Exemestane for breast-cancer prevention in postmenopausal women

Cardio-Oncology and Breast Cancer Therapies

OPINION STATEMENT

Assessing cardiac risk prior to initiating breast cancer treatment, monitoring cardiac function during treatment, and implementing appropriate follow-up strategies are essential components of managing cardiotoxicity in breast cancer patients. A comprehensive cardiovascular evaluation should be conducted before treatment, including a detailed medical history, physical examination, and baseline cardiac imaging. Risk stratification tools can aid in determining the individual patient's risk profile. Close monitoring of cardiac function, including regular assessment of left ventricular ejection fraction (LVEF) and monitoring for signs and symptoms of cardiac dysfunction, is crucial during treatment. Prompt action should be taken if an adverse cardiovascular event is detected, including considering discontinuing or modifying the treatment regimen. Appropriate follow-up care is essential to monitor for long-term cardiac effects and optimize cardiovascular health in breast cancer survivors. Regular cardiovascular assessments, lifestyle modifications, and collaboration between healthcare professionals are important in managing cardiotoxicity effectively.

Cancer chemoprevention: signaling pathways and strategic approaches

Although cancer chemopreventive agents have been confirmed to effectively protect high-risk populations from cancer invasion or recurrence, only over ten drugs have been approved by the U.S. Food and Drug Administration. Therefore, screening potent cancer chemopreventive agents is crucial to reduce the constantly increasing incidence and mortality rate of cancer. Considering the lengthy prevention process, an ideal chemopreventive agent should be nontoxic, inexpensive, and oral. Natural compounds have become a natural treasure reservoir for cancer chemoprevention because of their superior ease of availability, cost-effectiveness, and safety. The benefits of natural compounds as chemopreventive agents in cancer prevention have been confirmed in various studies. In light of this, the present review is intended to fully delineate the entire scope of cancer chemoprevention, and primarily focuses on various aspects of cancer chemoprevention based on natural compounds, specifically focusing on the mechanism of action of natural compounds in cancer prevention, and discussing in detail how they exert cancer prevention effects by affecting classical signaling pathways, immune checkpoints, and gut microbiome. We also introduce novel cancer chemoprevention strategies and summarize the role of natural compounds in improving chemotherapy regimens. Furthermore, we describe strategies for discovering anticancer compounds with low abundance and high activity, revealing the broad prospects of natural compounds in drug discovery for cancer chemoprevention. Moreover, we associate cancer chemoprevention with precision medicine, and discuss the challenges encountered in cancer chemoprevention. Finally, we emphasize the transformative potential of natural compounds in advancing the field of cancer chemoprevention and their ability to introduce more effective and less toxic preventive options for oncology.

Understanding Susceptibility to Breast Cancer: From Risk Factors to Prevention Strategies

Breast cancer is the most common malignancy among women globally, with incidence rates continuing to rise. A comprehensive understanding of its risk factors and the underlying biological mechanisms that drive tumor initiation is essential for developing effective prevention strategies. This review examines key non-modifiable risk factors, such as genetic predisposition, demographic characteristics, family history, mammographic density, and reproductive milestones, as well as modifiable risk factors like exogenous hormone exposure, obesity, diet, and physical inactivity. Importantly, reproductive history plays a dual role, providing long-term protection while temporarily increasing breast cancer risk shortly after pregnancy. Current chemoprevention strategies primarily depend on selective estrogen receptor modulators (SERMs), including tamoxifen and raloxifene, which have demonstrated efficacy in reducing the incidence of estrogen receptor-positive breast cancer but remain underutilized due to adverse effects. Emerging approaches such as aromatase inhibitors, RANKL inhibitors, progesterone antagonists, PI3K inhibitors, and immunoprevention strategies show promise for expanding preventive options. Understanding the interactions between risk factors, hormonal influences, and tumorigenesis is critical for optimizing breast cancer prevention and advancing safer, more targeted chemopreventive interventions.

A Review of the Clinical and Epidemiologic Evidence Relevant to the Impact of Postdiagnosis Isoflavone Intake on Breast Cancer Outcomes

PURPOSE OF REVIEW

This narrative review aims to determine the impact of postdiagnosis isoflavone intake, via supplements and foods, on breast cancer outcomes. Foods derived from soybeans are uniquely rich sources of isoflavones, naturally occurring compounds that can bind to estrogen receptors although the extent to which they exert estrogen-like effects in humans is unclear. Isoflavones have been rigorously investigated for a wide range of health benefits including breast cancer prevention. However, their classification as phytoestrogens has led to concern that isoflavones and hence, soy food consumption, could worsen the prognosis of women with breast cancer and interfere with the efficacy of endocrine therapy for this disease.

RECENT FINDINGS

Research in athymic ovariectomized mice shows isoflavones stimulate the growth of existing estrogen-sensitive mammary tumors. However, extensive clinical research indicates that neither soy foods nor isolated isoflavones affect markers of breast cancer risk including mammographic density and breast cell proliferation. No effects are observed even when isoflavone exposure greatly exceeds typical intake in Asian countries. Furthermore, the results from epidemiologic studies indicate postdiagnosis isoflavone intake from soy foods reduces recurrence and possibly mortality from breast cancer. Additionally, the limited observational data do not show that isoflavones interfere with the efficacy of tamoxifen or aromatase inhibitors. Regardless of their treatment status, evidence indicates that women with breast cancer can safely consume soy foods. Limiting intake to no more than two servings of traditional Asian soy foods daily, an amount that provides approximately 50 mg isoflavones, is recommended, not because data indicate exceeding this amount is harmful, but because few population-based studies involved participants consuming more than this intake recommendation.

Prolonged Low-Dose Administration of FDA-Approved Drugs for Non-Cancer Conditions: A Review of Potential Targets in Cancer Cells

Though not specifically designed for cancer therapy, several FDA-approved drugs such as metformin, aspirin, and simvastatin have an effect in lowering the incidence of cancer. However, there is a great discrepancy between in vitro concentrations needed to eliminate cancer cells and the plasma concentration normally tolerated within the body. At present, there is no universal explanation for this discrepancy and several mechanisms have been proposed including targeting cancer stem cells (CSCs) or cellular senescence. CSCs are cells with the ability of self-renewal and differentiation known to be resistant to chemotherapy. Senescence is a response to damage and stress, characterized by permanent cell-cycle arrest and apoptotic resistance. Although, for both situations, there are few examples where low concentrations of the FDA-approved drugs were the most effective, there is no satisfactory data to support that either CSCs or cellular senescence are the target of these drugs. In this review, we concisely summarize the most used FDA-approved drugs for non-cancer conditions as well as their potential mechanisms of action in lowering cancer incidence. In addition, we propose that prolonged low-dose administration (PLDA) of specific FDA-approved drugs can be useful for effectively preventing metastasis formation in selected patients.

Group-Based Trajectory Modeling to Identify Patterns and Predictors of Adherence to Oral Endocrine Therapies in Underserved Population of Greater Houston Area

Background

Poor adherence to oral endocrine therapy (OET) is a significant problem among patients with hormone receptor-positive breast cancer as it results in higher risk of recurrence and mortality. Non-adherence to OET is prevalent among underserved patients, often attributable to socioeconomic factors and limited healthcare access. We evaluated OET adherence patterns over time using group-based trajectory modeling (GBTM) and identified predictors of suboptimal adherence trajectory among patients seen at Harris Health System, serving underserved patients in Houston, Texas.

Methods

A single-center, retrospective study was conducted from October 2019 through December 2020. OET adherence was measured using proportion of days covered (PDC). A logistic GBTM was conducted using 2-5 adherence groups considering the Bayesian information criteria, clinical relevance, and a 5% minimum membership requirement. Multinomial logistic regression was used to assess the predictors of non-adherence trajectories.

Results

Among 496 patients, majority were Hispanic (62.50%) or African American (15.12%) and <65 years of age (82.66%). Four distinct adherence trajectories were identified: consistent high adherence (41.4%); constant PDC at ~0.6 (32.6%); rapid decline (14.6%); low adherence with gradual decline (11.5%). African Americans had higher likelihood of having low adherence with gradual decline [odds ratio (OR): 2.462 (confidence interval (CI): 1.1149-5.276), p=0.0205]. Patients with diabetes were more likely to have constant PDC at ~0.6 [OR: 1.714 (CI: 1.042-2.820), p=0.0338]. Longer time (4 or greater years) on therapy predicted low adherence with gradual decline [OR: 2.463 (CI: 1.266-4.793), p=0.008) and constant PDC at ~0.6 (OR: 1.966 (CI: 1.141-3.388), p=0.0149] trajectories.

Conclusion

The identified predictors, including comorbidities like diabetes, African American descent, and longer OET treatment are crucial considerations when developing patient-centered interventions to enhance OET adherence among underserved populations. These insights can guide the implementation of initiatives such as mobile health applications, community-based educational programs, and financial aid efforts.

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.

Duration of aromatase inhibitor use and long-term cardiovascular risk in breast cancer survivors

BACKGROUND

There are limited data on duration of aromatase inhibitor (AI) and cardiovascular disease (CVD) risk in breast cancer (BC) survivors. We examined the risk of CVD and mortality associated with the duration of AI use in postmenopausal women with early stage hormone receptor-positive BC.

METHODS

Postmenopausal women diagnosed with hormone receptor-positive BC (n = 5853) who used an AI were included. Cause-specific hazards models estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for associations between AI use duration (short term: >0 and <2 years; intermediate term: ≥2 and <5 years; long term: ≥5 years) and CVD and mortality outcomes. The landmark method was used to avoid immortal time bias; the selected landmark was 6 years after BC diagnosis.

RESULTS

Anastrozole was the AI predominantly prescribed (95.4%). Over a median follow-up of 3 years for women who survived 6 years after BC diagnosis, a lower risk of stroke was observed in intermediate-term AI users (HR = 0.60, 95% CI = 0.37 to 0.96) and long-term AI users (HR = 0.51, 95% CI = 0.30 to 0.85), than in short-term AI users. The longer duration of AI use was also associated with lower risk of all-cause mortality and non-CVD-related mortality. In addition, long-term AI users were at 37% lower risk of CVD-related mortality than short-term AI users. No statistically significant differences were observed in risks of major adverse cardiovascular events, ischemic heart disease, and heart failure across the 3 groups.

CONCLUSION

Among postmenopausal women with early stage hormone receptor-positive BC who survived 6 years after BC diagnosis, longer duration of AI use was not associated with elevated CVD risk.

Targeting Oestrogen Receptor Signalling in Breast Cancer Therapy

There has been over 130 years of research into the treatment of breast cancer using approaches that target oestrogen receptor signalling. Here, we summarise the development of the key pillars of such endocrine therapy, namely, oestrogen deprivation, achieved through ovarian suppression and/or aromatase inhibition, and oestrogen receptor blockade, through selective oestrogen receptor modulators, downregulators and novel compounds entering early phase development. The translation of these compounds from advanced to early breast cancer settings is discussed with a focus on the placebo-controlled breast cancer prevention studies to most accurately describe the side effect profiles of the main approaches.

RANK/RANKL Signaling Pathway in Breast Development and Cancer

RANK pathway has attracted increasing interest as a promising target in breast cancer, given the availability of denosumab, an anti-RANKL drug. RANK signaling mediates progesterone-driven regulation of mammary gland development and favors breast cancer initiation by controlling mammary cell proliferation and stem cell fate. RANK activation promotes luminal mammary epithelial cell senescence, acting as an initial barrier to tumorigenesis but ultimately facilitating tumor progression and metastasis. Comprehensive analyses have demonstrated that RANK protein expression is an independent biomarker of poor prognosis in postmenopausal and estrogen receptor-negative breast cancer patients. RANK pathway also has multiple roles in immunity and inflammation, regulating innate and adaptive responses. In the tumor microenvironment, RANK and RANKL are expressed by different immune cell populations and contribute to the regulation of tumor immune surveillance, mainly driving immunosuppressive effects.Herein, we discuss the preventive and therapeutic potential of targeting RANK signaling in breast cancer given its tumor cell intrinsic and extrinsic effects. RANKL inhibition has been shown to induce mammary tumor cell differentiation and an antitumor immune response. Moreover, loss of RANK signaling increases sensitivity of breast cancer cells to chemotherapy, targeted therapies such as HER2 and CDK4/6 inhibitors, and immunotherapy. Finally, we describe clinical trials of denosumab for breast cancer prevention, such as those ongoing in women with high risk of developing breast cancer, large phase III clinical trials where the impact of adjuvant denosumab on disease-free survival has been assessed, and window trials to evaluate the immunomodulatory effects of denosumab in breast cancer and other solid tumors.

Drug and biomarker tissue levels in a randomized presurgical trial on exemestane alternative schedules

The drug's activity at the target tissue could help to define the minimal effective dose to promote cancer preventive therapy. Here we present exemestane and sex hormone concentrations within breast tissue from a presurgical study of alternative exemestane schedules. Postmenopausal women candidates for breast surgery for estrogen receptor-positive breast cancer were randomly assigned to exemestane 25 mg once daily (QD), 25 mg 3 times/week (TIW), or 25 mg per week (QW) for 4-6 weeks before surgery. Drug and sex hormones were analyzed from homogenized frozen tissue using a QTRAP 6500+ LC-MS/MS System. Tissue drug concentrations were detectable only in the QD arm with higher concentrations in nonmalignant tissue. Estradiol was nearly suppressed in all groups in the nonmalignant tissue (QD vs TIW P = .364 and QD vs QW P = .693). In contrast, a dose-response trend was observed in cancer tissue. Based on estradiol suppression in nonmalignant tissue, lower exemestane schedules should be explored for breast cancer preventive therapy. Trial Registration: Clinical Trials.gov NCT02598557 and EudraCT 2015-005063-1.

Atypical ductal or lobular hyperplasia, lobular carcinoma in-situ, flat epithelial atypia, and future risk of developing breast cancer: Systematic review and meta-analysis

BACKGROUND

Biopsy-proven breast lesions such as atypical ductal hyperplasia (ADH) or atypical lobular hyperplasia (ALH), lobular carcinoma in situ (LCIS) and flat epithelial atypia (FEA) increase subsequent risk of breast cancer (BC), but long-term risk has not been synthesized. A systematic review was conducted to quantify future risk of breast cancer accounting for time since diagnosis of these high-risk lesions.

METHODS

A systematic search of literature from 2000 was performed to identify studies reporting BC as an outcome following core-needle or excision biopsy histology diagnosis of ADH, ALH, LCIS, lobular neoplasia (LN) or FEA. Meta-analyses were conducted to estimate cumulative BC incidence at five-yearly intervals following initial diagnosis for each histology type.

RESULTS

Seventy studies reporting on 47,671 subjects met eligibility criteria. BC incidence at five years post-diagnosis with a high-risk lesion was estimated to be 9.3 % (95 % CI 6.9-12.5 %) for LCIS, 6.6 % (95 % CI 4.4-9.7 %) for ADH, 9.7 % (95 % CI 5.3-17.2 %) for ALH, 8.6 % (95 % CI 6.5-11.4 %) for LN, and 3.8 % (95 % CI 1.2-11.7 %) for FEA. At ten years post-diagnosis, BC incidence was estimated to be 11.8 % (95 % CI 9.0-15.3 %) for LCIS, 13.9 % (95 % CI 7.8-23.6 %) for ADH, 15.4 % (95 % CI 7.2-29.3 %) for ALH, 17.0 % (95 % CI 7.2-35.3 %) for LN and 7.2 % (95 % CI 2.2-21.2 %) for FEA.

CONCLUSION

Our findings demonstrate increased BC risk sustained over time since initial diagnosis of high-risk breast lesions, varying by lesion type, with relatively less evidence for FEA.

Chemoprevention strategies in hereditary breast and ovarian cancer syndromes

Hereditary breast and/or ovarian cancer syndromes are inherited disorders in which there is an increased risk of developing breast and/or ovarian cancer in the lifetime, usually at a younger age compared to the general population. Cancer prevention in these syndromes includes prophylactic surgeries, personalized surveillance programs and chemopreventive strategies. Chemoprevention exploits the use of certain drugs or other substances to help lower the risk of developing cancer. In this context, tamoxifen was the first agent considered for breast cancer prevention, followed by raloxifene and the third-generation aromatase inhibitors. On the other hand, the first and most widespread type of chemoprevention for ovarian cancer was combined hormonal contraceptive use. Although several strategies have been studied and showed promising results, only a few of these are currently applied in daily clinical practice. Side effects along with several psychological variables such as cancer perceived risk, worries and related distress, strongly influence women's decision on chemoprevention. The present review explores and summarizes the available evidence on breast and ovarian cancer chemoprevention approaches.

Selection of Patients With Early-Stage Breast Cancer for Extended Endocrine Therapy: A Secondary Analysis of the IDEAL Randomized Clinical Trial

Importance

There is a need for biomarkers that predict late recurrence risk and extended endocrine therapy (EET) benefit among patients with early-stage breast cancer (EBC). MammaPrint, a 70-gene expression risk-of-recurrence assay, has been found to project significant EET benefit in patients with assay-classified low-risk tumors.

Objective

To determine the test's utility in identifying which patients with EBC in the IDEAL (Investigation on the Duration of Extended Adjuvant Letrozole) trial could benefit from 5-year vs 2.5-year letrozole treatment.

Design, Setting, and Participants

This secondary analysis of the IDEAL randomized clinical trial evaluated postmenopausal women with hormone receptor-positive EBC who were assigned to either 2.5 or 5 years of EET, with 10 years of follow-up after randomization. A 70-gene assay was used to classify tumors as high, low, or ultralow risk. Adverse event (AE) frequency and treatment compliance were evaluated. Statistical analyses were performed from April 2022 to September 2024.

Interventions

After 5 years of endocrine therapy, patients were randomized to 2.5 or 5 years of EET with letrozole.

Main Outcomes and Measures

Primary end point was distant recurrence (DR). Cox proportional hazard regression models and likelihood ratios tested the interaction between treatment and gene expression assay.

Results

Among 515 women included (mean [SD] age at randomization, 59.9 [9.5] years), 265 were in the 2.5-year treatment arm and 250 in the 5-year treatment arm. Of these patients, 223 (43.3%) patients with 70-gene assay-classified low-risk tumors had a significant absolute benefit of 10.1% for DR (hazard ratio, 0.32; 95% CI, 0.12-0.87; P = .03). Treatment interaction was not significant for DR. Of patients with either 70-gene assay-classified high-risk tumors (259 [50.3%]) or ultralow risk tumors (33 [6.4%]), 5 years vs 2.5 years of EET was not associated with improved benefit for DR. As expected, rates of AEs and treatment discontinuation were comparable among the different 70-gene assay risk groups in each treatment arm.

Conclusions and Relevance

This secondary analysis of the IDEAL trial found that the 70-gene assay identified patients with low-risk tumors who could benefit from 5-year vs 2.5-year EET. These findings suggest that this gene expression assay could go beyond guiding neoadjuvant and adjuvant chemotherapy decisions to informing the optimal duration of adjuvant endocrine therapy.

Trial Registration

EU Clinical Trials Register Eudra CT: 2006-003958-16.

Overcoming challenges in conducting early phase breast cancer prevention trials: Bazedoxifene and conjugated estrogens vs waitlist control

BACKGROUND

The combination of bazedoxifene 20 mg (BZA) and conjugated estrogens 0.45 mg (CE) marketed as Duavee® is approved for vasomotor symptom relief and osteoporosis prevention. Our pilot study suggested it had potential breast cancer risk reduction, and we proposed a multisite Phase IIB primary prevention trial assessing change in breast imaging and tissue risk biomarkers. By the time funding was acquired in February 2021, Duavee® was unavailable with an uncertain return date. A redesign was needed to salvage the study.

METHODS

The basic trial design was minimally altered. Women age 45-64 at elevated risk for breast cancer with vasomotor symptoms and no menses for at least 2 months have mammography, phlebotomy, and benign breast tissue sampling before and after 6 months of intervention. However, instead of Duavee® (single pill) vs placebo, women are randomized to 6 months of BZA + CE vs Waitlist. Those initially randomized to Waitlist can receive BZA + CE after 6 months. The primary endpoint is between arm difference in change in a fully automated measure of mammographic density with blood and tissue-based secondary endpoints.

OUTCOMES

Accrual initiation was delayed due to contractual difficulties surrounding BZA importation during COVID-19 and deploying a fully automated method (Volpara®) to assess the primary endpoint. To accommodate this delay, a mid-grant no cost extension along with amended eligibility requirements were employed. 61/120 participants needed were entered in the initial 27 months of accrual and 37 months of funding. Despite a late start, accrual is likely to be completed within the funding period.

Use of web-based decision support to improve informed choice for chemoprevention: a qualitative analysis of pre-implementation interviews (SWOG S1904)

BACKGROUND

Women with high-risk breast lesions, such as atypical hyperplasia (AH) or lobular carcinoma in situ (LCIS), have a 4- to tenfold increased risk of breast cancer compared to women with non-proliferative breast disease. Despite high-quality data supporting chemoprevention, uptake remains low. Interventions are needed to break down barriers.

METHODS

The parent trial, MiCHOICE, is a cluster randomized controlled trial evaluating the effectiveness and implementation of patient and provider decision support tools to improve informed choice about chemoprevention among women with AH or LCIS. For this pre-implementation analysis, 25 providers participated in semi-structured interviews prior to accessing decision support tools. Interviews sought to understand attitudes/beliefs and barriers/facilitators to chemoprevention.

RESULTS

Interviews with 25 providers (18 physicians and 7 advanced practice providers) were included. Providers were predominantly female (84%), white (72%), and non-Hispanic (88%). Nearly all providers (96%) had prescribed chemoprevention for eligible patients. Three themes emerged in qualitative analysis. The first theme describes providers' confidence in chemoprevention and the utility of decision support tools. The second theme elucidates barriers to chemoprevention, including time constraints, risk communication and perceptions of patients' fear of side effects and anxiety. The third theme is the need for early implementation of decision support tools.

CONCLUSIONS

This qualitative study suggests that providers were interested in the early inclusion of decision aids (DA) in their chemoprevention discussion workflow. The DAs may help overcome certain barriers which were elucidated in these interviews, including patient level concerns about side effects, clinic time constraints and difficulty communicating risk. A multi-faceted intervention with a DA as one active component may be needed.

TRIAL REGISTRATION

This trial was registered with the NIH clinical trial registry, clinicaltrials.gov, NCT04496739.

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.

The Antioxidant and HDAC-Inhibitor α-Lipoic Acid Is Synergistic with Exemestane in Estrogen Receptor-Positive Breast Cancer Cells

Anti-estrogenic therapy is established in the management of estrogen receptor (ER)-positive breast cancer. However, to overcome resistance and improve therapeutic outcome, novel strategies are needed such as targeting widely recognized aberrant epigenetics. The study aims to investigate the combination of the aromatase inhibitor exemestane and the histone deacetylase (HDAC) inhibitor and antioxidant α-lipoic acid in ER-positive breast cancer cells. First, the enantiomers and the racemic mixture of α-lipoic acid, and rac-dihydro-lipoic acid were investigated for HDAC inhibition. We found HDAC inhibitory activity in the 1-3-digit micromolar range with a preference for HDAC6. Rac-dihydro-lipoic acid is slightly more potent than rac-α-lipoic acid. The antiproliferative IC50 value of α-lipoic acid is in the 3-digit micromolar range. Notably, the combination of exemestane and α-lipoic acid resulted in synergistic behavior under various incubation times (24 h to 10 d) and readouts (MTT, live-cell fluorescence microscopy, caspase activation) analyzed by the Chou-Talalay method. α-lipoic acid increases mitochondrial fusion and the expression of apoptosis-related proteins p21, APAF-1, BIM, FOXO1, and decreases expression of anti-apoptotic proteins survivin, BCL-2, and c-myc. In conclusion, combining exemestane with α-lipoic acid is a promising novel treatment option for ER-positive breast cancer.

Effects of vitamin D supplementation on a deep learning-based mammographic evaluation in SWOG S0812

Deep learning-based mammographic evaluations could noninvasively assess response to breast cancer chemoprevention. We evaluated change in a convolutional neural network-based breast cancer risk model applied to mammograms among women enrolled in SWOG S0812, which randomly assigned 208 premenopausal high-risk women to receive oral vitamin D3 20 000 IU weekly or placebo for 12 months. We applied the convolutional neural network model to mammograms collected at baseline (n = 109), 12 months (n = 97), and 24 months (n = 67) and compared changes in convolutional neural network-based risk score between treatment groups. Change in convolutional neural network-based risk score was not statistically significantly different between vitamin D and placebo groups at 12 months (0.005 vs 0.002, P = .875) or at 24 months (0.020 vs 0.001, P = .563). The findings are consistent with the primary analysis of S0812, which did not demonstrate statistically significant changes in mammographic density with vitamin D supplementation compared with placebo. There is an ongoing need to evaluate biomarkers of response to novel breast cancer chemopreventive agents.

Hormone therapy in women with benign breast disease - What little is known and suggestions for clinical implementation

Benign breast disease encompasses a spectrum of lesions within the breast. While some lesions pose no increase in risk, others may elevate the likelihood of developing breast cancer by four- to five-fold. This necessitates a personalized approach to screening and lifestyle optimization for women. The menopausal transition is a critical time for the development of benign breast lesions. Increased detection can be attributed to the heightened precision and utilization of screening mammography, with or without the use of supplemental imaging. While it is widely acknowledged that combined hormone therapy involving estrogen and progesterone may elevate the risk of breast cancer, data from the Women's Health Initiative (WHI) indicates that estrogen-alone therapies may actually reduce the overall risk of cancer. Despite this general understanding, there is a notable gap in information regarding the impact of hormone therapy on the risk profile of women with specific benign breast lesions. This review comprehensively examines various benign breast lesions, delving into their pathophysiology and management. The goal is to enhance our understanding of when and how to judiciously prescribe hormone therapy, particularly in the context of specific benign breast conditions. By bridging this knowledge gap, the review provides valuable insights into optimizing healthcare strategies for women with benign breast disease, and offers a foundation for more informed decision-making regarding hormone therapy.

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.

Nonsurgical Management of High-Risk Lesions

This article highlights the recent publications and changing trends in practice regarding management of high-risk lesions of the breast. Traditional management has always been a surgical operation but this is recognized as overtreatment. It is recognized that overdiagnosis is inevitable but what we can control is overtreatment. Vacuum-assisted excision is now established as an alternative technique to surgery for further sampling of these high-risk lesions in the United Kingdom. Guidelines from the United Kingdom and Europe now recognize this alternative pathway, and data are available showing that vacuum-assisted excision is a safe alternative to surgery.

Making Informed Choices On Incorporating Chemoprevention into carE (MiCHOICE, SWOG 1904): Design and methods of a cluster randomized controlled trial

INTRODUCTION

Women with atypical hyperplasia (AH) or lobular carcinoma in situ (LCIS) have a significantly increased risk of breast cancer, which can be substantially reduced with antiestrogen therapy for chemoprevention. However, antiestrogen therapy for breast cancer risk reduction remains underutilized. Improving knowledge about breast cancer risk and chemoprevention among high-risk patients and their healthcare providers may enhance informed decision-making about this critical breast cancer risk reduction strategy.

METHODS/DESIGN

We are conducting a cluster randomized controlled trial to evaluate the effectiveness and implementation of patient and provider decision support tools to improve informed choice about chemoprevention among women with AH or LCIS. We have cluster randomized 26 sites across the U.S. through the SWOG Cancer Research Network. A total of 415 patients and 200 healthcare providers are being recruited. They are assigned to standard educational materials alone or combined with the web-based decision support tools. Patient-reported and clinical outcomes are assessed at baseline, after a follow-up visit at 6 months, and yearly for 5 years. The primary outcome is chemoprevention informed choice after the follow-up visit. Secondary endpoints include other patient-reported outcomes, such as chemoprevention knowledge, decision conflict and regret, and self-reported chemoprevention usage. Barriers and facilitators to implementing decision support into clinic workflow are assessed through patient and provider interviews at baseline and mid-implementation.

RESULTS/DISCUSSION

With this hybrid effectiveness/implementation study, we seek to evaluate if a multi-level intervention effectively promotes informed decision-making about chemoprevention and provide valuable insights on how the intervention is implemented in U.S.

CLINICAL SETTINGS

TRIAL REGISTRATION

NCT04496739.

DREAM On, DREAM Off: A Review of the Estrogen Paradox in Luminal A Breast Cancers

It is generally assumed that all estrogen-receptor-positive (ER+) breast cancers proliferate in response to estrogen and, therefore, examples of the estrogen-induced regression of ER+ cancers are paradoxical. This review re-examines the estrogen regression paradox for the Luminal A subtype of ER+ breast cancers. The proliferative response to estrogen is shown to depend on the level of ER. Mechanistically, a window of opportunity study of pre-operative estradiol suggested that with higher levels of ER, estradiol could activate the DREAM-MMB (Dimerization partner, Retinoblastoma-like proteins, E2F4, and MuvB-MYB-MuvB) pathway to decrease proliferation. The response of breast epithelium and the incidence of breast cancers during hormonal variations that occur during the menstrual cycle and at the menopausal transition, respectively, suggest that a single hormone, either estrogen, progesterone or androgen, could activate the DREAM pathway, leading to reversible cell cycle arrest. Conversely, the presence of two hormones could switch the DREAM-MMB complex to a pro-proliferative pathway. Using publicly available data, we examine the gene expression changes after aromatase inhibitors and ICI 182,780 to provide support for the hypothesis. This review suggests that it might be possible to integrate all current hormonal therapies for Luminal A tumors within a single theoretical schema.

A review of synthetic strategy, SAR, docking, simulation studies, and mechanism of action of isoxazole derivatives as anticancer agents

Breast cancer (BC) is a global health concern and the leading cause of cancerous death among women across the world, BC has been characterized by fresh lump in the breast or underarm (armpit), thickened or swollen. Worldwide estimated 9.6 million deaths in 2018-2019. Numerous drugs have been approved by FDA for BC treatment but showed numerous adverse effects like bioavailability issues, selectivity issues, and toxicity issues. Therefore, there is an immediate need to develop new molecules that are non-toxic and more efficient for treating cancer. Isoxazole derivatives have gained popularity over the few years due to their effective antitumor potential. These derivatives work against cancer by inhibiting the thymidylate enzyme, inducing apoptosis, inhibiting tubulin polymerization, protein kinase inhibition, and aromatase inhibition. In this study, we have concentrated on the isoxazole derivative with structure-activity relationship study, various synthesis techniques, mechanism of action, docking, and simulation studies pertaining to BC receptors. Hence the development of isoxazole derivatives with improved therapeutic efficacy will inspire further progress in improving human health.Communicated by Ramaswamy H. Sarma.

Influence of tumor microenvironment on the different breast cancer subtypes and applied therapies

Despite the significant improvements made in breast cancer therapy during the last decades, this disease still has increasing incidence and mortality rates. Different targets involved in general processes, like cell proliferation and survival, have become alternative therapeutic options for this disease, with some of them already used in clinic, like the CDK4/6 inhibitors for luminal A tumors treatment. Nevertheless, there is a demand for novel therapeutic strategies focused not only on tumor cells, but also on their microenvironment. Tumor microenvironment (TME) is a very complex and dynamic system that, more than surrounding and supporting tumor cells, actively participates in tumor development and progression. During the last decades, it has become clear that the cellular and acellular components of TME differ between the various breast cancer subtypes and shape the differences regarding their severity and prognosis. The pivotal role of the TME in controlling tumor growth and influencing responses to therapy represents a potential source for novel targets and therapeutic strategies. In this review, we present a description of the multiple therapeutic options used for different breast cancer subtypes, as well as the influence that the TME may exert on the development of the disease and on the response to the distinct therapies, which in some cases may explain their failure by the occurrence of relapses and resistance. Furthermore, the ongoing studies focused on the use of TME components for developing potential cancer treatments are described.

Upgrade Rates and Breast Cancer Development Among Germline Pathogenic Variant Carriers with High-Risk Breast Lesions

BACKGROUND

High-risk lesions (HRL) of the breast are risk factors for future breast cancer development and may be associated with a concurrent underlying malignancy when identified on needle biopsy; however, there are few data evaluating HRLs in carriers of germline pathogenic variants (PVs) in breast cancer predisposition genes.

METHODS

We identified patients from two institutions with germline PVs in high- and moderate-penetrance breast cancer predisposition genes and an HRL in an intact breast, including atypical ductal hyperplasia (ADH), flat epithelial atypia (FEA), and lobular neoplasia (LN). We calculated upgrade rates at surgical excision and used Kaplan-Meier methods to characterize 3-year breast cancer risk in patients without upgrade.

RESULTS

Of 117 lesions in 105 patients, 65 (55.6%) were ADH, 48 (41.0%) were LN, and 4 (3.4%) were FEA. Most PVs (83.8%) were in the BRCA1/2, CHEK2 and ATM genes. ADH and FEA were excised in most cases (87.1%), with upgrade rates of 11.8% (95% confidence interval [CI] 5.5-23.4%) and 0%, respectively. LN was selectively excised (53.8%); upgrade rate in the excision group was 4.8% (95% CI 0.8-22.7%), and with 20 months of median follow-up, no same-site cancers developed in the observation group. Among those not upgraded, the 3-year risk of breast cancer development was 13.1% (95% CI 6.3-26.3%), mostly estrogen receptor-positive (ER +) disease (89.5%).

CONCLUSIONS

Upgrade rates for HRLs in patients with PVs in breast cancer predisposition genes appear similar to non-carriers. HRLs may be associated with increased short-term ER+ breast cancer risk in PV carriers, warranting strong consideration of surgical or chemoprevention therapies in this population.

Challenges and Opportunities in Breast Cancer Care in Low-Resourced Countries, Jordan as An Example

Jordan is a relatively small country with a rapidly growing population and a challenged economy. Breast cancer is the most diagnosed cancer among women worldwide and also in Jordan. Though the age-standardized rate (ASR) of breast cancer incidence is still lower than that in Western societies, the number of newly diagnosed cases continues to increase, involving younger women, and new cases are usually detected at more advanced stages. Improvements in breast cancer care across the health care continuum, including early detection, prevention, treatment, and survivorship and palliative care, have become very visible, but may not match the magnitude of the problem. More organized, goal-oriented work is urgently needed to downstage the disease and improve awareness of, access to, and participation in early detection programs. The cost of recently introduced anti-cancer therapies poses a great challenge, but the impact of these therapies on treatment outcomes, including overall survival, is becoming very noticeable. Though the concept of a multidisciplinary approach to breast cancer treatment is often used at most health care facilities, its implementation in real practice varies significantly. The availability of breast reconstruction procedures, survivorship programs, germline genetic testing, counselling, and palliative care is improving, but these are not widely practiced. In this manuscript, we review the status of breast cancer in Jordan and highlight some of the existing challenges and opportunities.

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.

Breast Cancer Screening and Prophylactic Mastectomy for High-Risk Women in Romania

Breast cancer remains a significant contributor to morbidity and mortality within oncology. Risk factors, encompassing genetic and environmental influences, significantly contribute to its prevalence. While germline mutations, notably within the BRCA genes, are commonly associated with heightened breast cancer risk, a spectrum of other variants exists among affected individuals. Diagnosis relies on imaging techniques, biopsies, biomarkers, and genetic testing, facilitating personalised risk assessment through specific scoring systems. Breast cancer screening programs employing mammography and other imaging modalities play a crucial role in early detection and management, leading to improved outcomes for affected individuals. Regular screening enables the identification of suspicious lesions or abnormalities at earlier stages, facilitating timely intervention and potentially reducing mortality rates associated with breast cancer. Genetic mutations guide screening protocols, prophylactic interventions, treatment modalities, and patient prognosis. Prophylactic measures encompass a range of interventions, including chemoprevention, hormonal inhibition, oophorectomy, and mastectomy. Despite their efficacy in mitigating breast cancer incidence, these interventions carry potential side effects and psychological implications, necessitating comprehensive counselling tailored to individual cases.

Low-dose acetylsalicylic acid reduces local inflammation and tissue perfusion in dense breast tissue in postmenopausal women

PURPOSE

One major risk factor for breast cancer is high mammographic density. It has been estimated that dense breast tissue contributes to ~ 30% of all breast cancer. Prevention targeting dense breast tissue has the potential to improve breast cancer mortality and morbidity. Anti-estrogens, which may be associated with severe side-effects, can be used for prevention of breast cancer in women with high risk of the disease per se. However, no preventive therapy targeting dense breasts is currently available. Inflammation is a hallmark of cancer. Although the biological mechanisms involved in the increased risk of cancer in dense breasts is not yet fully understood, high mammographic density has been associated with increased inflammation. We investigated whether low-dose acetylsalicylic acid (ASA) affects local breast tissue inflammation and/or structural and dynamic changes in dense breasts.

METHODS

Postmenopausal women with mammographic dense breasts on their regular mammography screen were identified. A total of 53 women were randomized to receive ASA 160 mg/day or no treatment for 6 months. Magnetic resonance imaging (MRI) was performed before and after 6 months for a sophisticated and continuous measure breast density by calculating lean tissue fraction (LTF). Additionally, dynamic quantifications including tissue perfusion were performed. Microdialysis for sampling of proteins in vivo from breasts and abdominal subcutaneous fat, as a measure of systemic effects, before and after 6 months were performed. A panel of 92 inflammatory proteins were quantified in the microdialysates using proximity extension assay.

RESULTS

After correction for false discovery rate, 20 of the 92 inflammatory proteins were significantly decreased in breast tissue after ASA treatment, whereas no systemic effects were detected. In the no-treatment group, protein levels were unaffected. Breast density, measured by LTF on MRI, were unaffected in both groups. ASA significantly decreased the perfusion rate. The perfusion rate correlated positively with local breast tissue concentration of VEGF.

CONCLUSIONS

ASA may shape the local breast tissue microenvironment into an anti-tumorigenic state. Trials investigating the effects of low-dose ASA and risk of primary breast cancer among postmenopausal women with maintained high mammographic density are warranted. Trial registration EudraCT: 2017-000317-22.

Breast Cancer Polygenic-Risk Score Influence on Risk-Reducing Endocrine Therapy Use: Genetic Risk Estimate (GENRE) Trial 1-Year and 2-Year Follow-Up

Refinement of breast cancer risk estimates with a polygenic-risk score (PRS) may improve uptake of risk-reducing endocrine therapy (ET). A previous clinical trial assessed the influence of adding a PRS to traditional risk estimates on ET use. We stratified participants according to PRS-refined breast cancer risk and evaluated ET use and ET-related quality of life (QOL) at 1-year (previously reported) and 2-year follow-ups. Of 151 participants, 58 (38.4%) initiated ET, and 22 (14.6%) discontinued ET by 2 years; 42 (27.8%) and 36 (23.8%) participants were using ET at 1- and 2-year follow-ups, respectively. At the 2-year follow-up, 39% of participants with a lifetime breast cancer risk of 40.1% to 100.0%, 18% with a 20.1% to 40.0% risk, and 16% with a 0.0% to 20.0% risk were taking ET (overall P = 0.01). Moreover, 40% of participants whose breast cancer risk increased by 10% or greater with addition of the PRS to a traditional breast cancer-risk model were taking ET versus 0% whose risk decreased by 10% or greater (P = 0.004). QOL was similar for participants taking or not taking ET at 1- and 2-year follow-ups, although most who discontinued ET did so because of adverse effects. However, these QOL results may have been skewed by the long interval between QOL surveys and lack of baseline QOL data. PRS-informed breast cancer prevention counseling has a lasting, but waning, effect over time. Additional follow-up studies are needed to address the effect of PRS on ET adherence, ET-related QOL, supplemental breast cancer screening, and other risk-reducing behaviors.

PREVENTION RELEVANCE

Risk-reducing medications for breast cancer are considerably underused. Informing women at risk with precise and individualized risk assessment tools may substantially affect the incidence of breast cancer. In our study, a risk assessment tool (IBIS-polygenic-risk score) yielded promising results, with 39% of women at highest risk starting preventive medication.

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.

Awareness and Candidacy for Endocrine Prevention and Risk Reducing Mastectomy in Unaffected High-Risk Women Referred for Breast Cancer Risk Assessment

INTRODUCTION

Primary prevention of breast cancer in women at elevated risk includes several strategies such as endocrine prevention and risk-reducing mastectomy (RRM). The objective of this study was to evaluate awareness of different preventive strategies across high-risk subgroups.

PATIENTS AND METHODS

Women referred for high risk evaluation between 2020 and 2023 completed an initial risk-assessment questionnaire that included questions around perceived lifetime risk and consideration of preventive strategies. One-way analysis of variance (ANOVA) and chi-squared tests were used to compare differences across different high-risk subgroups.

RESULTS

482 women with a median age of 43 years (20-79 years) met inclusion criteria; 183 (38.0%) germline pathogenic variant carriers (GPV), 90 (18.7%) with high-risk lesions (HRL) on breast biopsy, and 209 (43.4%) with strong family history (FH) without a known genetic predisposition. Most high-risk women reported that they had considered increased screening and surveillance (83.7%) and lifestyle strategies (80.6%), while fewer patients had considered RRM (39.8%) and endocrine prevention (27.0%). Prior to initial consultation, RRM was more commonly considered in GPV carriers (59.4%) relative to those with HRL (33.3%) or strong FH (26.3%, p < 0.001). Based on current guidelines, 206 (43%) patients were deemed eligible for endocrine prevention, including 80.5% with HRL and 39.0% with strong FH. Prior consideration of endocrine prevention was highest in patients with HRL and significantly lower in those with strong FH (47.2% HRL versus 31.1% GPV versus 18.7% FH, p = 0.001).

CONCLUSIONS

Endocrine prevention is the least considered preventive option for high-risk women, despite eligibility in a significant proportion of those presenting with HRL or strong FH.

Transcriptomics analysis reveals distinct mechanism of breast cancer stem cells regulation in mammospheres from MCF-7 and T47D cells

Luminal A breast cancer, constituting 70 % of breast cancer cases, presents a challenge due to the development of resistance and recurrence caused by breast cancer stem cells (BCSC). Luminal breast tumors are characterized by TP53 expression, a tumor suppressor gene involved in maintaining stem cell attributes in cancer. Although a previous study successfully developed mammospheres (MS) from MCF-7 (with wild-type TP53) and T47D (with mutant TP53) luminal breast cancer cells for BCSC enrichment, their transcriptomic profiles remain unclear. We aimed to elucidate the transcriptomic disparities between MS of MCF-7 and T47D cells using bioinformatics analyses of differentially expressed genes (DEGs), including the KEGG pathway, Gene Ontology (GO), drug-gene association, disease-gene association, Gene Set Enrichment Analysis (GSEA), DNA methylation analysis, correlation analysis of DEGs with immune cell infiltration, and association analysis of genes and small-molecule compounds via the Connectivity Map (CMap). Upregulated DEGs were enriched in metabolism-related KEGG pathways, whereas downregulated DEGs were enriched in the MAPK signaling pathway. Drug-gene association analysis revealed that both upregulated and downregulated DEGs were associated with fostamatinib. The KEGG pathway GSEA results indicated that the DEGs were enriched for oxidative phosphorylation, whereas the downregulated DEGs were negatively enriched for the p53 signaling pathway. Examination of DNA methylation revealed a noticeable disparity in the expression patterns of the PKM2, ERO1L, SLC6A6, EPAS1, APLP2, RPL10L, and NEDD4 genes when comparing cohorts with low- and high-risk breast cancer. Furthermore, a significant positive correlation was identified between SLC6A6 expression and macrophage presence, as well as MSN, and AKR1B1 expression and neutrophil and dentritic cell infiltration. CMap analysis unveiled SA-83851 as a potential candidate to counteract the effects of DEGs, specifically in cells harbouring mutant TP53. Further research, including in vitro and in vivo validations, is warranted to develop drugs targeting BCSCs.

Alternative dosing regimen of exemestane in a randomized presurgical trial: the role of obesity in biomarker modulation

In a 3-arm presurgical trial, four-six weeks exemestane 25 mg three times/week (TIW) was non-inferior to 25 mg/day (QD) in suppressing circulating estradiol in postmenopausal women with ER-positive breast cancer. Since obesity may decrease exemestane efficacy, we analyzed changes in sex steroids, adipokines, Ki-67, and drug levels in relation to obesity. Postmenopausal women with early-stage ER-positive breast cancer were randomized to either exemestane 25 mg QD (n = 57), 25 mg TIW (n = 57), or 25 mg/week (QW, n = 62) for 4-6 weeks before breast surgery. Serum and tissue pre- and post-treatment biomarkers were stratified by body mass index (BMI)< or ≥30 kg/m2. Post-treatment median exemestane and 17-OH exemestane levels were 5-6 times higher in the QD arm compared to the TIW arm. For obese women, TIW maintained comparable reductions to QD in systemic estradiol levels, although the reduction in estrone was less with the TIW regimen. There was less suppression of SHBG with the TIW versus the QD dose schedule in obese women which should result in less systemic bioavailable estrogens. Metabolically, the effect of the TIW regimen was similar to the QD regimen for obese women in terms of leptin suppression and increase in the adiponectin-leptin ratio. Reduction in tissue Ki-67 was less for obese women on the TIW regimen than QD, although changes were similar for non-obese women. Our findings suggest that TIW exemestane should be explored further for primary cancer prevention in both normal weight and obese cohorts.

Interventions to improve oral endocrine therapy adherence in breast cancer patients

PURPOSE

Oral endocrine therapy (OET) is recommended in prevention and treatment of hormone receptor-positive breast cancer (HR+ BC). Despite the reduced incidence, recurrence, and mortality, OET adherence is poor in this patient population. The aim of this study was to review the latest literature to identify effective interventions to improve medication adherence in patients taking OET for prevention or treatment of HR+ BC.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) framework was used to perform this review. We utilized PubMed, SCOPUS, EMBASE, Cochrane, and Web of Science to acquire articles using search terms including breast cancer, adherence, persistence, and acceptability. Inclusion criteria included publication in peer-reviewed journal, primary data source, longitudinal, patients on OET such as aromatase inhibitors (AIs) or selective estrogen receptor modulators (SERMs), measuring adherence, persistence, or acceptability.

RESULTS

Out of 895 articles identified, 10 articles were included. Majority of patients had early-stage HR+ BC. Two out of two studies incorporating technological intervention, two out of three studies with text communication-based intervention, and three out of five studies with verbal communication-based intervention reported significant improvement in OET adherence and/or persistence.

CONCLUSIONS

While the interventions tested so far have shown to improve OET adherence in HR+ BC patients in some studies, there is a need to design combination interventions addressing multiple barriers in this population.

IMPLICATIONS FOR CANCER SURVIVORS

This study showcases effectiveness of novel interventions to improve OET adherence and the need to further develop patient-centered strategies to benefit all patients with HR+ BC.

Systemic and Local Strategies for Primary Prevention of Breast Cancer

One in eight women will develop breast cancer in the US. For women with moderate (15-20%) to average (12.5%) risk of breast cancer, there are few options available for risk reduction. For high-risk (>20%) women, such as BRCA mutation carriers, primary prevention strategies are limited to evidence-based surgical removal of breasts and/or ovaries and anti-estrogen treatment. Despite their effectiveness in risk reduction, not many high-risk individuals opt for surgical or hormonal interventions due to severe side effects and potentially life-changing outcomes as key deterrents. Thus, better communication about the benefits of existing strategies and the development of new strategies with minimal side effects are needed to offer women adequate risk-reducing interventions. We extensively review and discuss innovative investigational strategies for primary prevention. Most of these investigational strategies are at the pre-clinical stage, but some are already being evaluated in clinical trials and others are expected to lead to first-in-human clinical trials within 5 years. Likely, these strategies would be initially tested in high-risk individuals but may be applicable to lower-risk women, if shown to decrease risk at a similar rate to existing strategies, but with minimal side effects.

Anti-cancer therapeutic agents and carpal tunnel syndrome: Clinical, electrodiagnostic, and ultrasound findings in seven patients

INTRODUCTION

Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy and rarely develops after drug therapy. This study describes the clinical, electrodiagnostic (EDX), and ultrasound (US) findings in seven patients who experienced CTS due to anti-cancer therapeutic agents.

METHODS

All patients underwent EDX testing, and four patients had an US study.

RESULTS

CTS occurred in four patients with aromatase inhibitors, two with immune checkpoint inhibitors, and one with a selective estrogen receptor modulator. The mean duration between initiation of the anti-cancer therapeutic agents and symptom onset was 6 weeks (range: 2-12 weeks). Decreased digit sensation was noted in all patients; wasting and weakness of the abductor pollicis brevis (APB) was observed in three (42.8%) patients. The compound muscle action potentials (CMAP) of the APB and sensory nerve action potentials of the second or third digit could not be recorded in two (28.5%) and four (57.1%) patients, respectively. The needle EMG detected fibrillations and positive sharp waves in the APB in two patients. The motor unit potentials of the APB were decreased with large polyphasics in three (42.8%) patients. Of the four patients who underwent US testing, all had increased cross-sectional area of the median nerve at the carpal tunnel inlet, three (75%) had thenar muscle atrophy, and two (50%) had a loss of fascicular pattern. Three (42.8%) patients underwent a CTR.

CONCLUSIONS

Physicians should be cognizant of the relationship between anti-cancer therapeutic agents and CTS. EDX studies and US play important roles in the diagnostic assessment of such patients.

Effect of baseline oestradiol serum concentration on the efficacy of anastrozole for preventing breast cancer in postmenopausal women at high risk: a case-control study of the IBIS-II prevention trial

BACKGROUND

An increased risk of breast cancer is associated with high serum concentrations of oestradiol and testosterone in postmenopausal women, but little is known about how these hormones affect response to endocrine therapy for breast cancer prevention or treatment. We aimed to assess the effects of serum oestradiol and testosterone concentrations on the efficacy of the aromatase inhibitor anastrozole for the prevention of breast cancer in postmenopausal women at high risk.

METHODS

In this case-control study we used data from the IBIS-II prevention trial, a randomised, controlled, double-blind trial in postmenopausal women aged 40-70 years at high risk of breast cancer, conducted in 153 breast cancer treatment centres across 18 countries. In the trial, women were randomly assigned (1:1) to receive anastrozole (1 mg/day, orally) or placebo daily for 5 years. In this pre-planned case-control study, the primary analysis was the effect of the baseline oestradiol to sex hormone binding globulin (SHBG) ratio (oestradiol-SHBG ratio) on the development of all breast cancers, including ductal carcinoma in situ (the primary endpoint in the trial). Cases were participants in whom breast cancer was reported after trial entry and until the cutoff on Oct 22, 2019, and who had valid blood samples and no use of hormone replacement therapy within 3 months of trial entry or during the trial. For each case, two controls without breast cancer were selected at random, matched on treatment group, age (within 2 years), and follow-up time (at least that of the matching case). For each treatment group, we applied a multinominal logistic regression likelihood-ratio trend test to assess what change in the proportion of cases was associated with a one-quartile change in hormone ratio. Controls were used only to determine quartile cutoffs. Profile likelihood 95% CIs were used to indicate the precision of estimates. A secondary analysis also investigated the effect of the baseline testosterone-SHBG ratio on breast cancer development. We also assessed relative benefit of anastrozole versus placebo (calculated as 1 - the ratio of breast cancer cases in the anastrozole group to cases in the placebo group). The trial was registered with ISRCTN (number ISRCTN31488319) and completed recruitment on Jan 31, 2012, but long-term follow-up is ongoing.

FINDINGS

3864 women were recruited into the trial between Feb 2, 2003, and Jan 31, 2012, and randomly assigned to receive anastrozole (n=1920) or placebo (n=1944). Median follow-up time was 131 months (IQR 106-156), during which 85 (4·4%) cases of breast cancer in the anastrozole group and 165 (8·5%) in the placebo group were identified. No data on gender, race, or ethnicity were collected. After exclusions, the case-control study included 212 participants from the anastrozole group (72 cases, 140 controls) and 416 from the placebo group (142 cases, 274 controls). A trend of increasing breast cancer risk with increasing oestradiol-SHBG ratio was found in the placebo group (trend per quartile 1·25 [95% CI 1·08 to 1·45], p=0·0033), but not in the anastrozole group (1·06 [0·86 to 1·30], p=0·60). A weaker effect was seen for the testosterone-SHBG ratio in the placebo group (trend 1·21 [1·05 to 1·41], p=0·011), but again not in the anastrozole group (trend 1·18 [0·96 to 1·46], p=0·11). A relative benefit of anastrozole was seen in quartile 2 (0·55 [95% CI 0·13 to 0·78]), quartile 3 (0·54 [0·22 to 0·74], and quartile 4 (0·56 [0·23 to 0·76]) of oestradiol-SHBG ratio, but not in quartile 1 (0·18 [-0·60 to 0·59]).

INTERPRETATION

These results suggest that serum hormones should be measured more routinely and integrated into risk management decisions. Measuring serum hormone concentrations is inexpensive and might help clinicians differentiate which women will benefit most from an aromatase inhibitor.

FUNDING

Cancer Research UK, National Health and Medical Research Council (Australia), Breast Cancer Research Foundation, and DaCosta Fund.

Cardiotoxicity of Agents Used in Patients With Breast Cancer

Cancer and cardiovascular diseases are the two major causes of mortality, morbidity, and disability worldwide. The improvement in effective therapeutic options for the management of breast cancer (BC) has led to an increased number of BC survivors, who can experience long-term toxicities from cancer treatments. Adverse events including cardiovascular toxicities must be considered in light of effectiveness of recently approved drugs for BC treatment, including elacestrant, tucatinib, neratinib, olaparib, the immune checkpoint inhibitors, trastuzumab deruxtecan, or sacituzumab govitecan. Many cancer drugs affect the cardiovascular system with a range of clinical manifestations. Prompt diagnosis and treatment as well as a multidisciplinary approach involving a cardio-oncologist is optimal for management of these cardiovascular events.

Deregulated transcription factors in the emerging cancer hallmarks

Cancer progression is a multifaceted process that entails several stages and demands the persistent expression or activation of transcription factors (TFs) to facilitate growth and survival. TFs are a cluster of proteins with DNA-binding domains that attach to promoter or enhancer DNA strands to start the transcription of genes by collaborating with RNA polymerase and other supporting proteins. They are generally acknowledged as the major regulatory molecules that coordinate biological homeostasis and the appropriate functioning of cellular components, subsequently contributing to human physiology. TFs proteins are crucial for controlling transcription during the embryonic stage and development, and the stability of different cell types depends on how they function in different cell types. The development and progression of cancer cells and tumors might be triggered by any anomaly in transcription factor function. It has long been acknowledged that cancer development is accompanied by the dysregulated activity of TF alterations which might result in faulty gene expression. Recent studies have suggested that dysregulated transcription factors play a major role in developing various human malignancies by altering and rewiring metabolic processes, modifying the immune response, and triggering oncogenic signaling cascades. This review emphasizes the interplay between TFs involved in metabolic and epigenetic reprogramming, evading immune attacks, cellular senescence, and the maintenance of cancer stemness in cancerous cells. The insights presented herein will facilitate the development of innovative therapeutic modalities to tackle the dysregulated transcription factors underlying cancer.

European guidelines for the diagnosis, treatment and follow-up of breast lesions with uncertain malignant potential (B3 lesions) developed jointly by EUSOMA, EUSOBI, ESP (BWG) and ESSO

INTRODUCTION

Breast lesions of uncertain malignant potential (B3) include atypical ductal and lobular hyperplasias, lobular carcinoma in situ, flat epithelial atypia, papillary lesions, radial scars and fibroepithelial lesions as well as other rare miscellaneous lesions. They are challenging to categorise histologically, requiring specialist training and multidisciplinary input. They may coexist with in situ or invasive breast cancer (BC) and increase the risk of subsequent BC development. Management should focus on adequate classification and management whilst avoiding overtreatment. The aim of these guidelines is to provide updated information regarding the diagnosis and management of B3 lesions, according to updated literature review evidence.

METHODS

These guidelines provide practical recommendations which can be applied in clinical practice which include recommendation grade and level of evidence. All sections were written according to an updated literature review and discussed at a consensus meeting. Critical appraisal by the expert writing committee adhered to the 23 items in the international Appraisal of Guidelines, Research and Evaluation (AGREE) tool.

RESULTS

Recommendations for further management after core-needle biopsy (CNB) or vacuum-assisted biopsy (VAB) diagnosis of a B3 lesion reported in this guideline, vary depending on the presence of atypia, size of lesion, sampling size, and patient preferences. After CNB or VAB, the option of vacuum-assisted excision or surgical excision should be evaluated by a multidisciplinary team and shared decision-making with the patient is crucial for personalizing further treatment. De-escalation of surgical intervention for B3 breast lesions is ongoing, and the inclusion of vacuum-assisted excision (VAE) will decrease the need for surgical intervention in further approaches. Communication with patients may be different according to histological diagnosis, presence or absence of atypia, or risk of upgrade due to discordant imaging. Written information resources to help patients understand these issues alongside with verbal communication is recommended. Lifestyle interventions have a significant impact on BC incidence so lifestyle interventions need to be suggested to women at increased BC risk as a result of a diagnosis of a B3 lesion.

CONCLUSIONS

These guidelines provide a state-of-the-art overview of the diagnosis, management and prognosis of B3 lesions in modern multidisciplinary breast practice.

Effect of whole-body cryotherapy versus placebo cryotherapy on joint pain induced by aromatase inhibitors in women with early stage breast cancer: a randomised clinical trial

INTRODUCTION

Hormone therapy (HT) is a major adjuvant treatment for breast cancer. Despite their effectiveness, aromatase inhibitors can cause several side effects, including arthralgia in 35%-50% of patients. These side effects frequently lead to the premature discontinuation of HT. Whole-body cryotherapy (WBC) can be used for managing arthritic pain. The primary objective of this study will be to evaluate the effect of WBC on aromatase-induced joint pain, compared with placebo cryotherapy, in patients with hormone-dependent breast cancer receiving adjuvant aromatase inhibitors. The secondary objectives will be to evaluate WBC safety and its effect on analgesic consumption, HT adherence and quality of life.

METHODS AND ANALYSIS

In this randomised, placebo-controlled, double-blinded clinical trial, 56 patients with aromatase inhibitor-induced joint pain and a Brief Pain Inventory-Short Form (BPI-SF) score ≥3 for the worst pain experienced in the previous week will be randomised into the WBC or placebo cryotherapy arm (10 sessions in each group). The primary outcome will be the BPI-SF score at week 6 post-treatment. The secondary outcomes will include the BPI-SF scores at months 3 and 6 post-treatment, the BPI-SF pain severity index and pain interference index, the Health Assessment Questionnaire score, the number of days of aromatase inhibitor treatment and analgesic consumption in the 15 days before the visits at week 6 and months 3 and 6 after cryotherapy. The incidence of adverse events will also be investigated.

ETHICS AND DISSEMINATION

Ethics approval was obtained from the Ethics Committee Est IV of Hospital Civil, Strasbourg, France. Protocol V.5 was approved in December 2022. The results will be disseminated in a peer-reviewed journal and presented at international congresses.

TRIAL REGISTRATION NUMBER

NCT05315011.

Presurgical Oral Tamoxifen vs Transdermal 4-Hydroxytamoxifen in Women With Ductal Carcinoma In Situ: A Randomized Clinical Trial

Importance

Oral tamoxifen citrate benefits women with ductal carcinoma in situ (DCIS), but concern about toxic effects has limited acceptance. Previous pilot studies have suggested transdermal 4-hydroxytamoxifen gel has equivalent antiproliferative efficacy to oral tamoxifen, with low systemic exposure.

Objective

To demonstrate that 4-hydroxytamoxifen gel applied to the breast skin is noninferior to oral tamoxifen in its antiproliferative effect in DCIS lesions.

Design, Setting, and Participants

This randomized, double-blind, phase 2 preoperative window trial was performed at multicenter breast surgery referral practices from May 31, 2017, to January 27, 2021. Among 408 women with estrogen receptor-positive DCIS who were approached, 120 consented and 100 initiated study treatment. The most common reasons for nonparticipation were surgical delay, disinterest in research, and concerns about toxic effects. Data were analyzed from January 26, 2021, to October 5, 2022.

Intervention

Random assignment to oral tamoxifen citrate, 20 mg/d, and gel placebo or 4-hydroxytamoxifen gel, 2 mg/d per breast, and oral placebo, for 4 to 10 weeks, followed by DCIS resection.

Main Outcomes and Measures

The primary end point was absolute change in DCIS Ki-67 labeling index (Ki67-LI). Secondary end points included 12-gene DCIS Score, breast tissue tamoxifen metabolite concentrations, tamoxifen-responsive plasma protein levels, and patient-reported symptoms. Noninferiority of Ki67-LI reduction by 4-hydroxytamoxifen gel was tested using analysis of covariance; within- and between-arm comparisons were performed with paired t tests for mean values or the Wilcoxon rank sum test for medians.

Results

Of 90 participants completing treatment (mean [SD] age, 55 [11] years; 8 [8.9%] Asian, 16 [17.8%] Black, 8 [8.9%] Latina, and 53 [58.9%] White), 15 lacked residual DCIS in the surgical sample, leaving 75 evaluable for the primary end point analysis (40 in the oral tamoxifen group and 35 in the 4-hydroxytamoxifen gel group). Posttreatment Ki67-LI was 3.3% higher (80% CI, 2.1%-4.6%) in the 4-hydroxytamoxifen gel group compared with the oral tamoxifen group, exceeding the noninferiority margin (2.6%). The DCIS Score decreased more with oral tamoxifen treatment (-16 [95% CI, -22 to -9.4]) than with 4-hydroxytamoxifen gel (-1.8 [95% CI, -5.8 to 2.3]). The median 4-hydroxytamoxifen concentrations deep in the breast were nonsignificantly higher in the oral tamoxifen group (5.7 [IQR, 4.0-7.9] vs 3.8 [IQR, 1.3-7.9] ng/g), whereas endoxifen was abundant in the oral tamoxifen group and minimal in the 4-hydroxytamoxifen gel group (median, 13.0 [IQR, 8.9-20.6] vs 0.3 [IQR, 0-0.3] ng/g; P < .001). Oral tamoxifen caused expected adverse changes in plasma protein levels and vasomotor symptoms, with minimal changes in the transdermal group.

Conclusions and Relevance

In this randomized clinical trial, antiproliferative noninferiority of 4-hydroxytamoxifen gel to oral tamoxifen was not confirmed, potentially owing to endoxifen exposure differences. New transdermal approaches must deliver higher drug quantities and/or include the most potent metabolites.

Trial Registration

ClinicalTrials.gov Identifier: NCT02993159.

Discovery and biological evaluation of pregnenolone selenocyanoamides with potential anticancer and antimicrobial activities

Starting with pregnenolone, a 20-carbonyl group was converted into an amino group through a series of chemical reactions. This amino group was further converted into selenocyanoalkylamide, leading to the synthesis of six pregnenolone selenocyanoalkylamide derivatives. These compounds were then screened for antitumor activity in vitro, yielding promising results. Compounds 4b-4f show higher inhibitory activity than the positive control abiraterone and 2-methoxyestradiol, with IC50 values lower than 10 μmol/L against breast, ovarian, and cervical cancer cell lines that closely related to human hormone expression levels. The Annexin V assay of compound 4f revealed that compounds inhibited tumor cell proliferation primarily through the induction of programmed apoptosis. The zebrafish test results indicated that compound 4d had significant inhibitory activity against MCF-7 cell xenografts in vivo. Moreover, the antibacterial test indicated that compounds 4a and 4d-4e had better inhibitory activity against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE) than the positive controls vancomycin and ampicillin. These results suggest that these compounds may hold promise as novel antitumor agents or antimicrobial agents for further study.

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.

Thyroid hormone enhances estrogen-mediated proliferation and cell cycle regulatory pathways in steroid receptor-positive breast Cancer

Estrogen receptor (ER) α expression and associated signaling is a major driver of over two-thirds of all breast cancers (BC). ER targeting strategies are typically used as a first-line therapy in patients with steroid receptor positive (SR+) disease. Secondary resistance to anti-estrogenic agents may occur with clonal expansion and disease progression. Mechanisms underlying hormone resistance are an expanding field of significant translational importance. Cross-talk with other nuclear hormones, receptors, and signaling pathways, including thyroid hormones (TH) and their receptors (THRs), have been shown to promote endocrine therapy resistance in some studies. We have shown that TH replacement therapy (THRT) was independently and significantly associated with higher rates of relapse and mortality in SR positive (+), node-negative (LN-) BC patients, whereas it showed no association with outcomes in SR negative (-) patients. LN-, SR+ patients receiving THRT and tamoxifen had the worst outcomes, suggesting a pro-carcinogenic interaction that significantly and independently shortened survival and increased mortality. Using in vivo and in vitro models, we previously showed hormonal cross-talk, altered gene signaling, target gene activation, and resistance to tamoxifen in the presence of TH. In this report, we show TH ± E2 ± tamoxifen inhibits cell cycle control signaling, reduces apoptosis, and enhances cell proliferation, tumor growth, tamoxifen resistance, and clonal expansion. Mechanistically these changes involve numerous genes and pathways, including critical cell cycle regulatory proteins and genes identified using various molecular methods. These studies facilitate a greater mechanistic understanding of the biological and molecular impact of TH on SR+ BC.