The purpose of breast cancer screening is to find cancers early to reduce mortality and to allow successful treatment with less aggressive therapy. Mammography is the gold standard for breast cancer screening. Its efficacy in reducing mortality from breast cancer was proven in randomized controlled trials (RCTs) conducted from the early 1960s to the mid 1990s. Panels that recommend breast cancer screening guidelines have traditionally relied on the old RCTs, which did not include considerations of breast density, race/ethnicity, current hormone therapy, and other risk factors. Women do not all benefit equally from mammography. Mortality reduction is significantly lower in women with dense breasts because normal dense tissue can mask cancers on mammograms. Moreover, women with dense breasts are known to be at increased risk. To provide equity, breast cancer screening guidelines should be created with the goal of maximizing mortality reduction and allowing less aggressive therapy, which may include decreasing the interval between screening mammograms and recommending consideration of supplemental screening for women with dense breasts. This review will address the issue of dense breasts and the impact on the stage of breast cancer at the time of diagnosis, and discuss options for supplemental screening.

In shear wave absolute vibro-elastography (S-WAVE), a steady-state multi-frequency external mechanical excitation is applied to tissue, while a time-series of ultrasound radio-frequency (RF) data are acquired. Our objective is to determine the potential of S-WAVE to classify breast tissue lesions as malignant or benign. We present a new processing pipeline for feature-based classification of breast cancer using S-WAVE data, and we evaluate it on a new data set collected from 40 patients. Novel bi-spectral and Wigner spectrum features are computed directly from the RF time series and are combined with textural and spectral features from B-mode and elasticity images. The Random Forest permutation importance ranking and the Quadratic Mutual Information methods are used to reduce the number of features from 377 to 20. Support Vector Machines and Random Forest classifiers are used with leave-one-patient-out and Monte Carlo cross-validations. Classification results obtained for different feature sets are presented. Our best results (95% confidence interval, Area Under Curve = 95%±1.45%, sensitivity = 95%, and specificity = 93%) outperform the state-of-the-art reported S-WAVE breast cancer classification performance. The effect of feature selection and the sensitivity of the above classification results to changes in breast lesion contours is also studied. We demonstrate that time-series analysis of externally vibrated tissue as an elastography technique, even if the elasticity is not explicitly computed, has promise and should be pursued with larger patient datasets. Our study proposes novel directions in the field of elasticity imaging for tissue classification.

OBJECTIVE. This study correlates ductal intraepithelial neoplasia (DIN) 1A diagnosed at stereotactic spring core needle biopsy (CNB) or vacuum-assisted biopsy (VAB) with the subsequent surgical histologic results or long-term follow-up imaging findings to predict the likelihood of upgrade to ductal carcinoma in situ (DCIS) or invasive carcinoma. MATERIALS AND METHODS. Stereotactic imaging-guided CNBs and VABs were performed principally for assessment of microcalcifications seen on mammography. DIN 1A diagnoses made at CNB or VAB were correlated with subsequent excisional biopsy results or imaging follow-up. Patients were included only if there was no concomitant CNB or VAB diagnosis of DIN 1B, atypical lobular hyperplasia, lobular carcinoma in situ or DCIS, papillary lesion, or invasive carcinoma. Surgical biopsy results were obtained for 239 patients. Upgrade was defined as a diagnosis of DCIS or invasive carcinoma at surgery. Patients who did not undergo surgical excision were followed with imaging. RES...

During the COVID-19 pandemic, breast imaging must be performed using safe practices. Balancing the need to avoid delays in the diagnosis of breast cancer while avoiding infection requires careful attention to personal protective equipment and physical distancing and vigilance to maintain these practices. The Canadian Society of Breast Imaging/Canadian Association of Radiologists guideline for breast imaging during COVID-19 is provided based on priority according to risk of breast cancer and impact of delaying treatment. A review of the best practices is presented that allow breast imaging during COVID-19 to maximize protection of patients, technologists, residents, fellows, and radiologists and minimize spread of the infection. The collateral damage of delaying diagnosis of breast cancer due to COVID-19 should be avoided when possible.

Two randomized trials were conducted in Canada in the 1980s to test the efficacy of breast cancer screening. Neither of the trials demonstrated benefit. Concerns were raised regarding serious errors in trial design and conduct. Here we describe the conditions that could allow subversion of randomization to occur and the inclusion of many symptomatic women in a screening trial. We examine anomalies in data where the balance would be expected between trial arms. “Open book” randomization and performance of clinical breast examination on all women before allocation to a trial arm allowed women with palpable findings to be mis-randomized into the mammography arm. Multiple indicators raising suspicion of subversion are present including a large excess in poor-prognosis cancers in the mammography trial arm at prevalence screen. Personnel described shifting of women from the control group into the mammography group. There is compelling evidence of subversion of randomization in Canadian National Breast Screening Study. Mis-randomization of even a few women with advanced breast cancer could markedly affect measured screening efficacy. The Canadian National Breast Screening Study trials should not influence breast screening policies.

Objective: Breast ultrasound is one of several tools proposed for supplemental screening of women with dense breasts but is not widely available in Canada. Methods: An IRB-approved, evaluation of ultrasound-guided breast biopsies prompted by screening breast ultrasound performed from August 1, 2021, to December 31, 2022, offered to asymptomatic women with category C and D breast tissue density after normal screening mammography (2D) in the provincial organized screening program, or surveillance diagnostic mammography after breast cancer. Risk factors, stage (AJCC 8th ed), incremental cancer detection rate (ICDR), biopsy rates, and positive predictive values for biopsy (PPV3) were evaluated. Results: 5257 women were screened, yielding 247 women (ages 34-82, median age of 56) who underwent biopsies (281 masses), 32 of whom were diagnosed with breast cancer, 27 invasive and 5 DCIS for PPV3 13.0% (32/247), and ICDR 6.1/1000. Ductal cancers found were stage 0 in 5/32 (15.6%), stage 1A in 18/32 (56.3%), and stage 1B in 2/32 (6.3%), 1 ductal/lobular cancer was stage 3B (3.1%), 5 lobular cancers (16.6%) were stage 1A (1), 1B (2), and 2B (2) and 1 adenoid cystic carcinoma was stage 2A (3.1%); 3 cancers were found on incident and 29 on prevalent screens, 27 (84.4%) in category c and 20 (62.5%) in women with no personal or first-degree family history of breast cancer. Conclusion: A high ICDR for screening breast ultrasound of 6.1/1000 was found. Clinical Relevance Statement: In women with dense breasts screened with 2D mammography where access to supplemental screening with MRI and contrast mammography is limited, supplemental screening ultrasound can play a significant role in cancer detection with a high ICDR in women in both category c and d densities that is higher than in jurisdictions offering annual screening mammography, or where MRI is used for surveillance after cancer.