Medication Use for the Risk Reduction of Primary Breast Cancer in Women: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

Society of Surgical Oncology Breast Disease Site Working Group Statement on Bilateral Risk-Reducing Mastectomy: Indications, Outcomes, and Risks

Bilateral risk-reducing mastectomy (BRRM) is the surgical removal of both breasts to reduce the risk of cancer. In this Society of Surgical Oncology position statement, we review the literature addressing the indications, outcomes, and risks of BRRM to update the society's 2017 statement. We held a virtual meeting to outline key topics and conducted a literature search using PubMed to identify relevant articles. After literature review, recommendations were made according to group consensus. Individuals with a high lifetime risk of breast cancer due to pathogenic variants in high penetrance breast cancer-predisposition genes, early chest or breast radiation exposure, or a compelling family history should be counseled on the option of BRRM. However, BRRM is not recommended for most patients with high-risk lesions and may be contraindicated in patients who have other competing cancers and/or a high risk of surgical complications. BRRM effectively reduces the risk of breast cancer development, although the survival benefit is unclear. For patients with low-to-moderate breast cancer risk, alternative management strategies should be encouraged, including lifestyle modifications, high-risk screening, and risk-reducing medications. Discussions of BRRM should cover: (1) breast-cancer risk estimates; (2) the procedure's degree of risk reduction and impact on survival; (3) surgical techniques, potential surgical complications and long-term sequelae; and (4) alternatives to surgery. Surgeons should encourage shared and informed decision making with patients who have an elevated lifetime risk of developing breast cancer.

Breast cancer incidence and mortality by metabolic syndrome and obesity: The Women's Health Initiative

BACKGROUND

In the Women's Health Initiative (WHI) randomized trial, dietary intervention significantly reduced breast cancer mortality, especially in women with more metabolic syndrome (MetS) components. Therefore, this study investigated the associations of MetS and obesity with postmenopausal breast cancer after long-term follow-up in the WHI clinical trials.

METHODS

A total of 68,132 postmenopausal women, without prior breast cancer and with normal mammogram, were entered into WHI randomized clinical trials; 63,330 women with an entry MetS score comprised the study population. At entry, body mass index (BMI) was determined; MetS score (0, 1-2, and 3-4) included the following: (1) high waist circumference (≥88 cm), (2) high blood pressure (systolic ≥130 mm Hg and/or diastolic ≥85 mm Hg, or hypertension history), (3) high-cholesterol history, and (4) diabetes history. Study outcomes included breast cancer incidence, breast cancer mortality, deaths after breast cancer, and results by hormone receptor status.

RESULTS

After a >20-year mortality follow-up, a higher MetS score (3-4), adjusted for BMI, was significantly associated with more poor prognosis, estrogen receptor (ER)-positive, progesterone receptor (PR)-negative cancers (p = .03), 53% more deaths after breast cancer (p < .001), and 44% higher breast cancer mortality (p = .03). Obesity status, adjusted for MetS score, was significantly associated with more good prognosis, ER-positive, PR-positive cancers (p < .001), more total breast cancers (p < .001), and more deaths after breast cancer (p < .001), with higher breast cancer mortality only in women with severe obesity (BMI, ≥35 kg/m2; p < .001).

CONCLUSIONS

MetS and obesity status have independent, but differential, adverse associations with breast cancer receptor subtypes and breast cancer mortality risk. Both represent separate targets for breast cancer prediction and prevention strategies.

Breast Cancer Risk Assessment Tool (BCRAT) and long-term breast cancer mortality in the Women's Health Initiative

BACKGROUND

While the Breast Cancer Risk Assessment Tool (BCRAT) predicts breast cancer incidence, the model's performance, re-purposed to predict breast cancer mortality, is uncertain. Therefore, we examined whether the BCRAT model predicts breast cancer mortality in postmenopausal women in the Women's Health Initiative (WHI).

METHODS

BCRAT 5-year breast cancer incidence risk estimates were calculated for 145,408 women (aged 50-79 years) enrolled in the WHI at 40 US clinical centers to examine associations of BCRAT risk groups (< 1%, 1-< 3%, ≥ 3%) with breast cancer mortality using Cox proportional regression modeling in all participants and in those with incident breast cancer.

RESULTS

Women with BCRAT ≥ 3% risk, compared to women with BCRAT < 1% risk, were older (age 70-79 years: 38.3% versus 5.3%), less commonly Black (1.1% versus 40.2%), and had stronger breast cancer family history. With 20-years follow-up, considering all participants, with 8,849 breast cancers and 1,076 breast cancer deaths, breast cancer mortality in BCRAT group ≥ 3% was not higher versus BCRAT group < 1% (Hazard Ratio [HR] 1.06 95% Confidence Interval [CI] 0.80-1.40): percent without 20-year breast cancer mortality; 99.4% [group < 1%] and 98.8% [group ≥ 3%]. Considering women with incident breast cancer, breast cancer mortality was also not higher in BCRAT group ≥ 3% versus BCRAT group < 1% (HR 1.07 95% CI 0.79-1.45).

CONCLUSIONS

The BCRAT model, at ≥ 3% 5-year incidence risk (US guideline threshold for chemoprevention), does not identify women with higher breast cancer mortality risk, with implications for breast cancer prevention strategies.

Randomized trials of estrogen-alone and breast cancer incidence: a meta-analysis

PURPOSE

In the Women's Health initiative (WHI) randomized clinical trial, conjugated equine estrogen (CEE)-alone significantly reduced breast cancer incidence (P = 0.005). As cohort studies had opposite findings, other randomized clinical trials were identified to conduct a meta-analysis of estrogen-alone influence on breast cancer incidence.

METHODS

We conducted literature searches on randomized trials and: estrogen, hormone therapy, and breast cancer, and searches from a prior meta-analysis and reviews. In the meta-analysis, for trials with published relative risks (RR) and 95% confidence intervals (CI), each log-RR was multiplied by weight = 1/V, where V = variance of the log-RR, and V was derived from the corresponding 95% CI. For smaller trials with only breast cancer numbers, the corresponding log-RR = (O - E)/weight, where O is the observed case number in the oestrogen-alone group and E the corresponding expected case number, E = nP.

RESULTS

Findings from 10 randomized trials included 14,282 participants and 591 incident breast cancers. In 9 smaller trials, with 1.2% (24 of 2029) vs 2.2% (33 of 1514) randomized to estrogen-alone vs placebo (open label, one trial) (RR 0.65 95% CI 0.38-1.11, P = 0.12). For 5 trials evaluating estradiol formulations, RR = 0.63 95% CI 0.34-1.16, P = 0.15. Combining the 10 trials, 3.6% (262 of 7339) vs 4.7% (329 of 6943) randomized to estrogen-alone vs placebo (overall RR 0.77 95% CI 0.65-0.91, P = 0.002).

CONCLUSION

The totality of randomized clinical trial evidence supports a conclusion that estrogen-alone use significantly reduces breast cancer incidence.

Different Oncogenes and Reproductive Histories Shape the Progression of Distinct Premalignant Clones in Multistage Mouse Breast Cancer Models

A remote carcinogen exposure can predispose to breast cancer onset decades later, suggesting that carcinogen-induced mutations generate long-lived premalignant clones. How subsequent events influence the progression of specific premalignant clones remains poorly understood. Herein, multistage mouse models of mammary carcinogenesis were generated by combining chemical carcinogen exposure [using 7,12-dimethylbenzanthracene (DMBA)] with transgenes that enable inducible expression of one of two clinically relevant mammary oncogenes: c-MYC (MYC) or PIK3CAH1047R (PIK). In prior work, DMBA exposure generated mammary clones bearing signature HrasQ61L mutations, which only progressed to mammary cancer after inducible Wnt1 oncogene expression. Here, after an identical DMBA exposure, MYC versus PIK drove cancer progression from mammary clones bearing mutations in distinct Ras family paralogs. For example, MYC drove cancer progression from either Kras- or Nras-mutant clones, whereas PIK transformed Kras-mutant clones only. These Ras mutation patterns were maintained whether oncogenic transgenes were induced within days of DMBA exposure or months later. Completing a full-term pregnancy (parity) failed to protect against either MYC- or PIK-driven tumor progression. Instead, a postpartum increase in mammary tumor predisposition was observed in the context of PIK-driven progression. However, parity decreased the overall prevalence of tumors bearing Krasmut, and the magnitude of this decrease depended on both the number and timing of pregnancies. These multistage models may be useful for elucidating biological features of premalignant mammary neoplasia.

Implementation of risk assessment process for breast cancer risk in primary care

Background

Current cancer prevention guidelines recommend assessing breast cancer risk using validated risk calculators such as Tyrer-Cuzick and assessing genetic testing eligibility with NCCN. Women at high-risk of breast cancer may be recommended to undergo additional or earlier screening. Risk assessment is not consistently implemented in the primary care setting resulting in increased morbidity and mortality in unidentified high-risk individuals.

Methods

A single-arm interventional study was conducted in an academic primary care clinic for women 25-50 years old presenting for primary care appointments. Pre-visit workflows evaluated breast cancer risk using the Cancer Risk Assessment (CRA) Tool and information was provided to the clinician with guideline-based recommendations. Post-visit questionnaires and chart review were conducted.

Results

The survey response rate was 24.5% (144/587) with 80.3% of responses completed online (94/117). The average age of respondents was 35.8 years with 50.4% White and 35.9% Black. There were no differences in response rate based on race. Risk discussion was documented in the medical record in 15.4% of cases with a higher rate of documentation in high-risk patient based on risk assessment as compared with average risk respondents (34.6% vs. 9.7%, p<0.01). In the high-risk women identified 11.4% (4/35) were seen by the high-risk breast clinic, and 5.7% (2/35) were referred for genetic evaluation. None had previously obtained MRI screening or genetic testing.

Conclusions

There is limited identification and evaluation of women at high risk for breast cancer. Pre-visit surveys can be used as a tool to assess breast cancer risk in the primary care setting; however additional strategies are needed to implement systematic risk assessment and facilitate appropriate treatment based on risk level.

Online Provision of BRCA1 and BRCA2 Health Information: A Search Engine Driven Systematic Web-Based Analysis

BRCA genetic testing is available for UK Jewish individuals but the provision of information online for BRCA is unknown. We aimed to evaluate online provision of BRCA information by UK organisations (UKO), UK Jewish community organisations (JCO), and genetic testing providers (GTP). Google searches for organisations offering BRCA information were performed using relevant sets of keywords. The first 100 website links were categorised into UKOs/JCOs/GTPs; additional JCOs were supplemented through community experts. Websites were reviewed using customised questionnaires for BRCA information. Information provision was assessed for five domains: accessibility, scope, depth, accuracy, and quality. These domains were combined to provide a composite score (maximum score = 5). Results were screened (n = 6856) and 45 UKOs, 16 JCOs, and 18 GTPs provided BRCA information. Accessibility was high (84%,66/79). Scope was lacking with 35% (28/79) addressing >50% items. Most (82%, 65/79) described BRCA-associated cancers: breast and/or ovarian cancer was mentioned by 78%(62/79), but only 34% (27/79) mentioned ≥1 pancreatic, prostate, melanoma. Few websites provided carrier frequencies in the general (24%,19/79) and Jewish populations (20%,16/79). Only 15% (12/79) had quality information with some/minimal shortcomings. Overall information provision was low-to-moderate: median scores UKO = 2.1 (IQR = 1), JCO = 1.6 (IQR = 0.9), and GTP = 2.3 (IQR = 1) (maximum-score = 5). There is a scarcity of high-quality BRCA information online. These findings have implications for UK Jewish BRCA programmes and those considering BRCA testing.

Tumor initiation and early tumorigenesis: molecular mechanisms and interventional targets

Tumorigenesis is a multistep process, with oncogenic mutations in a normal cell conferring clonal advantage as the initial event. However, despite pervasive somatic mutations and clonal expansion in normal tissues, their transformation into cancer remains a rare event, indicating the presence of additional driver events for progression to an irreversible, highly heterogeneous, and invasive lesion. Recently, researchers are emphasizing the mechanisms of environmental tumor risk factors and epigenetic alterations that are profoundly influencing early clonal expansion and malignant evolution, independently of inducing mutations. Additionally, clonal evolution in tumorigenesis reflects a multifaceted interplay between cell-intrinsic identities and various cell-extrinsic factors that exert selective pressures to either restrain uncontrolled proliferation or allow specific clones to progress into tumors. However, the mechanisms by which driver events induce both intrinsic cellular competency and remodel environmental stress to facilitate malignant transformation are not fully understood. In this review, we summarize the genetic, epigenetic, and external driver events, and their effects on the co-evolution of the transformed cells and their ecosystem during tumor initiation and early malignant evolution. A deeper understanding of the earliest molecular events holds promise for translational applications, predicting individuals at high-risk of tumor and developing strategies to intercept malignant transformation.

Authorization of anastrazole to prevent breast cancer in postmenopausal women: a bad idea

Anastrazole has recently been approved for the prevention of breast cancer in high-risk women in the UK. When given to high-risk women anastrazole halves the risk of developing breast cancer but doesn't reduce the risk of breast cancer death and is associated with significant harms. Women need to be counselled about both the benefits and risks associated with anastrazole use to enable an informed treatment choice.

Personalized survivorship care: Routine breast cancer risk assessment in the gynecologic oncology clinic

INTRODUCTION

Gynecologic and breast cancers share several risk factors. Breast cancer risk assessment tools can identify those at elevated risk and allow for enhanced breast surveillance and chemoprevention, however such tools are underutilized. We aim to evaluate the use of routine breast cancer risk assessment in a gynecologic oncology clinic.

METHODS

A patient-facing web-based tool was used to collect personal and family history and run four validated breast cancer risk assessment models (Tyrer-Cuzick (TC), Gail, BRCAPRO, and Claus) in a gynecologic oncology clinic. We evaluated completion of the tools and identification of patients at elevated risk for breast cancer using the four validated models.

RESULTS

A total of 99 patients were included in this analysis. The BRCAPRO model had the highest completion rate (84.8%), followed by the TC model (74.7%), Gail model (74.7%), and the Claus model (52.1%). The TC model identified 21.6% of patients completing the model as having ≥20% lifetime risk of breast cancer, compared to 6.8% by the Gail model, and 0% for both the BRCAPRO and Claus models. The Gail model identified 52.5% of patients as having ≥1.67% 5-year risk of breast cancer. Among patients identified as high-risk for breast cancer and eligible for screening, 9/9 (100%) were referred to a high-risk breast clinic.

CONCLUSION

Among patients that completed the TC breast cancer risk assessment in a gynecologic oncology clinic, approximately 1 in 5 were identified to be at significantly elevated lifetime risk for breast cancer. The gynecologic oncologist's office might offer a convenient and feasible setting to incorporate this risk assessment into routine patient care, as gynecologic oncologists often have long-term patient relationships and participate in survivorship care.

Cabergoline as a Novel Strategy for Post-Pregnancy Breast Cancer Prevention in Mice and Human

Post-pregnancy breast cancer often carries a poor prognosis, posing a major clinical challenge. The increasing trend of later-life pregnancies exacerbates this risk, highlighting the need for effective chemoprevention strategies. Current options, limited to selective estrogen receptor modulators, aromatase inhibitors, or surgical procedures, offer limited efficacy and considerable side effects. Here, we report that cabergoline, a dopaminergic agonist, reduces the risk of breast cancer post-pregnancy in a Brca1/P53-deficient mouse model, with implications for human breast cancer prevention. We show that a single dose of cabergoline administered post-pregnancy significantly delayed the onset and reduced the incidence of breast cancer in Brca1/P53-deficient mice. Histological analysis revealed a notable acceleration in post-lactational involution over the short term, characterized by increased apoptosis and altered gene expression related to ion transport. Over the long term, histological changes in the mammary gland included a reduction in the ductal component, decreased epithelial proliferation, and a lower presence of recombinant Brca1/P53 target cells, which are precursors of tumors. These changes serve as indicators of reduced breast cancer susceptibility. Additionally, RNA sequencing identified gene expression alterations associated with decreased proliferation and mammary gland branching. Our findings highlight a mechanism wherein cabergoline enhances the protective effect of pregnancy against breast cancer by potentiating postlactational involution. Notably, a retrospective cohort study in women demonstrated a markedly lower incidence of post-pregnancy breast cancer in those treated with cabergoline compared to a control group. Our work underscores the importance of enhancing postlactational involution as a strategy for breast cancer prevention, and identifies cabergoline as a promising, low-risk option in breast cancer chemoprevention. This strategy has the potential to revolutionize breast cancer prevention approaches, particularly for women at increased risk due to genetic factors or delayed childbirth, and has wider implications beyond hereditary breast cancer cases.

A randomized Phase I pre-operative window trial of transdermal endoxifen in women planning mastectomy: Evaluation of dermal safety, intra-mammary drug distribution, and biologic effects

Breast cancer prevention only requires local exposure of the breast to active drug. However, oral preventive agents entail systemic exposure, causing adverse effects that limit acceptance by high-risk women. Drug-delivery through the breast skin is an attractive option, but requires demonstration of dermal safety and drug distribution throughout the breast. We formulated the tamoxifen metabolite (E/Z)-endoxifen for transdermal delivery and tested it in a placebo-controlled, double-blinded Phase I trial with dose escalation from 10 to 20 mg daily. The primary endpoint was dermal toxicity. Thirty-two women planning mastectomy were randomized (2:1) to endoxifen-gel or placebo-gel applied to both breasts for 3-5 weeks. Both doses of endoxifen-gel incurred no dermal or systemic toxicity compared to placebo. All endoxifen-treated breasts contained the drug at each of five sampling locations; the median per-person tissue concentration in the treated participants was 0.6 ng/g (IQR 0.4-1.6), significantly higher (p < 0.001) than the median plasma concentration (0.2 ng/mL, IQR 0.2-0.2). The median ratio of the more potent (Z)-isomer to (E)-isomer at each breast location was 1.50 (IQR 0.96-2.54, p < 0.05). No discernible effects of breast size or adiposity on tissue concentrations were observed. At the endoxifen doses and duration used, and the tissue concentration achieved, we observed a non-significant overall reduction of tumor proliferation (Ki67 LI) and significant downregulation of gene signatures known to promote cancer invasion (FN1, SERPINH1, PLOD2, PDGFA, ITGAV) (p = 0.03). Transdermal endoxifen is an important potential breast cancer prevention agent but formulations with better dermal penetration are needed.

Factors associated with adherence to medications for lowering breast cancer risk between female Medicare beneficiaries in Alabama and nationwide

PURPOSE

The U.S. Preventive Services Task Force recommends use of selective estrogen receptor modulators (SERMs) and aromatase inhibitors (AIs) for breast cancer (BC) prevention. We examined factors associated with adherence to SERMs/AI treatments among female Medicare beneficiaries in Alabama and those nationwide.

METHODS

This retrospective new user cohort study analyzed the 2013-2016 Medicare administrative claims data files (100% Alabama and random 5% national samples). Female Medicare beneficiaries without invasive BC and osteoporosis, continuously enrolled in Medicare Parts A, B, and D for at least 18 months (with a 6-month washout and a 12-month follow-up period) in 2013-2016. Among beneficiaries who initiated (6-month washout) any of the SERMs/AIs (tamoxifen, raloxifene, anastrozole, and exemestane), we examined their 1-year treatment adherence using proportion of days covered (PDC) and operationalized as both continuous (0-1) and dichotomized (≥ 80% as adherent and < 80% as non-adherent) outcomes. Multivariable logistic models were used to identify factors associated with adherence (PDC ≥ 80%) among Alabama and national samples, respectively.

RESULTS

A total of 885 women in Alabama and 1,213 women in national sample initiated these SERMs/AI treatments. Among those with ≥ 2 prescriptions (n = 479 in Alabama and n = 870 in national sample), Mean PDC was 0.74 [standard deviation (SD) = 0.30] among Alabamian women, similar to those in the national sample [0.71 (SD = 0.31), p = 0.09]. Use of mammography prior to treatment initiation was associated with higher likelihood of adherence to treatments in both samples.

CONCLUSION

Our findings highlight the importance of access to preventive services such as mammography to better adherence to BC preventive treatments among female Medicare beneficiaries.

Development of a Hereditary Breast and Ovarian Cancer and Genetics Curriculum for Community Health Workers: KEEP IT (Keeping Each other Engaged Program via IT) Community Health Worker Training

We developed a curriculum for community health workers (CHWs) using an innovative, community-engaged focus group and Delphi process approach. Equipping CHWs with knowledge of hereditary breast and ovarian cancer syndrome (HBOC) and genetics could help enhance identification of women at risk for HBOC, referral, and navigation through genetic services. We conducted focus groups with five CHWs and a three-round Delphi process with eight experts. In the first round of the Delphi process, participants rated and commented on draft curriculum modules. The second round involved live video discussion to highlight points of confusion and concern in the modules. The curriculum was revised and refined based on quantitative and qualitative data and reassessed by the experts in Round 3. Ultimately, agreement was achieved on eight of 10 modules when assessing for clarity of learning objectives, seven out of 10 when assessing for adult learning theory, and nine out of 10 when assessing for participants' ability to learn desired knowledge. We plan to virtually deliver this curriculum to CHWs to enhance their HBOC and genomic competencies. By equipping CHWs to understand and participate in genomics education, we can enable more equitable participation in genomics-informed clinical care and research. Beyond this curriculum, the Delphi methodology can further be used to design content for new CHW curriculums.

Identifying actionable druggable targets for breast cancer: Mendelian randomization and population-based analyses

BACKGROUND

Drug repurposing provides a cost-effective approach to address the need for breast cancer prevention and therapeutics. We aimed to identify actionable druggable targets using Mendelian randomization (MR) and then validate the candidate drugs using population-based analyses.

METHODS

We identified genetic instruments for 1406 actionable targets of approved non-oncological drugs based on gene expression, DNA methylation, and protein expression quantitative trait loci (eQTL, mQTL, and pQTL, respectively). Genome-wide association study (GWAS) summary statistics were obtained from the Breast Cancer Association Consortium (122,977 cases, 105,974 controls). We further conducted a nested case-control study using data retrieved from Swedish registers to validate the candidate drugs that were identified from MR analyses.

FINDINGS

We identified six significant MR associations with gene expression levels (TUBB, MDM2, CSK, ULK3, MC1R and KCNN4) and two significant associations with gene methylation levels across 21 CpG islands (RPS23 and MAPT). Results from the nested case-control study showed that the use of raloxifene (targeting MAPT) was associated with 35% reduced breast cancer risk (odds ratio, OR, 0.65; 95% confidence interval, CI, 0.51-0.83). However, usage of estradiol, tolterodine, and nitrofurantoin (also targeting MAPT) was associated with increased breast cancer risk, with adjusted ORs and 95% CI of 1.10 (1.07-1.13), 1.16 (1.09-1.24), and 1.09 (1.05-1.13), respectively. The effect of raloxifene and nitrofurantoin lost significance in further validation analyses using active-comparator and new-user design.

INTERPRETATION

This large-scale MR analysis, combined with population-based validation, identified eight druggable target genes for breast cancer and suggested that raloxifene is an effective chemoprevention against breast cancer.

FUNDING

Swedish Research Council, Cancerfonden, Crafoordska Stiftelsen, Allmänna Sjukhusets i Malmö Stiftelsen för bekämpande av cancer, 111 Project and MAS cancer.

Dynamic Risk Prediction of Treatment Discontinuation Using Patient-Reported Outcomes Data in the Phase III NSABP B-35 Trial

Predicting an individual's risk of treatment discontinuation is critical for the implementation of precision chemoprevention. We developed partly conditional survival models to predict discontinuation of tamoxifen or anastrozole using patient-reported outcome (PRO) data from postmenopausal women with ductal carcinoma in situ enrolled in the NSABP B-35 clinical trial. In a secondary analysis of the NSABP B-35 clinical trial PRO data, we proposed two models for treatment discontinuation within each treatment arm (anastrozole or tamoxifen treated patients) using partly conditional Cox-type models with time-dependent covariates. A 70/30 split of the sample was used for the training and validation datasets. The predictive performance of the models was evaluated using calibration and discrimination measures based on the Brier score and AUC from time-dependent ROC curves. The predictive models stratified high-risk versus low-risk early discontinuation at a 6-month horizon. For anastrozole-treated patients, predictive factors included baseline body mass index (BMI) and longitudinal patient-reported symptoms such as insomnia, joint pain, hot flashes, headaches, gynecologic symptoms, and vaginal discharge, all collected up to 12 months [Brier score, 0.039; AUC, 0.76; 95% confidence interval (CI), 0.57-0.95]. As for tamoxifen-treated patients, predictive factors included baseline BMI, and time-dependent covariates: cognitive problems, feelings of happiness, calmness, weight problems, and pain (Brier score, 0.032; AUC, 0.78; 95% CI, 0.65-0.91). A real-time calculator based on these models was developed in Shiny to create a web-based application with a future goal to aid healthcare professionals in decision-making.

PREVENTION RELEVANCE

The dynamic prediction provided by partly conditional models offers valuable insights into the treatment discontinuation risks using PRO data collected over time from clinical trial participants. This tool may benefit healthcare professionals in identifying patients at high risk of premature treatment discontinuation and support interventions to prevent potential discontinuation.

Breast Cancer Screening and Prevention

Breast cancer is the most common cancer among U.S. women and its incidence increases with age. Endogenous estrogen exposure, proliferative benign breast disease, breast density, and family history may also indicate increased risk for breast cancer. Early detection with screening mammography reduces breast cancer mortality, but the net benefits vary by age. Assessing a patient's individual breast cancer risk can guide decisions regarding breast cancer screening. All women benefit from healthy behaviors which may reduce breast cancer risk. Some women at increased risk for breast cancer may benefit from risk-reducing medications. Use of screening measures remains suboptimal, especially for uninsured women.

Chemoprevention and Lifestyle Modifications for Risk Reduction in Sporadic and Hereditary Breast Cancer

Female breast cancer is the most commonly diagnosed malignancy worldwide. Risk assessment helps to identify women at increased risk of breast cancer and allows the adoption of a comprehensive approach to reducing breast cancer incidence through personalized interventions, including lifestyle modification, chemoprevention, intensified surveillance with breast imaging, genetic counseling, and testing. Primary prevention means acting on modifiable risk factors to reduce breast cancer occurrence. Chemoprevention with tamoxifen, raloxifene, anastrozole, and exemestane has already shown benefits in decreasing breast cancer incidence in women at an increased risk for breast cancer. For healthy women carrying BRCA 1 or BRCA 2 pathogenic/likely pathogenic (P/LP) germline variants, the efficacy of chemoprevention is still controversial. Adopting chemoprevention strategies and the choice among agents should depend on the safety profile and risk-benefit ratio. Unfortunately, the uptake of these agents has been low. Lifestyle modifications can reduce breast cancer incidence, and the recommendations for BRCA 1 or BRCA 2 P/LP germline variant carriers are comparable to the general population. This review summarizes the most recent evidence regarding the efficacy of chemoprevention and lifestyle interventions in women with sporadic and hereditary breast cancer.

Tamoxifen and the risk of breast cancer in women with a BRCA1 or BRCA2 mutation

PURPOSE

Chemoprevention with a selective estrogen receptor modulator (tamoxifen or raloxifene) is a non-surgical option offered to high-risk women to reduce the risk of breast cancer. The evidence for tamoxifen benefit is based on trials conducted among predominantly postmenopausal women from the general population and on studies of contralateral breast cancer in women with a pathogenic variant (mutation hereafter) in BRCA1 or BRCA2. Tamoxifen has not been assessed as a primary prevention agent in women with an inherited BRCA mutation.

METHODS

We conducted a prospective analysis of tamoxifen chemoprevention and the risk of breast cancer in women with a BRCA1 or BRCA2 mutation. Data on tamoxifen (and raloxifene) use was collected by questionnaire and updated biennially. Information on incident cancers was collected by self-report and was confirmed by medical record review. In a matched analysis, we estimated the hazard ratio (HR) and 95% confidence intervals (CI) for developing a first primary breast cancer associated with tamoxifen or raloxifene use, using Cox proportional hazards analysis.

RESULTS

There were 4578 unaffected women in the cohort, of whom 137 reported tamoxifen use (3%), 83 reported raloxifene use (2%) and 12 used both drugs (0.3%). Women who used tamoxifen or raloxifene were matched 1:3 with women who used neither drug on year of birth, country of residence, year of study entry and gene (BRCA1 or BRCA2). We generated 202 matched pairs. After a mean follow-up of 6.8 years, there were 22 incident breast cancers diagnosed among tamoxifen/raloxifene users (10.9% of users) and 71 cases diagnosed among non-users (14.3% of non-users; HR = 0.64; 95% CI 0.40-1.03; P = 0.07).

CONCLUSION

Chemoprevention may be an effective risk-reduction option for BRCA mutation carriers, but further studies with longer follow-up are necessary.

A comparison of cardiovascular and pulmonary morbidities and risk factors in breast cancer survivors compared to an age-matched female control group in the Lifelines prospective population cohort

PURPOSE

To provide more insight into late treatment-related toxicities among breast cancer (BC) survivors by comparing morbidities and risk factors between BC survivors and age-matched controls.

MATERIALS AND METHODS

All female participants diagnosed with BC before inclusion in Lifelines, a population-based cohort in the Netherlands, were selected and matched 1:4 to female controls without any oncological history on birth year. Baseline was defined as the age at BC diagnosis. Outcomes were obtained from questionnaires and functional analyses performed at entry to Lifelines (follow-up 1; FU1) and several years later (FU2). Cardiovascular and pulmonary events were defined as morbidities that were absent at baseline but present at FU1 or FU2.

RESULTS

The study consisted of 1,325 BC survivors and 5,300 controls. The median period from baseline (i.e., BC treatment) to FU1 and FU2 was 7 and 10 years, respectively. Among BC survivors more events of heart failure (OR: 1.72 [1.10-2.68]) and less events of hypertension (OR: 0.79 [0.66-0.94]) were observed. At FU2, more electrocardiographic abnormalities were found among BC survivors compared to controls (4.1% vs. 2.7%, respectively; p = 0.027) and Framingham scores for the 10-year risk of coronary heart disease were lower (difference: 0.37%; 95% CI [-0.70 to -0.03%]). At FU2, BC survivors had more frequently a forced vital capacity below the lower limit of normal than controls (5.4% vs. 2.9%, respectively; p = 0.040).

CONCLUSION

BC survivors are at risk of late treatment-related toxicities despite a more favourable cardiovascular risk profile compared to age-matched female controls.

Identification of BRCA1/2 mutation female carriers using circulating microRNA profiles

Identifying germline BRCA1/2 mutation carriers is vital for reducing their risk of breast and ovarian cancer. To derive a serum miRNA-based diagnostic test we used samples from 653 healthy women from six international cohorts, including 350 (53.6%) with BRCA1/2 mutations and 303 (46.4%) BRCA1/2 wild-type. All individuals were cancer-free before and at least 12 months after sampling. RNA-sequencing followed by differential expression analysis identified 19 miRNAs significantly associated with BRCA mutations, 10 of which were ultimately used for classification: hsa-miR-20b-5p, hsa-miR-19b-3p, hsa-let-7b-5p, hsa-miR-320b, hsa-miR-139-3p, hsa-miR-30d-5p, hsa-miR-17-5p, hsa-miR-182-5p, hsa-miR-421, hsa-miR-375-3p. The final logistic regression model achieved area under the receiver operating characteristic curve 0.89 (95% CI: 0.87-0.93), 93.88% sensitivity and 80.72% specificity in an independent validation cohort. Mutated gene, menopausal status or having preemptive oophorectomy did not affect classification performance. Circulating microRNAs may be used to identify BRCA1/2 mutations in patients of high risk of cancer, offering an opportunity to reduce screening costs.

FGFR2 Controls Growth, Adhesion and Migration of Nontumorigenic Human Mammary Epithelial Cells by Regulation of Integrin β1 Degradation

The role of fibroblast growth factor receptor 2 (FGFR2), an important mediator of stromal paracrine and autocrine signals, in mammary gland morphogenesis and breast cancer has been extensively studied over the last years. However, the function of FGFR2 signalling in the initiation of mammary epithelial oncogenic transformation remains elusive. Here, FGFR2-dependent behaviour of nontumorigenic model of mammary epithelial cells was studied. In vitro analyses demonstrated that FGFR2 regulates epithelial cell communication with extracellular matrix (ECM) proteins. Silencing of FGFR2 significantly changed the phenotype of cell colonies in three-dimensional cultures, decreased integrins α2, α5 and β1 protein levels and affected integrin-driven processes, such as cell adhesion and migration. More detailed analysis revealed the FGFR2 knock-down-induced proteasomal degradation of integrin β1. Analysis of RNA-seq databases showed significantly decreased FGFR2 and ITGB1 mRNA levels in breast tumour samples, when compared to non-transformed tissues. Additionally, high risk healthy individuals were found to have disrupted correlation profiles of genes associated with FGFR2 and integrin signalling, cell adhesion/migration and ECM remodelling. Taken together, our results strongly suggest that FGFR2 loss with concomitant integrin β1 degradation is responsible for deregulation of epithelial cell-ECM interactions and this process may play an important role in the initiation of mammary gland epithelial tumorigenesis.

Side effects of low-dose tamoxifen: results from a six-armed randomised controlled trial in healthy women

BACKGROUND

Adherence to adjuvant tamoxifen therapy is suboptimal, and acceptance of tamoxifen for primary prevention is poor. Published results indicate effect of low-dose tamoxifen therapy. Using questionnaire data from a randomised controlled trial, we describe side effects of standard and low-dose tamoxifen in healthy women.

METHODS

In the KARISMA trial, 1440 healthy women were randomised to 6 months of daily intake of 20, 10, 5, 2.5, 1 mg of tamoxifen or placebo. Participants completed a 48-item, five-graded Likert score symptom questionnaire at baseline and follow-up. Linear regression models were used to identify significant changes in severity levels across doses and by menopausal status.

RESULTS

Out of 48 predefined symptoms, five were associated with tamoxifen exposure (hot flashes, night sweats, cold sweats, vaginal discharge and muscle cramps). When comparing these side effects in premenopausal women randomised to low doses (2.5, 5 mg) versus high doses (10, 20 mg), the mean change was 34% lower in the low-dose group. No dose-dependent difference was seen in postmenopausal women.

CONCLUSIONS

Symptoms related to tamoxifen therapy are influenced by menopausal status. Low-dose tamoxifen, in contrast to high-dose, was associated with less pronounced side effects, a finding restricted to premenopausal women. Our findings give new insights which may influence future dosing strategies of tamoxifen in both the adjuvant and preventive settings.

TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT03346200.

Randomized Placebo Controlled Trial of Low-Dose Tamoxifen to Prevent Recurrence in Breast Noninvasive Neoplasia: A 10-Year Follow-Up of TAM-01 Study

PURPOSE

Five-year data of the phase III trial TAM-01 showed that low-dose tamoxifen at 5 mg once daily administered for 3 years in women with intraepithelial neoplasia (IEN) reduced by 52% the recurrence of invasive breast cancer or ductal carcinoma in situ (DCIS), without additional adverse events over placebo. Here, we present the 10-year results.

METHODS

We randomly assigned 500 women with breast IEN (atypical ductal hyperplasia, lobular carcinoma in situ [LCIS], or hormone-sensitive or unknown DCIS) to low-dose tamoxifen or placebo after surgery with or without irradiation. The primary end point was the incidence of invasive breast cancer or DCIS.

RESULTS

The TAM-01 population included 500 women (20% atypical ductal hyperplasia, 11% LCIS, and 69% DCIS). The mean (±SD) age at the start of treatment was 54 ± 9 years, and 58% of participants were postmenopausal. After a median follow-up of 9.7 years (IQR, 8.3-10.9 years), 66 breast cancers (15 in situ; 51 invasive) were diagnosed: 25 in the tamoxifen group and 41 in the placebo group (annual rate per 1,000 person-years, 11.3 with tamoxifen v 19.5 with placebo; hazard ratio [HR], 0.58; 95% CI, 0.35 to 0.95; log-rank P = .03). Most recurrences were invasive (77%) and ipsilateral (59%). Regarding contralateral breast cancer incidence, there were six events in the tamoxifen arm and 16 in the placebo arm (HR, 0.36; 95% CI, 0.14 to 0.92; P = .025). The number needed to be treated to prevent one case of breast event with tamoxifen therapy was 22 in 5 years and 14 in 10 years. The benefit was seen across all patient subgroups. There was a significant 50% reduction of recurrence with tamoxifen in the DCIS cohort, which represents 70% of the overall population (HR, 0.50; 95% CI, 0.28 to 0.91; P = .02). No between-group difference in the incidence of serious adverse events was reported during the prolonged follow-up period.

CONCLUSION

Tamoxifen 5 mg once daily for 3 years significantly prevents recurrence from noninvasive breast cancer after 7 years from treatment cessation without long-term adverse events.

Breast Cancer Risk and Breast-Cancer-Specific Mortality following Risk-Reducing Salpingo-Oophorectomy in BRCA Carriers: A Systematic Review and Meta-Analysis

BACKGROUND

Risk-reducing salpingo-oophorectomy (RRSO) is the gold standard method of ovarian cancer risk reduction, but the data are conflicting regarding the impact on breast cancer (BC) outcomes. This study aimed to quantify BC risk/mortality in BRCA1/BRCA2 carriers after RRSO.

METHODS

We conducted a systematic review (CRD42018077613) of BRCA1/BRCA2 carriers undergoing RRSO, with the outcomes including primary BC (PBC), contralateral BC (CBC) and BC-specific mortality (BCSM) using a fixed-effects meta-analysis, with subgroup analyses stratified by mutation and menopause status.

RESULTS

RRSO was not associated with a significant reduction in the PBC risk (RR = 0.84, 95%CI: 0.59-1.21) or CBC risk (RR = 0.95, 95%CI: 0.65-1.39) in BRCA1 and BRCA2 carriers combined but was associated with reduced BC-specific mortality in BC-affected BRCA1 and BRCA2 carriers combined (RR = 0.26, 95%CI: 0.18-0.39). Subgroup analyses showed that RRSO was not associated with a reduction in the PBC risk (RR = 0.89, 95%CI: 0.68-1.17) or CBC risk (RR = 0.85, 95%CI: 0.59-1.24) in BRCA1 carriers nor a reduction in the CBC risk in BRCA2 carriers (RR = 0.35, 95%CI: 0.07-1.74) but was associated with a reduction in the PBC risk in BRCA2 carriers (RR = 0.63, 95%CI: 0.41-0.97) and BCSM in BC-affected BRCA1 carriers (RR = 0.46, 95%CI: 0.30-0.70). The mean NNT = 20.6 RRSOs to prevent one PBC death in BRCA2 carriers, while 5.6 and 14.2 RRSOs may prevent one BC death in BC-affected BRCA1 and BRCA2 carriers combined and BRCA1 carriers, respectively.

CONCLUSIONS

RRSO was not associated with PBC or CBC risk reduction in BRCA1 and BRCA2 carriers combined but was associated with improved BC survival in BC-affected BRCA1 and BRCA2 carriers combined and BRCA1 carriers and a reduced PBC risk in BRCA2 carriers.

Progesterone Receptor Gene Polymorphisms and Breast Cancer Risk

The objective of this systematic review was to investigate the association between polymorphisms in the progesterone receptor gene (PGR) and breast cancer risk. A search of PubMed, Scopus, and Web of Science databases was performed in November 2021. Study characteristics, minor allele frequencies, genotype frequencies, and odds ratios were extracted. Forty studies met the eligibility criteria and included 75 032 cases and 89 425 controls. Of the 84 PGR polymorphisms reported, 7 variants were associated with breast cancer risk in at least 1 study. These polymorphisms included an Alu insertion (intron 7) and rs1042838 (Val660Leu), also known as PROGINS. Other variants found to be associated with breast cancer risk included rs3740753 (Ser344Thr), rs10895068 (+331G/A), rs590688 (intron 2), rs1824128 (intron 3), and rs10895054 (intron 6). Increased risk of breast cancer was associated with rs1042838 (Val660Leu) in 2 studies, rs1824128 (intron 3) in 1 study, and rs10895054 (intron 6) in 1 study. The variant rs3740753 (Ser344Thr) was associated with decreased risk of breast cancer in 1 study. Mixed results were reported for rs590688 (intron 2), rs10895068 (+331G/A), and the Alu insertion. In a pooled analysis, the Alu insertion, rs1042838 (Val660Leu), rs3740753 (Ser344Thr), and rs10895068 (+331G/A) were not associated with breast cancer risk. Factors reported to contribute to differences in breast cancer risk associated with PGR polymorphisms included age, ethnicity, obesity, and postmenopausal hormone therapy use. PGR polymorphisms may have a small contribution to breast cancer risk in certain populations, but this is not conclusive with studies finding no association in larger, mixed populations.

Reassessing the Benefits and Harms of Risk-Reducing Medication Considering the Persistent Risk of Breast Cancer Mortality in Estrogen Receptor-Positive Breast Cancer

PURPOSE

Recent studies, including a meta-analysis of 88 trials, have shown higher than expected rates of recurrence and death in hormone receptor-positive breast cancer. These new findings suggest a need to re-evaluate the use of risk-reducing medication to avoid invasive breast cancer and breast cancer death in high-risk women.

METHODS

We adapted an established Cancer Intervention and Surveillance Modeling Network model to evaluate the lifetime benefits and harms of risk-reducing medication in women with a ≥ 3% 5-year risk of developing breast cancer according to the Breast Cancer Surveillance Consortium risk calculator. Model input parameters were derived from meta-analyses, clinical trials, and large observational data. We evaluated the effects of 5 years of risk-reducing medication (tamoxifen/aromatase inhibitors) with annual screening mammography ± magnetic resonance imaging (MRI) compared with no screening, MRI, or risk-reducing medication. The modeled outcomes included invasive breast cancer, breast cancer death, side effects, false positives, and overdiagnosis. We conducted subgroup analyses for individual risk factors such as age, family history, and prior biopsy.

RESULTS

Risk-reducing tamoxifen with annual screening (± MRI) decreased the risk of invasive breast cancer by 40% and breast cancer death by 57%, compared with no tamoxifen or screening. This is equivalent to an absolute reduction of 95 invasive breast cancers, and 42 breast cancer deaths per 1,000 high-risk women. However, these drugs are associated with side effects. For example, tamoxifen could increase the number of endometrial cancers up to 11 per 1,000 high-risk women. Benefits and harms varied by individual characteristics.

CONCLUSION

The addition of risk-reducing medication to screening could further decrease the risk of breast cancer death. Clinical guidelines for high-risk women should consider integrating shared decision making for risk-reducing medication and screening on the basis of individual risk factors.

Using Protection Motivation Theory to Predict Intentions for Breast Cancer Risk Management: Intervention Mechanisms from a Randomized Controlled Trial

The purpose of this study is to evaluate the direct and indirect effects of a web-based, Protection Motivation Theory (PMT)-informed breast cancer education and decision support tool on intentions for risk-reducing medication and breast MRI among high-risk women. Women with ≥ 1.67% 5-year breast cancer risk (N = 995) were randomized to (1) control or (2) the PMT-informed intervention. Six weeks post-intervention, 924 (93% retention) self-reported PMT constructs and behavioral intentions. Bootstrapped mediations evaluated the direct effect of the intervention on behavioral intentions and the mediating role of PMT constructs. There was no direct intervention effect on intentions for risk-reducing medication or MRI (p's ≥ 0.12). There were significant indirect effects on risk-reducing medication intentions via perceived risk, self-efficacy, and response efficacy, and on MRI intentions via perceived risk and response efficacy (p's ≤ 0.04). The PMT-informed intervention effected behavioral intentions via perceived breast cancer risk, self-efficacy, and response efficacy. Future research should extend these findings from intentions to behavior. ClinicalTrials.gov Identifier: NCT03029286 (date of registration: January 24, 2017).

A Randomized Controlled Trial of Soy Isoflavone Intake on Mammographic Density among Malaysian Women

Soy intake is associated with lower breast cancer risk in observational studies concerning Asian women, however, no randomized controlled trials (RCT) have been conducted among Asian women living in Asia. This three-armed RCT assessed the effects of one-year soy isoflavone (ISF) intervention on mammographic density (MD) change among healthy peri- and postmenopausal Malaysian women. This study was registered at ClinicalTrials.gov (NCT03686098). Participants were randomized into the 100 mg/day ISF Supplement, 50 mg/day ISF Diet, or control arm, and assessed for change in absolute and relative dense area from digital mammograms conducted at enrolment and after 12 months, compared over time across study arms using Kruskal-Wallis tests. Out of 118 women enrolled, 91 women completed the intervention, while 27 women (23%) were lost in follow up. The ISF supplement arm participants observed a larger decline in dense area (−1.3 cm2), compared to the ISF diet (−0.5 cm2) and control arm (−0.8 cm2), though it was not statistically significant (p = 0.48). Notably, among women enrolled within 5 years of menopause; dense area declined by 6 cm2 in the ISF supplement arm, compared to <1.0 cm2 in the control arm (p = 0.13). This RCT demonstrates a possible causal association between soy ISF intake and MD, a biomarker of breast cancer risk, among Asian women around the time of menopause, but these findings require confirmation in a larger trial.

Screening Programs for Breast Cancer: Toward Individualized, Risk-Adapted Strategies of Early Detection

Early detection of breast cancer (BC) comprises two approaches: screening of asymptomatic women in a specified target population at risk (usually a target age range for women at average risk), and early diagnosis for women with BC signs and symptoms. Screening for BC is a key health intervention for early detection. While population-based screening programs have been implemented for age-selected women, the pivotal clinical trials have not addressed the global utility nor the improvement of screening performance by utilizing more refined parameters for patient eligibility, such as individualized risk stratification. In addition, with the exception of the subset of women known to carry germline pathogenetic mutations in (high- or moderately-penetrant) cancer predisposition genes, such as BRCA1 and BRCA2, there has been less success in outreach and service provision for the unaffected relatives of women found to carry a high-risk mutation (i.e., "cascade testing") as it is in these individuals for whom such actionable information can result in cancers (and/or cancer deaths) being averted. Moreover, even in the absence of clinical cancer genetics services, as is the case for the immediate and at least near-term in most countries globally, the capacity to stratify the risk of an individual to develop BC has existed for many years, is available for free online at various sites/platforms, and is increasingly being validated for non-Caucasian populations. Ultimately, a precision approach to BC screening is largely missing. In the present chapter, we aim to address the concept of risk-adapted screening of BC, in multiple facets, and understand if there is a value in the implementation of adapted screening strategies in selected women, outside the established screening prescriptions, in the terms of age-range, screening modality and schedules of imaging.

Qualitative analysis of shared decision-making for chemoprevention in the primary care setting: provider-related barriers

Background

Chemoprevention with anti-estrogens, such as tamoxifen, raloxifene or aromatase inhibitors, have been shown to reduce breast cancer risk in randomized controlled trials; however, uptake among women at high-risk for developing breast cancer remains low. The aim of this study is to identify provider-related barriers to shared decision-making (SDM) for chemoprevention in the primary care setting.

Methods

Primary care providers (PCPs) and high-risk women eligible for chemoprevention were enrolled in a pilot study and a randomized clinical trial of web-based decision support tools to increase chemoprevention uptake. PCPs included internists, family practitioners, and gynecologists, whereas patients were high-risk women, age 35–75 years, who had a 5-year invasive breast cancer risk ≥ 1.67%, according to the Gail model. Seven clinical encounters of high-risk women and their PCPs who were given access to these decision support tools were included in this study. Audio-recordings of the clinical encounters were transcribed verbatim and analyzed using grounded theory methodology.

Results

Six primary care providers, of which four were males (mean age 36 [SD 6.5]) and two were females (mean age 39, [SD 11.5]) and seven racially/ethnically diverse high-risk female patients participated in this study. Qualitative analysis revealed three themes: (1) Competing demands during clinical encounters; (2) lack of knowledge among providers about chemoprevention; and (3) limited risk communication during clinical encounters.

Conclusions

Critical barriers to SDM about chemoprevention were identified among PCPs. Providers need education and resources through decision support tools to engage in risk communication and SDM with their high-risk patients, and to gain confidence in prescribing chemoprevention in the primary care setting.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12911-022-01954-y.

Mechanistic Effects of Estrogens on Breast Cancer

PURPOSE

Current concepts regarding estrogen and its mechanistic effects on breast cancer in women are evolving. This article reviews studies that address estrogen-mediated breast cancer development, the prevalence of occult tumors at autopsy, and the natural history of breast cancer as predicted by a newly developed tumor kinetic model.

METHODS

This article reviews previously published studies from the authors and articles pertinent to the data presented.

RESULTS

We discuss the concepts of adaptive hypersensitivity that develops in response to long-term deprivation of estrogen and results in both increased cell proliferation and apoptosis. The effects of menopausal hormonal therapy on breast cancer in postmenopausal women are interpreted based on the tumor kinetic model. Studies of the administration of a tissue selective estrogen complex in vitro, in vivo, and in patients are described. We review the various clinical studies of breast cancer prevention with selective estrogen receptor modulators and aromatase inhibitors. Finally, the effects of the underlying risk of breast cancer on the effects of menopausal hormone therapy are outlined.

DISCUSSION

The overall intent of this review is to present data supporting recent concepts, discuss pertinent literature, and critically examine areas of controversy.

Management of Postmenopausal Osteoporosis: ACOG Clinical Practice Guideline No. 2

PURPOSE

To provide updated evidence-based recommendations for the treatment of postmenopausal osteoporosis.

TARGET POPULATION

Postmenopausal patients with primary osteoporosis.

METHODS

This guideline was developed using an a priori protocol in conjunction with a writing team consisting of two specialists in obstetrics and gynecology appointed by the ACOG Committee on Clinical Practice Guidelines-Gynecology and one external subject matter expert. ACOG medical librarians completed a comprehensive literature search for primary literature within Cochrane Library, Cochrane Collaboration Registry of Controlled Trials, EMBASE, PubMed, and MEDLINE. Studies that moved forward to the full-text screening stage were assessed by two authors from the writing team based on standardized inclusion and exclusion criteria. Included studies underwent quality assessment, and a modified GRADE (Grading of Recommendations Assessment, Development, and Evaluation) evidence-to-decision framework was applied to interpret and translate the evidence into recommendation statements.

RECOMMENDATIONS

This Clinical Practice Guideline includes updated recommendations on who should receive osteoporosis pharmacotherapy, the benefits and risks of available pharmacotherapy options, treatment monitoring and follow-up, and the role of calcium and vitamin D in the management of postmenopausal osteoporosis. Recommendations are classified by strength and evidence quality. Ungraded Good Practice Points are included to provide guidance when a formal recommendation could not be made because of inadequate or nonexistent evidence.

Women's health behaviour change after receiving breast cancer risk estimates with tailored screening and prevention recommendations

Background

The Predicting Risk of Cancer at Screening (PROCAS) study provided women who were eligible for breast cancer screening in Greater Manchester (United Kingdom) with their 10-year risk of breast cancer, i.e., low (≤1.5%), average (1.5–4.99%), moderate (5.-7.99%) or high (≥8%). The aim of this study is to explore which factors were associated with women’s uptake of screening and prevention recommendations. Additionally, we evaluated women’s organisational preferences regarding tailored screening.

Methods

A total of 325 women with a self-reported low (n = 60), average (n = 125), moderate (n = 80), or high (n = 60) risk completed a two-part web-based survey. The first part contained questions about personal characteristics. For the second part women were asked about uptake of early detection and preventive behaviours after breast cancer risk communication. Additional questions were posed to explore preferences regarding the organisation of risk-stratified screening and prevention. We performed exploratory univariable and multivariable regression analyses to assess which factors were associated with uptake of primary and secondary breast cancer preventive behaviours, stratified by breast cancer risk. Organisational preferences are presented using descriptive statistics.

Results

Self-reported breast cancer risk predicted uptake of (a) supplemental screening and breast self-examination, (b) risk-reducing medication and (c) preventive lifestyle behaviours. Further predictors were (a) having a first degree relative with breast cancer, (b) higher age, and (c) higher body mass index (BMI). Women’s organisational preferences for tailored screening emphasised a desire for more intensive screening for women at increased risk by further shortening the screening interval and moving the starting age forward.

Conclusions

Breast cancer risk communication predicts the uptake of key tailored primary and secondary preventive behaviours. Effective communication of breast cancer risk information is essential to optimise the population-wide impact of tailored screening.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09174-3.

Breast cancer risk reduction: who, why, and what?

Women at increased risk of breast cancer have options to mitigate that risk. Understanding factors that increase risk and utilizing tools for quantitative estimates are important to be able to adequately counsel and target strategies for patients. On the basis of these estimates, patients may be able to engage in risk reduction interventions and increased screening, including chemoprevention or surgical risk reduction. Multiple organizations have published guidelines supporting risk assessment, genetic assessment, increased screening, and prevention measures for these women.

Sulindac, a Nonselective NSAID, Reduces Breast Density in Postmenopausal Women with Breast Cancer Treated with Aromatase Inhibitors

PURPOSE

To evaluate the effect of sulindac, a nonselective anti-inflammatory drug (NSAID), for activity to reduce breast density (BD), a risk factor for breast cancer.

EXPERIMENTAL DESIGN

An open-label phase II study was conducted to test the effect of 12 months' daily sulindac at 150 mg twice daily on change in percent BD in postmenopausal hormone receptor-positive breast cancer patients on aromatase inhibitor (AI) therapy. Change in percent BD in the contralateral, unaffected breast was measured by noncontrast magnetic resonance imaging (MRI) and reported as change in MRI percent BD (MRPD). A nonrandomized patient population on AI therapy (observation group) with comparable baseline BD was also followed for 12 months. Changes in tissue collagen after 6 months of sulindac treatment were explored using second-harmonic generated microscopy in a subset of women in the sulindac group who agreed to repeat breast biopsy.

RESULTS

In 43 women who completed 1 year of sulindac (86% of those accrued), relative MRPD significantly decreased by 9.8% [95% confidence interval (CI), -14.6 to -4.7] at 12 months, an absolute decrease of -1.4% (95% CI, -2.5 to -0.3). A significant decrease in mean breast tissue collagen fiber straightness (P = 0.032), an investigational biomarker of tissue inflammation, was also observed. MRPD (relative or absolute) did not change in the AI-only observation group (N = 40).

CONCLUSIONS

This is the first study to indicate that the NSAID sulindac may reduce BD. Additional studies are needed to verify these findings and determine if prostaglandin E₂ inhibition by NSAIDs is important for BD or collagen modulation.

Impact of Stilbenes as Epigenetic Modulators of Breast Cancer Risk and Associated Biomarkers

With the recent advancement of genetic screening for testing susceptibility to mammary oncogenesis in women, the relevance of the gene−environment interaction has become progressively apparent in the context of aberrant gene expressions. Fetal exposure to external stressors, hormones, and nutrients, along with the inherited genome, impact its traits, including cancer susceptibility. Currently, there is increasing interest in the role of epigenetic biomarkers such as genomic methylation signatures, plasma microRNAs, and alterations in cell-signaling pathways in the diagnosis and primary prevention of breast cancer, as well as its prognosis. Polyphenols like natural stilbenes have been shown to be effective in chemoprevention by exerting cytotoxic effects that can stall cell proliferation. Besides possessing antioxidant properties against the DNA-damaging effects of reactive oxygen species, stilbenes have also been observed to modulate cell-signaling pathways. With the increasing trend of early-life screening for hereditary breast cancer risks, the potency of different phytochemicals in harnessing the epigenetic biomarkers of breast cancer risk demand more investigation. This review will explore means of exploiting the abilities of stilbenes in altering the underlying factors that influence breast cancer risk, as well as the appearance of associated biomarkers.

Topical transdermal chemoprevention of breast cancer: where will nanomedical approaches deliver us?

Despite the high incidence of breast cancer, there are few pharmacological prevention strategies for the high-risk population and those that are available have low adherence. Strategies that deliver drugs directly to the breasts may increase drug local concentrations, improving efficacy, safety and acceptance. The skin of the breast has been proposed as an administration route for local transdermal therapy, which may improve drug levels in the mammary tissue, due to both deep local penetration and percutaneous absorption. In this review, we discuss the application of nanotechnology-based strategies for the delivery of well established and new agents as well as drug repurposing using the topical transdermal route to improve the outcomes of preventive therapy for breast cancer.

Endogenous hormones and risk of invasive breast cancer in pre- and post-menopausal women: findings from the UK Biobank

BACKGROUND

Some endogenous hormones have been associated with breast cancer risk, but the nature of these relationships is not fully understood.

METHODS

UK Biobank was used. Hormone concentrations were measured in serum collected in 2006-2010, and in a repeat subsample (N ~ 5000) in 2012-13. Incident cancers were identified through data linkage. Cox regression models were used, and hazard ratios (HRs) corrected for regression dilution bias.

RESULTS

Among 30,565 pre-menopausal and 133,294 post-menopausal women, 527 and 2,997, respectively, were diagnosed with invasive breast cancer during a median follow-up of 7.1 years. Cancer risk was positively associated with testosterone in post-menopausal women (HR per 0.5 nmol/L increment: 1.18; 95% CI: 1.14, 1.23) but not in pre-menopausal women (pheterogeneity = 0.03), and with IGF-1 (insulin-like growth factor-1) (HR per 5 nmol/L increment: 1.18; 1.02, 1.35 (pre-menopausal) and 1.07; 1.01, 1.12 (post-menopausal); pheterogeneity = 0.2), and inversely associated with SHBG (sex hormone-binding globulin) (HR per 30 nmol/L increment: 0.96; 0.79, 1.15 (pre-menopausal) and 0.89; 0.84, 0.94 (post-menopausal); pheterogeneity = 0.4). Oestradiol, assessed only in pre-menopausal women, was not associated with risk, but there were study limitations for this hormone.

CONCLUSIONS

This study confirms associations of testosterone, IGF-1 and SHBG with breast cancer risk, with heterogeneity by menopausal status for testosterone.

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.

Since 2000, our research teams have used computer models of breast cancer to address important clinical and policy-relevant questions as part of the National Cancer Institute’s Cancer Intervention and Surveillance Modeling Network (CISNET). Our 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 represent the burden of breast cancer. We have used our models to investigate questions related to breast cancer biology, compare strategies to improve the balance of benefits and harms of screening mammography, and support insights into the delivery of care by modeling outcomes following clinical decisions about breast cancer treatment. Moving forward, our research will continue to use systems modeling to address issues related to reducing the burden of breast cancer including modeling structural inequities affecting racial disparities. Our future work will also leverage lessons from engaging multidisciplinary scientific teams, expand efforts to share modeling resources with other researchers, and foster the careers of early stage modeling scientists to ensure the sustainability of these efforts.

The effect of sex on the mouse lens transcriptome

The transcriptome of mammalian tissues differs between males and females, and these differences can change across the lifespan, likely regulating known sexual dimorphisms in disease prevalence and severity. Cataract, the most prevalent disease of the ocular lens, occurs at similar rates in young individuals, but its incidence is elevated in older women compared to men of the same age. However, the influence of sex on the lens transcriptome was unknown. RNAseq based transcriptomic profiling of young adult C57BL/6J mouse lens epithelial and fiber cells revealed that few genes are differentially expressed between the sexes. In contrast, lens cells from aged (24 month old) male and female C57BL/6J mice differentially expressed many genes, including several whose expression is lens preferred. Like cataracts, posterior capsular opacification (PCO), a major sequela of cataract surgery, may also be more prevalent in women. Lens epithelial cells isolated from mouse eyes 24 h after lens fiber cell removal exhibited numerous transcriptomic differences between the sexes, including genes implicated in complement cascades and extracellular matrix regulation, and these differences are much more pronounced in aged mice than in young mice. These results provide an unbiased basis for future studies on how sex affects the lens response to aging, cataract development, and cataract surgery.

Endocrine prevention of breast cancer

Breast cancer (BC) is the most common non-cutaneous malignancy among women worldwide and is a significant cause of morbidity, mortality, and national health care expenditure. Unfortunately, with few exceptions like alcohol consumption, obesity, and physical activity, most BC risk factors are unmodifiable. Antiestrogen endocrine therapy, commonly known as BC chemoprevention, is an effective method of BC prevention. In multiple randomized trials, two selective estrogen receptor modulators - tamoxifen and raloxifene, and two aromatase inhibitors - exemestane and anastrozole have reduced BC incidence by 50%-65% in high-risk women. An estimated 15% of the US women between 35 and 79 years of age may qualify as high risk for BC, yet a small percentage of these women will ever have a formal BC risk assessment or a discussion of endocrine prevention options. The etiology of underutilization of endocrine prevention of BC is multifactorial - infrequent use of BC risk assessment tools in the primary care settings, insufficient knowledge of BC risk assessment tools and antiestrogen agents among primary care providers, concerns of side effects, inadequate time for counseling during primary care visit, and lack of predictive biomarkers may play significant roles. Many small studies incorporating risk assessment tools and decision-making aids showed minimal success in enhancing endocrine prevention. One critical factor for underutilization of endocrine prevention is low uptake of endocrine prevention by high-risk women even when appropriately recommended. Furthermore, adherence to BC endocrine prevention is unsatisfactorily low. Despite the current infrequent usage, endocrine prevention has the potential to reduce the public health burden of BC significantly. Innovative approaches like finding new agents, alternative dosing and schedule of currently available agents, transdermal medication delivery, increased public and professional awareness, and policymakers' commitments may bring the desired changes.

Current Landscape of Targeted Therapy in Hormone Receptor-Positive and HER2-Negative Breast Cancer

Background: Hormone receptor-positive and HER2-negative breast cancer (HR + BC) is the most prevalent breast cancer. Endocrine therapy is the mainstay of treatment, however, due to the heterogeneous nature of the disease, resistance to endocrine therapy is not uncommon. Over the past decades, the emergence of novel targeted therapy in combination with endocrine therapy has shown improvement in outcomes of HR + BC. This paper reviews available data of targeted therapy and the results of pivotal clinical trials in the management of HR + BC. Methods: A literature search in PubMed and Google Scholar was performed using keywords related to HR + BC and targeted therapy. Major relevant studies that were presented in international cancer research conferences were also included. Results: Endocrine therapy with tamoxifen and aromatase inhibitors are backbone treatments for women with early-stage HR + BC leading to a significant reduction in mortality. They can also be used for primary prevention in women with a high risk of breast cancer. Preliminary data has shown the efficacy of adjuvant cyclin-dependent kinase (CDK) 4/6 inhibitor, abemaciclib, in high-risk disease in combination with aromatase inhibitors. For most women with advanced HR + BC, endocrine therapy is the primary treatment. Recent evidence has shown that the use of CKD 4/6 inhibitors, mTOR inhibitors, and PI3K inhibitors in combination with endocrine therapy has been associated with better outcomes and delays initiation of chemotherapy. Several novel agents are under study for HR + BC. Discussion: Targeted treatment options for HR + BC have evolved. The future of overcoming resistance to targeted therapy, novel compounds, and predictive markers are key to improving HR + BC outcomes.

Lessons Learned from Setting Up a Prospective, Longitudinal, Multicenter Study with Women at High Risk for Breast Cancer

Women identified with an increased risk of breast cancer due to mutations in cancer susceptibility genes or a familial history of breast cancer undergo tailored screening with the goal of detecting tumors earlier, when potential curative interventions are still possible. Ideally, screening would identify signs of carcinogenesis even before a tumor is detectable by imaging. This could be achieved by timely signaling of altered biomarker levels for precancerous processes in liquid biopsies. Currently, the Nipple Aspirate Fluid (NAF) and the Trial Early Serum Test BREAST cancer (TESTBREAST), both ongoing, prospective, multicenter studies, are investigating biomarkers in liquid biopsies to improve breast cancer screening in high-risk women. The NAF study focuses on changes over time in miRNA expression levels both in blood and NAF samples, whereas the TESTBREAST study analyzes changes in protein levels in blood samples at sequential interval timepoints. These within-subject changes are studied in relation to later occurrence of breast cancer using a nested case-control design. These longitudinal studies face their own challenges in execution, such as hindrances in logistics and in sample processing that were difficult to anticipate. This article offers insight into those challenges and concurrently aims to provide useful strategies for the set-up of similar studies.See related commentary by Sauter, p. 429.

Inhibition Lysosomal Degradation of Clusterin by Protein Kinase D3 Promotes Triple-Negative Breast Cancer Tumor Growth

Triple negative breast cancer (TNBC), with its lack of targeted therapies, shows the worst mortality rate among all breast cancer subtypes. Clusterin (CLU) is implicated to play important oncogenic roles in cancer via promoting various downstream oncogenic pathways. Here, protein kinase D3 (PRKD3) is defined to be a key regulator of CLU in promoting TNBC tumor growth. Mechanically, PRKD3 with kinase activity binding to CLU is critical for CLU protein stability via inhibiting CLU's lysosomal distribution and degradation. CLU and PRKD3 protein level are significantly elevated and positively correlated in collected TNBC tumor samples. CLU silencer (OGX-011) and PRKDs inhibitor (CRT0066101) can both result in impressive tumor growth suppression in vitro and in vivo, suggesting targeting CLU and its key regulator-PRKD3 are promisingly efficient against TNBC. Finally, secreted CLU (sCLU) is found to be elevated in serums from TNBC patients and reduced in serum from TNBC murine models post OGX-011 and/or CRT0066101 treatment, suggesting serum sCLU is a promising blood-based biomarker for clinical management of TNBC. Taken together, this study provides a thorough molecular basis as well as preclinical evidences for targeting CLU pathway as a new promising strategy against TNBC via revealing PRKD3 as the key regulator of CLU in TNBC.