Reporting of performance indicators of mammography screening in Europe

How much do we know about the metastatic process?

Cancer cells can leave their primary sites and travel through the circulation to distant sites, where they lodge as disseminated cancer cells (DCCs), even during the early and asymptomatic stages of tumor progression. In experimental models and clinical samples, DCCs can be detected in a non-proliferative state, defined as cellular dormancy. This state can persist for extended periods until DCCs reawaken, usually in response to niche-derived reactivation signals. Therefore, their clinical detection in sites like lymph nodes and bone marrow is linked to poor survival. Current cancer therapy designs are based on the biology of the primary tumor and do not target the biology of the dormant DCC population and thus fail to eradicate the initial or subsequent waves of metastasis. In this brief review, we discuss the current methods for detecting DCCs and highlight new strategies that aim to target DCCs that constitute minimal residual disease to reduce or prevent metastasis formation. Furthermore, we present current evidence on the relevance of DCCs derived from early stages of tumor progression in metastatic disease and describe the animal models available for their study. We also discuss our current understanding of the dissemination mechanisms utilized by genetically less- and more-advanced cancer cells, which include the functional analysis of intermediate or hybrid states of epithelial-mesenchymal transition (EMT). Finally, we raise some intriguing questions regarding the clinical impact of studying the crosstalk between evolutionary waves of DCCs and the initiation of metastatic disease.

Determinants of mammography screening participation-a cross-sectional analysis of the German population-based Gutenberg Health Study (GHS)

PURPOSE

We investigated the association between social inequality and participation in a mammography screening program (MSP). Since the German government offers mammography screening free of charge, any effect of social inequality on participation should be due to educational status and not due to the financial burden.

METHODS

The 'Gutenberg Health Study' is a cohort study in the Rhine-Main-region, Germany. A health check-up was performed, and questions about medical history, health behavior, including secondary prevention such as use of mammography, and social status are included. Two indicators of social inequality (equivalence income and educational status), an interaction term of these two, and different covariables were used to explore an association in different logistic regression models.

RESULTS

A total of 4,681 women meeting the inclusion criteria were included. Only 6.2% never participated in the MSP. A higher income was associated with higher chances of ever participating in a mammography screening (odds ratios (OR): 1.67 per €1000; 95%CI:1.26-2.25, model 3, adjusted for age, education and an interaction term of income and education). Compared to women with a low educational status, the odds ratios for ever participating in the MSP was lower for the intermediate educational status group (OR = 0.64, 95%CI:0.45-0.91) and for the high educational status group (0.53, 95%CI:0.37-0.76). Results persisted also after controlling for relevant confounders.

CONCLUSIONS

Despite the absence of financial barriers for participation in the MSP, socioeconomic inequalities still influence participation. It would be interesting to examine whether the educational effect is due to an informed decision.

Performance indicators in breast cancer screening in the European Union: A comparison across countries of screen positivity and detection rates

Comparable performance indicators for breast cancer screening in the European Union (EU) have not been previously reported. We estimated adjusted breast cancer screening positivity rate (PR) and detection rates (DR) to investigate variation across EU countries. For the age 50-69 years, the adjusted EU-pooled PR for initial screening was 8.9% (cross-programme variation range 3.2-19.5%) while DR of invasive cancers was 5.3/1,000 (range 3.8-7.4/1,000) and DR of ductal carcinoma in situ (DCIS) was 1.3/1,000 (range 0.7-2.7/1,000). For subsequent screening, the adjusted EU-pooled PR was 3.6% (range 1.4-8.4%), the DR was 4.0/1,000 (range 2.2-5.8/1,000) and 0.8/1,000 (range 0.5-1.3/1,000) for invasive and DCIS, respectively. Adjusted performance indicators showed remarkable heterogeneity, likely due to different background breast cancer risk and awareness between target populations, and also different screening protocols and organisation. Periodic reporting of the screening indicators permits comparison and evaluation of the screening activities between and within countries aiming to improve the quality and the outcomes of screening programmes. Cancer Screening Registries would be a milestone in this direction and EU Screening Reports provide a fundamental contribution to building them.

The Feasibility of Classifying Breast Masses Using a Computer-Assisted Diagnosis (CAD) System Based on Ultrasound Elastography and BI-RADS Lexicon

OBJECTIVES

To determine the applicability of a computer-aided diagnostic system strain elastography system for the classification of breast masses diagnosed by ultrasound and scored using the criteria proposed by the breast imaging and reporting data system ultrasound lexicon and to determine the diagnostic accuracy and interobserver variability.

METHODS

This prospective study was conducted between March 1, 2016, and May 30, 2016. A total of 83 breast masses subjected to percutaneous biopsy were included. Ultrasound elastography images before biopsy were interpreted by 3 radiologists with and without the aid of computer-aided diagnostic system for strain elastography. The parameters evaluated by each radiologist results were sensitivity, specificity, and diagnostic accuracy, with and without computer-aided diagnostic system for strain elastography. Interobserver variability was assessed using a weighted κ test and an intraclass correlation coefficient. The areas under the receiver operating characteristic curves were also calculated.

RESULTS

The areas under the receiver operating characteristic curve were 0.835, 0.801, and 0.765 for readers 1, 2, and 3, respectively, without computer-aided diagnostic system for strain elastography, and 0.900, 0.926, and 0.868, respectively, with computer-aided diagnostic system for strain elastography. The intraclass correlation coefficient between the 3 readers was 0.6713 without computer-aided diagnostic system for strain elastography and 0.811 with computer-aided diagnostic system for strain elastography.

CONCLUSION

The proposed computer-aided diagnostic system for strain elastography system has the potential to improve the diagnostic performance of radiologists in breast examination using ultrasound associated with elastography.

Outcome of breast cancer screening in Denmark

BACKGROUND

In Denmark, national roll-out of a population-based, screening mammography program took place in 2007-2010. We report on outcome of the first four biennial invitation rounds.

METHODS

Data on screening outcome were retrieved from the 2015 and 2016 national screening quality reports. We calculated coverage by examination; participation after invitation; detection-, interval cancer- and false-positive rates; cancer characteristics; sensitivity and specificity, for Denmark and for the five regions.

RESULTS

At the national level coverage by examination remained at 75-77%; lower in the Capital Region than in the rest of Denmrk. Detection rate was slightly below 1% at first screen, 0.6% at subsequent screens, and one region had some fluctuation over time. Ductal carcinoma in situ (DCIS) constituted 13-14% of screen-detected cancers. In subsequent rounds, 80% of screen-detected invasive cancers were node negative and 40% ≤10 mm. False-positive rate was around 2%; higher for North Denmark Region than for the rest of Denmark. Three out of 10 breast cancers in screened women were diagnosed as interval cancers.

CONCLUSIONS

High coverage by examination and low interval cancer rate are required for screening to decrease breast cancer mortality. Two pioneer local screening programs starting in the 1990s were followed by a decrease in breast cancer mortality of 22-25%. Coverage by examination and interval cancer rate of the national program were on the favorable side of values from the pioneer programs. It appears that the implementation of a national screening program in Denmark has been successful, though regional variations need further evaluation to assure optimization of the program.

Presence, characteristics and equity of access to breast cancer screening programmes in 27 European countries in 2010 and 2014. Results from an international survey

The European Union Council Recommendation of 2 December 2003 on cancer screening suggests the implementation of organised, population-based breast cancer screening programmes based on mammography every other year for women aged 50 to 69years, ensuring equal access to screening, taking into account potential needs for targeting particular socioeconomic groups. A European survey on coverage and participation, and key organisational and policy characteristics of the programmes, targeting years 2010 and 2014, was undertaken in 2014. Overall, 27 countries contributed to this survey, 26 of the 28 European Union member states (92.9%) plus Norway. In 2014, 25 countries reported an ongoing population-based programme, one country reported a pilot programme and another was planning a pilot. In eight countries, the target age range was broader than that proposed by the Council Recommendation, and in three countries the full range was not covered. Fifteen countries reported not reaching some vulnerable populations, such as immigrants, prisoners and people without health insurance, while 22 reported that participation was periodically monitored by socioeconomic variables (e.g. age and territory). Organised, population-based breast cancer screening programmes based on routine mammograms are in place in most EU member states. However, there are still differences in the way screening programmes are implemented, and participation by vulnerable populations should be encouraged.

Breast cancer screening attendance in two Swiss regions dominated by opportunistic or organized screening

BACKGROUND

In Switzerland, the French-speaking region has an organized breast cancer (BC) screening program; in the German-speaking region, only opportunistic screening until recently had been offered. We evaluated factors associated with attendance to breast cancer screening in these two regions.

METHODS

We analyzed the data of 50-69 year-old women (n = 2769) from the Swiss Health Survey 2012. Factors of interest included education level, place of residence, nationality, marital status, smoking history, alcohol consumption, physical activity, diet, self-perceived health, history of chronic diseases and mental distress, visits to medical doctors and cervical and colorectal cancer screening. Outcome measures were dichotomized into ≤2 years since most recent mammography versus >2 years or never.

RESULTS

In the German- and French-speaking regions, mammography attendance within the last two years was 34.9 % and 77.8 %, respectively. In the French region, moderate alcohol consumption (adjusted OR 2.01, 95 % CI 1.28-3.15) increased screening attendance. Compared to those with no visit to a physician during the recent year, women in both regions with such visits attended statistically significantly more often BC screening (1-5 times vs. no visit: German (adjusted OR 3.96, 95 % CI 2.58-6.09); French: OR 7.25, 95 % CI 4.04-13.01). Non-attendance to cervical screening had a negative effect in both the German (adjusted OR 0.44, 95 % CI 0.25-0.79) and the French region (adjusted OR 0.57, 95 % CI 0.35-0.91). The same was true for colorectal cancer screening (German (adjusted OR 0.66, 95 % CI 0.52-0.84); French: OR 0.52, 95 % CI 0.33-0.83). No other factor was associated with BC screening and none of the tests of interaction comparing the two regions revealed statistically significant results.

CONCLUSION

The effect of socio-demographic characteristics, lifestyle, health factors and screening behavior other than mammography on non-attendance to BC screening did not differ between the two regions with mainly opportunistic and organized screening, respectively, and did not explain the large differences in attendance between regions. Other potential explanations such as public promotion of attendance for BC screening, physicians' recommendations regarding mammography participation or women's beliefs should be further investigated.

European Code against Cancer, 4th Edition: Cancer screening

In order to update the previous version of the European Code against Cancer and formulate evidence-based recommendations, a systematic search of the literature was performed according to the methodology agreed by the Code Working Groups. Based on the review, the 4th edition of the European Code against Cancer recommends: "Take part in organized cancer screening programmes for: Bowel cancer (men and women); Breast cancer (women); Cervical cancer (women)." Organized screening programs are preferable because they provide better conditions to ensure that the Guidelines for Quality Assurance in Screening are followed in order to achieve the greatest benefit with the least harm. Screening is recommended only for those cancers where a demonstrated life-saving effect substantially outweighs the potential harm of examining very large numbers of people who may otherwise never have, or suffer from, these cancers, and when an adequate quality of the screening is achieved. EU citizens are recommended to participate in cancer screening each time an invitation from the national or regional screening program is received and after having read the information materials provided and carefully considered the potential benefits and harms of screening. Screening programs in the European Union vary with respect to the age groups invited and to the interval between invitations, depending on each country's cancer burden, local resources, and the type of screening test used For colorectal cancer, most programs in the EU invite men and women starting at the age of 50-60 years, and from then on every 2 years if the screening test is the guaiac-based fecal occult blood test or fecal immunochemical test, or every 10 years or more if the screening test is flexible sigmoidoscopy or total colonoscopy. Most programs continue sending invitations to screening up to the age of 70-75 years. For breast cancer, most programs in the EU invite women starting at the age of 50 years, and not before the age of 40 years, and from then on every 2 years until the age of 70-75 years. For cervical cancer, if cytology (Pap) testing is used for screening, most programs in the EU invite women starting at the age of 25-30 years and from then on every 3 or 5 years. If human papillomavirus testing is used for screening, most women are invited starting at the age of 35 years (usually not before age 30 years) and from then on every 5 years or more. Irrespective of the test used, women continue participating in screening until the age of 60 or 65 years, and continue beyond this age unless the most recent test results are normal.

Performance indicators evaluation of the population-based breast cancer screening programme in Northern Portugal using the European Guidelines

OBJECTIVE

To evaluate the first 10 years of operation of the population-based breast cancer screening programme implemented in the Northern Region of Portugal, using selected recommended standard performance indicators.

METHODS

Data from women aged 50-69 screened with two-view mammography, biennially, in the period 2000-2009, were included. Main performance indicators were compared with the recommended levels of the European Guidelines.

RESULTS

A total of 202,039 screening examinations were performed, 71,731 (35.5%) in the initial screening and 130,308 (64.5%) in the subsequent screening. Coverage rate by examination reached 74.3% of the target population, in the last period evaluated. Recall rates were 8.1% and 2.4% and cancer detection rates were 4.4/1000 and 2.9/1000 respectively, for initial and subsequent screenings. The breast cancer detection rate, expressed as a multiple of the background expected incidence was 3.1 in initial screen and 2.2 in subsequent screen. The incidence of invasive interval cancers met the desirable recommended levels both the first and second years since last screening examination, in the initial and subsequent screenings. Invasive tumours <15mm were 50.4% and 53.8% of the invasive cancers detected in initial and subsequent screenings. Less favourable size, grading and biomarkers expression were found in interval cancers compared to screen-detected cancers.

CONCLUSIONS

Breast cancer screening programme in the Northern Region of Portugal was well accepted by the population. Most of the performance indicators were consistent with the desirable levels of the European Guidelines, which indicate an effective screening programme. Future research should verify the consistency of some of these results by using updated information from a larger population.

To what extent is women's economic situation associated with cancer screening uptake when nationwide screening exists? A study of breast and cervical cancer screening in France in 2010

PURPOSE

In France, larger social inequalities are reported for cervical cancer screening, based on individual practice, than for breast cancer screening for which organized screening exists. Our aim was to investigate the association between women's economic situation and breast and cervical cancer screening.

METHODS

We used data from a large French national health survey conducted in 2010. The economic situation was assessed using the number of adverse economic conditions respondents were facing, based on three variables (low income, lacking food, and perceived financial difficulties). Logistic regressions were adjusted for socioeconomic and sociodemographic characteristics, healthcare use and insurance, and health behaviors.

RESULTS

Mammography was less frequent among women experiencing two or more adverse economic conditions, whereas Pap smear was less frequent among women experiencing at least one adverse economic condition. For both screenings, higher rates were observed among women who lived in the Paris region. Sociodemographic indicators and health behaviors were associated with Pap smear, whereas healthcare use and insurance characteristics were associated with mammography.

CONCLUSIONS

The women's economic situation is an important determinant of breast and cervical cancer screening in France in 2010. Alleviating economic barriers to female cancers screening should be a priority in future programs implementation.

The association between general practitioners' attitudes towards breast cancer screening and women's screening participation

BACKGROUND

Breast cancer screening in Denmark is organised by the health services in the five regions. Although general practitioners (GPs) are not directly involved in the screening process, they are often the first point of contact to the health care system and thus play an important advisory role. No previous studies, in a health care setting like the Danish system, have investigated the association between GPs' attitudes towards breast cancer screening and women's participation in the screening programme.

METHODS

Data on women's screening participation was obtained from the regional screening authorities. Data on GPs' attitudes towards breast cancer screening was taken from a previous survey among GPs in the Central Denmark Region. This study included women aged 50-69 years who were registered with a singlehanded GP who had participated in the survey.

RESULTS

The survey involved 67 singlehanded GPs with a total of 13,288 women on their lists. Five GPs (7%) had a negative attitude towards breast cancer screening. Among registered women, 81% participated in the first screening round. Multivariate analyses revealed that women registered with a GP with a negative attitude towards breast cancer screening were 17% (95% CI: 2-34%) more likely to be non-participants compared with women registered with a GP with a positive attitude towards breast cancer screening.

CONCLUSION

The GPs' attitudes may influence the participation rate even in a system where GPs are not directly involved in the screening process. However, further studies are needed to investigate this association.

The Breast Imaging Reporting and Data System (BI-RADS) in the Dutch breast cancer screening programme: its role as an assessment and stratification tool

Objectives

To assess the suitability of the Breast Imaging Reporting and Data System (BI-RADS) as a quality assessment tool in the Dutch breast cancer screening programme.

Methods

The data of 93,793 screened women in the Amsterdam screening region (November 2005–July 2006) were reviewed. BI-RADS categories, work-up, age, final diagnosis and final TNM classification were available from the screening registry. Interval cancers were obtained through linkage with the cancer registry. BI-RADS was introduced as a pilot in the Amsterdam region before the nationwide introduction of digital mammography (2009–2010).

Results

A total of 1,559 women were referred to hospital (referral rate 1.7 %). Breast cancer was diagnosed in 485 women (detection rate 0.52 %); 253 interval cancers were reported, yielding a programme sensitivity of 66 % and specificity of 99 %. BI-RADS 0 had a lower positive predictive value (PPV, 14.1 %) than BI-RADS 4 (39.1 %) and BI-RADS 5 (92.9 %; P < 0.0001). The number of invasive procedures and tumour size also differed significantly between BI-RADS categories (P < 0.0001).

Conclusion

The significant differences in PPV, invasive procedures and tumour size match with stratification into BI-RADS categories. It revealed inter-observer variability between screening radiologists and can thus be used as a quality assessment tool in screening and as a stratification tool in diagnostic work-up.

Key Points

• The BI-RADS atlas is widely used in breast cancer screening programmes.

• There were significant differences in results amongst different BI-RADS categories.

• Those differences represented the radiologists’ degree of suspicion for malignancy, thus enabling stratification of referrals.

• BI-RADS can be used as a quality assessment tool in screening.

• Training should create more uniformity in applying the BI-RADS lexicon.

Breast cancer screening in the Czech Republic: time trends in performance indicators during the first seven years of the organised programme

Background

The Czech Breast Cancer Screening Programme (CBCSP) was initiated in September 2002 by establishing a network of accredited centres. The aim of this article is to describe progress in the programme quality over time after the inception of the organised programme.

Methods

The CBCSP is monitored using an information system consisting of three principal components: 1) the national cancer registry, 2) a screening registry collecting data on all screening examinations, further assessments and final diagnoses at accredited programme centres, and 3) administrative databases of healthcare payers. Key performance indicators from the European Guidelines have been adopted for continuous monitoring.

Results

Breast cancer incidence in the Czech Republic has steadily been increasing, however with a growing proportion of less advanced stages. The mortality rate has recently stabilised. The screening registry includes 2,083,285 records on screening episodes between 2002 and 2008. In 2007-2008, 51% of eligible women aged 45-69 were screened. In 2008, the detection rates were 6.1 and 3.7 per 1,000 women in initial and subsequent screening respectively. Corresponding recall rates are 3.9% and 2.2%, however, it is necessary to pay attention to further assessment performed during the screening visits. Benign to malignant open biopsy ratio was 0.1. Of invasive cases detected in screening, 35.6% was less than 10 mm in diameter. Values of early performance indicators, as measured by both crude and standardized estimates, are generally improving and fulfil desirable targets set by European Guidelines.

Conclusions

Mammography screening in the Czech Republic underwent successful transformation from opportunistic prevention to an organised programme. Values of early indicators confirm continuous improvement in different aspects of process quality. Further stimulation of participation through invitation system is necessary to exploit the full potential of screening mammography at the population level.

Early evaluation of an organised mammography screening program in Greece 2004-2009

OBJECTIVE

The aim of the current study was to present early performance indicators of a breast cancer screening program in Greece.

METHODS

Between March 2004 and July 2009, 9621 women aged between 40 and 69 years were recruited into programme on a voluntary basis. The participating women were residents of two adjacent administrative regions of Greece. Several performance indicators were calculated for the first and subsequent screen, separately.

RESULTS

A total of 9621 mammograms were 1st screens and 4462 were subsequent screens. The attendance rate was almost 1.5%. The technical repeat rate was 1.7%. On the 1st screen, the recall rate was 11.4%, while the recall rate of the subsequent screens was 5.5%. The vast majority of detected cancers were invasive and only the 1/7 of cancers was identified as DCIS. As concerns tumour size of invasive cancers, the 1.9% and 16.7% was unknown, in the first and subsequent screen, respectively. Moreover, 38.5% and 44.4% of cancers detected in the 1st and subsequent screen, respectively, were less than 15 mm in diameter. Almost 1/5 of diagnosed cancers were interval cancers.

CONCLUSIONS

This breast cancer screening programme is the first one in Greece and the attendance rate is extremely low. Taking into account that an organised screening programme may benefit women with a reduction in breast cancer mortality, there is an urgent need to develop a national-based screening programme, to increase participation and to improve the information system used to monitor programme performance.

Variation in performance in low-volume mammography screening programmes: experience from Switzerland

BACKGROUND

Reading volume and mammography screening performance appear positively correlated. Quality and effectiveness were compared across low-volume screening programmes targeting relatively small populations and operating under the same decentralised healthcare system. Except for accreditation of 2nd readers (restrictive vs non-restrictive strategy), these organised programmes had similar screening regimen/procedures and duration, which maximises comparability. Variation in performance and its determinants were explored in order to improve mammography practice and optimise screening performance.

METHODS

Circa 200,000 screens performed between 1999 and 2006 (4 rounds) in 3 longest standing Swiss cantonal programmes (of Vaud, Geneva and Valais) were assessed. Indicators of quality and effectiveness were assessed according to European standards. Interval cancers were identified through linkage with cancer registries records.

RESULTS

Swiss programmes met most European standards of performance with a substantial, favourable cancer stage shift. Up to a two-fold variation occurred for several performance indicators. In subsequent rounds, compared with programmes (Vaud and Geneva) that applied a restrictive selection strategy for 2nd readers, proportions of in situ lesions and of small cancers (≤1cm) were one third lower and halved, respectively, and the proportion of advanced lesions (stage II+) nearly 50% higher in the programme without a restrictive selection strategy. Discrepancy in second-year proportional incidence of interval cancers appears to be multicausal.

CONCLUSION

Differences in performance could partly be explained by a selective strategy for second readers and a prior experience in service screening, but not by the levels of opportunistic screening and programme attendance. This study provides clues for enhancing mammography screening performance in low-volume programmes.

'A low risk is still a risk': exploring women's attitudes towards genetic testing for breast cancer susceptibility in order to target disease prevention

BACKGROUND

Population breast cancer screening programs by mammography are offered to women based on age. It has been suggested that a screening program based on genetic risk profile could be more effective by targeting interventions at those at higher genetic risk. This study explores women's attitudes towards genetic testing for breast cancer susceptibility in order to target breast cancer prevention.

METHODS

A qualitative study was conducted using 4 focus groups with 26 women aged 42-73 years. Women were selected irrespective of personal or family history of breast cancer. Discussions were audiotaped and content analyzed.

RESULTS

The results show that in general women are positive towards a breast cancer screening program based on genetic risk profile, provided that in the low-risk group, though less frequent, women are still offered mammography screening (i.e. right to screening (a)). Other themes that women addressed were: (b) value of the genetic risk information (e.g. possibilities for cancer prevention at younger ages, less screening burden for low-risk women), (c) personal autonomy (e.g. free choice to undergo testing), (d) dealing with test results (e.g. burden of risk, motivation to reduce the risk), (e) discrimination, and (f) financial aspects and priority (e.g. with respect to other health care programs).

CONCLUSION

These results suggest that women currently offered breast cancer screening based on age have a positive attitude towards population susceptibility screening for breast cancer, but also identified issues that need to be discussed and studied further, especially if women in the low-risk group were no longer to be offered mammography screening.

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.

Cancer survival analysis in Hamburg 1995-2003: assessing the data quality within a population-based registry

INTRODUCTION

Population-based cancer survival analysis constitutes valuable reference material for the clinical field of oncology. The objectives of this study were to assess the quality of the Hamburg Cancer Registry's (HCR) database in this respect, to perform survival analyses by means of selected sites, and to evaluate the results in relation to prevalent opinions and external estimates.

METHODS

Data quality was assessed by the proportion of cases documented as diagnosed at death, external estimates of completeness, reliability of follow-up, histological verification and information on stage. Included were first primary malignancies of the colon (ICD10 C18, n=4,544), female breast (C50, n=9,259), prostate (C61, n=5,707) and urinary bladder (C67, D09.0, n=3,148), diagnosed in Hamburg residents 1995-2003. Observed and relative survival (OS, RS) were estimated by site, sex, time, age and stage.

RESULTS

Regarding female breast cancer in Hamburg, high levels of data quality and completeness exist while the explanatory power concerning malignancies of the colon, prostate and urinary bladder is limited. Age-standardised 5-year relative cancer survival estimates amounted for female breast to 81%, for colon to 49% (male) and 52% (female), for prostate to 81% and for urinary bladder to 71% (male) and 62% (female).

CONCLUSION

The study demonstrates the capacities and limitations of an epidemiological cancer registry to produce convincing survival estimates for clinical use, under the terms of a voluntary case reporting system.

Effectiveness of organised versus opportunistic mammography screening

BACKGROUND

Detailed comparison of effectiveness between organised and opportunistic mammography screening operating in the same country has seldom been carried out.

PATIENTS AND METHODS

Prognostic indicators, as defined in the European Guidelines, were used to evaluate screening effectiveness in Switzerland. Matching of screening programmes' records with population-based cancer registries enabled to compare indicators of effectiveness by screening and detection modality (organised versus opportunistic screening, unscreened, interval cancers). Comparisons of prognostic profile were also drawn with two Swiss regions uncovered by service screening of low and high prevalence of opportunistic screening, respectively.

RESULTS

Opportunistic and organised screening yielded overall little difference in prognostic profile. Both screening types led to substantial stage shifting. Breast cancer prognostic indicators were systematically more favourable in Swiss regions covered by a programme. In regions without a screening programme, the higher the prevalence of opportunistic screening, the better was the prognostic profile.

CONCLUSIONS

Organised screening appeared as effective as opportunistic screening. Mammography screening has strongly influenced the stage distribution of breast cancer in Switzerland, and a favourable impact on mortality is anticipated. Extension of organised mammography screening to the whole of Switzerland can be expected to further improve breast cancer prognosis in a cost-effective way.

Cancer screenings, diagnostic technology evolution, and cancer control

Screening should allow for the anticipation of cancer diagnosis at an earlier stage, when curative treatment is possible. Screening for cervical, large bowel, and breast cancer were shown to be effective in reducing mortality. The wide acceptance of the screening concept led to the wide diffusion also of screening of uncertain benefit against prostate cancer and skin melanoma. Diagnostic technologies are continuously evolving, and new tests are proposed to improve existing screenings or as screening tests for additional cancer sites (e.g., lung cancer). Cancer screening, however, is a complex and costly intervention that does not result only in benefits but also may cause harm. A major emerging problem of screening is overdiagnosis, or the detection of cases that would have not progressed to the symptomatic phase in the absence of screening. Thus, both experimental and observational evaluation studies are needed to reduce harm caused by screenings and to select effective interventions among many proposed innovations. Finally, the research of markers to assess the aggressive nature of screen-detected lesions is of great importance to improve screenings ' harm/benefit ratio.

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.

Determinants of the number of mammography units in 31 countries with significant mammography screening

In the 2000s, most of the female population of industrialised countries had access to mammography breast cancer screening, but with variable modalities among the countries. We assessed the number of mammography units (MUs) in 31 European, North American and Asian countries where significant mammography activity has existed for over 10 years, collecting data on the number of such units and of radiologists by contacting institutions in each country likely to provide the relevant information. Around 2004, there were 32,324 MU in 31 countries, the number per million women ranging from less than 25 in Turkey, Denmark, the Netherlands, the United Kingdom, Norway, Poland and Hungary to more than 80 in Cyprus, Italy, France, the United States and Austria. In a multivariate analysis, the number of MUs was positively associated with the number of radiologists (P=0.0081), the number of women (P=0.0023) and somewhat with the country surface area (P=0.077). There is considerable variation in the density of MU across countries and the number of MUs in service are often well above what would be necessary according to local screening recommendations. High number of MUs in some countries may have undesirable consequences, such as unnecessarily high screening frequency and decreased age at which screening is started.

Getting adequate information across to colorectal cancer screening subjects can be difficult

Objectives

Participation in screening should be the outcome of an informed decision. We evaluated whether invitees in the first Dutch colorectal cancer (CRC) screening programme were adequately informed after having received a detailed information leaflet.

Methods

A total of 20,623 subjects aged 50–75 years were invited to the fecal occult blood test (FOBT) screening programme. All received a detailed information leaflet by mail between May 2006 and January 2007. After two weeks, a reminder letter was sent to all invitees, accompanied by a survey on CRC and screening.

Results

The survey was completed by 9594 invitees (47%). Almost all responders (99%) found the leaflet clear and readable. Almost all indicated that CRC can be treated better if found early (99%). Only 20% of the responders answered all knowledge-related answers correctly. Almost half of the responders (47%) believed that a negative FOBT excludes the presence of CRC. Older age and having a positive family member for CRC were correctly identified as risk factors by 80%.

Conclusion

This study demonstrates that although an information leaflet was reported as being clear and readable, the information provided in it was not always understood well. This suggests that other educational options should be investigated in order to improve general knowledge of CRC in screening invitees.

Effectiveness of service screening: a case-control study to assess breast cancer mortality reduction

The aim of this study was the evaluation of the impact of service screening programmes on breast cancer mortality in five regions of Italy. We conducted a matched case-control study with four controls for each case. Cases were defined as breast cancer deaths occurred not later than 31 December 2002. Controls were sampled from the local municipality list and matched by date of birth. Screening histories were assessed by the local, computerised, screening database and subjects were classified as either invited or not-yet-invited and as either screened or unscreened. There were a total of 1750 breast cancer deaths within the 50 to 74-year-old breast cancer cases and a total of 7000 controls. The logistic conditional estimate of the cumulative odds ratios comparing invited with not-yet-invited women was 0.75 (95% CI: 0.62-0.92). Restricting the analyses to invited women, the odds ratio of screened to never-respondent women corrected for self-selection bias was 0.55 (95% CI: 0.36-0.85). The introduction of breast cancer screening programmes in Italy is associated with a reduction in breast cancer mortality attributable to the additional impact of service screening over and above the background access to mammography.

Does educational level determine screening participation?

The objective of this study was to test the hypothesis that nonparticipation in organized mammography screening is due to insufficient understanding of the information in the invitation letter by relating educational level to user pattern. Data from two Danish mammography screening programmes in Copenhagen, 1991-1999, and Funen, 1993-2001 were taken for this study. The Danish Central Population Register was used to define target groups; screened participation data were provided by the health authority, and data on highest obtained education came from Statistics Denmark. Data on all breast imaging in 2000 outside organized screening were provided by radiology clinics. Included were all women eligible for at least three screens, and participation was classified into four mutually exclusive user groups. Organized mammography screening programmes in Copenhagen and Funen, Denmark were used as field of this study. Main outcome measures were age-adjusted relative risks (RR) and 95% confidence intervals (CI) of 'never use' versus 'always use' of screening by educational level, using women with secretarial/sales education as baseline. The RR of 'never use' was 1.65 (95% CI: 1.37-1.99) in Copenhagen and 1.93 (95% CI: 1.42-2.62) in Funen for academics, 1.60 (95% CI: 1.48-1.73) in Copenhagen and 1.26 (95% CI: 1.14-1.39) Funen for women with lower primary educational level. Taking other breast imaging into account, the RR was 1.60 (95% CI: 1.32-1.95) for academics in Copenhagen, and 1.90 (95% CI: 1.75-2.07) for women with lower primary education. In conclusion, our results did not support the hypothesis that lack of understanding the information in the invitation letter explains nonparticipation. 'Never use' was not inversely associated with the level of education, but showed a U-shaped association, even when use of breast imaging outside organized screening was taken into account.

Organised mammography screening reduces breast cancer mortality: a cohort study from Finland

We evaluated the effectiveness and the efficacy of population-based mammography programme in Finland, and explored associations between the screening performance and the screening efficacy. The main outcome, incidence-based mortality from breast cancer, was estimated by invitation, participation, age at death, and screening centres categorised by recall rates. The study was based on an individual followup of screening invitees and participants from 1992 to 2003. The coverage of screening invitations was 95% among 50-59 years old women, and 20-40% among women aged 60-69 years. We compared observed deaths from breast cancer to expected breast cancer deaths without screening in ages 50-69 at death. The observed deaths were obtained from a cohort of individual invitees (n = 361,848). The expected deaths were defined by modelling breast cancer mortality from 1974 to 1985 and 1992 to 2003 at population level. The population data were derived from the same municipalities (n = 260) that were incorporated into the cohort. The breast cancer mortality among the invited women was reduced by 22% (relative risk 0.78, 95% confidence interval 0.70-0.87). After adjusting for the self-selection, the efficacy among the participants was 28% (0.72,0.56-0.88). No clear association between the recall rates and the screening efficacy was observed. The organised mammography screening in Finland is effective. The relationship between the estimates of process and outcome of mammography is not yet straightforward: effectiveness and efficacy remain the best estimates for evaluating the success of mammography screening.

Socio-demographic determinants of participation in mammography screening

Our objective was to use individual data on socio-demographic characteristics to identify predictors of participation in mammography screening and control to what extent they can explain the regional difference. We used data from mammography screening programmes in Copenhagen, 1991-1999, and Funen, 1993-2001, Denmark. Target groups were identified from the Population Register, screening data came from the health authority, and socio-demographic data from Statistics Denmark. Included were women eligible for at least 3 screens. The crude RR of never use versus always use was 3.21 (95%CI, 3.07-3.35) for Copenhagen versus Funen, and the adjusted RR was 2.55 (95%CI, 2.43-2.67). The adjusted RR for never use among women without contact to a primary care physician was 2.50 (95% CI, 2.31-2.71) and 2.89 (95% CI, 2.66-3.14), and for women without dental care 2.94 (95% CI, 2.77-3.12) and 2.88 (95% CI, 2.68-3.10) for Copenhagen and Funen, respectively. Other important predictive factors for nonparticipation were not being married and not being Danish. In conclusion, to enhance participation in mammography screening programmes special attention needs to be given to women not using other primary health care services. All women in Copenhagen, irrespective of their socio-demographic characteristics, had low participation. Screening programmes have to find ways to handle this urbanity factor.

Evaluating Population-Based Screening Mammography Programs Internationally

This report describes the purpose and activities of the International Breast Cancer Screening Network (IBSN), a voluntary consortium of countries that focuses on collaborative research to identify and promote efficient, effective approaches to breast cancer control world-wide through population-based screening mammography. Sponsored by the U.S. National Cancer Institute, the IBSN was established in 1988 with eleven participating countries. By 2005, membership had grown to 27 countries. Recent IBSN efforts have involved gathering information on program organization and quality assurance activities, evaluating measures and methodologies for assessing screening mammography performance and outcomes, and examining the information that programs are providing to women as a means of facilitating informed decision-making about the benefits and risks of screening mammography. The ongoing IBSN effort demonstrates that-despite marked differences in health care systems-international collaborative work can contribute new knowledge to the monitoring and evaluation of organized, population-based screening mammography programs, and identify potential areas for improvement in screening performance in practice.

Women's patterns of participation in mammography screening in Denmark

The objective of the study is to analyse individual women's participation patterns in mammography screening in Denmark. The study is set in the capital of Copenhagen and the county of Fyn representing around 95,000 women aged 50-69. The Central Population Register (CPR) was used to define the total target group, and supply information on migrations and deaths. Invitation and participation data came from the mammography screening programmes in Copenhagen (1991-1999) and Fyn (1993-2001), containing personal identification number, data on invitation date, participation and examination date for each screening round. In Copenhagen the coverage went from 70.5% in the first round to 63.1% in the fourth round, and the equivalent data for Fyn is 84.6% in the first round and 82.8% in the fourth round. Of the women eligible for at least three invitation rounds, 52.6% in Copenhagen and 76.4% in Fyn were faithful users, i.e. had participated in all screenings they were invited to. The conclusion is that the programme participation rates tend to overestimate the protection of the individual women covered by the programme. Behind the urban-rural gradient in programme participation is an even greater gradient in programme protection.

The organisation and results of first screening round of the Hungarian nationwide organised breast cancer screening programme

BACKGROUND

The aim of this paper is to give an overview of organisational issues of the Hungarian nationwide organised breast cancer screening programme and to provide the results of the first screening round of the programme for the years 2002-2003.

PATIENTS AND METHODS

Data were derived from the financial database of the National Health Insurance Fund Administration covering the period 2000-2003. Women who underwent mammography screening were included into the study.

RESULTS

Uptake of the organised screening programme in 2002-2003 was 45.09%, while the recall rate was 7.23%. Malignant cases represented 65.38% of total surgeries and 0.36% of total number of screened women yielding a cancer detection rate 3.6 per 1000 screened women. Malignant cases of 10.78% were identified as ductal carcinoma in situ, while 89.22% was invasive cancer. Benign to malignant ratio was 0.54 : 1.

CONCLUSION

There is therefore an urgent need to closely monitor performance and to review programme policies and procedures with the aim of increasing both the participation rate and the proportion of women eligible to attend screening.

Importance of Comparison of Current and Prior Mammograms in Breast Cancer Screening

PURPOSE

To retrospectively determine the influence of comparing current mammograms with prior mammograms on breast cancer detection in screening and to investigate a protocol in which prior mammograms are viewed only when necessary.

MATERIALS AND METHODS

Institutional review board approval was not required. Participants gave written informed consent. Twelve experienced screening radiologists read 160 soft-copy screening mammograms twice, once with and once without prior mammograms. Eighty mammograms were obtained in women in whom breast cancer was diagnosed later; the other 80 mammograms had been reported as normal or benign. All cancers were visible in retrospect. Readers located potential abnormalities, estimated likelihood of malignancy for each finding, and indicated whether prior mammograms were considered necessary. The effect of prior mammograms on detection was determined by computing the mean lesion localized fraction in a range of low fractions of nonlesion locations corresponding to operating points in screening. Scores for both reading sessions were combined to assess the effect of making prior mammograms available only when requested. Data were analyzed by comparing the number of localized lesions between the two reading conditions with a paired two-tailed Student t test and applying a linear mixed model to test differences in average mean lesion localized fraction between reading conditions. P values less than .05 indicated statistical significance.

RESULTS

Without prior mammograms, significantly more annotations were made. When only positive cases were considered, no difference was observed. Reading performance was significantly better when prior screening mammograms were available. At fixed lesion localized fraction, nonlesion localized fraction was reduced by 44% (P<.001) on average when prior mammograms were read. Performance was also increased for combined reading mode (ie, when prior mammograms were available on request only). However, this increase was smaller than that when prior mammograms were always available. Prior mammograms were requested in 24%-33% of all cases and were requested more often in positive cases.

CONCLUSION

Comparison with prior mammograms significantly improves overall performance and can reduce referrals due to nonlesion locations. Limiting the availability of prior mammograms to cases selected by the reader reduces the beneficial effect of prior mammograms.

Fatores associados à realização de exames preventivos para câncer nas mulheres brasileiras, PNAD 2003

Estudar fatores associados à realização dos exames Papanicolaou e mamografia por mulheres brasileiras. Foram analisadas informações sobre mulheres com 25 anos ou mais, no suplemento Saúde da Pesquisa Nacional de Amostras Domiciliares (PNAD) do IBGE 2003, de realização de Papanicolaou nos últimos 5 anos e mamografia nos últimos 2 anos, sua prevalência por variáveis demográficas, socioeconômicas e saúde, acesso e utilização de serviços de saúde. Foram realizadas análise estatística bivariada e regressão logística para os dois procedimentos. A prevalência para Papanicolaou foi 75,5% e mamografia 36,1%. A regressão logística mostrou como principais fatores preditivos para Papanicolaou: ter filhos, consulta médica no último ano, renda elevada, médio a alto grau de escolaridade, ter plano de saúde e morar em zona urbana. Para mamografia mostraram-se fatores preditivos importantes: distribuição etária (40-59 anos), consulta médica no último ano, morar em zona urbana, renda elevada e ter plano de saúde. No Papanicolaou há maior incorporação na assistência, e o acesso à consulta médica fator essencial para a realização do exame. Na mamografia, a prevalência é mais elevada nas faixas etárias recomendadas, perfil diferenciado por acesso à consulta médica e condição socioeconômica, e muitos exames em mulheres em faixas etárias não recomendadas.

Cumulative false positive recall rate and association with participant related factors in a population based breast cancer screening programme

STUDY OBJECTIVE

To investigate the cumulative false positive recall rate throughout the period of participation in a population based breast cancer screening programme and to examine its association with women related factors.

DESIGN

Analysis of a database to estimate the cumulative false positive recall rate after 10 biennial mammograms in a cohort of women. Cumulative risk after 10 rounds was calculated by projecting forward the information available on the four rounds. Logistic regression was used to evaluate the association between the cumulative risk of false positive recall and women related factors.

SETTING

Population based breast cancer screening programme in Barcelona City (Spain).

PARTICIPANTS

8502 women aged 50-69 years who participated in four consecutive screening rounds. Eligible women had received a mammogram in the first screening round between 1 December 1995 and 31 December 1996.

MAIN RESULTS

The false positive recall rate in the first screening for women who entered the screening programme at the age of 50-51 years was assessed at 10.6% (95% CI 8.9, 12.3). In the second screening this risk decreased to 3.8% (95% CI 2.7, 4.9) and remained almost constant in subsequent rounds. After 10 mammograms, the cumulative false positive recall rate was estimated at 32.4% (95% CI 29.7, 35.1). The factors associated with a higher cumulative risk of false positive recall were: previous benign breast disease (OR = 8.48; CI 7.39, 9.73), perimenopausal status (OR = 1.62; CI 1.12, 2.34), body mass index above 27.3 (OR = 1.17; CI 1.02, 1.34), and age 50-54 years (OR = 1.15; CI 1.00, 1.31).

CONCLUSIONS

One third of women could have at least one false positive recall over 10 biennial screens. Women participating in screening programmes should be informed about this risk, especially those with associated factors.

Inducción sanitaria de los cribados: impacto y consecuencias. Aspectos éticos

The main aim of screening is to identify people with an increased probability to benefit from preventive interventions, generally from secondary prevention but also from primary prevention activities. The goal is to facilitate early diagnosis and treatment in order to modify positively the prognosis (the former case), or to recognize people exposed to risk factors which increase the incidence rate of disease, and then to prevent the disease (the latter case). Good intentions are not enough to achieve good results in terms of effectiveness, safety, efficiency or equity. It is necessary to have a systematic assessment of the consequences of screening, particularly on the impact on peoples health and on the health services. Due to the diversity of types of screenings that are done, it is very difficult to estimate the net impact caused by their implementation. Moreover, the changes in the health of a population depend on many factors other than health service interventions. Thus, it is very important to determine the effectiveness and safety of the screening methods that are most frequently applied. Unfortunately, assessment of the benefits and the harm potentially caused by preventive interventions has not been done often. In Spain only a few partial assessments have been published, and they focus on the activities and the processes themselves rather than the final outcomes. Given that screening activities are carried out in health care services, and that the populations screened are mostly healthy people, the ethical issues have great importance when health policies are designed and implemented. Thus, it is recommended that screenings activities be analyzed applying the ethical principles of autonomy, benefit, safety and justice. If any screening program cannot reasonably satisfy these principles then they should be removed from the list of public health activities that are financed by public resources. In the same sense, all screening procedures offered to the population must be subjected to a systematic evaluation of their effectiveness, safety, efficiency and equity in terms of how the procedure would be applied. Lastly, to achieve an effective implementation of the principle of autonomy as well the desired goal of empowering the population to exercise some control over their determinants of health, it is recommended to explore new ways of achieving active citizen participation to establish preventive priorities and to assess the impact of screening interventions.

Performance measures from 10 years of breast screening in the Ontario Breast Screening Program, 1990/91 to 2000

Performance measures for the Ontario Breast Screening Program (OBSP) by age group, time period and screening modality from 10 years of breast screening were evaluated. Data were available from routine information collected on 283,962 women aged 50 to 69 screened at 73 screening centres between 1 July 1990 and 31 December 2000. Although, initially, participation in the OBSP was low, this rate increased over time and the majority of women screened returned for subsequent screening. Abnormal call rates increased slightly over the time period, were higher in women aged 50 to 59, and for women with mammographic abnormalities. Detection rates of invasive cancer were higher and prognostic features of cancers were better for women age 60 to 69, and those referred by mammography. Along with the prognostic features of cancers, the benign to malignant surgical ratio and diagnostic interval improved over the time periods and for women aged 60 to 69. Greater proportions of women had shorter diagnostic intervals and were more likely to have a diagnosis of breast cancer after surgery if they were referred by both clinical breast examination and mammography. Although some enhancements of the programme are necessary, the OBSP met or exceeded Canadian targets for most performance measures.

The influence of mammographic screening on national trends in breast cancer incidence

Introducing an organized mammographic screening programme affects the breast cancer incidence rate in a population. The diagnosis is advanced in time, and initially, an increase will occur in the number of cases, followed by a drop in the rate when women leave the programme. The aim of this study was to quantify the potential effects that mammographic screening programmes have on breast cancer incidence. In addition, we wanted to investigate how the incidence of breast cancer varies between different birth cohorts, age groups and time periods in the five Nordic countries Finland, Denmark, Iceland, Norway and Sweden, adjusting for the effects of the screening programmes. Time trends were analysed over the period 1978-1997, using age-period-cohort models. In Sweden, the rates more than doubled (relative risk (RR)=2.20, 95% confidence interval (CI) 1.8-2.6) in women offered screening for the first time compared with women not offered screening. The risk remained elevated (RR=1.34, 95% CI 1.2-1.6) for women who were continued to be offered screening, compared with women who were not offered screening. Finally, the rates dropped (RR=0.68, 95% CI 0.6-0.8) when the women left the programme. This indicates that screening advances the time of diagnosis, which is a prerequisite to subsequent reduction in mortality. Analysis of secular trends, corrected for the influence of screening, showed that the rates in Finland increased by 13% per 5-year period, with a more modest increase in the other countries. There were strong cohort effects in all Nordic countries, and the risk seemed to be flattening for the youngest cohorts in most of the countries.

Effect of Recall Rate on Earlier Screen Detection of Breast Cancers Based on the Dutch Performance Indicators

BACKGROUND

The recall rate (i.e., the rate at which mammographically screened women are recalled for additional assessment) in the Dutch breast screening program (0.89% in 2000 for subsequent examinations) is the lowest worldwide, with possible consequences including higher rates of late-detected (i.e., "missed") interval and screen-detected cancers. To estimate the effect of changes in recall rate on earlier detection of cancers, we carried out a blinded review of interval and screen-detected cancers in the Dutch screening program.

METHODS

A total of 495 sets of screen-negative mammograms (prediagnostic mammogram and the immediate previous mammogram) were collected from women participating in the biennial Dutch screening program. Of these, 250 were from control subjects, and 245 were from women who were subsequently diagnosed with breast cancer (123 interval and 122 screen-detected cancers). These mammograms were read by 15 radiologists who specialize in screening mammography and were blinded to outcome. Mean detection sensitivities for different false-positive rates were calculated using a linear mixed model. These results were used to calculate the effect of recall rate adjustment on earlier detection of cancers and numbers of false-positives.

RESULTS

Increasing the recall rate to 2.0% would increase the detection rate from 4.20 per thousand to 4.52 per thousand due to the earlier detection of interval cancers. Moreover, 0.54 per thousand of the screen-detected cancers would be detected 2 years earlier (late screen-detected cancers). At recall rates of 3.0% and 4.0% the detection rate would increase to 4.58 per thousand and 4.63 per thousand, respectively, and 0.64 per thousand and 0.72 per thousand, respectively, of the screen-detected cancers would be detected 2 years earlier. For each 1.0% incremental increase in recall rate above 5.0%, the detection rate would increase by approximately 0.03 per thousand, with positive predictive values decreasing to below 10%.

CONCLUSION

Breast cancer can be detected earlier by lowering the threshold for recall, especially for recall rates of 1%-4%. With further recall rate increases, cancer detection levels off with a disproportionate increase of false-positive rates.

Comparison of early performance indicators for screening projects within the European Breast Cancer Network: 1989–2000

In 1989 the European Breast Cancer Network (EBCN) was established by the first pilot projects for breast cancer screening, co-funded by the Europe Against Cancer programme. We report early performance indicators for these EBCN projects while taking into account their organizational setting. Out of 17 projects in the network, 10 projects from six European countries contributed aggregated data on number of invitations, screening examinations, and breast cancers detected over the period 1989-2000. Results were summarized separately for projects in centralized versus decentralized health care environments. The European Guidelines for quality assurance in mammography screening provided reference values for the performance indicators. The most prominent finding in this study was the higher participation rate in centralized versus decentralized projects (average participation in 1998: 74 versus 33%; P<0.001), whereas the invitation system and screening policy in these projects were similar. Detection rates and characteristics of cancers detected at initial and subsequent screening examinations showed no significant differences between centralized and decentralized projects. Even though early performance indicators for centralized versus decentralized projects were similar, the impact of breast screening on mortality from this disease at the population level will differ since the decentralized projects reach only part of the target population.

Association between mammography timing and measures of screening performance in the United States

PURPOSE

To evaluate whether there is an association between the number of months since previous mammography (MSPM) and performance measures (sensitivity, specificity, recall rate, cancer detection rate, and positive predictive value) in women who underwent U.S. community-based screening mammography.

MATERIALS AND METHODS

Data from seven registries (Breast Cancer Surveillance Consortium) and mammographic data and cancer outcome in regard to 1 213 754 screening mammographic examinations performed in 680 641 women who were 40-89 years old for the years 1996-2000 were used in this study. These data are submitted annually in a standard format to a central statistical coordinating center that is subject to institutional review board approval, quality control, and confidentiality standards. Performance measures were calculated for first and subsequent screening mammography. For subsequent mammography, performance measures were calculated according to categories of MSPM (9-15, 16-20, 21-27, and >/=28 months). Receiver operating characteristic and multivariable logistic regression analyses were conducted to test the association between the number of MSPM and performance measures.

RESULTS

With increasing MSPM in each category from 9-15 to 28 months or more and for first mammographic examinations, respectively, there was increased sensitivity (70.9%, 75.7%, 85.4%, 82.5%, and 88.6%), decreased specificity (93.3%, 92.7%, 91.6%, 91.0%, and 85.9%), increased recall rate (7.0%, 7.6%, 8.8%, 9.4%, and 14.7%), and increased cancer detection rates (3.2, 3.5, 4.5, 4.6, and 6.1 per 1000 mammographic examinations). When the category of 9-15 MSPM was compared with that of 21-27 MSPM, there was a slight increase in positive predictive value from 4.6% to 5.1%. Confidence intervals were narrow and did not overlap. Age affected these associations for all performance measures except sensitivity.

CONCLUSION

Performance measures increased as MSPM increased, except for specificity, which decreased. Time between mammograms is an important factor to consider when audits are reviewed or screening performance measures are compared.

Do nonattenders in mammography screening programmes seek mammography elsewhere?

The objectives of our study were to analyse the use of diagnostic mammography among nonattenders and attenders in organised mammography screening in Denmark in 2000, to assess the contamination from organised screening of noninvited age groups and to measure the impact of local policy on opportunistic screening. Data on all diagnostic mammographies performed in Denmark in 2000 and data on women targeted by the 2 organised mammography screening programmes in Copenhagen and the county of Fyn were collected. All data were linked by the Danish personal identification number. Information on the official policy in 2000 with regard to opportunistic screening was collected from all counties. The proportion of women using diagnostic mammography was only 1-3% for both attenders and nonattenders in organised mammography screening, but it was significantly higher in Copenhagen than in Fyn, due to availability of mammography in private clinics. The proportion of women using diagnostic mammography varied from 1-4% across counties. The official policy on access to diagnostic mammography and contamination from organised mammography screening of adjacent age groups had no impact on the use. Instead, urbanisation was positively correlated with use of diagnostic mammography. In conclusion, our results clearly showed that nonattenders in organised mammography screening programmes do not seek mammography outside the programme. Since a positive policy toward opportunistic screening did not have any effect, our results add further evidence to existing knowledge that the only reasonable way to achieve high mammography coverage is through a well-organised screening programme.