M.J.M. Broeders

Decreased rates of advanced breast cancer due to mammography screening in The Netherlands.

The effect of the implementation of the Dutch breast cancer screening programme during 1990–1997 on the incidence rates of breast cancer, particularly advanced breast cancer, was analysed according to stage at diagnosis in seven regions, where no screening took place before 1990. The Netherlands Cancer Registry provided detailed data on breast cancer incidence in 1989–1997 by tumour stage, age and region. Annual age-adjusted incidence rates of all breast cancers and advanced cancers, defined as large tumours T2+ with lymph node and/or distant metastases, were compared with rates in 1989. In general, breast cancer incidence rose strongly in the early 1990s, especially in the age category 50–69 years (estimated annual percentage change (EAPC) 4.25; 95% CI 1.70, 6.86). The increase was mainly due to the increase in small T1 cancers and ductal carcinoma in situ. However, in women aged 50–69, advanced cancer incidence rates showed a significant decline by 12.1% in 1997 compared with 1989 (EAPC –2.14, 95% CI −3.47, −0.80), followed by a breast cancer mortality reduction of similar size after approximately 2 years. We confirm that breast cancer screening initially leads to a temporary strong increase in the breast cancer incidence, which is followed by a significant decrease in advanced diseases in the women invited for screening. It is evident that breast cancer screening contributes to a reduction in advanced breast cancers and breast cancer mortality.

Increasingly strong reduction in breast cancer mortality due to screening

Background:Favourable outcomes of breast cancer screening trials in the 1970s and 1980s resulted in the launch of population-based service screening programmes in many Western countries. We investigated whether improvements in mammography and treatment modalities have had an influence on the effectiveness of breast cancer screening from 1975 to 2008.Methods:In Nijmegen, the Netherlands, 55u2009529 women received an invitation for screening between 1975 and 2008. We designed a case–referent study to evaluate the impact of mammographic screening on breast cancer mortality over time from 1975 to 2008. A total number of 282 breast cancer deaths were identified, and 1410 referents aged 50–69 were sampled from the population invited for screening. We estimated the effectiveness by calculating the odds ratio (OR) indicating the breast cancer death rate for screened vs unscreened women.Results:The breast cancer death rate in the screened group over the complete period was 35% lower than in the unscreened group (OR=0.65; 95% CI=0.49–0.87). Analysis by calendar year showed an increasing effectiveness from a 28% reduction in breast cancer mortality in the period 1975–1991 (OR=0.72; 95% CI=0.47–1.09) to 65% in the period 1992–2008 (OR=0.35; 95% CI=0.19–0.64).Conclusion:Our results show an increasingly strong reduction in breast cancer mortality over time because of mammographic screening.

Interval cancers in the Dutch breast cancer screening programme.

The nationwide breast cancer screening programme in The Netherlands for women aged 50–69 started in 1989. In our study we assessed the occurrence and stage distribution of interval cancers in women screened during 1990–1993. Records of 0.84 million screened women were linked to the regional cancer registries yielding a follow-up of at least 2.5 years. Age-adjusted incidence rates and relative (proportionate) incidences per tumour size including ductal carcinoma in-situ were calculated for screen-detected and interval cancers, and cancers in not (yet) screened women, comparing them with published data from the UK regions North West and East Anglia. In total 1527 interval cancers were identified: 0.95 and 0.99 per 1000 woman-years of follow-up in the 2-year interval after initial and subsequent screens respectively. In the first year after initial screening interval cancers amounted to 27% (26% after subsequent screens) of underlying incidence, and in the second year to 52% (55%). Generally, interval cancers had a more favourable tumour size distribution than breast cancer in not (yet) screened women. The Dutch programme detected relatively less (favourable) invasive cancers in initial screens than the UK programme, whereas the number of interval cancers confirms UK findings. Measures should be considered to improve the detection of small invasive cancers and to reduce false-negative rates, even if this will lead to increasing referral rates.

Impressive time-related influence of the Dutch screening programme on breast cancer incidence and mortality, 1975-2006.

The aim of this study was to assess changes in the trends in breast cancer mortality and incidence from 1975 to 2006 among Dutch women, in relation to the implementation of the national breast cancer screening programme. Screening started in 1989 for women aged 50–69 and was extended to women aged 70–75 years in 1998 (attendance rate approximately >80%). A joinpoint Poisson regression analysis was used to identify significant changes in rates over time. Breast cancer mortality rates increased until 1994 (age group 35–84), but thereafter showed a marked decline of 2.3–2.8% per annum for the age groups 55–64 and 65–74 years, respectively. For the age group of 75–84 years, a decrease started in the year 2001. In women aged 45–54, an early decline in breast cancer mortality rates was noted (1971–1980), which is ongoing from 1992. For all ages, breast cancer incidence rates showed an increase between 1989 and 1993, mainly caused by the age group 50–69, and thereafter, a moderate increase caused by age group 70–74 years. This increase can partly be explained by the introduction of screening. The results indicate an impressive decrease in breast cancer mortality in the age group invited for breast cancer screening, starting to show quite soon after implementation.

Mammographic compression after breast conserving therapy: Controlling pressure instead of force

PURPOSEnX-ray mammography is the primary tool for early detection of breast cancer and for follow-up after breast conserving therapy (BCT). BCT-treated breasts are smaller, less elastic, and more sensitive to pain. Instead of the current force-controlled approach of applying the same force to each breast, pressure-controlled protocols aim to improve standardization in terms of physiology by taking breast contact area and inelasticity into account. The purpose of this study is to estimate the potential for pressure protocols to reduce discomfort and pain, particularly the number of severe pain complaints for BCT-treated breasts.nnnMETHODSnA prospective observational study including 58 women having one BCT-treated breast and one untreated nonsymptomatic breast, following our hospitals 18 decanewton (daN) compression protocol was performed. Breast thickness, applied force, contact area, mean pressure, breast volume, and inelasticity (mean E-modulus) were statistically compared between the within-women breast pairs, and data were used as predictors for severe pain, i.e., scores 7 and higher on an 11-point Numerical Rating Scale. Curve-fitting models were used to estimate how pressure-controlled protocols affect breast thickness, compression force, and pain experience.nnnRESULTSnBCT-treated breasts had on average 27% smaller contact areas, 30% lower elasticity, and 30% higher pain scores than untreated breasts (all p < 0.001). Contact area was the strongest predictor for severe pain (p < 0.01). Since BCT-treatment is associated with an average 0.36 dm(2) decrease in contact area, as well as increased pain sensitivity, BCT-breasts had on average 5.3 times higher odds for severe pain than untreated breasts. Model estimations for a pressure-controlled protocol with a 10 kPa target pressure, which is below normal arterial pressure, suggest an average 26% (range 10%-36%) reduction in pain score, and an average 77% (range 46%-95%) reduction of the odds for severe pain. The estimated increase in thickness is +6.4% for BCT breasts.nnnCONCLUSIONSnAfter BCT, women have hardly any choice in avoiding an annual follow-up mammogram. Model estimations show that a 10 kPa pressure-controlled protocol has the potential to reduce pain and severe pain particularly for these women. The results highly motivate conducting further research in larger subject groups.

Life expectancy of screen-detected invasive breast cancer patients compared with women invited to the Nijmegen Screening Program

Screening can lead to earlier detection of breast cancer and thus to an improvement in survival. The authors studied the life expectancy of women with screen‐detected invasive breast cancer (patients) compared with women invited to the breast cancer screening program in Nijmegen, the Netherlands (comparison group).

Immediate and delayed effects of mammographic screening on breast cancer mortality and incidence in birth cohorts

Background:Trend studies investigating the impact of mammographic screening usually display age-specific mortality and incidence rates over time, resulting in an underestimate of the benefit of screening, that is, mortality reduction, and an overestimate of its major harmful effect, that is, overdiagnosis. This study proposes a more appropriate way of analysing trends.Methods:Breast cancer mortality (1950–2009) and incidence data (1975–2009) were obtained from Statistics Netherlands, ‘Stg. Medische registratie’ and the National Cancer Registry in the Netherlands for women aged 25–85 years. Data were visualised in age–birth cohort and age–period figures.Results:Birth cohorts invited to participate in the mammographic screening programme showed a deflection in the breast cancer mortality rates within the first 5 years after invitation. Thereafter, the mortality rate increased, although less rapidly than in uninvited birth cohorts. Furthermore, invited birth cohorts showed a sharp increase in invasive breast cancer incidence rate during the first 5 years of invitation, followed by a moderate increase during the following screening years and a decline after passing the upper age limit.Conclusion:When applying a trend study to estimate the impact of mammographic screening, we recommend using a birth cohort approach.

Variations in screening outcome among pairs of screening radiologists at non-blinded double reading of screening mammograms: a population-based study

ObjectivesSubstantial inter-observer variability in screening mammography interpretation has been reported at single reading. However, screening results of pairs of screening radiologists have not yet been published. We determined variations in screening performances among pairs of screening radiologists at non-blinded double reading.MethodsWe included pairs of screening radiologists with at least 7,500 screening examinations per pair, obtained between 1997 and 2011. During 2-year follow-up, breast imaging reports, surgical reports and pathology results were collected of all referred women and interval cancers. Referral rate, cancer detection rate, positive predictive value and sensitivity were calculated for each pair.ResultsA total of 310,906 screening mammograms, read by 26 pairs of screening radiologists, were included for analysis. The referral rate ranged from 1.0xa0% (95xa0% CI 0.8xa0%–1.2xa0%) to 1.5xa0% (95xa0% CI 1.3xa0%–1.8xa0%), the cancer detection rate from 4.0 (95xa0% CI 2.8–5.2) to 6.3 (95xa0% CI 4.5–8.0) per 1,000 screens. The programme sensitivity and positive predictive value of referral ranged from 55.1xa0% (95xa0% CI 45.1xa0%–65.1xa0%) to 81.5xa0% (95xa0% CI 73.4xa0%–89.6xa0%) and from 28.7xa0% (95xa0% CI 20.8xa0%–36.6xa0%) to 49.5xa0% (95xa0% CI 39.7xa0%–59.3xa0%), respectively.ConclusionWe found significant variations in screening outcomes among pairs of screening radiologists at non-blinded double reading. This stresses the importance of monitoring screening results on a local scale.Key Points• Substantial inter-observer variability in screening mammography interpretation is known at single reading• Population-based study showed significant variations in outcomes among pairs of screening radiologists• Local monitoring and regular feedback are important to optimise screening outcome

The potential use of ultra-low radiation dose images in digital mammography—a clinical proof-of-concept study in craniocaudal views

OBJECTIVEnTo estimate the potential of low-dose images in digital mammography by analysing the effect of substantial dose reduction in craniocaudal (CC) views on clinical performance.nnnMETHODSnAt routine mammography, additional CC views were obtained with about 10% of the standard dose. Five radiologists retrospectively read the standard [mediolateral oblique (MLO)u2009+u2009CC] and combination low-dose mammograms (standard MLOu2009+u2009low-dose CC). If present, lesion type, conspicuity and suggested work-up were recorded. Final diagnoses were made by histology or follow up. A t-test or χ(2) test was used to compare results.nnnRESULTSn421 cases were included, presenting 5 malignancies, 66 benign lesions and multiple non-specific radiologic features. Using MLO with low-dose CC, all lesions were detected by at least one reader, but altogether less often than with standard mammography (sensitivity, 73.9% vs 81.5%). Missed lesions concerned all types. Lesions detected with both protocols were described similarly (pu2009=u20090.084) with comparable work-up recommendations (pu2009=u20090.658).nnnCONCLUSIONnMammography with ultra-low-dose CC images particularly influences detection. While sensitivity decreased, specificity was unaffected. In this proof-of-concept study a lower limit was to be determined that is not intended nor applicable for clinical practice. This should facilitate further research in optimization of a low-dose approach, which has potential in a relatively young and largely asymptomatic population.nnnADVANCES IN KNOWLEDGEnTungsten/silver-acquired mammography images might facilitate substantial dose reduction. Ultra-low-dose CC images reduce sensitivity, but not specificity. Low-dose images have potential in a largely young and asymptomatic population; a baseline is set for further research in optimization of a low-dose approach.

Women's decision-making regarding risk-stratified breast cancer screening and prevention from the perspective of international healthcare professionals

Introduction Increased knowledge of breast cancer risk factors may enable a paradigm shift from one-size-fits-all breast cancer screening to screening and subsequent prevention guided by a woman’s individual risk of breast cancer. Professionals will play a key role in informing women about this new personalised screening and prevention programme. Therefore, it is essential to explore professionals’ views of the acceptability of this new programme, since this may affect shared decision-making. Methods Professionals from three European countries (the Netherlands, United Kingdom, and Sweden) participated in digital concept mapping, a systematic mixed methods approach used to explore complex multidimensional constructs. Results Across the three countries, professionals prioritised the following five themes which may impact decision-making from the perspective of eligible women: (1) Anxiety/worry; (2) Proactive approach; (3) Reassurance; (4) Lack of knowledge; and (5) Organisation of risk assessment and feedback. Furthermore, Dutch and British professionals expressed concerns regarding the acceptability of a heterogeneous screening policy, suggesting women will question their risk feedback and assigned pathway of care. Swedish professionals emphasised the potential impact of the programme on family relations. Conclusions The perspectives of Dutch, British, and Swedish professionals of women’s decision-making regarding personalised breast cancer screening and prevention generally appear in line with women’s own views of acceptability as previously reported. This will facilitate shared decision-making. However, concerns regarding potential consequences of this new programme for screening outcomes and organisation need to be addressed, since this may affect how professionals communicate the programme to eligible women.