Addressing Misinformation About the Canadian Breast Screening Guidelines.

Screening mammography has been shown to reduce breast cancer mortality by 41% in screened women ages 40-69 years. There is misinformation about breast screening and the Canadian breast screening guidelines. This can decrease confidence in screening mammography and can lead to suboptimal recommendations. We review some of this misinformation to help radiologists and referring physicians navigate the varied international and provincial guidelines. We address the ages to start and stop breast screening. We explore how these recommendations may vary for specific populations such as patients who are at increased risk, transgender patients and minorities. We identify who would benefit from supplemental screening and review the available supplemental screening modalities including ultrasound, MRI, contrast-enhanced mammography and others. We describe emerging technologies including the potential use of artificial intelligence for breast screening. We provide background on why screening policies vary across the country between provinces and territories. This review is intended to help radiologists and referring physicians understand and navigate the varied international and provincial recommendations and guidelines and make the best recommendations for their patients.

The Impact of Dense Breasts on the Stage of Breast Cancer at Diagnosis: A Review and Options for Supplemental Screening.

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.

The randomized trial of mammography screening that was not-A cautionary tale.

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.

Errors in Conduct of the CNBSS Trials of Breast Cancer Screening Observed by Research Personnel.

OBJECTIVE: To investigate why the Canadian National Breast Screening Study (CNBSS) did not show mortality reduction with mammography. This study explored long-standing concerns related to the validity of the randomization process, methods of recruiting women to participate in the trials, and training of the staff working in the CNBSS. METHODS: Surviving former CNBSS personnel, whose roles involved direct recruitment, enrollment, randomization, clinical examination, image interpretation, and management of patients in the CNBSS were interviewed. Individuals were contacted and consented to provide firsthand accounts of daily operations and adherence to research protocols via standardized questions. Consistency of observational data with quantitative results from the CNBSS trials was evaluated. RESULTS: Eleven of 28 (39.3%) staff confirmed that women with preexisting symptoms of breast cancer were systematically recruited at some centers; 57.1% (16/28) confirmed that personnel performing screening in CNBSS had very limited training and experience; 39.3% (11/28) verified that imaging equipment was often substandard; 50% (14/28) indicated that mammography image quality was generally poor; and 28.6% (8/28) corroborated that in some cases surgeons were unwilling to perform biopsies or surgeries for women with suspicious abnormalities found only on screening mammography that lacked a palpable correlate. CONCLUSION: These firsthand accounts provide new information confirming that the CNBSS did not consistently and rigorously assess the true efficacy of screening mammography. The staff accounts clarify reasons why the CNBSS results were outliers compared with the six other randomized trials of screening mammography and should not be used as credible scientific evidence to inform health policy.

Upgrade Rate of Flat Epithelial Atypia Diagnosed at Stereotactic Core Needle Biopsy of Microcalcifications: Is Excisional Biopsy Indicated?

OBJECTIVE: Whether the optimal management of pure flat epithelial atypia (FEA) found on core needle biopsy (CNB) specimens is surgical excision or imaging follow-up remains controversial. This study aimed to determine the upgrade rate to ductal carcinoma in situ (DCIS), invasive carcinoma or a high-risk lesion (atypical ductal hyperplasia, atypical lobular hyperplasia, or lobular carcinoma in situ), and it explored the relationship between a family history of breast cancer and the risk of upgrade. METHODS: Cases with pure FEA found on stereotactic CNB of microcalcifications between March 2011 to December 2017 were followed by excisional biopsy or periodic imaging. The proportion of cases upgraded to a high-risk lesion and the odds of upgrade as related to a family history of breast cancer were determined with 95% confidence intervals (CIs). RESULTS: We identified 622 cases of pure FEA; 101 (16.2%) underwent surgical excision and 269 (43.2%) had imaging follow-up of ≥ 24 months. There were no upgrades to DCIS or invasive cancer in any of these 370 individuals (0%), and 4.6% (17/370; 95% CI: 2.9%-7.2%) were upgraded to a high-risk lesion. There was a nonstatistically significant trend between family history and upgrade to high-risk lesion (odds ratio 1.72 [95% CI: 0.65%-4.57%]). CONCLUSION: In our study, the upgrade rate of pure FEA to malignancy was 0%. We suggest that regular imaging follow-up is an appropriate alternative to surgery. Because of potential differences in biopsy techniques and pathologist interpretation of the primary biopsy, individual institutions should audit their own results prior to altering their management of FEA.

Canadian Radiologists Do Not Support Screening Mammography Guidelines of the Canadian Task Force on Preventive Health Care.

PURPOSE: The study sought to determine screening mammography recommendations that radiologists in Canada promote to average-risk patients and family or friends, and do or would do for themselves. METHODS: An online survey was delivered from February 19, 2014, to July 11, 2014. Data included radiologists' recommendations for mammography and their personal screening habits based on gender. The 3 radiologists' cohorts were women ≥40 years of age, women <40 years of age, and men. The distribution of responses for each question was summarized, and proportions for the entire group and individual cohorts were computed. RESULTS: Of 402 surveys collected, 97% (299 of 309) radiologists recommended screening every 1-2 years, 62% (192 of 309) starting ≥40 years of age and 2% (5 of 309) recommended screening every 2-3 years for women 50-74 years of age. Recommendations were similar for family and friends: 96% (294 of 305) recommended screening every 1-2 years, 66% (202 of 305) recommended screening every 1-2 years for women ≥40 years of age, and 2% (5 of 305) recommended screening every 2-3 years. For women radiologists ≥40 years of age, 76% (48 of 63) underwent screening every 1-2 years and started at 40 years of age, 76% (16 of 21) female radiologists <40 years of age would undergo screening ≥40 years of age, 100% every 1-2 years, and 90% (151 of 167) male radiologists would undergo screening every 1-2 years, with 71% (120 of 169) beginning at 40 years of age. CONCLUSION: The majority of Canadian radiologists recommend screening mammography every 1-2 years for average-risk women ≥40 years of age, whether they are patients or family and friends.

"Do unto others as you would have them do unto you": breast imagers' perspectives regarding screening mammography for others and for themselves--do they practice what they preach?

OBJECTIVE: Our aim was to determine the screening recommendations that breast radiologists promote to average-risk patients and family or friends and do or would follow for themselves. MATERIALS AND METHODS: A survey of breast radiologists in the United States collected data regarding their personal and practice backgrounds, their recommendations to others for mammography and clinical and self-breast examination, and their personal screening habits based on respondent sex. The radiologists were divided into three cohorts: women 40 years old or older (group 1), women younger than 40 years (group 2), and men (group 3). The distribution of responses for each question was summarized, and proportions of total radiologists and cohorts were computed. RESULTS: Four hundred eighty-seven surveys were collected. None of the radiologists recommended biennial mammography for patients ages 50-74 years, 98% (477/487) recommended yearly mammography for patients 40 years old and older, and 99% (470/476) recommended yearly mammography for family and friends 40 years old and older. The most common reasons for variance were institutional policy or provider preferences. In group 1, 96% (191/198) have yearly mammography. In group 2, 100% (83/83) have or will have yearly mammography at age 40 years and beyond. In group 3, 97% (171/176) would have yearly mammography at age 40 years and beyond if they were women. Overall, 97% (445/457) of radiologists have or would have yearly mammography at age 40 years and beyond. CONCLUSION: Nearly all (98%) of the radiologists recommend yearly mammography for average-risk women 40 years old and older and were consistent in that they "practice what they preach." Because radiologists diagnose all stages of breast cancer, their personal convictions should influence providers, patients, and the public when considering the U.S. Preventive Services Task Force screening guidelines.