Population-based Mammography Screening Research Articles

Automated Breast Ultrasound With Remote Reading for Primary Breast Cancer Screening: A Prospective Study Involving 46 Community Health Centers in China.

Background: China has faced barriers to implementation of a population-based mammographic screening program. Breast ultrasound provides an alternative screening modality to mammography in low-resource settings. Objective: To evaluate the performance of ABUS with remote reading as the primary screening modality for breast cancer. Methods: This prospective study enrolled asymptomatic women 35-69 years old from 46 community health centers across 18 provinces representing all six regions of China from January 2021 to December 2021. Participants underwent screening ABUS as the sole breast cancer screening modality, with images acquired by a technologist at the community health center. The 3D volumetric data were transferred via cloud-based software to a single remote reading center, where examinations were interpreted independently in batches by two subspecialized breast radiologists using BI-RADS; a third radiologist at the remote reader center resolved discrepancies. Diagnostic reports were returned to the community centers, and patients sought follow-up care at local hospitals. The reference standard incorporated a combination of histopathology and 24-month follow-up. Outcomes measures included cancer detection rate, abnormal interpretation rate (AIR), sensitivity, specificity, biopsy rate, and PPV. Results: The final analysis included 5978 enrolled participants (median age, 46 years [IQR 40-52 years]) who underwent screening ABUS at the community health centers with subsequent remote reading. A total of 24 ABUS-detected cancers and two interval cancers were diagnosed. The cancer detection rate was 4.0 per 1000 women (95% CI: 2.7-5.9), and the AIR was 11.9% (95% CI: 11.1-12.7). A total of 95.8% (23/24) of ABUS-detected cancers were invasive. The 23 invasive cancers had a median diameter of 10.0 mm; 73.9% (17/23) were node-negative. Sensitivity was 92.3% (95% CI: 75.9-97.9), and specificity was 88.4% (95% CI: 87.6-89.2). The biopsy rate was 1.7% (95% CI: 1.4-2.0), and the PPV of biopsy was 24.0% (95% CI: 16.7-33.2). Conclusion: ABUS screening with remote reading met benchmark performance for cancer detection in comparison to mammography, with infrequent interval cancers. Clinical Impact: ABUS with remote reading holds promise in enhancing access to breast cancer screening and early detection in low-resource settings or underserved regions where mammographic screening is not established.

Introduction of one-view tomosynthesis in population-based mammography screening: Impact on detection rate, interval cancer rate and false-positive rate.

To assess performance endpoints of a combination of digital breast tomosynthesis (DBT) and full-field digital mammography (FFDM) compared with FFDM only in breast cancer screening. This was a prospective population-based screening study, including eligible (50-69 years) women attending the Capital Region Mammography Screening Program in Denmark. All attending women were offered FFDM. A subgroup was consecutively allocated to a screening room with DBT. All FFDM and DBT underwent independent double reading, and all women were followed up for 2 years after screening date or until next screening date, whichever came first. 6353 DBT + FFDM and 395 835 FFDM were included in the analysis and were undertaken in 196 267 women in the period from 1 November 2012 to 12 December 2018. Addition of DBT increased sensitivity: 89.9% (95% confidence interval (CI): 81.0-95.5) for DBT + FFDM and 70.1% (95% CI: 68.6-71.6) for FFDM only, p < 0.001. Specificity remained similar: 98.2% (95% CI: 97.9-98.5) for DBT + FFDM and 98.3% (95% CI: 98.2-98.3) for FFDM only, p = 0.9. Screen-detected cancer rate increased statistically significantly: 11.18/1000 for DBT + FFDM and 6.49/1000 for FFDM only, p < 0.001. False-positive rate was unchanged: 1.75% for DBT + FFDM and 1.73% for FFDM only, p = 0.9. Positive predictive value for recall was 39.0% (95% CI: 31.9-46.5) for DBT + FFDM and 27.3% (95% CI: 26.4-28.2), for FFDM only, p < 0.0005. The interval cancer rate decreased: 1.26/1000 for DBT + FFDM and 2.76/1000 for FFDM only, p = 0.02. DBT + FFDM yielded a statistically significant increase in cancer detection and program sensitivity.

Age-specific differences in breast cancer treatment between screen-detected and non-screen-detected breast cancers in women aged 40-74 years at diagnosis in Sweden 2008-2017.

We have recently demonstrated that screen-detected invasive breast cancers had more favourable tumour characteristics than non-screen-detected. The objective of the study was to analyse differences in breast cancer treatment between screen-detected and non-screen-detected cases by age at diagnosis, with and without adjustment for tumour (T) and nodal (N) status, within a nationwide, population-based mammography screening programme utilising register data. Data spanning 2008-2017 were collected from the National Quality Register for Breast Cancer. Multivariable logistic regression analysis was used to estimate odds ratios and 95% confidence intervals for treatment disparities between screen-detected and non-screen-detected breast cancer. Among 46,481 women diagnosed with invasive breast cancer aged 40-74 and invited for mammography screening, significant differences in treatment were observed. Screen-detected cases showed higher likelihoods of partial mastectomy compared to mastectomy, endocrine therapy, and radiotherapy, whereas chemotherapy and antibody therapy were less likely compared to non-screen-detected cases. However, when adjusting for surgery type, screen-detected cases showed lower likelihoods of radiotherapy. Age at diagnosis significantly influenced treatment odds ratios, with interactions observed for all treatments except radiotherapy adjusted for surgery. Differences increased with age, except for endocrine therapy. Radiotherapy adjusted for surgery type showed no age-related interaction. Adjusting for T and N did not alter these patterns. In general, screen-detected cases received less aggressive treatment, such as mastectomy, chemotherapy, and antibody therapy, compared to non-screen-detected cases. Disparities increased with age, except for endocrine therapy and radiotherapy adjusted for surgery. Differences persisted after adjusting for T and N, suggesting that these factors cannot solely explain the results.

Early Indicators of the Impact of Using AI in Mammography Screening for Breast Cancer.

Background Retrospective studies have suggested that using artificial intelligence (AI) may decrease the workload of radiologists while preserving mammography screening performance. Purpose To compare workload and screening performance for two cohorts of women who underwent screening before and after AI system implementation. Materials and Methods This retrospective study included 50-69-year-old women who underwent biennial mammography screening in the Capital Region of Denmark. Before AI system implementation (October 1, 2020, to November 17, 2021), all screenings involved double reading. For screenings conducted after AI system implementation (November 18, 2021, to October 17, 2022), likely normal screenings (AI examination score ≤5 before May 3, 2022, or ≤7 on or after May 3, 2022) were single read by one of 19 senior full-time breast radiologists. The remaining screenings were read by two radiologists with AI-assisted decision support. Biopsy and surgical outcomes were retrieved between October 1, 2020, and April 15, 2023, ensuring at least 180 days of follow-up. Screening metrics were compared using the χ2 test. Reading workload reduction was measured as saved screening reads. Results In total, 60 751 and 58 246 women were screened before and after AI system implementation, respectively (median age, 58 years [IQR, 54-64 years] for both cohorts), with a median screening interval before AI of 845 days (IQR, 820-878 days) and with AI of 993 days (IQR, 968-1013 days; P < .001). After AI system implementation, the recall rate decreased by 20.5% (3.09% before AI [1875 of 60 751] vs 2.46% with AI [1430 of 58 246]; P < .001), the cancer detection rate increased (0.70% [423 of 60 751] vs 0.82% [480 of 58 246]; P = .01), the false-positive rate decreased (2.39% [1452 of 60 751] vs 1.63% [950 of 58 246]; P < .001), the positive predictive value increased (22.6% [423 of 1875] vs 33.6% [480 of 1430]; P < .001), the rate of small cancers (≤1 cm) increased (36.6% [127 of 347] vs 44.9% [164 of 365]; P = .02), the rate of node-negative cancers was unchanged (76.7% [253 of 330] vs 77.8% [273 of 351]; P = .73), and the rate of invasive cancers decreased (84.9% [359 of 423] vs 79.6% [382 of 480]; P = .04). The reading workload was reduced by 33.5% (38 977 of 116 492 reads). Conclusion In a population-based mammography screening program, using AI reduced the overall workload of breast radiologists while improving screening performance. Published under a CC BY 4.0 license. Supplemental material is available for this article. See also the editorial by Lee and Friedewald in this issue.

Abstract PO5-07-12: Feasibility of organized population-based mass-level mammography screening (0.2 million women) –Report from LMIC-Uzbekistan

Abstract Background. Breast cancer is one of the leading diseases worldwide. The early detection of breast cancer is the best way to improve survival. Mammography is included in the standard guidelines of all the leading organizations. The procedure is technically demanding and cost sensitive. Despite being a standard, it is not practical in many countries, and more so in LMIC. The state of Uzbekistan embarked on a massive, unique, organized population-based program of mass-level mammography screening, starting from one region of the country and expanding to others. Here, we report the process of such establishment and the feasibility of this innovative model. Methods. Realizing the importance of breast cancer screening, the Republic of Uzbekistan initiated a pilot project in the Bukhara Region. The area is divided into 12 districts. Every district was equipped with a stationary mammography machine in a regional polyclinic and one mobile van. The personnel were appropriately trained and a selection process was established to invite women for screening. The invitation was sent using the local area's existing municipality residential directory, which contains the complete demographic details of every individual living in the area. The state has 100 % coverage in the registry. The study targeted every woman aged 45-65 starting May 2021. All mammographs were digitally recorded and sent in real time to a centralized server at the National Republican Cancer Center in Tashkent, Uzbekistan. Reporting is performed at a centralized reading center on the information system platform. The program envisages a complete care pathway, from screening to diagnosis and treatment. Results. Over a period of two years, 140506 women in the age range–45-65 underwent mammography screening. Depending on the size of the target group of the district, an average of 30-60 mammograms were performed per day. A reported preliminary analysis shows the presence of BIRADS 0 in 4495, BIRADS 1 IN 78634, BIRADS 2 in 64345, BIRADS 4 in 4998, BIRADS 5 in 893. All women with BIRADS 4 and 5 were referred to the regional comprehensive cancer center for further evaluation. A total of 7570 patients underwent cytology and 408 underwent core biopsy. Depending on the reports, the patients were appropriately managed. A total of 1885 patients were recalled for additional screening owing to their inappropriate quality. After a year of function, the project was expanded with “Mobile Vans” to other regions of the country. An additional 13 mobile mammography vans were added after 1.5 years. From January 2023, approximately 50000 mammograms were additionally performed, taking the total number of screened women to 190506. Conclusion. Thus, it is feasible to plan and successfully implement state-owned mass-level mammography screenings. This project has the potential for duplication in any part of the world, and other organizations can learn from this extensive, wide program. Citation Format: Mirzagaleb Tillyashaykhov, Aysulu Seytmuratova, Alexander Ososkov, Saide Djanklich, Yakhyo Ziyaev, Dinesh Pendharlkar. Feasibility of organized population-based mass-level mammography screening (0.2 million women) –Report from LMIC-Uzbekistan [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-07-12.

Structured screening for sporadic breast cancer

The aim of secondary prevention of breast cancer is to detect the disease at the earliest curable stage and thus to reduce breast cancer-specific mortality. To this end, the nationwide population-based mammography screening program (MSP) was set up in Germany in 2005 in addition to an interdisciplinary prevention project for high-risk groups. Overview of the current state of the MSP, the upcoming age expansion, and potential further developments. Narrative review article with topic-guided literature and data search. Approximately 50% of the 70,500 new cases of breast cancer that occur each year are related to the age group of the MSP. 10years after introduction of the MSP, the incidence of advanced breast cancer stages and breast cancer-related mortality of the screening target group have steadily decreased by about one quarter, while no relevant trends were seen in the neighboring age groups at the population level. The MSP has effectively contributed to areduction of breast cancer mortality. With the expansion of the age groups to 45-75years, more women have access to structured, quality assured screening. With the use of advanced stratifications and diagnostics as well as artificial intelligence, the MSP could be further optimized.

Age-specific differences in tumour characteristics between screen-detected and non-screen-detected breast cancers in women aged 40-74 at diagnosis in Sweden from 2008 to 2017.

To analyze differences between screen-detected and non-screen-detected invasive breast cancers by tumour characteristics and age at diagnosis in the nationwide population-based mammography screening program in Sweden. Data were retrieved from the National Quality Register for Breast Cancer for 2008-2017. Logistic regression analysis was used to estimate the likelihood for a tumour to be screen-detected by tumour characteristics and age group at diagnosis. In total there were 51,429 invasive breast cancers in the target age group for mammography screening of 40-74 years. Likelihood of screen detection decreased with larger tumour size, lymph node metastases, higher histological grade and distant metastasis. Odds ratios (ORs) for negative oestrogen (ER) and progesterone (PgR) were 0.41 and 0.57; for positive HER2, 0.62; for Ki-67 high versus low, 0.49. Molecular sub-types had OR of 0.56, 0.40 and 0.28, respectively, for luminal B-like, HER2-positive and triple negative versus luminal A-like. Adjusting for tumour size (T), lymph node status (N), age, year and county at diagnosis slightly elevated the ORs. Statistically significant interactions between tumour characteristics and age were found (p < 0.05) except for ER and PgR. The age group 40-49 deviated most from the other age groups. Our study demonstrates that screen-detected invasive breast cancers had more favourable tumour characteristics than non-screen-detected after adjusting for age, year and county of diagnosis, and even after adjusting for T and N. The trend towards favourable tumour characteristics was less pronounced in the 40-49 age group compared to the other age groups, except for ER and PgR.

Rethinking screening mammography in Japan: next-generation breast cancer screening through breast awareness and supplemental ultrasonography.

Breast cancer mortality has not been reduced in Japan despite more than 20years of population-based screening mammography. Screening mammography might not be suitable for Japanese women who often have dense breasts, thus decreasing mammography sensitivity because of masking. The J-START study showed that breast ultrasonography increases the sensitivity and the detection rate for early invasive cancers and lowers the rate of interval cancers for Japanese women in their 40s. Breast awareness and breast cancer survival are directly correlated; however, breast awareness is not widely known in Japan. Next-generation breast cancer screening in Japan should consist of breast awareness campaigns for improving breast cancer literacy and supplemental breast ultrasonography to address the problem of false-negative mammograms attributable to dense breasts.

Prevalence of women with breast implants in Sweden: a study based on the population-based mammography screening programme.

Knowledge about the prevalence of women with breast implants is paramount in calculations of risks and in estimations of effects on screening and breast cancer treatment. Most of the estimations of prevalence made to date are rough and often based on sales data. The main aim of this study was to calculate the prevalence of breast implants in Swedish women. The secondary aim was to investigate if it is feasible to establish the occurrence of breast implants with the help of the public mammography screening programme, in a country with a publicly funded welfare-type healthcare system and with a clear documentation of screening. Information on implants was prospectively collected from all screening attendants from 1st of February 2022 to 1st of August 2022 based on a question from the radiographer to the woman and later verified on the mammogram. During the study period 4,639 women were screened, of which 182 had implants (3.9%). The frequency varies between 1.6 and 6.4% in different age groups. The prevalence of breast implants in Swedish women is estimated to be around 4%. The population-based mammography screening programme in countries with a publicly funded welfare-type healthcare system and a clear documentation of mammography screening attendance, seems to be a feasible way to establish the prevalence of breast implants in the population. The large number of women with breast implants warrants further studies regarding the best diagnostic and treatment alternatives for this group. Pre-registration: ClinicalTrials.Gov identifier NCT05222100.

The effect of a pre-scheduled appointment on attendance in a population-based mammography screening programme.

Pre-scheduled appointments can increase attendance in breast cancer screening programmes compared to 'open invitations' but relatively few randomized controlled trials exist. We investigated the effect of a pre-scheduled appointment on uptake in the Flemish population-based mammography screening programme. Between September and December 2022, a total of 4798 women were randomly assigned to receive either a pre-scheduled appointment or open invitation. The difference in attendance was compared with Poisson regression analysis for the primary endpoint (attendance ≤92 days after date of invitation), yielding relative risks (RRs). This was done separately for three groups: women invited to a mobile unit and a history of nonattendance (group M-NA); women invited to a hospital-based unit and a history of nonattendance (group HB-NA); women invited to a hospital-based unit and a history of irregular attendance (group HB-IA). There were no women invited to a mobile unit and a history of irregular attendance. The RRs in favour of the pre-scheduled appointment were 2.3 [95% confidence interval (CI) 1.80-2.88], 1.8 (95% CI 1.07-2.97) and 1.8 (95% CI 1.43-2.39), for groups M-NA, HB-NA and HB-IA, respectively. We found no statistically significant difference between the various RRs. The respective absolute gains in attendance between pre-scheduled appointment and open invitation were 8.3%, 4.4% and 15.8%. Sending an invitation with a pre-scheduled appointment is an effective tool to increase screening attendance in both mobile and hospital-based screening units. The pre-scheduled appointment is associated with a considerable absolute gain in attendance which varies depending on the screening history.

Overcoming the limitations of screening mammography in Japan and Korea: a paradigm shift to personalized breast cancer screening based on ultrasonography.

Screening mammography programs have been implemented in numerous Western countries with the aim of reducing breast cancer mortality. However, despite over 20 years of population-based screening mammography, the mortality rates in Japan and Korea continue to rise. This may be due to the fact that screening mammography is not as effective for Japanese and Korean women, who often have dense breasts. This density decreases the sensitivity of mammography due to a masking effect. Therefore, the early detection of small invasive cancers requires more than just mammography, particularly for women in their 40s. This review discusses the limitations and challenges of screening mammography, as well as the keys to successful population-based breast cancer screening in Japan and Korea. This includes a focus on breast ultrasonography techniques, which are based on histopathologic anatomical knowledge, and personalized screening strategies that are based on risk assessments measured by glandular tissue components.

Screening outcome for interpretation by the first and second reader in a population-based mammographic screening program with independent double reading.

Double reading of screening mammograms is associated with a higher rate of screen-detected cancer than single reading, but different strategies exist regarding reader pairing and blinding. Knowledge about these aspects is important when considering strategies for future use of artificial intelligence in mammographic screening. To investigate screening outcome, histopathological tumor characteristics, and mammographic features stratified by the first and the second reader in a population based screening program for breast cancer. The study sample consisted of data from 3,499,048 screening examinations from 834,691 women performed during 1996-2018 in BreastScreen Norway. All examinations were interpreted independently by two radiologists, 272 in total. We analyzed interpretation score, recall, and cancer detection, as well as histopathological tumor characteristics and mammographic features of the cancers, stratified by the first and second readers. For Reader 1, the rate of positive interpretations was 4.8%, recall 2.3%, and cancer detection 0.5%. The corresponding percentages for Reader 2 were 4.9%, 2.5%, and 0.5% (P < 0.05 compared with Reader 1). No statistical difference was observed for histopathological tumor characteristics or mammographic features when stratified by Readers 1 and 2. Recall and cancer detection were statistically higher and histopathological tumor characteristics less favorable for cases detected after concordant positive compared with discordant interpretations. Despite reaching statistical significance, mainly due to the large study sample, we consider the differences in interpretation scores, recall, and cancer detection between the first and second readers to be clinically negligible. For practical and clinical purposes, double reading in BreastScreen Norway is independent.

The effect of the Flemish breast cancer screening program on breast cancer-specific mortality: A case-referent study

BackgroundBreast cancer screening programs were introduced in many countries worldwide following randomized controlled trials in the 1980s showing a reduction in breast cancer-specific mortality. However, their effectiveness remains debated and estimates vary. A breast cancer screening program was introduced in 2001 in Flanders, Belgium where high levels of opportunistic screening practices are observed. The effectiveness of this program was estimated by measuring its effect on breast cancer-specific mortality. MethodsWe performed a case-referent study to investigate the effect of participation in the Flemish population-based mammography screening program (PMSP) on breast cancer-specific mortality from 2005 to 2017. A multiple logistic regression model assessed the association between breast cancer-specific death and screening program participation status in the four years prior to (pseudo)diagnosis (yes/no), with adjustment for potential confounders (individual socio-economic position and calendar year of diagnosis) and stratified for age. In addition, we performed different sensitivity analyses. ResultsWe identified 1571 cases and randomly selected 6284 referents. After adjustment, women who participated in PMSP had a 51 % lower risk of breast cancer-specific mortality compared to those who did not (adjusted odds ratio [aOR] =0.49, 95 % CI: 0.44–0.55). Sensitivity analyses did not markedly change the estimated associations. Correction for self-selection bias reduced the effect size, but the estimate remained significant. ConclusionOur results indicate that in a context of high opportunistic screening rates, participation in breast cancer screening program substantially reduces breast cancer-specific mortality. For policy, these results should be balanced against the potential harms of screening, including overdiagnosis and overtreatment.

Our experience using synthesized mammography vs full field digital mammography in population-based screening

BackgroundSynthesized Mammogram (SM) from Digital Breast Tomosynthesis (DBT) images is introduced to replace the routine Full Field Digital Mammography (FFDM) to reduce radiation dose. Purposeto compare the conspicuity of cancer related findings between SM and FFDM and combination of these methods with DBT MethodsThe study was conducted in a tertiary breast imaging center, where 200 women referred for screening were enrolled in the study sequentially. Patients underwent FFDM and DBT simultaneously and a two-year follow-up was done. Data was evaluated for Breast Imaging Reporting and Data System (BI-RADS) score, breast density, mass lesions, calcification, and focal asymmetry by two expert breast radiologists. Comparison between different methods was made by Cohen Kappa test. Results22 patients with likely malignant findings went under biopsy. Taking histopathologic findings and two-year follow up as reference, the overall sensitivity and specificity for FFDM+DBT (86.1 and 88.9 respectively) and SM+DBT (86.1 and 88.2) didn’t show a meaningful difference. Comparing SM and FFDM, calcification in 20 subjects were overlooked on SM, but later detected when combined with DBT. Considering breast composition and BI-RADS categorization, an excellent agreement existed between the readers. ConclusionScreening with SM+DBT shows comparable results with FFDM+DBT considering BI-RADS categorization of the patients. Although SM showed slightly inferior sensitivity compared to FFDM, after combining DBT with SM no malignant appearing calcification or mass lesion was missed.

Breast cancer risk predictions by birth cohort and ethnicity in a population-based screening mammography program.

To examine whether birth cohorts affect the risk of breast cancer for East Asian, First Nations, African, South Asian and Caucasian ethnicities in British Columbia (BC). We used Cox PH models adjusted for well-known risk factors, such as age, breast density, mammographic features on false positives, and family history, to examine risk of breast cancer among East Asian, First Nations, African and South Asian ethnicities, relative to Caucasian, across three birth cohorts. There were 813,280 participants and 11,166 in situ and invasive breast cancer diagnoses. East Asians screened in BC were found to have a lower risk of breast cancer in the birth cohort born pre-1946 compared to Caucasian, but there was no statistically significant decrease for East Asians born after 1946. First Nations had an increased risk of breast cancer compared with Caucasian for all birth cohorts ranging from 1.1 to 2.0x the risk, which was statistically significant for those born after 1965. South Asians showed a statistically significant decrease in risk ranging from 0.58 to 0.81x lower compared with Caucasians for all birth cohorts. Risk of breast cancer for South Asians living in BC was found to be lower than Caucasians for each birth cohort examined, while East Asians had a comparable risk of breast cancer, First Nations had a consistently higher risk than Caucasians. When accounting for birth cohort, compared to Caucasians, South Asians have a decreased risk, First Nations have an increased risk, and East Asians have a similar risk of breast cancer.

Isolated ductal carcinoma in situ in patients presenting to two breast units in Johannesburg

BACKGROUND: Ductal carcinoma in situ (DCIS) represents approximately 20% of all new breast cancers in countries with population-based mammography screening. South Africa is an upper middle-income country with no such screening programmes in place, and the proportion of isolated DCIS appears much lower than this. Most patients present with symptomatic disease and high-risk features. There are numerous controversies regarding the diagnosis and optimal management strategy for this premalignant condition, and the issue of overtreatment is much debated. Our study aimed to determine the proportion of patients presenting with isolated DCIS, to describe the clinical presentation and to describe the treatment provided. METHODS: This is a retrospective cohort study of patients with histologically confirmed isolated DCIS at Charlotte Maxeke Johannesburg Academic Hospital and Chris Hani Baragwanath Academic Hospital from July 2015 to March 2018. Records were collected from the existing clinical databases in both breast units and from the South African National Health Laboratory System. RESULTS: Out of 1 813 patients diagnosed and managed with breast malignancies in this period, 58 (3.1%) patients were identified with isolated DCIS. Forty-three (74.1%) of these patients were symptomatic. Thirty-four (58.6%) patients had a primary mastectomy, and 12 (20.6%) had breast-conserving surgery. CONCLUSION: The diagnosis of isolated DCIS is rare in our setting, and the majority of patients present with more advanced, symptomatic disease that is not deemed suitable for breast-conserving surgery. The short-term follow-up of our patients has shown a low rate of recurrence and mortality thus far. However, further long-term follow-up is needed.

Mammographic Breast Density, Benign Breast Disease, and Subsequent Breast Cancer Risk in 3.9 Million Korean Women.

Background Mammographic breast density and benign breast disease are strong risk factors for breast cancer. Accordingly, women with both risk factors may have a markedly high risk for developing breast cancer. Purpose To investigate the risk of breast cancer associated with the combination of mammographic density and benign breast disease in Korean women, where population-based mammographic breast cancer screening is provided for all women aged at least 40 years. Materials and Methods This is a retrospective analysis of data from a nationwide breast cancer screening program linked with the national cancer registry. The study included Korean women between 40-74 years of age screened for breast cancer between January 2009 and December 2010 and observed up to December 2020 (median follow-up of 10.6 years). Benign breast disease and breast density were extracted from mammography screening results. Cox proportional hazard regression analysis was used to calculate adjusted hazard ratios (HRs) for breast cancer risk. Results In this study, 3 911 348 women (mean age, 53 years ± 9 [SD]) were analyzed. During follow-up (median, 10.6 years), 58 321 women developed breast cancer. At screening, 10 729 (18.4%) cases of benign breast disease were detected among women who developed breast cancer. Women with extremely dense breasts (Breast Imaging Reporting and Data System [BI-RADS] density category D) and benign breast disease had a greater risk of breast cancer when compared with women presenting with fatty breast (BI-RADS density category A) and those without benign breast disease (HR, 2.75; 95% CI: 2.63, 2.88; P < .001). Women with benign breast disease and fatty breasts (HR, 1.49; 95% CI: 1.40, 1.58; P < .001) and women with extremely dense breasts and without benign breast disease (HR, 2.28; 95% CI: 2.20, 2.35; P < .001) also had an elevated breast cancer risk compared with women with fatty breast tissue. Conclusion Women with dense breasts and benign breast disease at screening mammography had an elevated risk of future breast cancer. © RSNA, 2022 Online supplemental material is available for this article.

The Fundamental Flaws of the CNBSS Trials: A Scientific Review.

Although the two Canadian National Breast Screening Study (CNBSS) trials were performed 40 years ago, their negative findings continue to heavily influence screening policies around the world. These policies, based on underestimates of the mortality reduction attributable to mammography particularly for women in the 40-49-year age range, contribute to increased mortality and morbidity from breast cancer. This review summarizes principles of a randomized controlled trial (RCT) and evaluates the compliance of the CNBSS1 and CNBSS2 RCTs in the context of these principles. We describe the fundamental flaws of the CNBSS trials, which failed to demonstrate mortality benefit of screening mammography and contribute to their being the only two outlier studies of eight screening mammography RCTs. The most significant flaws of the trials are (1) inadequate power to detect significant differences in breast cancer mortality; (2) very poor quality mammography with low sensitivity and cancer detection rates; (3) inclusion of women with symptoms of breast cancer; and (4) study design that allowed for violation of the randomization of the allocation process. Finally, we demonstrate that the conditions of the screening intervention in the CNBSS do not reflect the environment of modern population-based screening mammography programs.

Current status of breast cancer undetected by mammography in population-based breast cancer screening and associated factors

Objective This study aimed to promote the application of mammography (MMG) screening without performing a clinical breast examination (CBE). It examined population-based screening data, including history taking findings, to elucidate the status of breast cancer cases, detected solely by CBE, and to reveal the factors associated with breast cancer. Through this, it explored alternative methods for evaluating breast cancer cases, undetected by MMG, when CBE is omitted.Methods The linked anonymized data from women, who underwent breast cancer screening in 2014, 2016, or 2017, were prepared. The data were obtained from the Nishinomiya City database. Breast cancer, undetected by MMG, were defined as breast cancer cases diagnosed by close examination based on CBE only (MMG findings were category 2 or lower, with no abnormalities). To assess the quality of breast cancer screening, process indices were calculated for the overall population, and for patients indicated for close examination based on CBE but not MMG. The association of breast cancer with each factor was statistically analyzed (χ2 test, etc.).Results In total, 13,504 women underwent breast cancer screening. Close examination was required in 1,247 women (9.2%). Breast cancer was diagnosed in 44 women (3.5%), including four, who had breast cancer undetected by MMG. All of the process indices satisfied the acceptable values. Three of the four women with breast cancer, undetected by MMG, noticed a lump. Breast cancer was significantly associated with "subjective symptoms". The presence of a "lump" and "nipple discharge" were significantly more common in breast cancer patients.Conclusion Three of the four breast cancer cases, undetected by MMG screening, had a subjective symptom (lump). There was a significant association between subjective symptoms (lump and nipple discharge) and breast cancer. To avoid missing breast cancer, undetected by MMG alone, these symptoms should be especially evaluated in women to compensate for the omission of a CBE. This can be achieved by encouraging women experiencing symptoms to seek consult, performing a thorough history-taking and observation, engaging in multidisciplinary collaboration (communication from medical staff to physicians), and promoting breast awareness.

The impact of breast density notification on rescreening rates within a population-based mammographic screening program

BackgroundHigh participation in mammographic screening is essential for its effectiveness to detect breast cancers early and thereby, improve breast cancer outcomes. Breast density is a strong predictor of breast cancer risk and significantly reduces the sensitivity of mammography to detect the disease. There are increasing mandates for routine breast density notification within mammographic screening programs. It is unknown if breast density notification impacts the likelihood of women returning to screening when next due (i.e. rescreening rates). This study investigates the association between breast density notification and rescreening rates using individual-level data from BreastScreen Western Australia (WA), a population-based mammographic screening program.MethodsWe examined 981,705 screening events from 311,656 women aged 40+ who attended BreastScreen WA between 2008 and 2017. Mixed effect logistic regression was used to investigate the association between rescreening and breast density notification status.ResultsResults were stratified by age (younger, targeted, older) and screening round (first, second, third+). Targeted women screening for the first time were more likely to return to screening if notified as having dense breasts (Percentunadjusted notified vs. not-notified: 57.8% vs. 56.1%; Padjusted = 0.016). Younger women were less likely to rescreen if notified, regardless of screening round (all P < 0.001). There was no association between notification and rescreening in older women (all P > 0.72).ConclusionsBreast density notification does not deter women in the targeted age range from rescreening but could potentially deter younger women from rescreening. These results suggest that all breast density notification messaging should include information regarding the importance of regular mammographic screening to manage breast cancer risk, particularly for younger women. These results will directly inform BreastScreen programs in Australia as well as other population-based screening providers outside Australia who notify women about breast density or are considering implementing breast density notification.