A Population-Based Study of Genes Previously Implicated in Breast Cancer.

BACKGROUND: Population-based estimates of the risk of breast cancer associated with germline pathogenic variants in cancer-predisposition genes are critically needed for risk assessment and management in women with inherited pathogenic variants. METHODS: In a population-based case-control study, we performed sequencing using a custom multigene amplicon-based panel to identify germline pathogenic variants in 28 cancer-predisposition genes among 32,247 women with breast cancer (case patients) and 32,544 unaffected women (controls) from population-based studies in the Cancer Risk Estimates Related to Susceptibility (CARRIERS) consortium. Associations between pathogenic variants in each gene and the risk of breast cancer were assessed. RESULTS: Pathogenic variants in 12 established breast cancer-predisposition genes were detected in 5.03% of case patients and in 1.63% of controls. Pathogenic variants in BRCA1 and BRCA2 were associated with a high risk of breast cancer, with odds ratios of 7.62 (95% confidence interval [CI], 5.33 to 11.27) and 5.23 (95% CI, 4.09 to 6.77), respectively. Pathogenic variants in PALB2 were associated with a moderate risk (odds ratio, 3.83; 95% CI, 2.68 to 5.63). Pathogenic variants in BARD1, RAD51C, and RAD51D were associated with increased risks of estrogen receptor-negative breast cancer and triple-negative breast cancer, whereas pathogenic variants in ATM, CDH1, and CHEK2 were associated with an increased risk of estrogen receptor-positive breast cancer. Pathogenic variants in 16 candidate breast cancer-predisposition genes, including the c.657_661del5 founder pathogenic variant in NBN, were not associated with an increased risk of breast cancer. CONCLUSIONS: This study provides estimates of the prevalence and risk of breast cancer associated with pathogenic variants in known breast cancer-predisposition genes in the U.S. population. These estimates can inform cancer testing and screening and improve clinical management strategies for women in the general population with inherited pathogenic variants in these genes. (Funded by the National Institutes of Health and the Breast Cancer Research Foundation.).

Analysis of Breast Cancer Mortality in the US-1975 to 2019.

Importance: Breast cancer mortality in the US declined between 1975 and 2019. The association of changes in metastatic breast cancer treatment with improved breast cancer mortality is unclear. Objective: To simulate the relative associations of breast cancer screening, treatment of stage I to III breast cancer, and treatment of metastatic breast cancer with improved breast cancer mortality. Design, Setting, and Participants: Using aggregated observational and clinical trial data on the dissemination and effects of screening and treatment, 4 Cancer Intervention and Surveillance Modeling Network (CISNET) models simulated US breast cancer mortality rates. Death due to breast cancer, overall and by estrogen receptor and ERBB2 (formerly HER2) status, among women aged 30 to 79 years in the US from 1975 to 2019 was simulated. Exposures: Screening mammography, treatment of stage I to III breast cancer, and treatment of metastatic breast cancer. Main Outcomes and Measures: Model-estimated age-adjusted breast cancer mortality rate associated with screening, stage I to III treatment, and metastatic treatment relative to the absence of these exposures was assessed, as was model-estimated median survival after breast cancer metastatic recurrence. Results: The breast cancer mortality rate in the US (age adjusted) was 48/100 000 women in 1975 and 27/100 000 women in 2019. In 2019, the combination of screening, stage I to III treatment, and metastatic treatment was associated with a 58% reduction (model range, 55%-61%) in breast cancer mortality. Of this reduction, 29% (model range, 19%-33%) was associated with treatment of metastatic breast cancer, 47% (model range, 35%-60%) with treatment of stage I to III breast cancer, and 25% (model range, 21%-33%) with mammography screening. Based on simulations, the greatest change in survival after metastatic recurrence occurred between 2000 and 2019, from 1.9 years (model range, 1.0-2.7 years) to 3.2 years (model range, 2.0-4.9 years). Median survival for estrogen receptor (ER)-positive/ERBB2-positive breast cancer improved by 2.5 years (model range, 2.0-3.4 years), whereas median survival for ER-/ERBB2- breast cancer improved by 0.5 years (model range, 0.3-0.8 years). Conclusions and Relevance: According to 4 simulation models, breast cancer screening and treatment in 2019 were associated with a 58% reduction in US breast cancer mortality compared with interventions in 1975. Simulations suggested that treatment for stage I to III breast cancer was associated with approximately 47% of the mortality reduction, whereas treatment for metastatic breast cancer was associated with 29% of the reduction and screening with 25% of the reduction.

Collaborative Modeling to Compare Different Breast Cancer Screening Strategies: A Decision Analysis for the US Preventive Services Task Force.

Importance: The effects of breast cancer incidence changes and advances in screening and treatment on outcomes of different screening strategies are not well known. Objective: To estimate outcomes of various mammography screening strategies. Design, Setting, and Population: Comparison of outcomes using 6 Cancer Intervention and Surveillance Modeling Network (CISNET) models and national data on breast cancer incidence, mammography performance, treatment effects, and other-cause mortality in US women without previous cancer diagnoses. Exposures: Thirty-six screening strategies with varying start ages (40, 45, 50 years) and stop ages (74, 79 years) with digital mammography or digital breast tomosynthesis (DBT) annually, biennially, or a combination of intervals. Strategies were evaluated for all women and for Black women, assuming 100% screening adherence and "real-world" treatment. Main Outcomes and Measures: Estimated lifetime benefits (breast cancer deaths averted, percent reduction in breast cancer mortality, life-years gained), harms (false-positive recalls, benign biopsies, overdiagnosis), and number of mammograms per 1000 women. Results: Biennial screening with DBT starting at age 40, 45, or 50 years until age 74 years averted a median of 8.2, 7.5, or 6.7 breast cancer deaths per 1000 women screened, respectively, vs no screening. Biennial DBT screening at age 40 to 74 years (vs no screening) was associated with a 30.0% breast cancer mortality reduction, 1376 false-positive recalls, and 14 overdiagnosed cases per 1000 women screened. Digital mammography screening benefits were similar to those for DBT but had more false-positive recalls. Annual screening increased benefits but resulted in more false-positive recalls and overdiagnosed cases. Benefit-to-harm ratios of continuing screening until age 79 years were similar or superior to stopping at age 74. In all strategies, women with higher-than-average breast cancer risk, higher breast density, and lower comorbidity level experienced greater screening benefits than other groups. Annual screening of Black women from age 40 to 49 years with biennial screening thereafter reduced breast cancer mortality disparities while maintaining similar benefit-to-harm trade-offs as for all women. Conclusions: This modeling analysis suggests that biennial mammography screening starting at age 40 years reduces breast cancer mortality and increases life-years gained per mammogram. More intensive screening for women with greater risk of breast cancer diagnosis or death can maintain similar benefit-to-harm trade-offs and reduce mortality disparities.

Building relationships to connect cancer researchers with community members: 'bench to community pipeline'.

PURPOSE: Partnerships between researchers and community members and organizations can offer multiple benefits for research relevance and dissemination. The goal of this project was to build infrastructure to create bidirectional relationships between University of Wisconsin Carbone Cancer Center (UWCCC) researchers and community educators in the Division of Extension, which connects the knowledge and resources of the university to communities across the state. METHODS: This project had three aims: (1) create linkages with Extension; (2) establish an in-reach program to educate and train researchers on the science of Community Outreach and Engagement (COE); and (3) identify and facilitate collaborative projects between scientists and communities. Survey and focus group-based needs assessments were completed with both researchers and Extension educators and program activity evaluations were conducted. RESULTS: Most Extension educators (71%) indicated a strong interest in partnering on COE projects. UWCCC faculty indicated interest in further disseminating their research, but also indicated barriers in connecting with communities. Outreach webinars were created and disseminated to community, a "COE in-reach toolkit" for faculty was created and a series of "speed networking" events were hosted to pair researchers and community. Evaluations indicated the acceptability and usefulness of these activities and supported continuation of collaborative efforts. CONCLUSION: Continued relationship and skill building, along with a sustainability plan, is critical to support the translation of basic, clinical, and population research to action in the community outreach and engagement context. Further incentives for faculty should be explored for the recruitment of basic scientists into community engagement work.

Mortality risk and physical activity across the lifespan in endometrial cancer survivors.

PURPOSE: Physical activity (pre- and post-diagnosis) has been studied in prevention and survivorship contexts for endometrial cancer. However, the association of physical activity (PA) across the lifespan on mortality risk among endometrial cancer survivors is understudied. The study's objective was to identify the association of lifetime PA on mortality risk in endometrial cancer survivors. METHODS: Seven hundred forty-five endometrial cancer survivors drawn from a population-based cancer registry (diagnosed between 1991 and 1994) reported the frequency (sessions/week) of moderate- and vigorous intensity physical activity (MVPA) at age 12, age 20, and 5 years pre-interview (post-diagnosis). Cox proportional hazards were used to estimate hazard ratios (HR) and 95% confidence intervals for the association between PA, all-cause, and cardiovascular disease mortality as assessed in 2016. MVPA was modeled using natural cubic splines. RESULTS: Diagnosis age, body mass index, and smoking (pack-years) were each positively associated with increased all-cause mortality risk. Those who did one session of MVPA 5 years pre-interview had a lower mortality risk (HR 0.61; 95% CI 0.41-0.92) compared to those with no MVPA. Those reporting one session of MVPA was similarly observed at age 12 (HR 0.95; 95% CI 0.86-1.06) and at age 20 (HR 0.87; 95% CI 0.65-1.16). CONCLUSION: Those who participated in PA, compared to those who did not, in the 5 years before diagnosis had a lower mortality risk. While PA was not independently protective against mortality risk at ages 12 or 20, PA is still important for endometrial cancer survivors for other non-mortality outcomes.

Reflecting on 20 years of breast cancer modeling in CISNET: Recommendations for future cancer systems modeling efforts.

Since 2000, the National Cancer Institute's Cancer Intervention and Surveillance Modeling Network (CISNET) modeling teams have developed and applied microsimulation and statistical models of breast cancer. Here, we illustrate the use of collaborative breast cancer multilevel systems modeling in CISNET to demonstrate the flexibility of systems modeling to address important clinical and policy-relevant questions. Challenges and opportunities of future systems modeling are also summarized. The 6 CISNET breast cancer models embody the key features of systems modeling by incorporating numerous data sources and reflecting tumor, person, and health system factors that change over time and interact to affect the burden of breast cancer. Multidisciplinary modeling teams have explored alternative representations of breast cancer to reveal insights into breast cancer natural history, including the role of overdiagnosis and race differences in tumor characteristics. The models have been used to compare strategies for improving the balance of benefits and harms of breast cancer screening based on personal risk factors, including age, breast density, polygenic risk, and history of Down syndrome or a history of childhood cancer. The models have also provided evidence to support the delivery of care by simulating outcomes following clinical decisions about breast cancer treatment and estimating the relative impact of screening and treatment on the United States population. The insights provided by the CISNET breast cancer multilevel modeling efforts have informed policy and clinical guidelines. The 20 years of CISNET modeling experience has highlighted opportunities and challenges to expanding the impact of systems modeling. Moving forward, CISNET research will continue to use systems modeling to address cancer control issues, including modeling structural inequities affecting racial disparities in the burden of breast cancer. Future work will also leverage the lessons from team science, expand resource sharing, and foster the careers of early stage modeling scientists to ensure the sustainability of these efforts.

Identifying Equitable Screening Mammography Strategies for Black Women in the United States Using Simulation Modeling.

BACKGROUND: Screening mammography guidelines do not explicitly consider racial differences in breast cancer epidemiology, treatment, and survival. OBJECTIVE: To compare tradeoffs of screening strategies in Black women versus White women under current guidelines. DESIGN: An established model from the Cancer Intervention and Surveillance Modeling Network simulated screening outcomes using race-specific inputs for subtype distribution; breast density; mammography performance; age-, stage-, and subtype-specific treatment effects; and non-breast cancer mortality. SETTING: United States. PARTICIPANTS: A 1980 U.S. birth cohort of Black and White women. INTERVENTION: Screening strategies until age 74 years with varying initiation ages and intervals. MEASUREMENTS: Outcomes included benefits (life-years gained [LYG], breast cancer deaths averted, and mortality reduction), harms (mammographies, false positives, and overdiagnoses), and benefit-harm ratios (tradeoffs) by race. Efficiency (benefits per unit resource), mortality disparity reduction, and equity in tradeoffs were evaluated. Equitable strategies for Black women were defined as those with tradeoffs closest to benchmark values for screening White women biennially from ages 50 to 74 years. RESULTS: Biennial screening from ages 45 to 74 years was most efficient for Black women, whereas biennial screening from ages 40 to 74 years was most equitable. Initiating screening 10 years earlier in Black versus White women reduced Black-White mortality disparities by 57% with similar LYG per mammogram for both populations. Selection of the most equitable strategy was sensitive to assumptions about disparities in real-world treatment effectiveness: The less effective treatment was for Black women, the more intensively Black women could be screened before tradeoffs fell short of those experienced by White women. LIMITATION: Single model. CONCLUSION: Initiating biennial screening in Black women at age 40 years reduces breast cancer mortality disparities and yields benefit-harm ratios that are similar to tradeoffs of White women screened biennially from ages 50 to 74 years. PRIMARY FUNDING SOURCE: National Cancer Institute at the National Institutes of Health.

Does margin width impact breast cancer recurrence rates in women with breast conserving surgery for ductal carcinoma in situ?

PURPOSE: Controversy remains regarding the optimal margin width for patients with ductal carcinoma in situ (DCIS) who undergo breast conserving surgery (BCS). METHODS: Women with a primary DCIS diagnosis were enrolled in a statewide population-based cohort from 1997 to 2006. Patients were surveyed every two years with follow-up data available through 2016. Surgical pathology reports were collected for 559 participants following breast conserving surgery. Multivariable Cox proportional hazard models evaluated relationships between locoregional recurrence (LRR) and margin width in the presence or absence of adjuvant radiation therapy while controlling for age, menopausal status and duration of endocrine therapy use. RESULTS: The majority of women in this study were over 50yo (74%), 34% had high grade disease, and 77% underwent radiation. The overall LRR rate was 12%. A LRR occurred in 46 women who had radiation (11%) and 23 women who did not undergo radiation (19%). Univariate analysis identified smaller margin width, younger age, premenopausal status, no radiotherapy, and shorter endocrine therapy use associated with LRR. Multivariable models demonstrated that close margins (< 2 mm) were associated with an increased risk of recurrence when compared to margins ≥ 2 mm in width whether women received radiation (HR 1.98 CI 0.87-4.54) or not (HR 1.32 CI 0.27-6.49), but confidence intervals were wide. CONCLUSIONS: In this study, patients with DCIS and close margins were less likely to experience recurrence after routine re-excision to margins greater than 2 mm.

Recent Changes in the Patterns of Breast Cancer as a Proportion of All Deaths According to Race and Ethnicity.

BACKGROUND: Recent reports suggest that racial differences in breast cancer incidence rates have decreased. We examined whether these findings apply to breast cancer mortality while considering age, period, and cohort influences on both absolute and relative measures of breast cancer mortality. METHODS: Using publicly available datasets (CDC WONDER, Human Mortality Database), we developed an age-period-cohort model of breast cancer mortality and breast cancer deaths as a proportion of all deaths during 1968-2019 among all women and by 5 race/ethnicity groups with sufficient numbers for estimation: Hispanic (all races), American Indian/Alaska Native and Asian/Pacific Islanders (regardless of ethnicity), non-Hispanic Black, and non-Hispanic White. RESULTS: Initially increasing after 1968, age-adjusted breast cancer mortality rates have decreased among all racial/ethnic groups since 1988. The age-adjusted percent of all deaths due to breast cancer also has been declining for non-Hispanic White women since about 1990 while increasing or holding steady for other race/ethnic groups. In 2019, the age-adjusted percent of deaths due to breast cancer for women was highest for Asian/Pacific Islanders (5.6%) followed by non-Hispanic Black (4.5%), Hispanic (4.4%), non-Hispanic White (4.1%), and American Indian/Alaska Native women (2.6%). CONCLUSIONS: Breast cancer mortality disparities are now greater on both relative and absolute scales for non-Hispanic Black women, and using the relative scale for Asian/Pacific Islander and Hispanic women, compared with non-Hispanic White women for the first time in 50 years.

Surgical Decision-Making Surrounding Contralateral Prophylactic Mastectomy: Comparison of Treatment Goals, Preferences, and Psychosocial Outcomes from a Multicenter Survey of Breast Cancer Patients.

BACKGROUND: Differences in patient characteristics and decision-making preferences have been described between those who elect breast-conserving surgery (BCS), unilateral mastectomy (UM), or contralateral prophylactic mastectomy (CPM) for breast cancer. However, it is not known whether preferred and actual decision-making roles differ across these surgery types, or whether surgery choice reflects a woman's goals or achieves desired outcomes. METHODS: Women diagnosed with stage 0-III unilateral breast cancer across eight large medical centers responded to a mailed questionnaire regarding treatment decision-making goals, roles, and outcomes. These data were linked to electronic medical records. Differences were assessed using descriptive analyses and logistic regression. RESULTS: There were 750 study participants: 60.1% BCS, 17.9% UM, and 22.0% CPM. On multivariate analysis, reducing worry about recurrence was a more important goal for surgery in the CPM group than the others. Although women's preferred role in the treatment decision did not differ by surgery, the CPM group was more likely to report taking a more-active-than-preferred role than the BCS group. On multivariate analysis that included receipt of additional surgery, posttreatment worry about both ipsilateral and contralateral recurrence was higher in the BCS group than the CPM group (both p < 0.001). The UM group was more worried than the CPM group about contralateral recurrence only (p < 0.001). CONCLUSIONS: Women with CPM were more likely to report being able to reduce worry about recurrence as a very important goal for surgery. They were also the least worried about ipsilateral breast recurrence and contralateral breast cancer almost two years postdiagnosis.

A population-based study of causes of death after endometrial cancer according to major risk factors.

OBJECTIVE: To identify the most common causes of death and potentially modifiable risk factors in endometrial cancer patients. METHODS: 745 women diagnosed with incident endometrial cancer were enrolled in a population-based study from 1991 to 1994. Participants completed structured interviews about 1 year after diagnosis. Study files were linked with the National Death Index to identify dates and causes of death through 2016. Proportional hazards regression was used to estimate hazard rate ratios for cause of death adjusting for age and stage of disease. Hazard ratios were also examined according to comorbidities. RESULTS: Of the 745 women, 450 were deceased after a median of 19.9 years. The two most common causes of death were cardiovascular disease (N = 145, 32%) and any cancer (N = 135, 30%), with only 10% of women dying from endometrial cancer (N = 46). Obesity, diabetes and smoking increased risk of all-cause mortality (HRR 1.77, 95%CI 1.36-2.31; HRR 1.74, 95%CI 1.34-2.27; HRR 1.59, 95%CI 1.16-2.17). Diabetes also increased risk of cardiovascular disease-specific mortality (HRR 1.98, 95%CI 1.38-3.08), but not endometrial cancer mortality (HRR 0.55, 95%CI 0.21-1.48). Neither obesity nor smoking was associated with increased risk of cardiovascular disease-specific mortality (HRR 1.46, 95%CI 0.92-2.32; HRR 1.21, 95%CI 0.67-2.18) nor endometrial-cancer specific mortality (HRR 1.81, 95%CI 0.83-3.93; HRR 0.61, 95%CI 0.17-2.15). CONCLUSIONS: Endometrial cancer patients were 3 times more likely to die of cardiovascular disease than endometrial cancer. Obesity, smoking and diabetes increase the risk of death in these patients and are potentially modifiable. Clinical trials should be developed that incorporate counseling regarding these risk factors into survivorship care to determine impact on mortality.

Clinical Benefits, Harms, and Cost-Effectiveness of Breast Cancer Screening for Survivors of Childhood Cancer Treated With Chest Radiation : A Comparative Modeling Study.

BACKGROUND: Surveillance with annual mammography and breast magnetic resonance imaging (MRI) is recommended for female survivors of childhood cancer treated with chest radiation, yet benefits, harms, and costs are uncertain. OBJECTIVE: To compare the benefits, harms, and cost-effectiveness of breast cancer screening strategies in childhood cancer survivors. DESIGN: Collaborative simulation modeling using 2 Cancer Intervention and Surveillance Modeling Network breast cancer models. DATA SOURCES: Childhood Cancer Survivor Study and published data. TARGET POPULATION: Women aged 20 years with a history of chest radiotherapy. TIME HORIZON: Lifetime. PERSPECTIVE: Payer. INTERVENTION: Annual MRI with or without mammography, starting at age 25, 30, or 35 years. OUTCOME MEASURES: Breast cancer deaths averted, false-positive screening results, benign biopsy results, and incremental cost-effectiveness ratios (ICERs). RESULTS OF BASE-CASE ANALYSIS: Lifetime breast cancer mortality risk without screening was 10% to 11% across models. Compared with no screening, starting at age 25 years, annual mammography with MRI averted the most deaths (56% to 71%) and annual MRI (without mammography) averted 56% to 62%. Both strategies had the most screening tests, false-positive screening results, and benign biopsy results. For an ICER threshold of less than $100 000 per quality-adjusted life-year gained, screening beginning at age 30 years was preferred. RESULTS OF SENSITIVITY ANALYSIS: Assuming lower screening performance, the benefit of adding mammography to MRI increased in both models, although the conclusions about preferred starting age remained unchanged. LIMITATION: Elevated breast cancer risk was based on survivors diagnosed with childhood cancer between 1970 and 1986. CONCLUSION: Early initiation (at ages 25 to 30 years) of annual breast cancer screening with MRI, with or without mammography, might reduce breast cancer mortality by half or more in survivors of childhood cancer. PRIMARY FUNDING SOURCE: American Cancer Society and National Institutes of Health.

Evaluation of Long-Term Satisfaction with Breast Surgery in Patients Treated for Ductal Carcinoma In Situ: A Population-Based Longitudinal Cohort Study.

BACKGROUND: Breast-conserving surgery (BCS) and mastectomy have equivalent survival for ductal carcinoma in situ (DCIS), allowing patients to participate in selecting a personalized surgical option; however, this decision-making role can increase patient anxiety. Data evaluating patient satisfaction with their decision to undergo BCS versus mastectomy for the treatment of DCIS are limited. METHODS: Women with DCIS were enrolled in a population-based, state-wide cohort from 1997 to 2006. Participants were surveyed about their satisfaction with their surgical and reconstruction decisions. Quality-of-life (QoL) evaluations were performed with biennial follow-up surveys though 2016. Multivariable logistic regression modeling examined the relationship between type of surgery and reconstruction with patient satisfaction. RESULTS: Overall, 1537 women were surveyed, on average, 2.9 years following DCIS diagnosis. Over 90% reported satisfaction with their treatment decision regardless of surgery type. Women who underwent mastectomy with reconstruction were more likely to report lower levels of satisfaction than women who underwent BCS (odds ratio [OR] 2.98, 95% confidence interval [CI] 1.18-7.51, p < 0.01). However, over 80% of women who underwent mastectomies reported satisfaction with their reconstruction decision. Women without reconstruction had the highest levels of satisfaction, while women with implants were more likely to be dissatisfied (implant + autologous: OR 2.77, 95% CI 1.24-6.24; implant alone: OR 4.02, 95% CI 1.947-8.34, p ≤ 0.01). QoL scores were not associated with differences in surgical or reconstruction satisfaction at 5, 10, and 15 years following DCIS diagnosis. CONCLUSIONS: Women undergoing surgery for DCIS express satisfaction with their treatment decisions. Following mastectomy, most women are satisfied with their reconstruction decision, including women who did not undergo reconstruction.

The association between cancer care coordination and quality of life is stronger for breast cancer patients with lower health literacy: A Greater Plains Collaborative study.

PURPOSE: Health literacy (HL) and cancer care coordination (CCC) were examined for their relationship to quality of life (QOL) among breast cancer survivors. CCC was hypothesized to have a stronger relationship to QOL for women with lower HL. METHODS: Women (N = 1138) who had completed treatment for Stage 0-III, ductal carcinoma breast cancer between January 2013 and May 2014 at one of eight large medical centers responded to a mailed questionnaire. Responses to questions about survivorship care planning and presence of professional care coordinator were combined to form an index of CCC. An index of HL was also derived. QOL was measured using the Functional Assessment of Cancer Therapy-Breast (FACT-B) scales. RESULTS: 74.3% (N = 845) of patients reported having a health professional coordinate their care during treatment and 78.8% (N = 897) reported receiving survivorship care planning. CCC was classified as none, partial, or high for 7.1%, 32.7%, and 60.2% of the patients, respectively. Except for emotional well-being, the interaction between HL and CCC was significant for all QOL domains (p < .05); the effect of CCC on FACT-B scores was largest for people with lower HL. For the 39.8% of patients with less than high CCC, 111 (27.3%) had a level of HL associated with clinically meaningful lower QOL. CONCLUSIONS: The association between CCC and later QOL is strongest for people who have lower HL. Prioritizing care coordination for patients with lower health literacy may be an effective strategy in a setting of limited resources.

Environmental exposures during windows of susceptibility for breast cancer: a framework for prevention research.

BACKGROUND: The long time from exposure to potentially harmful chemicals until breast cancer occurrence poses challenges for designing etiologic studies and for implementing successful prevention programs. Growing evidence from animal and human studies indicates that distinct time periods of heightened susceptibility to endocrine disruptors exist throughout the life course. The influence of environmental chemicals on breast cancer risk may be greater during several windows of susceptibility (WOS) in a woman's life, including prenatal development, puberty, pregnancy, and the menopausal transition. These time windows are considered as specific periods of susceptibility for breast cancer because significant structural and functional changes occur in the mammary gland, as well as alterations in the mammary micro-environment and hormone signaling that may influence risk. Breast cancer research focused on these breast cancer WOS will accelerate understanding of disease etiology and prevention. MAIN TEXT: Despite the plausible heightened mechanistic influences of environmental chemicals on breast cancer risk during time periods of change in the mammary gland's structure and function, most human studies of environmental chemicals are not focused on specific WOS. This article reviews studies conducted over the past few decades that have specifically addressed the effect of environmental chemicals and metals on breast cancer risk during at least one of these WOS. In addition to summarizing the broader evidence-base specific to WOS, we include discussion of the NIH-funded Breast Cancer and the Environment Research Program (BCERP) which included population-based and basic science research focused on specific WOS to evaluate associations between breast cancer risk and particular classes of endocrine-disrupting chemicals-including polycyclic aromatic hydrocarbons, perfluorinated compounds, polybrominated diphenyl ethers, and phenols-and metals. We outline ways in which ongoing transdisciplinary BCERP projects incorporate animal research and human epidemiologic studies in close partnership with community organizations and communication scientists to identify research priorities and effectively translate evidence-based findings to the public and policy makers. CONCLUSIONS: An integrative model of breast cancer research is needed to determine the impact and mechanisms of action of endocrine disruptors at different WOS. By focusing on environmental chemical exposure during specific WOS, scientists and their community partners may identify when prevention efforts are likely to be most effective.

Time-varying risks of second events following a DCIS diagnosis in the population-based Vermont DCIS cohort.

PURPOSE: Long-term disease-free survival patterns following surgical, radiation, and endocrine therapy treatments for ductal carcinoma in situ (DCIS) are not well characterized in general US practice. METHODS: We identified 1252 women diagnosed with DCIS in Vermont during 1994-2012 using data from the Vermont Breast Cancer Surveillance System, a statewide registry of breast imaging and pathology records. Poisson regression and Cox regression with time-varying hazards were used to evaluate disease-free survival among self-selected treatment groups. RESULTS: With 7.8 years median follow-up, 192 cases experienced a second breast cancer diagnosis. For women treated with breast-conserving surgery (BCS) alone, the annual rate of second events decreased from 3.1% (95% CI 2.2-4.2%) during follow-up years 1-5 to 1.7% (95% CI 0.7-3.5%) after 10 years. In contrast, the annual rate of second events among women treated with BCS plus adjuvant radiation therapy increased from 1.8% (95% CI 1.1-2.6%) during years 1-5 to 2.8% (95% CI 1.6-4.7%) after 10 years (P < 0.05 for difference in trend compared to BCS alone). Annual rates of second events also increased over time among women treated with BCS plus adjuvant radiation and endocrine therapy (P = 0.01 for difference in trend compared to BCS alone). The rate of contralateral events increased after 10 years for all groups with adjuvant treatments. The rate of second events did not vary over time among women who underwent ipsilateral mastectomy (P = 0.62). CONCLUSIONS: Long-term risk of a second event after DCIS varies over time in a manner dependent on initial treatment.

Age-based versus Risk-based Mammography Screening in Women 40-49 Years Old: A Cross-sectional Study.

Background Risk-based screening in women 40-49 years old has not been evaluated in routine screening mammography practice. Purpose To use a cross-sectional study design to compare the trade-offs of risk-based and age-based screening for women 45 years of age or older to determine short-term outcomes. Materials and Methods A retrospective cross-sectional study was performed by using a database of 20 539 prospectively interpreted consecutive digital screening mammograms in 10 280 average-risk women aged 40-49 years who were screened at an academic medical center between January 1, 2006, and December 31, 2013. Two hypothetical screening scenarios were compared: an age-based (≥45 years) scenario versus a risk-based (a 5-year risk of breast cancer greater than that of an average 50-year-old) scenario. Risk factors for risk-based screening included family history, race, age, prior breast biopsy, and breast density. Outcomes included breast cancers detected at mammography, false-positive mammograms, and benign biopsy findings. Short-term outcomes were compared by using the χ2 test. Results The screening population included 71 148 screening mammograms in 24 928 women with a mean age of 55.5 years ± 8.9 (standard deviation) (age range, 40-74 years). In women 40-49 years old, usual care included 50 screening-detected cancers, 1787 false-positive mammograms, and 384 benign biopsy results. The age-based (≥45 years) screening strategy revealed more cancers than did the risk-based strategy (34 [68%] vs 13 [26%] of 50; P < .001), while prompting more false-positive mammograms (899 [50.3%] vs 216 [12.1%] of 1787; P < .001) and benign biopsy results (175 [45.6%] vs 49 [12.8%] of 384; P < .001). The risk-based strategy demonstrated low levels of eligibility (few screenings) in the 40-44-year age group. Differences in outcomes in the 45-49-year age group explained the overall hypothetical screening strategy differences. Conclusion Risk-based screening for women 40-49 years old includes few women in the 40-44-year age range. Significant trade-offs in the 45-49-year age group explain the overall difference between hypothetical screening scenarios, both of which reduce the benefits as well as the harms of mammography for women 40-49 years old. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Joe and Hayward in this issue.

Variation in coordination of care reported by breast cancer patients according to health literacy.

BACKGROUND: Health literacy is the ability to perform basic reading and numerical tasks to function in the healthcare environment. The purpose of this study is to describe how health literacy is related to perceived coordination of care reported by breast cancer patients. METHODS: Data were retrieved from the Patient-Centered Outcomes Research Institute-sponsored "Share Thoughts on Breast Cancer" Study including demographic factors, perceived care coordination and responsiveness of care, and self-reported health literacy obtained from a mailed survey completed by 62% of eligible breast cancer survivors (N = 1221). Multivariable analysis of variance was used to characterize the association between presence of a single healthcare professional that coordinated care ("care coordinator") and perceived care coordination, stratified by health literacy level. RESULTS: Health literacy was classified as low in 24% of patients, medium in 34%, and high in 42%. Women with high health literacy scores were more likely to report non-Hispanic white race/ethnicity, private insurance, higher education and income, and fewer comorbidities (all p < 0.001). The presence of a care coordinator was associated with 17.1% higher perceived care coordination scores among women with low health literacy when compared to those without a care coordinator, whereas a coordinator modestly improved perceived care coordination among breast cancer survivors with medium (6.9%) and high (6.2%) health literacy. CONCLUSION: The use of a single designated care coordinator may have a strong influence on care coordination in patients with lower levels of health literacy.

Factors associated with genetic testing in a cohort of breast cancer survivors.

We examined factors associated with self-reported use of genetic testing among breast cancer survivors based on a 2015 cross-sectional survey at eight Midwestern sites. Genetic testing was reported in 39% of our 1235 study participants, with higher utilization among those aged <50 and with a triple-negative cancer. Bilateral mastectomy, having relatives with breast cancer, and younger age were associated with increased genetic testing use. Increasing income, in interaction with age, was associated with use of genetic testing among younger but not older patients. Rural residency emerged as a possible barrier for genetic testing among women with triple-negative cancer.

Rat models of 17ß-estradiol-induced mammary cancer reveal novel insights into breast cancer etiology and prevention.

Numerous laboratory and epidemiologic studies strongly implicate endogenous and exogenous estrogens in the etiology of breast cancer. Data summarized herein suggest that the ACI rat model of 17ß-estradiol (E2)-induced mammary cancer is unique among rodent models in the extent to which it faithfully reflects the etiology and biology of luminal types of breast cancer, which together constitute ~70% of all breast cancers. E2 drives cancer development in this model through mechanisms that are largely dependent upon estrogen receptors and require progesterone and its receptors. Moreover, mammary cancer development appears to be associated with generation of oxidative stress and can be modified by multiple dietary factors, several of which may attenuate the actions of reactive oxygen species. Studies of susceptible ACI rats and resistant COP or BN rats provide novel insights into the genetic bases of susceptibility and the biological processes regulated by genetic determinants of susceptibility. This review summarizes research progress resulting from use of these physiologically relevant rat models to advance understanding of breast cancer etiology and prevention.