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Background: The low subject contrast between cancerous and fibroglandular tissue could obscure breast abnormalities. Purpose: To investigate radiologists' performance for detection of breast cancer in low and high mammographic density (MD) when cases are digitally acquired. Material and Methods: A test set of 60 digital mammography cases, of which 20 were cancerous, were examined by 17 radiologists. Mammograms were categorized as low (≤50%) or high (>50%) MD and rated for suspicion of malignancy using the Royal Australian and New Zealand College of Radiology (RANZCR) classification system. Radiologist demographics including cases read per year, age, subspecialty, and years of reporting were recorded. Radiologist performance was analyzed by the following metrics: sensitivity; specificity; area under the receiver operating characteristic (ROC) curve (AUC), location sensitivity, and jackknife free-response ROC (JAFROC) figure of merit (FOM). Results: Comparing high to low MD cases, radiologists showed a significantly higher sensitivity (P=0.015), AUC (P=0.003), location sensitivity (P=0.002), and JAFROC FOM (P=0.001). In high compared to low MD cases, radiologists with <1000 annual reads and radiologists with no mammographic subspecialty had significantly higher AUC, location sensitivity, and JAFROC FOM. Radiologists with ≥1000 annual reads and radiologists with mammography subspecialty demonstrated a significant increase in location sensitivity in high compared to low MD cases. Conclusion: In this experimental situation, radiologists' performance was higher when reading cases with high compared to low MD. Experienced radiologists were able to precisely localize lesions in breasts with higher MD. Further studies in unselected screening materials are needed to verify the results. [ABSTRACT FROM AUTHOR]

Digital breast tomosynthesis (DBT) for breast cancer screening has been shown in international trials to increase cancer detection compared with mammography; however, results have varied across screening settings, and currently there is limited and conflicting evidence on interval cancer rates (a surrogate for screening effectiveness). Australian pilot data also indicated substantially longer screen-reading time for DBT posing a barrier for adoption. There is a critical need for evidence on DBT to inform its role in Australia, including evaluation of potentially more feasible models of implementation, and quantification of screening outcomes by breast density which has global relevance. This study is a prospective trial embedded in population-based Australian screening services (Maroondah BreastScreen, Eastern Health, Victoria) comparing hybrid screening comprising DBT (mediolateral oblique view) and digital mammography (cranio-caudal view) with standard mammography screening in a concurrent group attending another screening site. All eligible women aged ≥40 years attending the Maroondah service for routine screening will be enrolled (unless they do not provide verbal consent and opt-out of hybrid screening; are unable to provide consent; or where a 'pushback' image on hybrid DBT cannot be obtained). Each arm will enrol 20,000 women. The primary outcomes are cancer detection rate (per 1000 screens) and recall rate (percentage). Secondary outcomes include 'opt-out' rate; cohort characteristics; cancer characteristics; assessment outcomes; screen-reading time; and interval cancer rate at 24-month follow-up. Automated volumetric breast density will be measured to allow stratification of outcomes by mammographic density. Stratification by age and screening round will also be undertaken. An interim analysis will be undertaken after the first 5000 screens in the intervention group. This is the first Australian prospective trial comparing hybrid DBT/mammography with standard mammography screening that is powered to show differences in cancer detection. Findings will inform future implementation of DBT in screening programs world-wide and provide evidence on whether DBT should be adopted in the broader BreastScreen program in Australia or in subgroups of screening participants. The trial is registered with the Australian New Zealand Clinical Trials Registry (ANZCTR, ACTRN12623001144606, https://www.anzctr.org.au/). Registration will be updated to reflect trial progress and protocol amendments. • Trials of DBT have varied across settings with limited evidence on interval cancer rates. • Substantially longer screen-reading time for DBT poses a barrier for adoption. • Hybrid DBT/DM will be evaluated to address reading time in this Australian trial. • 20,000 women per arm will be enrolled at two sites: hybrid DBT/DM vs mammography. • Cancer detection, recall, reading time, and interval cancer rates will be reported. [ABSTRACT FROM AUTHOR]

Background: Examination of factors associated with late stage diagnosis of breast cancer is useful to identify areas which are amenable to intervention. This study analyses trends in cancer stage at diagnosis and impact of socio-demographic, cancer biological and screening characteristics on cancer stage in a population-based series of women with invasive breast cancer in New Zealand.Methods: All women diagnosed with invasive breast cancer between 2000 and 2013 were identified from two regional breast cancer registries. Factors associated with advanced (stages III and IV) and metastatic (stage IV) cancer at diagnosis were analysed in univariate and multivariate models adjusting for covariates.Results: Of the 12390 women included in this study 2448 (19.7%) were advanced and 575 (4.6%) were metastatic at diagnosis. Māori (OR = 1.86, 1.39-2.49) and Pacific (OR = 2.81, 2.03-3.87) compared with NZ European ethnicity, other urban (OR = 2.00, 1.37-2.92) compared with main urban residency and non-screen (OR = 6.03, 4.41-8.24) compared with screen detection were significantly associated with metastatic cancer at diagnosis in multivariate analysis. A steady increase in the rate of metastatic cancer was seen which has increased from 3.8% during 2000-2003 to 5.0% during 2010-2013 period (p = 0.042).Conclusions: Providing equitable high quality primary care and increasing mammographic screening coverage needs to be looked at as possible avenues to reduce late-stage cancer at diagnosis and to reduce ethnic, socioeconomic and geographical disparities in stage of breast cancer at diagnosis in New Zealand. [ABSTRACT FROM AUTHOR]