Randomized Placebo Controlled Trial of Low-Dose Tamoxifen to Prevent Local and Contralateral Recurrence in Breast Intraepithelial Neoplasia

Risk-reducing mastectomy in healthy women with BRCA mutation: a narrative review

INTRODUCTION

Breast cancer (BC) prevention in BRCA1/2 mutation carriers remains a significant clinical challenge. Risk-reducing mastectomy (RRM) is the most effective preventive option, lowering BC incidence by over 90%. Despite its survival benefit, the decision to undergo RRM is complex and shaped by psychological, social, and healthcare access factors.

AREAS COVERED

This narrative review synthesizes evidence on the oncologic efficacy, safety, and outcomes of RRM in BRCA mutation carriers. Literature was identified through PubMed, Scopus, and Web of Science up to March 2025. Large cohort studies and systematic reviews confirm the effectiveness of RRM. Nipple-sparing mastectomy offers comparable oncologic safety with improved cosmetic and psychological outcomes. Histopathologic analyses frequently reveal occult malignancies, supporting the role of early surgery. However, surgical complications, sensory loss, and sexual health impacts remain important considerations.

EXPERT OPINION

RRM is cost-effective, especially when performed at younger ages, but disparities in access to genetic testing and surgery persist. Special populations, such as ovarian cancer survivors and those diagnosed before genetic testing, require individualized care. Advances in risk stratification, surgical techniques, and psychosocial support will enhance outcomes. A multidisciplinary, patient-centered approach is essential for informed decision-making.

Predictive Effect of IGFBP-3 on Low-Dose Tamoxifen Efficacy in Noninvasive Breast Cancer in the Phase III Tam-01 Trial

PURPOSE

Low-dose tamoxifen 5 mg/day (babytam) for 3 years can decrease the incidence of new breast cancer events in women with breast intraepithelial neoplasia by 42% with limited toxicity, which provides a new treatment option for these disorders. However, predictive biomarkers of babytam efficacy are lacking. We studied whether baseline levels of insulin-like growth factor-1 (IGF-I), IGF-binding protein-3 (IGFBP-3), estradiol, and sex hormone-binding globulin (SHBG) and their ratios predict babytam efficacy on breast cancer events in a preplanned secondary analysis.

PATIENTS AND METHODS

Within a 1:1 placebo-controlled, multicenter randomized trial of babytam or placebo administered for 3 years after surgery in women with hormone-sensitive or unknown breast intraepithelial neoplasia, including atypical ductal hyperplasia and lobular or ductal carcinoma in situ, 406 of 500 participants consented to blood sampling at baseline and at 1 and 3 years. Serum IGF-I, IGFBP-3, estradiol, and SHBG levels and their ratios were measured using chemiluminescent immunoassays. Biomarker changes were estimated using mixed-effects models, and incidence rate ratios were calculated after 10 years of follow-up with Poisson regression. Subgroup analyses were performed using an interaction test and subpopulation treatment effect pattern plot.

RESULTS

Baseline levels of IGFBP-3 in the three top quartiles (≥3.44 µg/mL), but not in the lower quartile, predicted greater babytam efficacy compared with placebo (Pinteraction = 0.006). Baseline IGF-I, estradiol, or SHBG levels were not predictive of babytam efficacy, whereas the IGF-I/IGFBP-3 ratio was borderline significant (Pinteraction = 0.067).

CONCLUSIONS

High baseline levels of IGFBP-3 (≥3.44 µg/mL) predicted babytam efficacy and may help differentiate which women benefit most from this treatment.

SREBP1-Dependent Metabolism as a Potential Target for Breast Cancer Risk Reduction

There are an estimated 10 million U [...].

Hormone Receptor Status of Second Breast Cancers in Women With Triple-Negative Breast Cancer

This cohort study investigates chemoprevention in patients with triple-negative breast cancer experiencing subsequent in-breast events.

Breast Cancer Risk, Screening, and Risk Reduction in Young Females

Screening and prevention strategies for breast cancer (BC) have focused on women over 40 years of age. While BC prevalence under 40 is low, affected patients have more aggressive cancers and a poorer prognosis. Those with identifiable risk factors may benefit from screening for early detection and prevention strategies. This paper reviews the current literature and guidelines regarding BC risk. Screening guidelines and prevention strategies are also reviewed, with a focus on females under the age of 40.

Low Dose Tamoxifen for Breast Cancer Prevention: A Real-World Experience

PURPOSE

There is limited data on the use of low dose tamoxifen (LDT) for chemoprevention since its introduction in 2019. This study sought to determine the rate of LDT uptake at our institution and describe factors associated with its use.

METHODS

We performed a retrospective chart review of women diagnosed with ductal carcinoma in situ (DCIS), lobular carcinoma in situ (LCIS), and/or atypical hyperplasia from 2019 to 2021. Log-binomial models were used to compare the probabilities of receiving standard dose tamoxifen (SDT) relative to LDT by patient and disease characteristics. Since most patients did not experience any AEs, a zero-inflated poison regression model was used to estimate and compare adverse event rates between groups.

RESULTS

Among 477 patients with DCIS, LCIS, and atypical hyperplasia, 27% (N = 129) initiated SDT, 19% (N = 89) LDT, 32% (N = 155) aromatase inhibitor, 2% (N = 9) raloxifene, and 20% (N = 95) declined therapy. LDT was used more frequently than SDT in patients with LCIS or atypical hyperplasia compared to DCIS (31.4% vs 17.4%, P < .0001). There were no significant differences in the frequency of adverse events between patients on SDT and LDT but the incidence rate of AEs in the SDT group was higher (1.9 vs. 1.3 per 1000 days, P = .0186).

CONCLUSION

In our population, 19% of women with DCIS, LCIS, or atypical hyperplasia, initiated chemoprevention with LDT with higher usage in patients with atypical lesions and/or LCIS. Physicians should strongly consider LDT in women with high-risk lesions who are eligible for chemoprevention.

Influence of endoxifen on mammographic density: results from the KARISMA-Tam trial

BACKGROUND

Monitoring metabolites of tamoxifen, such as endoxifen, has been suggested as a strategy to ascertain therapeutic effect of tamoxifen therapy, but clinical guidelines are missing. Herein, we aim to investigate the outcome of endoxifen concentrations of low-dose tamoxifen, using change in mammographic breast density as a proxy for therapy response.

METHODS

In the randomized KARISMA-Tam (Karolinska Mammography project for risk prediction of breast cancer -Intervention Study with Tamoxifen) trial, including 5 doses of tamoxifen, measurements of plasma endoxifen concentrations, determination of CYP2D6 metabolizer status, and mammographic breast density change over the trial period were carried out. Association between endoxifen concentrations and relative mammographic breast density change after 6 months treatment was analyzed using linear regression in a spline model.

RESULTS

A total of 824 women (335 premenopausal, 489 postmenopausal) were included. In analyses of premenopausal women, a spline model described a mammographic breast density decrease, equivalent to the mean (-18.5%) seen in women exposed to 20 mg tamoxifen, at endoxifen concentrations of 2-3 ng/mL. The mammographic breast density decrease reached a nadir at endoxifen levels of 3 ng/mL and did not decrease further at higher endoxifen concentrations. Most intermediate and normal tamoxifen metabolizers (about 90% of all participants) reached an endoxifen concentration of more than 2 ng/mL at tamoxifen doses of 5 and 10 mg. No mammographic breast density decrease was seen in the postmenopausal group.

CONCLUSIONS

We have identified a possible window of effect on mammographic breast density at endoxifen concentrations of 2-3 ng/mL in premenopausal women, which corresponds to the doses of 5 and 10 mg tamoxifen. Because mammographic breast density change was used as a surrogate marker for therapy response, results should be confirmed using clinically established outcomes measures.

Implementation of model-informed precision dosing for tamoxifen therapy in patients with breast cancer: A prospective intervention study

Tamoxifen is an estrogen-receptor (ER) antagonist, used as adjuvant treatment of ER-positive breast cancer. It is converted by CYP2D6 into endoxifen, its most active metabolite. Patients with endoxifen plasma concentrations <16 nM face a higher risk of recurrence. The use of a priori model-informed precision dosing (MIPD) may lead to faster target attainment and thus potentially improve patient outcomes. In total, 106 evaluable patients were prospectively included in this single-arm MIPD-intervention study. Patients received a model-predicted tamoxifen dose when starting tamoxifen-treatment (65.1 % of patients received 20 mg, 16.0 % received 30 mg and 18.9 % received 40 mg). Seventy-five percent of the 40 mg group was predicted to be unable to reach the threshold of 16 nM despite receiving the highest registered dose. After attaining steady-state, 84.0 % of patients reached endoxifen levels ≥16 nM, which was not significantly higher compared to a historical control cohort (77.9 %, p = 0.17). The model showed adequate performance and correctly identified patients requiring 40 mg tamoxifen. Endoxifen samples that were acquired 4-6 weeks after treatment initiation, are informative of steady-state endoxifen levels and can be used to inform MIPD and adjust tamoxifen dosing prior to steady-state attainment. In this first MIPD implementation study for patients treated with tamoxifen, MIPD did lead to more patients achieving endoxifen levels ≥16 nM as compared to the one-dose-fits-all strategy, albeit insignificant. This may partly be explained by a larger proportion of patients who were recommended to switch to an aromatase inhibitor (AI) in the intervention cohort. In conclusion, MIPD seems beneficial compared to one-size-fits-all-dosing, but TDM still remains an important addition.

Update on the management of ductal carcinoma in situ of the breast: current approach and future perspectives

The standard treatment for ductal carcinoma in situ became well established through the results of several valuable clinical trials, and its therapeutic benefits have now come to be taken for granted. Ductal carcinoma in situ has an extremely good prognosis with the current treatment approach, with a 10-year breast cancer-specific survival rate of 97-98%. According to one retrospective cohort study, the breast cancer-specific survival rate of patients with low-grade ductal carcinoma in situ does not differ significantly between patients undergoing and not undergoing surgery. Some patients with ductal carcinoma in situ are not at a risk of progression to invasive cancer, but the predictors of such progression have not yet been clearly identified. Therefore, the same therapeutic strategies have been used to treat ductal carcinoma in situ and under the assumption that they have risks of invasive breast cancer, and a well-balanced risk/benefit ratio in respect of treatment has not yet been achieved. Based on the results of several recent clinical trials aimed at ensuring provision of a well-balanced treatment for patients with ductal carcinoma in situ which carries a good prognosis, de-escalation of postoperative adjuvant therapy has now begun. Currently, not only is the optimization of postoperative adjuvant therapy accelerating, but also clinical trials to de-escalate basic surgical treatments are under way. There is a possibility of achieving individualized treatment for patients with ductal carcinoma in situ of the breast with reduced treatment intervention. In this review, we present an overview of the current treatment approaches and potential future management strategies for ductal carcinoma in situ of the breast.

A roadmap to reduce the incidence and mortality of breast cancer by rethinking our approach to women's health

Despite progress, breast cancer remains the most feared disease among women. In the USA alone, the incidence is now almost 300,000 new cancers per year, a rate that has nearly doubled in the last 30 years. Most women survive, but over 40,000 women a year still die of their disease [99]. It is the most diagnosed cancer among women and the second leading cause of cancer death. Important disparities exist in breast cancer outcomes among African American women, where women die of breast cancer at higher rates, are diagnosed younger, and at a more advanced stage. We are proposing a radical shift in our thinking about breast cancer prevention with an aspiration to dramatically lower breast cancer incidence. Most breast cancers are driven by steroid hormones. Throughout the life course, women are offered an array of hormonal treatments for menstrual cycle control, family planning, in vitro fertilization, postpartum weaning, and menopausal symptom management. There are mixed data on the extent to which each of these may contribute to increased or decreased risk for breast cancer. These endocrine manipulations could represent a great opportunity to potentially reduce breast cancer incidence and improve quality of life for survivors. To date, they have not been designed to explicitly reduce breast cancer risk. A new holistic approach will require scientists, drug developers, breast oncologists, obstetricians, gynecologists, endocrinologists, radiologists, and family medicine/internists to work together toward the common goal of reducing breast cancer risk while addressing other critical issues in women's health.

Identification and management of patients at increased risk for breast cancer

Breast cancer is the most diagnosed invasive cancer in the United States, with 1 in 8 people assigned female at birth (AFAB) being affected.1 It is imperative that health care practitioners remain current and well-versed in identifying individuals at high risk for developing breast cancer. This article outlines an approach for obstetrics/gynecology practitioners to identify high-risk patients and to counsel on appropriate breast cancer screening, prevention, and risk-reduction options.

Impact of prolactin treatment on enhancing the cellular responses of MCF7 breast cancer cells to tamoxifen treatment

Breast cancer remains one of the most challenging diseases to treat due to its heterogeneity, propensity to recur, capacity to spread to distant vital organs, and, ultimately, patient death. Estrogen receptor-positive illness comprises the most common breast cancer subtype. Preclinical progress is hampered by the scarcity of medication-naïve estrogen receptor-positive tumour models that recapitulate metastatic development and treatment resistance. It is becoming increasingly clear that loss of differentiation and increased cellular stemness and plasticity are important causes of cancer evolution, heterogeneity, recurrence, metastasis, and treatment failure. Therefore, it has been suggested that reprogramming cancer cell differentiation could offer an effective method of reversing cancer through terminal differentiation and maturation. In this context, the hormone prolactin is well recognized for its pivotal involvement in the development of the mammary glands lobuloalveolar tissue and the terminal differentiation that drives the production of the milk protein gene and lactation. Additionally, numerous studies have examined the engagement of prolactin in breast cancer as a differentiation player that resulted in the ablation of tumour growth and progression. Here, we showed that a pre-treatment of the estrogen-positive breast cancer cell line with prolactin led to a considerable improvement in the sensitivity of this cancer cell to Tamoxifen endocrine therapy. We also showed a favourable prognostic value of prolactin receptors/estrogen receptors 1 (or alpha) co-expression on breast cancer patients outcomes, and this co-expression is highly correlated with the well-differentiated breast tumour type. Our results revealed a fruitful aspect of the effects of prolactin in improving the responses of breast cancer cells to conventional endocrine therapy. Moreover, these findings further validated the ability of prolactin as a persuader of a more differentiated and less aggressive breast cancer phenotype. Hence, it suggested a potential implication of prolactin as a therapeutic candidate.

Management of Ductal Carcinoma In Situ: An Ontario Health (Cancer Care Ontario) Clinical Practice Guideline

(1) Background: To make recommendations on the most effective therapy options for Ductal Carcinoma of the Breast (DCIS) patients; (2) Methods: MEDLINE, EMBASE, Cochrane Library, PROSPERO databases, and main relevant guideline websites were searched. Draft versions of the guideline went through formal internal and external reviews, with a final approval by the Program in Evidence Based Care and the DCIS Expert Panel. The Grading of Recommendations, Assessment, Development, and Evaluation approach was followed; (3) Results: Based on the current evidence from the systematic review and this guideline authors' clinical opinions, initial draft recommendations were developed to improve the management of patients with DCIS. After a comprehensive internal and external review process, ten recommendations and 27 qualifying statements were eventually made. This guideline includes recommendations for the primary treatment of DCIS with surgical treatment and/or radiation therapy and the management of DCIS after primary treatment for patients with DCIS, including DCIS with microinvasion (<1 mm through the duct); (4) Conclusions: The current guideline was created after a systematic review and a comprehensive internal and external review process. We believe this guideline provides valuable insights that will be useful in clinical decision making for health providers.

Endocrine therapy initiation among women diagnosed with ductal carcinoma in situ from 2001 to 2018

PURPOSE

Trials demonstrating benefits of tamoxifen for women with ductal carcinoma in situ (DCIS) were published > 20 years ago; yet subsequent uptake of endocrine therapy was low. We estimated endocrine therapy initiation in women with DCIS between 2001 and 2018 in a community setting, reflecting more recent years of diagnosis than previous studies.

METHODS

This retrospective cohort included adult females ≥ 20 years diagnosed with first primary DCIS between 2001 and 2018, followed through 2019, and enrolled in one of three U.S. integrated healthcare systems. We collected data on endocrine therapy dispensings (tamoxifen, aromatase inhibitors [AIs]) from electronic pharmacy records within 12 months after DCIS diagnosis. Using generalized linear models with a log link and Poisson distribution, we estimated endocrine therapy initiation rates over time and by patient, tumor (including estrogen receptor [ER] status), and treatment characteristics.

RESULTS

Among 2020 women with DCIS, 587 (29%) initiated endocrine therapy within 12 months after diagnosis (36% among 1208 women with ER-positive DCIS). Among women who used endocrine therapy, 506 (86%) initiated tamoxifen and 81 (14%) initiated AIs. Age-adjusted endocrine therapy initiation declined from 34 to 21% between 2001 and 2017; between 2015 and 2018, AI use increased from 8 to 35%. Women less likely to initiate endocrine therapy were ER-negative or had borderline/unknown or no ER test results, ≥ 65 years at diagnosis, Black, and received no radiotherapy.

CONCLUSION

One-third of women diagnosed with DCIS initiated endocrine therapy, and use decreased over time. Understanding why women eligible for endocrine therapy do not initiate is important to maximizing disease-free survival following DCIS diagnosis.

Biomarkers in breast cancer 2024: an updated consensus statement by the Spanish Society of Medical Oncology and the Spanish Society of Pathology

This revised consensus statement of the Spanish Society of Medical Oncology (SEOM) and the Spanish Society of Pathological Anatomy (SEAP) updates the recommendations for biomarkers use in the diagnosis and treatment of breast cancer that we first published in 2018. The expert group recommends determining in early breast cancer the estrogen receptor (ER), progesterone receptor (PR), Ki-67, and Human Epidermal growth factor Receptor 2 (HER2), as well as BReast CAncer (BRCA) genes in high-risk HER2-negative breast cancer, to assist prognosis and help in indicating the therapeutic options, including hormone therapy, chemotherapy, anti-HER2 therapy, and other targeted therapies. One of the four available genetic prognostic platforms (Oncotype DX®, MammaPrint®, Prosigna®, or EndoPredict®) may be used in ER-positive patients with early breast cancer to establish a prognostic category and help decide with the patient whether adjuvant treatment may be limited to hormonal therapy. In second-line advanced breast cancer, in addition, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) and estrogen receptor 1 (ESR1) should be tested in hormone-sensitive cases, BRCA gene mutations in HER2-negative cancers, and in triple-negative breast cancer (TNBC), programmed cell death-1 ligand (PD-L1). Newer biomarkers and technologies, including tumor-infiltrating lymphocytes (TILs), homologous recombination deficiency (HRD) testing, serine/threonine kinase (AKT) pathway activation, and next-generation sequencing (NGS), are at this point investigational.

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.

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.

The Impact of a Breast Cancer Risk Assessment on the Decision for Gender-Affirming Chest Masculinization Surgery in Transgender and Gender-Diverse Individuals: A Pilot Single-Arm Educational Intervention Trial

BACKGROUND

Persons assigned female or intersex at birth and identify as transgender and/or gender-diverse (TGD) may undergo gender-affirming chest masculinization surgery (GACMS); however, GACMS is not considered equivalent to risk-reducing mastectomies (RRM). This study aimed to estimate the prevalence of elevated breast cancer (BC) risk in TGD persons, compare self-perceived versus calculated risk, and determine how risk impacts the decision for GACMS versus RRM.

METHODS

A prospective single-arm pilot educational intervention trial was conducted in individuals assigned female or intersex at birth, age ≥ 18 years, considering GACMS, without a BC history or a known pathogenic variant. BC risk was calculated using the Tyrer-Cuzik (all) and Gail models (age ≥ 35 years). Elevated risk was defined as ≥ 17%.

RESULTS

Twenty-five (N = 25) participants were enrolled with a median age of 24.0 years (interquartile range, IQR 20.0-30.0 years). All were assigned female sex at birth, most (84%) were Non-Hispanic (NH)-White, 48% identified as transgender and 40% as nonbinary, and 52% had a first- and/or second-degree family member with BC. Thirteen (52%) had elevated risk (prevalence 95% confidence interval (CI) 31.3-72.2%). Median self-perceived risk was 12% versus 17.5% calculated risk (p = 0.60). Of the 13 with elevated risk, 5 (38.5%) underwent/are scheduled to undergo GACMS, 3 (23%) of whom underwent/are undergoing RRM.

CONCLUSIONS

Over half of the cohort had elevated risk, and most of those who moved forward with surgery chose to undergo RRM. A BC risk assessment should be performed for TGD persons considering GACMS. Future work is needed to examine BC incidence and collect patient-reported outcomes. Trial Registration Number ClinicalTrials.gov (No. NCT06239766).

Ductal Carcinoma In Situ

In breast cancer (BC) pathogenesis models, normal cells acquire somatic mutations and there is a stepwise progression from high-risk lesions and ductal carcinoma in situ to invasive cancer. The precancer biology of mammary tissue warrants better characterization to understand how different BC subtypes emerge. Primary methods for BC prevention or risk reduction include lifestyle changes, surgery, and chemoprevention. Surgical intervention for BC prevention involves risk-reducing prophylactic mastectomy, typically performed either synchronously with the treatment of a primary tumor or as a bilateral procedure in high-risk women. Chemoprevention with endocrine therapy carries adherence-limiting toxicity.

Breast Articles From 2023: Informing Practice Across the Continuum of Care

With new investigations and clinical trials in breast oncology reported every year, it is critical that surgeons be aware of advances and insights into the evolving care paradigms and treatments available to their patients. This article highlights five publications found to be particularly impactful this past year. These articles report on efforts to select the minimal effective dose of tamoxifen for prevention, to challenge the existing age-based screening guidelines as they relate to race and ethnicity, to refine axillary management treatment standards, to optimize systemic therapy in multidisciplinary care settings, and to reduce the burden of breast cancer-related lymphedema after treatment. Taken together, these efforts have an impact on all facets of the continuum of care from prevention and screening through treatment and survivorship.

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.

Update on Management of Ductal Carcinoma in Situ

Ductal carcinoma in situ (DCIS) represents 18% to 25% of all diagnosed breast cancers, and is a noninvasive, nonobligate precursor lesion to invasive cancer. The diagnosis of DCIS represents a wide range of disease, including lesions with both low and high risk of progression to invasive cancer and recurrence. Over the past decade, research on the topic of DCIS has focused on the possibility of tailoring treatment for patients according to their risk for progression and recurrence, which is based on clinicopathologic, biomolecular and genetic factors. These efforts are ongoing, with recently completed and continuing clinical trials spanning the continuum of cancer care. We conducted a review to identify recent advances on the topic of diagnosis, risk stratification and management of DCIS. While novel imaging techniques have increased the rate of DCIS diagnosis, questions persist regarding the optimal management of lesions that would not be identified with conventional methods. Additionally, among trials investigating the potential for omission of surgery and use of active surveillance, 2 trials have completed accrual and 2 clinical trials are continuing to enroll patients. Identification of novel genetic patterns is expanding our potential for risk stratification and aiding our ability to de-escalate radiation and systemic therapies for DCIS. These advances provide hope for tailoring of DCIS treatment in the near future.

Tamoxifen Dose De-Escalation: An Effective Strategy for Reducing Adverse Effects?

Tamoxifen, a cornerstone in the adjuvant treatment of estrogen receptor-positive breast cancer, significantly reduces breast cancer recurrence and breast cancer mortality; however, its standard adjuvant dose of 20 mg daily presents challenges due to a broad spectrum of adverse effects, contributing to high discontinuation rates. Dose reductions of tamoxifen might be an option to reduce treatment-related toxicity, but large randomized controlled trials investigating the tolerability and, more importantly, efficacy of low-dose tamoxifen in the adjuvant setting are lacking. We conducted an extensive literature search to explore evidence on the tolerability and clinical efficacy of reduced doses of tamoxifen. In this review, we discuss two important topics regarding low-dose tamoxifen: (1) the incidence of adverse effects and quality of life among women using low-dose tamoxifen; and (2) the clinical efficacy of low-dose tamoxifen examined in the preventive setting and evaluated through the measurement of several efficacy derivatives. Moreover, practical tools for tamoxifen dose reductions in the adjuvant setting are provided and further research to establish optimal dosing strategies for individual patients are discussed.

Genome-wide analyses reveal the regulatory roles of DNA methylation-regulated alternative promoter transcripts in breast cancer

A certain proportion of genes are regulated by multiple, distinct promoters, revealing a dynamic landscape of the cancer transcriptome. However, the contribution of alternative promoters (APs) in breast cancer (BRCA) remains largely unexplored. Here, we identified 3654 genes with multiple promoters in BRCA patients, and 53 of them could generate distinct AP transcripts that are dysregulated and prognosis-related in BRCA, namely prognosis-related dysregulated AP (prdeAP) transcripts. Interestingly, when we searched for the genomic signatures of these prdeAP genes, we found that the promoter regions of 92% of the prdeAP genes were enriched with abundant DNA methylation signals. Through further bioinformatic analysis and experimental validation, we showed that AP selections of TANK, UNKL, CCL28, and MAP1LC3A were regulated by DNA methylation upon their corresponding promoter regions. Functionally, by overexpressing AP variants of TANK, we found that TANK|55731 could dramatically suppress MDA-MB-231 cell proliferation and migration. Meanwhile, pan-cancer survival analyses suggested that AP variants of TANK provided more accurate prognostic predictive ability than TANK gene in a variety of tumor types, including BRCA. Together, by uncovering the DNA methylation-regulated AP transcripts with tumor prognostic features, our work revealed a novel layer of regulators in BRCA progression and provided potential targets that served as effective biomarkers for anti-BRCA treatment.

Surgical De-Escalation for Re-Excision in Patients with a Margin Less Than 2 mm and a Diagnosis of DCIS

The current surgical guidelines recommend an optimal margin width of 2 mm for the management of patients diagnosed with ductal carcinoma in situ (DCIS). However, there are still many controversies regarding re-excision when the optimal margin criteria are not met in the first resection. The purpose of this study is to understand the importance of surgical margin width, re-excision, and treatments to avoid additional surgery on locoregional recurrence (LRR). The study is retrospective and analyzed surgical margins, adjuvant treatments, re-excision, and LRR in patients with DCIS who underwent breast-conserving surgery (BCS). A total of 197 patients were enrolled. Re-operation for a close margin rate was 13.5%, and the 3-year recurrence was 7.6%. No difference in the LRR was reported among the patients subjected to BCS regardless of the margin width (p = 0.295). The recurrence rate according to margin status was not significant (p = 0.484). Approximately 36.9% (n: 79) patients had resection margins < 2 mm. A sub-analysis of patients with margins < 2 mm showed no difference in the recurrence between the patients treated with a second surgery and those treated with radiation (p = 0.091). The recurrence rate according to margin status in patients with margins < 2 mm was not significant (p = 0.161). The margin was not a predictive factor of LRR p = 0.999. Surgical re-excision should be avoided in patients with a focally positive margin and no evidence of the disease at post-surgical imaging.

Epigenetic biomarkers for disease susceptibility and preventative medicine

The development of molecular biomarkers for disease makes it possible for preventative medicine approaches to be considered. Therefore, therapeutics, treatments, or clinical management can be used to delay or prevent disease development. The problem with genetic mutations as biomarkers is the low frequency with genome-wide association studies (GWASs), generally at best a 1% association of the patients with the disease. In contrast, epigenetic alterations have a high-frequency association of greater than 90%-95% of individuals with pathology in epigenome-wide association studies (EWASs). A wide variety of human diseases have been shown to have epigenetic biomarkers that are disease specific and that detect pathology susceptibility. This review is focused on the epigenetic biomarkers for disease susceptibility, and it distinct from the large literature on epigenetics of disease etiology or progression. The development of efficient epigenetic biomarkers for disease susceptibility will facilitate a paradigm shift from reactionary medicine to preventative medicine.

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.

Mitochondrial Disruption Nanosystem Simultaneously Depressed Programmed Death Ligand-1 and Transforming Growth Factor-β to Overcome Photodynamic Immunotherapy Resistance

Currently, limited photosensitizers possess the capacity to reverse tumor hypoxia and reduce programmed death ligand-1 (PD-L1) and transforming growth factor-β (TGF-β) expression simultaneously, hindering the perfect photodynamic therapy (PDT) effect due to acquired immune resistance and the tumor hypoxic microenvironment. To tackle these challenges, in this research, we demonstrated that mitochondrial energy metabolism depression can be utilized as an innovative and efficient approach for reducing the expression of PD-L1 and TGF-β simultaneously, which may offer a design strategy for a more ideal PDT nanosystem. Through proteomic analysis of 5637 cells, we revealed that tamoxifen (TMX) can incredibly regulate PD-L1 expression in tumor cells. Then, to selectively deliver clinically used mitochondrial energy metabolism depressant TMX to solid tumors as well as design an ideal PDT nanosystem, we synthesized MHI-TMX@ALB by combining a mitochondria-targeted heptamethine cyanine PDT-dye MHI with TMX through self-assembly with albumin (ALB). Interestingly enough, the MHI-TMX@ALB nanoparticle demonstrated effective reversion of tumor hypoxia and inhibition of PD-L1 protein expression at a lower dosage (7.5 times to TMX), which then enhanced the efficacy of photodynamic immunotherapy via enhancing T-cell infiltration. Apart from this, by leveraging the heptamethine dye's targeting capacity toward tumors and TMX's role in suppressing TGF-β, MHI-TMX@ALB also more effectively mitigated 4T1 tumor lung metastasis development. All in all, the MHI-TMX@ALB nanoparticle could be used as a multifunctional economical PD-L1 and TGF-β codepression immune-regulating strategy, broadening the potential clinical applications for a more ideal PDT nanosystem.

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.

Duration of Endocrine Treatment for DCIS impacts second events: Insights from a large cohort of cases at two academic medical centers

Ductal carcinoma in situ (DCIS) incidence has risen rapidly with the introduction of screening mammography, yet it is unclear who benefits from both the amount and type of adjuvant treatment (radiation therapy, (RT), endocrine therapy (ET)) versus what constitutes over-treatment. Our goal was to identify the effects of adjuvant RT, or ET+/- RT versus breast conservation surgery (BCS) alone in a large multi-center registry of retrospective DCIS cases (N = 1,916) with median follow up of 8.2 years. We show that patients with DCIS who took less than 2 years of adjuvant ET alone have a similar second event rate as BCS. However, patients who took more than 2 years of ET show a significantly reduced second event rate, similar to those who received either RT or combined ET+RT, which was independent of age, tumor size, grade, or period of diagnosis. This highlights the importance of ET duration for risk reduction.

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.

Comparing Breast Cancer and Cardiovascular Disease Risk and Use of Chemoprevention and Statins among Women with High-risk Breast Lesions

Breast cancer chemoprevention with selective estrogen receptor modulators (SERM) or aromatase inhibitors (AI) remains underutilized among high-risk women. A potential barrier to chemoprevention is competing comorbidities such as atherosclerotic cardiovascular disease (ASCVD), due to concern for additional medication side effects. We conducted a retrospective cohort study among women with atypical hyperplasia (AH) or lobular carcinoma in situ (LCIS), an important target population for chemoprevention. We compared risks for breast cancer and ASCVD, as well as use of SERMs/AIs versus statins among high-risk women (defined as a 5-year invasive breast cancer risk ≥1.67% and 10-year ASCVD risk ≥7.5%, respectively). We used clinical data extracted from the electronic health record to calculate breast cancer risk according to the Breast Cancer Surveillance Consortium model and ASCVD risk according to the 2013 American College of Cardiology/American Heart Association risk calculator. Among 298 evaluable women, mean age was 58.2 years (SD, 8.34), with 33% non-Hispanic White, 41% Hispanic, 9% non-Hispanic Black, 6% Asian, and 11% other/unknown race/ethnicity. About 98% of women met high-risk criteria for breast cancer, whereas 30% were high-risk for ASCVD. Mean 10-year risk of breast cancer was higher than mean 10-year risk of ASCVD (9.14% vs. 6.69%; P < 0.001). Among women who met high-risk criteria for both diseases, use of statins was higher compared with SERMs/AIs (58% vs. 21%; P < 0.001). Among women with AH or LCIS, statin use was higher compared with breast cancer chemoprevention among eligible women, despite having a higher mean risk of breast cancer than ASCVD.

PREVENTION RELEVANCE

Among women with high-risk breast lesions, mean absolute risk of breast cancer was higher compared with cardiovascular disease; however, statin use was significantly higher than chemoprevention. To address underutilization of breast cancer chemoprevention, these drugs should be placed in the context of medications used to prevent other chronic diseases.

Best practice & research clinical haematology: Screening for breast cancer in hodgkin lymphoma survivors

Childhood and young adult survivors of Hodgkin lymphoma are at an elevated risk of developing breast cancer. Breast cancer risk is felt to originate from chest wall radiation exposure prior to the third decade of life, with incidence beginning to rise approximately eight to ten years following Hodgkin lymphoma treatment. Although incidence varies according to age at radiation exposure, dosage, and treatment fields, cohort studies have documented a cumulative incidence of breast cancer of 10-20% by 40 years of age. Women with a history of chest radiation for Hodgkin lymphoma are counselled to begin screening with bilateral breast MRI at 25 years of age, or eight years after radiation, whichever occurs later. Outside of high-risk surveillance, the optimal management approach for women with prior radiation exposure continues to evolve. When diagnosed with breast malignancy, evidence supports consideration of unilateral therapeutic and contralateral prophylactic mastectomy, although breast conserving surgery may be considered following multidisciplinary assessment. This review will address the epidemiology, characteristics, screening and management guidelines, and breast-cancer prevention efforts for Hodgkin lymphoma survivors treated with radiation therapy in adolescence and young adulthood.

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.

Trends and variation in treatment of early breast cancer in European certified breast centres: an EUSOMA-based analysis

BACKGROUND

Practice indicators (PI) measure provided care making use of real-world data. This study describes trends and variations in adjuvant treatment of early breast cancer (EBC) using the European Society of Breast Cancer Specialists (EUSOMA) database.

METHODS

The analysis was conducted on anonymous cumulative data registered by 56 certified breast centres, which all entered at least 500 new diagnoses in the database in the 10-year period 2010-2019. Practice trends of radiotherapy, endocrine treatment, chemotherapy, and anti-HER2 therapy were evaluated. The association with age group (<50, 50-69, ≥70) and geographical area of the centre (Northern, Central, Southern Europe; NE, CE, SE) was assessed with the Pearson Chi2 test for independence in contingency tables.

RESULTS

In total, 150,150 patients with EBC were selected. Overall, radiotherapy was administered more frequently in NE centres, and conversely, endocrine, chemo-, and anti-HER2 therapy were used more frequently in SE centres (p<0.001). 46.9% of the pN1 patients received postmastectomy radiotherapy, with significant differences by age and geographical region (p < 0.001). Adjuvant endocrine treatment for endocrine-sensitive carcinoma in situ was administered in 46.1%, with a decreasing trend during the study period (58.5-34.5%; p < 0.001). Anti-HER2 therapy was delivered in 75.6% of all patients with HER2BC T1a/bN0, patients older than 70 received anti-HER2 in 67.6% in SE compared to 31.3% in NE centres.

CONCLUSION

Important variations in EBC management between European certified breast centres have been demonstrated. PI using real-world data can help to monitor, evaluate, and eventually guide and align good clinical practice in the management of breast cancer.

The Breast Surgeon's Role in Risk-Reducing Medication Uptake

The role of the breast surgeon continues to evolve in an era of improved precision pharmacological agents combating breast cancer and de-escalation of locoregional treatments. Surgical breast oncologists should lead the effort to create preventive strategies and help to improve the uptake of risk-reducing medications (RRMEDS) for women at higher risk of developing breast cancer. Helping women to understand their risk of developing breast cancer will help the initiation of RRMEDS. Fear of side effects caused by these RRMEDS remains a significant obstacle for uptake. Low-dose tamoxifen has shown to help mitigate side effects and reduce attrition rate of women who initiated therapy and should be considered as part of the surgeon's armamentarium for RRMEDS.

Management of breast cancer patients with BRCA gene mutations in Jordan: perspectives and challenges

BACKGROUND

This paper explores and discusses local challenges oncologists face for diagnosing and managing breast cancer patients with BRCA gene mutations in Jordan.

METHODS

A task force involving key opinion leaders, experts in the management of breast cancer, and stakeholders in healthcare systems where genetic testing is available in Jordan discussed current evidence and local real-life practice. The task force then formulated recommendations to achieve better patient outcomes and satisfaction based on evidence-based medicine and their clinical experience in BRCA-mutated breast cancer management.

RESULTS AND CONCLUSION

Eligibility of patients for genetic testing, physician acceptance and willingness to integrate genetic testing into routine practice is encouraging but remains restricted by testing availability and financial coverage. Until more data is available, genetic testing should be targeted for breast cancer patients based on tumor subtypes, as well as family and personal history of cancer, as per international guidelines. Whenever possible, genetic testing should aim to detect all actionable genes through a multigene panel including BRCA1/2. Major challenges faced in clinical practice in Jordan include fear of genetic discrimination and social stigmatization, as well as hesitancy toward risk-reducing surgery. Pre-testing counseling is therefore critical to promote acceptance of genetic testing. Since geneticists are in short supply in Jordan, genetic counseling can be offered through a specially trained genetic counselor or through a hybrid system that includes oncologist-based counselling. In addition to cancer prevention, germline genetic testing may assist in the selection of specific anti-cancer therapy, such as PARP inhibitors, in patients with BRCA1/2 mutation. Nationwide initiatives are also needed to ensure access to PARP inhibition therapy and provide financial coverage for genetic screening, mastectomies and reconstructive surgery across Jordan.

Breast Cancer Risk Reduction: Current Status and Emerging Trends to Increase Efficacy and Reduce Toxicity of Preventive Medication

The primary prevention of breast cancer is a worthwhile goal for which the efficacy of antiestrogens is well established. However, implementation has been problematic related to low prioritization by providers and the reluctance of high-risk women to experience medication side effects. Emerging solutions include improved risk estimation through the use of polygenic risk scores and the application of radiomics to screening mammograms; and optimization of medication dose to limit toxicity. The identification of agents to prevent estrogen receptor negative or HER2-positive tumors is being pursued, but personalization of medical risk reduction requires the prediction of tumor subtypes.

Radiotherapy versus low-dose tamoxifen following breast-conserving surgery for low-risk and estrogen receptor-positive breast ductal carcinoma in situ: an international open-label randomized non-inferiority trial (TBCC-ARO DCIS Trial)

BACKGROUND

Radiotherapy (RT) following breast-conserving surgery (BCS) is mainly used to decrease the rate of ipsilateral breast tumor recurrence (IBTR) in women with breast ductal carcinoma in situ (DCIS). Recent studies have demonstrated that low-dose tamoxifen significantly reduces IBTR in breast DCIS. Here, we aim to determine whether the administration of low-dose tamoxifen is non-inferior to RT in preventing IBTR in patients with low-risk characteristics of breast DCIS.

METHODS/DESIGN

This is a prospective, international, open-label, randomized, non-inferiority trial. Patients with low-risk clinicopathologic features (> 40 years old, low risk of breast cancer susceptibility gene (BRCA) 1 and BRCA2 mutations, mammographically detected unicentric and non-mass lesions, low- or intermediate-grade without comedo or necrosis, measuring < 2.5 cm with margins ≥ 3 mm, and estrogen receptor-positive status) of DCIS who underwent BCS will be randomized at a 1:1 ratio to either receive tamoxifen (5 mg/day) for 5 years or undergo RT with conventional fractions (50 Gy in 25 fractions) or hypofractionations (40.05 Gy in 15 fractions). Randomization will be stratified by the Taiwan Breast Cancer Consortium. As approximately 5% of patients cannot tolerate the side effects of low-dose tamoxifen and will receive RT, we estimate that 405 patients will be randomized to a low-dose tamoxifen arm and 405 patients to the RT arm, according to a non-inferiority margin within 5% of IBTR difference and 90% β-power noticing non-inferiority. The primary endpoints are breast tumor recurrence, including ipsilateral, regional, contralateral, and distant recurrence of breast DCIS or invasive cancer. The secondary endpoints are overall survival and adverse effects of RT and tamoxifen. Translational studies will also be conducted for this trial.

DISCUSSION

This is the first non-inferiority trial on breast DCIS. This study will provide an important recommendation for clinical physicians on whether to use low-dose adjuvant tamoxifen for patients with low-risk breast DCIS who do not want to receive adjuvant RT.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT04046159, Registered on April 30, 2019.

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.

Kaempferol induces mitochondrial dysfunction and mitophagy by activating the LKB1/AMPK/MFF pathway in breast precancerous lesions

Kaempferol has been suggested to be an effective anticancer agent in several malignant tumors. However, its function and mechanisms in breast precancerous lesions remain largely elusive. Here, we showed that kaempferol induced excessive mitochondrial fission and mitochondrial damage with activated mitochondrial fission factor (MFF)-mediated dynamin-related protein (DRP) 1 mitochondrial translocation. As a result, the PTEN-induced putative kinase 1 (PINK1)/Parkin signaling pathway was activated, accompanied by excessive mitophagy and reduced mitochondrial mass in cells. We also revealed that kaempferol-induced lethal mitophagy contributed to inhibiting breast precancerous lesion growth in vitro and in vivo. Furthermore, we verified serine/threonine kinase 11 (STK11/LKB1)/AMP-activated protein kinase (AMPK) pathway deficiency in breast precancerous lesions. Moreover, LKB1/AMPK pathway reactivation by kaempferol was required for excessive mitochondrial fission and lethal mitophagy. Taken together, our findings shed new light on the molecular mechanisms related to breast cancer prevention by kaempferol and provide evidence for its potential clinical application.

Targeting nuclear hormone receptors for the prevention of breast cancer

Advancements in research have led to the steady decline of breast cancer mortality over the past thirty years. However, breast cancer incidence has continued to rise, resulting in an undue burden on healthcare costs and highlighting a great need for more effective breast cancer prevention strategies, including targeted chemo preventative agents. Efforts to understand the etiology of breast cancer have uncovered important roles for nuclear receptors in the development and progression of breast cancer. Targeted therapies to inhibit estrogen receptor (ER) and progesterone receptor (PR) signaling (selective ER modulators, aromatase inhibitors and selective PR modulators) have shown great promise for the treatment and prevention of hormone receptor (HR)-positive breast cancer. However, these drugs do not prevent HR-negative disease. Therefore, recent efforts have focused on novel targeted therapies with the potential to prevent both HR-positive and HR-negative breast cancer. Among these include drugs that target other nuclear receptors, such as retinoic acid receptor (RAR), retinoid X receptor (RXR) and vitamin D receptor (VDR). In this review we provide an overview of recent preclinical and clinical trials targeting members of the nuclear receptor superfamily for the prevention of breast cancer.

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.

Preventative therapy for breast cancer: a clinical experience

BACKGROUND

Breast Cancer incidence in the UK is estimated to rise to 71,000 per year by 2035. Preventative strategies could significantly reduce this. Preventative therapy reduces women's risk of oestrogen receptor positive breast cancer, but uptake remains low. Having established a preventative therapy clinic as part of a wider breast cancer prevention project, we explored qualitative data to inform future preventative efforts.

METHOD

Women aged 30 to 60 who had benign diagnoses at a symptomatic breast clinic or were under mammographic surveillance in the moderate risk family history clinic were invited to participate in the study. Those who expressed an interest and completed an initial questionnaire had their breast cancer risk calculated using the IBIS risk calculator. Those at increased risk were invited to a consultation about preventative therapy.

RESULTS

182 women were identified as increased risk (≥ 17% lifetime or ≥ 3% 10-year risk NICE guidelines: Familial breast cancer: classification, care and managing breast cancer and related risks in people with a family history of breast cancer, 20131) of whom 91 women (50%) would not have been identified by family history criteria alone. 96% attended a risk/prevention consultation and all eligible women accepted screening mammography but only 14 (8%) women requested a preventative therapy prescription during the duration of the study. Reluctance to take medication and inconvenient time of life were common reasons for declining preventative therapy. Despite this, the majority were grateful for breast cancer risk and prevention information.

CONCLUSIONS

Women at increased risk of breast cancer accept additional screening but are reluctant to take preventative therapy. This suggests that stratified screening methods using risk calculations would have high uptake. Raising awareness of preventative therapy is important and the breast cancer community has yet to find the optimum timing and formula for discussing it and must accept women's informed preferences above artificial targets.

REGISTRATION NUMBERS

The PIONEER study was granted Health Research Authority (HRA) ethical approval by the Westminster Ethics Committee. IRAS project ID 265619, ClinicalTrials.gov Identifier: NCT04574063. Recruitment began in September 2020 and was completed in October 2021.