicit advice about recommended screening frequency.

Calibration methods used in cancer simulation models and suggested reporting guidelines

Increasingly, computer simulation models are used for economic and policy evaluation in cancer prevention and control. A model's predictions of key outcomes, such as screening effectiveness, depend on the values of unobservable natural history parameters. Calibration is the process of determining the values of unobservable parameters by constraining model output to replicate observed data. Because there are many approaches for model calibration and little consensus on best practices, we surveyed the literature to catalogue the use and reporting of these methods in cancer simulation models. We conducted a MEDLINE search (1980 through 2006) for articles on cancer-screening models and supplemented search results with articles from our personal reference databases. For each article, two authors independently abstracted pre-determined items using a standard form. Data items included cancer site, model type, methods used for determination of unobservable parameter values and description of any calibration protocol. All authors reached consensus on items of disagreement. Reviews and non-cancer models were excluded. Articles describing analytical models, which estimate parameters with statistical approaches (e.g. maximum likelihood) were catalogued separately. Models that included unobservable parameters were analysed and classified by whether calibration methods were reported and if so, the methods used. The review process yielded 154 articles that met our inclusion criteria and, of these, we concluded that 131 may have used calibration methods to determine model parameters. Although the term 'calibration' was not always used, descriptions of calibration or 'model fitting' were found in 50% (n = 66) of the articles, with an additional 16% (n = 21) providing a reference to methods. Calibration target data were identified in nearly all of these articles. Other methodological details, such as the goodness-of-fit metric, were discussed in 54% (n = 47 of 87) of the articles reporting calibration methods, while few details were provided on the algorithms used to search the parameter space. Our review shows that the use of cancer simulation modelling is increasing, although thorough descriptions of calibration procedures are rare in the published literature for these models. Calibration is a key component of model development and is central to the validity and credibility of subsequent analyses and inferences drawn from model predictions. To aid peer-review and facilitate discussion of modelling methods, we propose a standardized Calibration Reporting Checklist for model documentation.

Mammography with breast cushions

OBJECTIVE

We conducted a randomized clinical trial to determine the impact on pain and image quality when breast cushions were used to pad the surfaces of the mammography equipment during film-screen mammography.

METHODS

We recruited a consecutive volunteer sample of 394 participants. Breast cushions were used for only one breast, with laterality and sequence of use assigned randomly. Data collected from participants included demographic data, rating of pain from previous mammography, and rating of pain from present mammography using both a numeric rating scale and a visual analogue scale. Research assistants also collected breast compression and radiation exposure data. Radiologists were blinded to the laterality of cushion assignment while reading the mammograms and assessing image quality.

RESULTS

Participants were primarily white women (75.3%), mean age 55.4 years. Most (94.4%) reported having previous mammography. Eight percent (n = 32) of those surveyed had thought about skipping or delaying mammography because of the pain involved. The pain associated with mammography was significantly (p < .001) less during oblique and craniocaudal views when breast cushions were used during the procedure. Retakes were required for 2% of the 1576 views with the most common reason being positioning (53%).

CONCLUSION

The use of breast cushions significantly reduced the pain during film-screen mammography. Image quality with the cushions was reduced in a very small subset of women probably due to the difficulty in positioning the breast without visual clues. More research needs to be done prior to the routine use of these cushions in clinical practice.

Biennial Versus Annual Mammography and the Risk of Late-Stage Breast Cancer

BACKGROUND

Mammography screening may reduce breast cancer mortality by detecting cancers at an earlier stage. However, certain questions remain, including the ideal interval between mammograms.

METHODS

We conducted an observational study using information collected by seven mammography registries across the United States to investigate whether women diagnosed with breast cancer after having screening mammograms separated by a 2-year interval (n = 2440) are more likely to be diagnosed with late-stage disease (positive lymph nodes or metastases) than women diagnosed with breast cancer after having screening mammograms separated by a 1-year interval (n = 5400). Analyses were stratified by age and breast density to clarify whether groups that have the poorest mammography sensitivity (i.e., women under age 50 years and those with mammographically dense breasts) would benefit most from annual screening. The subjects were women diagnosed with breast cancer between 1996 and 2001 who were 40-89 years old at their index mammographic examination (i.e., the most recent screen at or before breast cancer diagnosis). Data were analyzed by logistic regression, adjusting for race, ethnicity, family history of breast cancer, and mammography registry.

RESULTS

Among women age 40-49 years at the index mammogram, those with a 2-year screening interval were more likely to have late-stage disease at diagnosis than those with a 1-year screening interval (28% versus 21%; odds ratio [OR] = 1.35, 95% confidence interval [CI] = 1.01 to 1.81). There was no increase in late-stage disease for women 50 years or older with a 2-year versus a 1-year screening interval (women age 50-59 years at index mammogram: OR = 0.97, 95% CI = 0.75 to 1.25; women age 60-69 years at index mammogram: OR = 0.99, 95% CI = 0.72 to 1.35; women age 70 years or older at index mammogram: OR = 0.88, 95% CI = 0.64 to 1.19). There was no indication that women with dense breasts would benefit more from a 1-year versus 2-year screening interval than women with fatty breasts.

CONCLUSION

These findings may be useful for policy decisions about appropriate screening intervals and for use in statistical models that estimate the costs and benefits of mammography by age and screening interval.

Adverse effects of screening mammography

The main risks and other adverse consequences from screening mammography include discomfort from breast compression, patient recall for additional imaging, and false positive biopsies. Although these risks affect a larger number of women than those who benefit from screening, the risks are less consequential than the life-sparing benefits from early detection. Radiation risk, even for multiple screenings, is negligible at current mammography doses. Anxiety before screening or resulting from supplementary imaging work-up, short-term follow-up, cyst aspiration, and biopsy has not dampened the enthusiasm of most women for the value of early detection.

Analysis of benefit:risk ratio and mortality reduction for the UK Breast Screening Programme

A quantitative analysis has been performed to predict the benefit:risk ratio and associated mortality reduction for the UK National Health Service Breast Screening Programme. The analysis is based on the results of an established biological simulation method coupled with dosimetric information and population statistics applicable to the UK breast screening programme. As well as the general breast screening population, the benefit:risk ratios for specific subgroups of women thought to be at higher risk are estimated. The effects of alterations in screening strategy are also investigated. The results indicate favourable benefit:risk ratios and mortality reductions for all women in the programme, with a breast cancer mortality reduction of approximately 9% over the whole UK female population, equivalent to a breast cancer mortality reduction in the region of 25% for the age range 55-69 years.

Overview of breast imaging

In summary, it is an exciting time in breast imaging with many tools being brought to bear on an ever more common problem. The challenge for this decade will be to develop optimal cost-effective strategies to use all the tools now available with minimal discomfort and disfigurement to the patient.

Breast cancer screening

Breast cancer is the most common malignancy among women in the United States; however, recent data demonstrates a decline in the mortality rate, which may be attributed to early detection from screening programs combined with effective therapies for early stage disease. As a result of the prevalence of breast cancer and its association with highly emotional issues, screening recommendations have aroused debate in the scientific, public, and legislative domains. A general consensus supports breast cancer screening among women between the ages of 50 and 70; however, much controversy exists regarding screening for women age 40 to 49 or above age 70. This article explores the issues involved in determining breast cancer screening recommendations among asymptomatic women with average risk in the United States.