A comparison of letrozole and tamoxifen in postmenopausal women with early breast cancer

Letrozole delays acquisition of water maze task in female BALB/c mice: Possible involvement of anxiety

Letrozole, an aromatase inhibitor preventing estrogen synthesis from testosterone, is used as an adjuvant therapy in estrogen receptor-positive breast cancer patients. However, like other aromatase inhibitors, it induces many side effects, including impaired cognition. Despite its negative effect in humans, results from animal models are inconsistent and suggest that letrozole can either impair or improve cognition. Here, we studied the effects of chronic letrozole treatment on cognitive behavior of adult female BALB/c mice, a relevant animal model for breast cancer studies, to develop an appropriate animal model aimed at testing therapies to mitigate side effects of letrozole. In Morris water maze, letrozole 0.1 mg/kg impaired reference learning and memory. Interestingly, most of the letrozole 0.1 mg/kg-treated mice were able to learn the new platform position in reversal training and performed similar to control mice in a reversal probe test. Results of the reversal test suggest that letrozole did not completely disrupt spatial navigation, but rather delayed acquisition of spatial information. The delay might be related to increased anxiety as suggested by increased thigmotactic behavior during the reference memory training. The learning impairment was water maze-specific since we did not observe impairment in other spatial tasks such as in Y-maze or object location test. In contrast, the dose of 0.3 mg/kg did not have effect on water maze learning and facilitated locomotor habituation and recognition in novel object recognition test. The current study shows that letrozole dose-dependently modulates behavioral response and that its effects are task-dependent.

Real-world data of cardio-oncologic interventions for cardiovascular adverse events with oral oncolytics

BACKGROUND

Oral cancer therapy-related cardiovascular (CV) toxicity has a wide variety of presentations including arrhythmia, cardiomyopathy, and myocardial infarction, but clinical evidence related to its management is limited. The purpose of this IRB-approved, single-center, retrospective, cohort study was to characterize cardio-oncologic interventions for CV adverse events related to oral oncolytics.

METHODS

The cohort included 67 patients who were admitted to a multi-hospital health system between June 1, 2016 and July 31, 2021, had at least one medical record order of oral oncolytics considered to have cardiotoxic potential, and had an ICD10 code for a cardiotoxic event added to their electronic medical records after initiation of oral oncolytics.

RESULTS

The majority (97%) had pre-existing cardiovascular disease (CVD) or a CV risk factor. The three most common classes of oral oncolytics were aromatase inhibitors (36%), BCR-ABL inhibitors (16%), and VEGFR inhibitors (13%). New-onset or worsening heart failure (HF) (n = 31), which occurred after a median of 148 days (Interquartile range (IQR) 43-476 days) was the most common cardiotoxic event. The most frequent interventions were pharmacological treatment of the CV adverse event (n = 44) and treatment interruption (n = 18), but guideline-directed medication therapy for HF could be further optimized.

CONCLUSION

Pre-existing CVD or CV risk factors predispose oncology patients to CV adverse events. Real-world practice reveals that CV adverse events require temporary interruption of treatment and initiation of pharmacologic treatment. A multidisciplinary, patient-centered approach that includes discussion of risks/benefits of treatment continuation, and initiation of guideline-directed treatment is recommended until high-quality, drug-specific data for monitoring and treatment become available.

The effect of exemestane administration on the lipid profile in women: Meta-analysis of randomized controlled trials

OBJECTIVE

Postmenopausal women are prone to develop cardiovascular disorders. In addition, cardiovascular risk in women can be influenced by the long-term prescription of drugs that lead to estrogen deprivation, e.g., aromatase inhibitors, and that can cause dyslipidemia. Little is known about the impact of exemestane, an aromatase inhibitor, on serum lipids' concentration in women. Hence, we conducted a meta-analysis of randomized controlled trials (RCTs) to assess the influence of this pharmacological agent on the lipid profile in women.

METHODS

The Scopus, Web of Science, PubMed/Medline and EMBASE databases were searched by two surveyors for manuscripts published from the inception of these databases until April 3rd, 2023. No language restrictions were applied to the search. The random effects model was used to generate the combined results as weighted mean difference (WMD) and 95% confidence interval (CI).

RESULTS

In total, 8 eligible RCTs were included in the meta-analysis. Overall results from the random effects model indicate that exemestane administration increases LDL-C (WMD: 4.42 mg/dL, 95 % CI: 0.44, 8.41, P = 0.02) and decreases HDL-C (WMD: -6.03 mg/dL, 95 % CI: -7.77, -4.29, P < 0.001) and TC (WMD: -5.40 mg/dL, 95 % CI: -9.95, -0.86, P = 0.02) levels, respectively. Moreover, exemestane prescription only lowered TG concentrations when it was administered for < 12 months (WMD: -14.60 mg/dL, 95 % CI: -23.57 to -5.62, P = 0.001).

CONCLUSION

Currently available evidence suggests that the administration of exemestane in females increases LDL-C values and reduces HDL-C, TC, and, when prescribed for less than 12 months, TG concentrations.

Adjuvant Abemaciclib Plus Endocrine Therapy for Hormone Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative, High-Risk Early Breast Cancer: Results From a Preplanned monarchE Overall Survival Interim Analysis, Including 5-Year Efficacy Outcomes

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical trial updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.Two years of adjuvant abemaciclib combined with endocrine therapy (ET) resulted in a significant improvement in invasive disease-free survival (IDFS) and distant relapse-free survival (DRFS) that persisted beyond the 2-year treatment period in patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative, node-positive, high-risk early breast cancer (EBC). Here, we report 5-year efficacy results from a prespecified overall survival (OS) interim analysis. In the intent-to-treat population, with a median follow-up of 54 months, the benefit of abemaciclib was sustained with hazard ratios of 0.680 (95% CI, 0.599 to 0.772) for IDFS and 0.675 (95% CI, 0.588 to 0.774) for DRFS. This persistence of abemaciclib benefit translated to continuous separation of the curves with a deepening in 5-year absolute improvement in IDFS and DRFS rates of 7.6% and 6.7%, respectively, compared with rates of 6% and 5.3% at 4 years and 4.8% and 4.1% at 3 years. With fewer deaths in the abemaciclib plus ET arm compared with the ET-alone arm (208 v 234), statistical significance was not reached for OS. No new safety signals were observed. In conclusion, abemaciclib plus ET continued to reduce the risk of developing invasive and distant disease recurrence beyond the completion of treatment. The increasing absolute improvement at 5 years is consistent with a carryover effect and further supports the use of abemaciclib in patients with high-risk EBC.

Importance of targeting various cell signaling pathways in solid cancers

Most adult human cancers are solid tumors prevailing in vital organs and lead to mortality all over the globe. Genetic and epigenetic alterations in cancer genes or genes of associated signaling pathways impart the most common characteristic of malignancy, that is, uncontrolled proliferation. Unless the mechanism of action of these cells signaling pathways (involved in cell proliferation, apoptosis, metastasis, and the maintenance of the stemness of cancer stem cells and cancer microenvironment) and their physiologic alteration are extensively studied, it is challenging to understand tumorigenesis as well as develop new treatments and precision medicines. Targeted therapy is one of the most promising strategies for treating various cancers. However, cancer is an evolving disease, and most patients develop resistance to these drugs by acquired mutations or mediation of microenvironmental factors or due to tumor heterogeneity. Researchers are striving to develop novel therapeutic options like combinatorial approaches targeting multiple responsible pathways effectively. Thus, in-depth knowledge of cell signaling and its components remains a critical topic of cancer research. This chapter summarized various extensively studied pathways in solid cancer and how they are targeted for therapeutic strategies.

Novel immunotherapies for breast cancer: Focus on 2023 findings

Immunotherapy has emerged as a revolutionary approach in cancer therapy, and recent advancements hold significant promise for breast cancer (BCa) management. Employing the patient's immune system to combat BCa has become a focal point in immunotherapeutic investigations. Strategies such as immune checkpoint inhibitors (ICIs), adoptive cell transfer (ACT), and targeting the tumor microenvironment (TME) have disclosed encouraging clinical outcomes. ICIs, particularly programmed cell death protein 1 (PD-1)/PD-L1 inhibitors, exhibit efficacy in specific BCa subtypes, including triple-negative BCa (TNBC) and human epidermal growth factor receptor 2 (HER2)-positive cancers. ACT approaches, including tumor-infiltrating lymphocytes (TILs) and chimeric antigen receptor (CAR) T-cell therapy, showed promising clinical outcomes in enhancing tumor recognition and elimination. Targeting the TME through immune agonists and oncolytic viruses signifies a burgeoning field of research. While challenges persist in patient selection, resistance mechanisms, and combination therapy optimization, these novel immunotherapies hold transformative potential for BCa treatment. Continued research and clinical trials are imperative to refine and implement these innovative approaches, paving the way for improved outcomes and revolutionizing the management of BCa. This review provides a concise overview of the latest immunotherapies (2023 studies) in BCa, highlighting their potential and current status.

Osteoporotic fracture risk in women with breast cancer treated with aromatase inhibitors: a health insurance claims database study in Japan

BACKGROUND

Hormone therapy with aromatase inhibitors (AIs) for estrogen receptor-dependent breast cancer may expose patients to an increased osteoporosis risk. This study was performed to estimate fracture risk in women with breast cancer to whom AIs were prescribed in Japan.

METHODS

This retrospective study used data from the Japanese Medical Data Vision database. Women with breast cancer prescribed AIs over a 12-month period were identified and matched to women not prescribed AIs using a propensity score. Fracture rates were estimated by a cumulative incidence function and compared using a cause-specific Cox hazard model. The proportion of women undergoing bone density tests was retrieved.

RESULTS

For all fractures sites combined, cumulative fracture incidence at 10 years was 0.19 [95%CI: 0.16-0.22] in women prescribed AIs and 0.18 [95%CI: 0.15-0.21] without AIs. AI prescription was not associated with any changes in risk (adjusted hazard ratio: 1.08 [95%CI: 0.99-1.17] p = 0.08). Women prescribed AI more frequently underwent bone density testing (31.9% [95% CI: 31.2%; 32.6%] versus 2.2% [95% CI: 2.0%; 2.4%]).

CONCLUSIONS

The anticipated association between AI exposure and osteoporotic fracture risk in Japanese women with breast cancer was not seen clearly.

Hormone, Targeted, and Combinational Therapies for Breast Cancers: From Humans to Dogs

Breast cancer (BC) is the most frequent cancer in women. In female dogs, canine mammary gland tumor (CMT) is also the leading neoplasm. Comparative oncology indicates similar tumor behaviors between human BCs (HBCs) and CMTs. Therefore, this review summarizes the current research in hormone and targeted therapies and describes the future prospects for HBCs and CMTs. For hormone receptor-expressing BCs, the first medical intervention is hormone therapy. Monoclonal antibodies against Her2 are proposed for the treatment of Her2+ BCs. However, the major obstacle in hormone therapy or monoclonal antibodies is drug resistance. Therefore, increasing alternatives have been developed to overcome these difficulties. We systemically reviewed publications that reported inhibitors targeting certain molecules in BC cells. The various treatment choices for humans decrease mortality in females with BC. However, the development of hormone or targeted therapies in veterinary medicine is still limited. Even though some clinical trials have been proposed, severe side effects and insufficient case numbers might restrict further explorations. This difficulty highlights the urgent need to develop updated hormone/targeted therapy or novel immunotherapies. Therefore, exploring new therapies to provide more precise use in dogs with CMTs will be the focus of future research. Furthermore, due to the similarities shared by humans and dogs, well-planned prospective clinical trials on the use of combinational or novel immunotherapies in dogs with CMTs to obtain solid results for both humans and dogs can be reasonably anticipated in the future.

Omission of radiation therapy after breast-conserving surgery for biologically favourable tumours in younger patients: The wrong answer to the right question

In this perspective paper, the findings of the recently published LUMINA study are critically evaluated, with an emphasis on the need for careful interpretation and a thoughtful approach in clinical practice. The LUMINA trial, which investigates the role of adjuvant endocrine therapy in low-risk breast cancer patients, is assessed for its limitations, including a highly selective patient cohort and an insufficient follow-up period. The importance of long-term data and further trials to inform clinical decisions effectively is emphasized. While the LUMINA study does not support an immediate change in practice, it is seen as a foundation for generating hypotheses to guide ongoing clinical trials. This important study has served as inspiration to develop this perspective paper, which takes into account ongoing studies and the toxicity profile of postoperative treatments in low-risk recurrence breast cancer. The need for a patient-cantered approach is stressed, considering individual wishes and desires in decision-making, despite the complexity of articulating these aspects in guidelines. A wise interpretation of available findings is essential to ensure sound clinical decision-making before broadly applying omission of radiation therapy.

Aromatase inhibitors: the journey from the state of the art to clinical open questions

Breast cancer is a major cause of death among females. Great advances have been made in treating this disease, and aromatase inhibitors (AIs) have been recognized as the cornerstone. They are characterized by high efficacy and low toxicity. The authors reviewed the available literature and defined state-of-the-art AI management. This study was designed to assist clinicians in addressing the need to equally weigh patients' needs and disease control rates in their everyday clinical practice. Today, AIs play a central role in the treatment of hormone receptor-positive breast cancer. In this study, an expert panel reviewed the literature on the use of AIs, discussing the evolution of their use in various aspects of breast cancer, from pre- and postmenopausal early breast cancer to metastatic breast cancer, along with their management regarding efficacy and toxicity. Given the brilliant results that have been achieved in improving survival in everyday clinical practice, clinicians need to address their concerns about therapy duration and the adverse effects they exert on bone health, the cardiovascular system, and metabolism. Currently, in addition to cancer treatment, patient engagement is crucial for improving adherence to therapy and supporting patients' quality of life, especially in a selected subset of patients, such as those receiving an extended adjuvant or combination with targeted therapies. A description of modern technologies that contribute to this important goal is provided.

Estrogen deprivation effects of endocrine therapy in breast cancer patients: Incidence, management and outcome

Endocrine therapy is one of the standard adjuvant treatments to reduce the risk of recurrence and mortality in patients with hormone receptor positive early breast cancer. Despite its proven efficacy, ET side effects, which persist over time even if low grade, may deteriorate quality of life. During follow-up visits, emphasis is generally placed on the risk of disease recurrence, while the topic of ET side effects is commonly neglected and discussed only briefly. This could lead to poor adherence to therapy and early treatment discontinuation, resulting in worse survival outcomes. The aim of this review is to provide an overview of the available evidence on the incidence and reporting of ET-related side effects (including vasomotor symptoms, musculoskeletal disorders and genitourinary syndrome of menopause, as well as fatigue, psychological and ocular disorders, dysmetabolic effects and loss of bone density) and of the pharmacological and non-pharmacological strategies available to mitigate symptom burden.

Obesity and Risk of Recurrence in Patients With Breast Cancer Treated With Aromatase Inhibitors

Importance

Clinical studies confirm that obesity is a risk factor for recurrence in postmenopausal women with hormone receptor-positive (HR+) breast cancer. Evidence suggests that women with obesity do not obtain similar protection from aromatase inhibitors as women with healthy weight.

Objective

To examine the associations of body mass index (BMI) with recurrence.

Design, Setting, and Participants

The cohort study was conducted using data from the Danish Breast Cancer Group and enrolled postmenopausal women diagnosed with stage I to III HR+ breast cancer from 1998 through 2016. Data analysis was conducted from November 2022 to April 2023.

Exposures

BMI was classified as (1) healthy weight (18.5-24.9), (2) overweight (25.0-29.9), (3) obesity (30.0-34.9), and (4) severe obesity (≥35.0) using the World Health Organization guidelines. Healthy weight was considered the reference group in statistical analyses.

Main Outcomes and Measures

Follow-up began 6 months after breast cancer surgery and continued until the first event of recurrence, contralateral breast cancer, new primary malignant neoplasm, death, emigration, end of clinical follow-up at 10 years, or September 25, 2018. Cox regression was used to estimate crude and adjusted hazard ratios with 95% CIs, adjusting for patient, tumor, and treatment characteristics.

Results

A total of 13 230 patients (median [IQR] age at diagnosis, 64.4 [58.6-70.2] years) with information on BMI were enrolled. There were 1587 recurrences with a median (IQR) potential estimated follow-up of 6.2 (3.6-8.5) years. Multivariable analyses revealed increased recurrence hazards associated with obesity (adjusted hazard ratio, 1.18 [95% CI, 1.01-1.37]) and severe obesity (adjusted hazard ratio, 1.32 [95% CI, 1.08-1.62]) vs patients with healthy weight. Patients with overweight had a greater risk, but the results were not statistically significant (adjusted hazard ratio, 1.10 [95% CI, 0.97-1.24]).

Conclusions and Relevance

In this study, obesity was associated with an increased risk of breast cancer recurrence among postmenopausal patients with HR+ early-stage breast cancer treated with aromatase inhibitors. Physicians should be aware of the significance of obesity on breast cancer outcomes to secure optimal treatment benefit in all patients.

[Venous thromboembolism and breast cancer]

Breast cancer is the most common cancer in women. Patients with breast cancer have a 4-fold increased risk of venous thromboembolism (VTE) compared to age- and sex-matched controls without cancer. VTE remains the second leading cause of death in cancer patients and an independent risk factor for mortality. In women with breast cancer, the main risk factors for developing VTE are increasing age, obesity, disease stage, central catheter placement and cancer treatments, including surgery, chemotherapy, hormonotherapy and cyclin-dependent kinase 4/6 inhibitors. In women receiving tamoxifen, the risk of VTE is particularly increased within the first 6 months after initiation of hormonotherapy, although some evidence suggests that this risk may persist through the first 2 years of treatment. The risk of VTE appears to be lower in patients receiving aromatase inhibitors. In breast cancer patients receiving cyclin-dependent kinase 4/6 inhibitors, the rate of VTE is approximately 6%. Current clinical practice guidelines for the treatment and prevention of VTE in patients with cancer suggest that thromboprophylaxis should not be used routinely in ambulatory cancer patients receiving chemotherapy or hormonotherapy. The risk-benefit ratio of thromboprophylaxis should be assessed on a case-by-case basis and be the subject of multidisciplinary discussion.

Breast cancer therapy in women under 35 years and between 50 and 69 years: influence of the observation period

PURPOSE

In recent years, therapeutic strategies based on tumour biology have increased significantly. We aimed to provide an overview of the recent changes in patient characteristics, treatment procedures and survival factors for two groups of patients: women younger than 35 years and women between 50 and 69 years.

METHODS

We used data from the population-based Cancer Registry Magdeburg. Subjects included women with non-metastatic breast cancer treated between 2000 and 2015. We compared between two observation periods: 2000-2007 and 2008-2015.

RESULTS

There was an increase in patient survival from the first to the second observation period. Tumour characteristics and treatment modalities changed, especially in the group of older patients. The proportion of prognostically more favourable tumour subtypes, such as Luminal A, increased significantly. Between 2008 and 2015, there were more hormone receptor-positive, lymph-node-negative, human epidermal growth factor receptor-2 (HER2)-negative and well-differentiated tumours. Surgical methods were associated with significantly reduced radicality, while the rate of neoadjuvant therapy increased in both groups. There was a decrease in cyclophosphamide, methotrexate and 5-fluoruracil (CMF) and anthracycline therapies, but taxane-containing chemotherapy increased. While tamoxifen was used more frequently in younger patients in the later observation period, its use was reduced in older patients, superseded by aromatase inhibitors. Furthermore, the use of immune therapy increased.

CONCLUSION

In both age groups, but primarily in older patients, there were significant changes in tumour biology and treatment options between the two observation periods. These changes have led to a continuous improvement in patient outcomes.

Importance of endocrine treatment adherence and persistence in breast cancer survivorship: a systematic review

PURPOSE

Adjuvant endocrine treatment is essential for treating luminal subtypes of breast cancer, which constitute 75% of all breast malignancies. However, the detrimental side effects of treatment make it difficult for many patients to complete the guideline-required treatment. Such non-adherence may jeopardize the lifesaving ability of anti-estrogen therapy. In this systematic review, we aimed to assess the consequences of non-adherence and non-persistence from available studies meeting strict statistical and clinical criteria.

METHODS

A systematic literature search was performed using several databases, yielding identification of 2,026 studies. After strict selection, 14 studies were eligible for systematic review. The review included studies that examined endocrine treatment non-adherence (patients not taking treatment as prescribed) or non-persistence (patients stopping treatment prematurely), in terms of the effects on event-free survival or overall survival among women with non-metastatic breast cancer.

RESULTS

We identified 10 studies measuring the effects of endocrine treatment non-adherence and non-persistence on event-free survival. Of these studies, seven showed significantly poorer survival for the non-adherent or non-persistent patient groups, with hazard ratios (HRs) ranging from 1.39 (95% CI, 1.07 to 1.53) to 2.44 (95% CI, 1.89 to 3.14). We identified nine studies measuring the effects of endocrine treatment non-adherence and non-persistence on overall survival. Of these studies, seven demonstrated significantly reduced overall survival in the groups with non-adherence and non-persistence, with HRs ranging from 1.26 (95% CI, 1.11 to 1.43) to 2.18 (95% CI, 1.99 to 2.39).

CONCLUSION

The present systematic review demonstrates that non-adherence and non-persistence to endocrine treatment negatively affect event-free and overall survival. Improved follow-up, with focus on adherence and persistence, is vital for improving health outcomes among patients with non-metastatic breast cancer.

Systematic review of economic evaluations of aromatase inhibitors in estrogen receptor-positive breast cancer: quality evaluation

BACKGROUND

Breast cancer (BC) is a leading cause of premature death in women and the most expensive malignancy to treat. Since the introduction of targeted therapies has resulted in changes to BC therapy practices, health economic evaluations have become more important in this area. Taking generic medications, Aromatase Inhibitors (AIs), as a case study, we conducted a systematic review of the recent economic evaluations of AIs for estrogen receptor-positive breast cancer patients and evaluated the quality of these health economic studies.

OBJECTIVE

To systematically review and examine the quality of the available economic studies of AIs in estrogen receptor-positive breast cancer.

METHODS

A literature search was performed using six relevant databases (MEDLINE, Embase, Database of Abstracts of Reviews of Effects, Health Technology Assessment Database, NHS Economic Evaluation Database, and SCOPUS) from January 2010 to July 2021. All economic studies were independently assessed by two reviewers using the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) checklist to evaluate the quality of the economic evaluations. This systematic review is registered in the PROSPERO database. To compare the different currencies used in these studies, all costs were converted to international dollars (2021).

RESULTS

A total of eight studies were included in the review; six (75%) were performed from the healthcare providers' perspective. They were conducted in seven different countries, and all were model-based analyses using Markov models. Six (75%) considered both Quality Adjusted Life Years (QALYs) and Life Years (LY) outcomes, and all costs were derived from national databases. When compared to tamoxifen, AIs were generally cost-effective in postmenopausal women. Only half of the studies addressed the increased mortality following adverse events, and none mentioned medication adherence. For the quality assessment, six studies fulfilled 85% of the CHEERS checklist requirements and are deemed good quality.

CONCLUSION

AIs are generally considered cost-effective compared to tamoxifen in estrogen receptor-positive breast cancer. The overall quality of the included studies was between high and average but characterizing heterogeneity, and distributional effects should be considered in any future economic evaluation studies of AIs. Studies should include adherence and adverse effects profiles to provide evidence to facilitate decision-making among policymakers.

More efficient and inclusive time-to-event trials with covariate adjustment: a simulation study

Adjustment for prognostic covariates increases the statistical power of randomized trials. The factors influencing the increase of power are well-known for trials with continuous outcomes. Here, we study which factors influence power and sample size requirements in time-to-event trials. We consider both parametric simulations and simulations derived from the Cancer Genome Atlas (TCGA) cohort of hepatocellular carcinoma (HCC) patients to assess how sample size requirements are reduced with covariate adjustment. Simulations demonstrate that the benefit of covariate adjustment increases with the prognostic performance of the adjustment covariate (C-index) and with the cumulative incidence of the event in the trial. For a covariate that has an intermediate prognostic performance (C-index=0.65), the reduction of sample size varies from 3.1% when cumulative incidence is of 10% to 29.1% when the cumulative incidence is of 90%. Broadening eligibility criteria usually reduces statistical power while our simulations show that it can be maintained with adequate covariate adjustment. In a simulation of adjuvant trials in HCC, we find that the number of patients screened for eligibility can be divided by 2.4 when broadening eligibility criteria. Last, we find that the Cox-Snell [Formula: see text] is a conservative estimation of the reduction in sample size requirements provided by covariate adjustment. Overall, more systematic adjustment for prognostic covariates leads to more efficient and inclusive clinical trials especially when cumulative incidence is large as in metastatic and advanced cancers. Code and results are available at https://github.com/owkin/CovadjustSim .

Proton therapy for reducing heart and cardiac substructure doses in Indian breast cancer patients

PURPOSE

Indians have a higher incidence of cardiovascular diseases, often at a younger age, than other ethnic groups. This higher baseline risk requires consideration when assessing additional cardiac morbidity of breast cancer treatment. Superior cardiac sparing is a critical dosimetric advantage of proton therapy in breast cancer radiotherapy. We report here the heart and cardiac-substructure doses and early toxicities in breast cancer patients treated post-operatively with proton therapy in India's first proton therapy center.

MATERIALS AND METHODS

We treated twenty breast cancer patients with intensity-modulated proton therapy (IMPT) from October 2019 to September 2022, eleven after breast conservation, nine following mastectomy, and appropriate systemic therapy, when indicated. The most prescribed dose was 40 GyE to the whole breast/chest wall and 48 GyE by simultaneous integrated boost to the tumor bed and 37.5 GyE to appropriate nodal volumes, delivered in 15 fractions.

RESULTS

Adequate coverage was achieved for clinical target volume (breast/chest wall), i.e., CTV40, and regional nodes, with 99% of the targets receiving 95% of the prescribed dose (V95% > 99%). The mean heart dose was 0.78 GyE and 0.87 GyE for all and left breast cancer patients, respectively. The mean left anterior descending artery (LAD) dose, LAD D0.02cc, and left ventricle dose were 2.76, 6.46, and 0.2 GyE, respectively. Mean ipsilateral lung dose, V20Gy, V5Gy, and contralateral breast dose (Dmean) were 6.87 GyE, 14.6%, 36.4%, and 0.38 GyE, respectively.

CONCLUSION

The dose to heart and cardiac substructures is lower with IMPT than published photon therapy data. Despite the limited access to proton therapy at present, given the higher cardiovascular risk and coronary artery disease prevalence in India, the cardiac sparing achieved using this technique merits consideration for wider adoption in breast cancer treatment.

Systemic Therapy of Premenopausal Patients with Early Stage Hormone Receptor-Positive, HER2-Negative Breast Cancer - Controversies and Standards in Healthcare

In patients with existing ovarian function, there are some special aspects to adjuvant endocrine therapy in premenopausal patients with hormone receptor-positive, HER2-negative (HR pos./HER2 neg.) breast cancer. Treatment options include tamoxifen with or without a GnRH analog, and aromatase inhibitors with a GnRH analog. Furthermore, ovarian function is affected by previous chemotherapy. Both aromatase inhibitors (+GnRH analogs) and GnRH analogs in combination with tamoxifen are supposed to be indicated for patients at increased risk of recurrence. However, national and international guidelines and therapy recommendations do not provide a clear definition of intermediate or high risk; as a result, therapy decisions are often made for each patient on an individual basis. This is also reflected in the considerable variability at national and international levels, e.g., with regard to the use of aromatase inhibitors + GnRH analogs. This review summarizes the data on completed studies (e.g., SOFT, TEXT, EBCTCG meta-analyses) and the current multigene testing studies (TailorX, RxPonder, ADAPT), discusses the rationale for current studies (e.g., CLEAR-B), and looks ahead to future questions.

Does the toxicity of endocrine therapy persist into long-term survivorship?: Patient-reported outcome results from a follow-up study beyond a 10-year-survival

BACKGROUND

Endocrine treatment (ET) is a highly effective breast cancer treatment but can distinctly impair breast cancer patients' quality of life (QOL). In a patient-reported outcome (PROs) study conducted by the authors in 2011, patients reported higher ET-induced symptom levels than known from the registration trials, and was underestimated. Based on these study results, we investigated the long-term sequelae of ET reported by breast cancer survivors (BCS) in a follow-up study conducted 5-10 years after an earlier assessment.

METHODS

BCS who had participated in the earlier study (n = 436) were approached for study participation either at one of their routine follow-up appointments or via mail; consenting patients were asked to completed the same PRO assessment used in the original study (FACT-B + ES). BCS with relapse/ progressive disease were excluded from the analysis. We compared long-term endocrine symptomatology and overall QOL outcome (i.e. FACT-G and -ES sum score).

RESULTS

A final sample of 268 BCS was included in the analysis. BCS reported a significant improvement of the overall endocrine symptomatology (baseline mean = 59 vs. follow-up mean = 62, p < 0.001), physical (baseline = 23.9 mean vs. follow-up mean = 24.8, p < 0.01) and functional well-being (baseline mean = 21.7 vs. follow-up mean = 22.7, p = 0.013) and overall QOL (mean baseline = 88.3 vs. mean follow-up = 90.9, p = 0.011). However, the prevalence of particular symptoms, well-known to be ET induced, did not change over time such as joint pain (baseline = 45.5% vs. 44.2%, n.s. difference), lack of energy (36.4% vs 33.8%, n.s. difference), weight gain (36.8% vs. 33.9%, n.s. difference) or vaginal dryness (30.2% vs. 33%, n.s. difference) and the proportion reporting lack of interest in sex increased (40.4% vs. 48.7%, p < 0.05).

CONCLUSION

Presented results indicate that BCS recover well in terms of overall endocrine symptomatology and quality of life but experience some clinically relevant and unfavorable ET-related long-term effects.

The Cardiovascular Risks Associated with Aromatase Inhibitors, Tamoxifen, and GnRH Agonists in Women with Breast Cancer

PURPOSE OF REVIEW

Cardiovascular disease accounts for up to 10% of all-cause mortality in women with a diagnosis of breast cancer, and the causes for this are multifaceted. Many women at risk of or with a diagnosis of breast cancer are on endocrine-modulating therapies. It is therefore important to understand the effect of hormone therapies on cardiovascular outcomes in breast cancer patients to mitigate against any adverse effects and to identify those most at risk so that they can be proactively managed. Here we discuss the pathophysiology of these agents, their effect on the cardiovascular system, and the latest evidence on their cardiovascular risks association.

RECENT FINDINGS

Tamoxifen appears to be cardioprotective during treatment but not over the longer term, while the effect of AIs on cardiovascular outcomes remains controversial. Heart failure outcomes remain understudied, and the cardiovascular effects of gonadotrophin-releasing hormone agonists (GNRHa) in women need further research, especially since data from men with prostate cancer have indicated an increased risk of cardiac events in GNRHa users. There remains a need for a greater understanding of the effects of hormone therapies on cardiovascular outcomes in breast cancer patients. Further areas of research in this area include developing evidence to better define the optimal preventive and screening methods for cardiovascular effects and the risk factors for patients on hormonal therapies.

Severe hyperlipidemia pancreatitis induced by taking tamoxifen after breast cancer surgery—Case report

Introduction

The research investigates the mechanism, diagnosis, treatment, and subsequent endocrine therapy of severe pancreatitis induced by tamoxifen treatment in patients who have undergone breast cancer surgery.

Case presentation

We studied two cases of breast cancer in whom severe acute pancreatitis developed after taking tamoxifen for endocrine therapy in our hospital. A brief literature review was provided to analyze the causes, clinical manifestations, treatment process, and prognosis of severe acute pancreatitis. Both cases involved patients with severe hyperlipidemic pancreatitis. After conservative treatment, none of them died. Pancreatitis did not recur after changing endocrine therapy drugs.

Discussion/conclusion

Endocrine therapy with tamoxifen in breast cancer patients can induce hyperlipidemia, which can subsequently cause severe pancreatitis. The treatment of severe pancreatitis should strengthen the regulation of blood lipids. The application of low-molecular-weight heparin combined with insulin therapy can rapidly lower blood lipids. Involved treatments, including acid suppression, enzyme suppression, and peritoneal dialysis, can accelerate the recovery of pancreatitis and reduce the occurrence of serious complications. Patients with severe pancreatitis should not continue to use tamoxifen for endocrine therapy. To complete follow-up endocrine therapy, switching to a steroidal aromatase inhibitor is better if the situation allows it.

Refining and optimising a behavioural intervention to support endocrine therapy adherence (ROSETA) in UK women with breast cancer: protocol for a pilot fractional factorial trial

INTRODUCTION

Women with breast cancer who do not adhere to adjuvant endocrine therapy (AET) have increased risks of mortality and recurrence. There are multiple barriers to AET adherence, including medication side-effects, beliefs about medication, memory and psychological distress. We developed four intervention components, each targeting a different barrier. This pilot trial is part of the preparation phase of the Multiphase Optimisation Strategy, and aims to establish key trial parameters, establish intervention component adherence, establish availability and feasibility of outcome and process data, estimate variability in planned outcome measures and estimate cost of developing and delivering each intervention component.

METHODS AND ANALYSIS

The four intervention components are as follows: short message service text reminders (target: memory); a written information leaflet (target: medication beliefs); a guided self-help Acceptance and Commitment Therapy programme (target: psychological flexibility to reduce distress) and a self-management website (target: side-effect management). To evaluate the feasibility of recruitment, acceptability of the intervention components and the availability of outcome data, we will conduct a multisite, exploratory pilot trial using a 2^4-1 fractional factorial design, with a nested process evaluation. We will randomise 80 women with early-stage breast cancer who have been prescribed AET to one of eight experimental conditions. This will determine the combination of intervention components they receive, ranging from zero to four, with all conditions receiving usual care. Key outcomes of interest include medication adherence and quality of life. Progression to the optimisation phase will be based on predefined criteria for consent rates, patient adherence to intervention components and availability of medication adherence data.

ETHICS AND DISSEMINATION

The study was reviewed by the Wales Research Authority Research Ethics Committee 3 (21/WA/0322). Written informed consent will be obtained from all patients before randomisation. The results of this trial will be disseminated in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

ISRTCN10487576.

Review of bone health in women with estrogen receptor-positive breast cancer receiving endocrine therapy

In estrogen-receptor-positive tumors, adjuvant endocrine therapy has been shown to be highly beneficial for both overall and disease-free survival. Estradiol is key in regulating bone and mineral physiology, and several studies found a strong correlation between these therapies and the risk of fractures. Since these therapies are often given for 5 through 10 years, the timing for bisphosphonates or denosumab initiation seems essential to managing bone metabolism. However, gray zones and discrepancies between guidelines remain as to the best threshold when to start antiresorptive treatment, or whether antiresorptive treatment should be administered to every woman undergoing adjuvant endocrine therapy, independent of their risk factors for fractures. Treatment options and strategies should be discussed at the start of hormone adjuvant therapy to come to a shared decision with the patient, with the final aim of reducing the risk of future fractures as much as possible. This review will cover present guidelines and literature on antiresorptive treatment in this setting, to provide clinicians with useful clues for managing these patients.

Re-Evaluating the Association Between Hormonal Contraception and Breast Cancer Risk

This review aims to summarize and assess key studies investigating the relationship between hormonal contraception and breast cancer risk. Approximately two-thirds of breast cancers express the estrogen receptor, and long-term exposure to estrogen is a debated risk factor for breast cancer development. This hypothesis is based on prior studies looking at reproductive risk factors (endogenous estrogen exposure) along with hormone replacement therapy (exogenous hormone exposure). Historically accepted reproductive risk factors include age at menarche, age at first delivery, and parity. Exogenous hormone exposure encompasses both receipt of hormonal contraception and menopausal hormone replacement therapy. This review highlights the reported risks associated with the most common hormonal contraception methods including oral, transdermal, and transvaginal routes. Large observational studies of the past and more recent works are summarized highlighting gaps in knowledge. Several themes emerge: difficulty accounting for well-established risk factors in analyses of epidemiologic studies, challenges determining whether associations between hormonal contraception and breast cancer are due to the exogenous hormones themselves or to increased engagement with the medical system, and discrepancies between statistically significant and clinically significant risk, odds, and hazard ratios. Understanding the strengths and limitations of these studies will help providers in and outside of oncology support women making decisions regarding both cancer risk-reduction and family planning.

Mathematically Modeling the Effect of Endocrine and Cdk4/6 Inhibitor Therapies on Breast Cancer Cells

Mathematical modeling of cancer systems is beginning to be used to design better treatment regimens, especially in chemotherapy and radiotherapy. The effectiveness of mathematical modeling to inform treatment decisions and identify therapy protocols, some of which are highly nonintuitive, is because it enables the exploration of a huge number of therapeutic possibilities. Considering the immense cost of laboratory research and clinical trials, these nonintuitive therapy protocols would likely never be found by experimental approaches. While much of the work to date in this area has involved high-level models, which look simply at overall tumor growth or the interaction of resistant and sensitive cell types, mechanistic models that integrate molecular biology and pharmacology can contribute greatly to the discovery of better cancer treatment regimens. These mechanistic models are better able to account for the effect of drug interactions and the dynamics of therapy. The aim of this chapter is to demonstrate the use of ordinary differential equation-based mechanistic models to describe the dynamic interactions between the molecular signaling of breast cancer cells and two key clinical drugs. In particular, we illustrate the procedure for building a model of the response of MCF-7 cells to standard therapies used in the clinic. Such mathematical models can be used to explore the vast number of potential protocols to suggest better treatment approaches.

Abemaciclib plus endocrine therapy for hormone receptor-positive, HER2-negative, node-positive, high-risk early breast cancer (monarchE): results from a preplanned interim analysis of a randomised, open-label, phase 3 trial

BACKGROUND

Adjuvant abemaciclib plus endocrine therapy previously showed a significant improvement in invasive disease-free survival and distant relapse-free survival in hormone receptor-positive, human epidermal growth factor receptor 2 (HER2; also known as ERBB2)-negative, node-positive, high-risk, early breast cancer. Here, we report updated results from an interim analysis to assess overall survival as well as invasive disease-free survival and distant relapse-free survival with additional follow-up.

METHODS

In monarchE, an open-label, randomised, phase 3 trial, adult patients (aged ≥18 years) who had hormone receptor-positive, HER2-negative, node-positive, early breast cancer at a high risk of recurrence with an Eastern Cooperative Oncology Group performance status of 0 or 1 were recruited from 603 sites including hospitals and academic and community centres in 38 countries. Patients were randomly assigned (1:1) by means of an interactive web-based response system (block size of 4), stratified by previous chemotherapy, menopausal status, and region, to receive standard-of-care endocrine therapy of physician's choice for up to 10 years with or without abemaciclib 150 mg orally twice a day for 2 years (treatment period). All therapies were administered in an open-label manner without masking. High-risk disease was defined as either four or more positive axillary lymph nodes, or between one and three positive axillary lymph nodes and either grade 3 disease or tumour size of 5 cm or larger (cohort 1). A smaller group of patients were enrolled with between one and three positive axillary lymph nodes and Ki-67 of at least 20% as an additional risk feature (cohort 2). This was a prespecified overall survival interim analysis planned to occur 2 years after the primary outcome analysis for invasive disease-free survival. Efficacy was assessed in the intention-to-treat population. Safety was assessed in all treated patients. The study is registered with ClinicalTrials.gov, NCT03155997, and is ongoing.

FINDINGS

Between July 17, 2017, and Aug 12, 2019, 5637 patients were randomly assigned (5601 [99·4%] were women and 36 [0·6%] were men). 2808 were assigned to receive abemaciclib plus endocrine therapy and 2829 were assigned to receive endocrine therapy alone. At a median follow-up of 42 months (IQR 37-47), median invasive disease-free survival was not reached in either group and the invasive disease-free survival benefit previously reported was sustained: HR 0·664 (95% CI 0·578-0·762, nominal p<0·0001). At 4 years, the absolute difference in invasive disease-free survival between the groups was 6·4% (85·8% [95% CI 84·2-87·3] in the abemaciclib plus endocrine therapy group vs 79·4% [77·5-81·1] in the endocrine therapy alone group). 157 (5·6%) of 2808 patients in the abemaciclib plus endocrine therapy group died compared with 173 (6·1%) of 2829 patients in the endocrine therapy alone group (HR 0·929, 95% CI 0·748-1·153; p=0·50). The most common grade 3-4 adverse events were neutropenia (in 548 [19·6%] of 2791 patients receiving abemaciclib plus endocrine therapy vs 24 [0·9%] of 2800 patients in the endocrine therapy alone group), leukopenia (318 [11·4%] vs 11 [0·4%]), and diarrhoea (218 [7·8%] vs six [0·2%]). Serious adverse events occurred in 433 (15·5%) of 2791 patients receiving abemaciclib plus endocrine therapy versus 256 (9·1%) of 2800 receiving endocrine therapy. There were two treatment-related deaths in the abemaciclib plus endocrine therapy group (diarrhoea and pneumonitis) and none in the endocrine therapy alone group.

INTERPRETATION

Adjuvant abemaciclib reduces the risk of recurrence. The benefit is sustained beyond the completion of treatment with an absolute increase at 4 years, further supporting the use of abemaciclib in patients with high-risk hormone receptor-positive, HER2-negative early breast cancer. Further follow-up is needed to establish whether overall survival can be improved with abemaciclib plus endocrine therapy in these patients.

FUNDING

Eli Lilly.

Acute pancreatitis secondary to tamoxifen-associated hypertriglyceridemia: A clinical update

INTRODUCTION

Drug-induced pancreatitis has been increasingly recognized, but it is frequently encountered as an inconspicuous etiology. The underlying mechanisms of injury vary with different drugs. Tamoxifen is a frequently used anticancer drug that acts by selective modulation of the estrogen receptor in patients with breast cancer. Tamoxifen-induced hypertriglyceridemia is a relatively rare etiological factor for acute pancreatitis. However, acute pancreatitis secondary to this adverse effect remains an exceedingly important clinicopathologic entity.

CASE REPORT

We hereby delineate a rare case of acute pancreatitis secondary to hypertriglyceridemia in a patient who was on tamoxifen treatment for the past 3 years. Her serum lipase and triglyceride levels were markedly elevated at 14,285 IU/L and 20,344 mg/dL, respectively. The diagnosis was considered based on the findings of a standard diagnostic workup and exclusion of alternative causes of acute pancreatitis.

MANAGEMENT AND OUTCOME

The patient was instituted prompt treatment with intravenous insulin infusion and gemfibrozil. The clinical outcome was favorable with no complications. Tamoxifen was permanently discontinued and was replaced with letrozole.

DISCUSSION

This article illustrates that acute pancreatitis should be considered in the differential diagnoses of abdominal pain and elevated pancreatic enzymes in patients undergoing tamoxifen treatment. It also underscores the importance of pre- and post-tamoxifen lipid screening, especially in patients with a history of dyslipidemia and diabetes mellitus. It will facilitate an expedient detection of hypertriglyceridemia, potentially saving patients from associated morbidity and mortality.

Prolylcarboxypeptidase promotes IGF1R/HER3 signaling and is a potential target to improve endocrine therapy response in estrogen receptor positive breast cancer

Prolylcarboxypeptidase (PRCP) is a lysosomal serine protease that cleaves peptide substrates when the penultimate amino acid is proline. Previous studies have linked PRCP to blood-pressure and appetite control through its ability to cleave peptide substrates such as angiotensin II and α-MSH. A potential role for PRCP in cancer has to date not been widely appreciated. Endocrine therapy resistance in breast cancer is an enduring clinical problem mediated in part by aberrant receptor tyrosine kinase (RTK) signaling. We previously found PRCP overexpression promoted 4-hydroxytamoxifen (4-OHT) resistance in estrogen receptor-positive (ER+) breast cancer cells. Currently, we tested the potential association between PRCP with breast cancer patient outcome and RTK signaling, and tumor responsiveness to endocrine therapy. We found high PRCP protein levels in ER+ breast tumors associates with worse outcome and earlier recurrence in breast cancer patients, including patients treated with TAM. We found a PRCP specific inhibitor (PRCPi) enhanced the response of ER+ PDX tumors and MCF7 tumors to endoxifen, an active metabolite of TAM in mice. We found PRCP increased IGF1R/HER3 signaling and AKT activation in ER+ breast cancer cells that was blocked by PRCPi. Thus, PRCP is an adverse prognostic marker in breast cancer and a potential target to improve endocrine therapy in ER+ breast cancers.

Managing Bone Health in Breast Cancer

OBJECTIVE

Osteoporosis is a common condition that can be caused or exacerbated by estrogen deficiency.

METHODS

This narrative review will discuss optimizing bone health in the setting of adjuvant endocrine treatments for hormone receptor-positive breast cancer and the current use of antiresorptive agents as adjuvant therapy and as bone modifying agents.

RESULTS

Adjuvant endocrine treatments for hormone receptor-positive breast cancer (tamoxifen and aromatase inhibitors) affect bone health. The exact effect depends on the agent used and the menopausal state of the woman. Antiresorptive medications for osteoporosis, bisphosphonates and denosumab, lower the risk of bone loss from aromatase inhibitors. Use of bisphosphonates as adjuvant treatment in breast cancer, regardless of hormone receptor status, is increasing because of benefits seen to cancer relapse and survival.

CONCLUSION

Optimizing bone health in women with breast cancer during and after cancer treatment is informed by an understanding of breast cancer treatment and its skeletal effect.

Predictors of adherence and the role of primary non-adherence in antihormonal treatment of breast cancer

BACKGROUND

Antihormonal treatment for hormone receptor (HR) positive breast cancer has highly beneficial effects on both recurrence rates and survival. We investigate adherence and persistence in this group of patients.

METHODS

The study population comprised 1192 patients with HR-positive breast cancer who were prescribed adjuvant antihormonal treatment from 2004 to 2013. Adherence was defined as a medical possession ratio (MPR) of ≥80.

RESULTS

Of the 1192 included patients, 903 (75.8%) were adherent and 289 (24.2%) were non-adherent. Primary non-adherence was seen in 101 (8.5%) patients. The extremes of age (< 40 and ≥ 80 years) were associated with poor adherence. Patients with metastasis to axillary lymph nodes and those who received radiotherapy and/or chemotherapy were more likely to be adherent. Better adherence was also shown for those who switched medication at 2 years after diagnosis. Primary non-adherence seems to be associated with cancers with a good prognosis.

CONCLUSION

Adherence to antihormonal therapy for breast cancer is suboptimal. Primary non-adherence occurs among patients with a relatively good prognosis. Non-adherent patients tend to terminate their antihormonal therapy in the initial part of the treatment period. Targeted interventions to improve adherence should be focused on the first part of the treatment period.

Adherence to adjuvant hormonal therapy in localised breast cancer

BACKGROUND

Hormonal therapies are the cornerstone of systemic adjuvant treatment of oestrogen receptor (ER) positive breast cancer. The full benefit of this treatment is obtained with long-term adherence. However, discontinuation of hormonal therapy is common. Factors associated with non-compliance to therapy are complex and worth of detailed evaluation.

PATIENTS AND METHODS

A retrospective analysis of medical records of 284 early ER-positive breast cancer patients prescribed adjuvant hormonal therapy during a 5-year period in a single centre was undertaken. Characteristics of the patients and their disease as well as adherence to therapy and continuation at 1 and 3 years were recorded. The group of patients that were on treatment at 3 years and the group that had discontinued therapy before 3 years were compared to identify differences predicting lack of adherence.

RESULTS

The discontinuation rate of hormonal therapy at 1 year was 13%, and the discontinuation rate at 3 years was 21.2%. Patient age and menopause status were not associated with hormone therapy adherence at 3 years. The type of hormonal therapy (aromatase inhibitor or tamoxifen) was also not associated with adherence. In contrast, patients that received adjuvant chemotherapy before starting hormonal therapy had a higher adherence to hormonal therapy (86.9% at 3 years vs. 75.7% in patients that had not received adjuvant chemotherapy, χ² p = 0.04). Among co-morbidities, patients with a concomitant diagnosis of psychiatric disease at the time of breast cancer diagnosis were at increased risk of hormone therapy non-adherence. Progression-free survival and overall survival were inferior in the non-adherent group compared with the patients who continued their hormonal therapy at 3 years.

CONCLUSION

Adjuvant chemotherapy is associated with better subsequent adherence to hormonal therapy in early breast cancer patients. On the other hand, psychiatric co-morbidities are associated with worse adherence. De-escalation of adjuvant therapy guided by genomic tests leads to a significant percentage of early ER-positive breast cancer patients not receiving chemotherapy. Non-adherence to hormonal therapy would leave a subset of these patients with no adjuvant systemic therapy. The current results will guide efforts to increase compliance to hormonal therapies in specific groups of patients.

Co-targeting CDK2 and CDK4/6 overcomes resistance to aromatase and CDK4/6 inhibitors in ER+ breast cancer

Resistance to aromatase inhibitor (AI) treatment and combined CDK4/6 inhibitor (CDK4/6i) and endocrine therapy (ET) are crucial clinical challenges in treating estrogen receptor-positive (ER+) breast cancer. Understanding the resistance mechanisms and identifying reliable predictive biomarkers and novel treatment combinations to overcome resistance are urgently needed. Herein, we show that upregulation of CDK6, p-CDK2, and/or cyclin E1 is associated with adaptation and resistance to AI-monotherapy and combined CDK4/6i and ET in ER+ advanced breast cancer. Importantly, co-targeting CDK2 and CDK4/6 with ET synergistically impairs cellular growth, induces cell cycle arrest and apoptosis, and delays progression in AI-resistant and combined CDK4/6i and fulvestrant-resistant cell models and in an AI-resistant autocrine breast tumor in a postmenopausal xenograft model. Analysis of CDK6, p-CDK2, and/or cyclin E1 expression as a combined biomarker in metastatic lesions of ER+ advanced breast cancer patients treated with AI-monotherapy or combined CDK4/6i and ET revealed a correlation between high biomarker expression and shorter progression-free survival (PFS), and the biomarker combination was an independent prognostic factor in both patients cohorts. Our study supports the clinical development of therapeutic strategies co-targeting ER, CDK4/6 and CDK2 following progression on AI-monotherapy or combined CDK4/6i and ET to improve survival of patients exhibiting high tumor levels of CDK6, p-CDK2, and/or cyclin E1.

Impact of cytochrome P450 2D6 polymorphisms on decision-making and clinical outcomes in adjuvant hormonal therapy for breast cancer

BACKGROUND

There are concerns that tamoxifen is less effective in Asian women because of the high prevalence of impaired function cytochrome P450 2D6 (CYP2D6) polymor-phisms.

AIM

To evaluate how knowledge of CYP2D6 genotype impacted the choice of hormonal agent and how CYP2D6 genotype and agent were associated with clinical outcomes.

METHODS

Eighty-two women were recruited. Seventy-eight completed CYP2D6 genotyping and were categorized into poor, intermediate (IM) and extensive or ultra metabolizer phenotypes. Women with poor metabolizer and IM phenotypes were recommended aromatase inhibitors as the preferred agent.

RESULTS

More than 70% of the women had an IM phenotype, 32% an extensive or ultra metabolizer phenotype, and 0% had a poor metabolizer phenotype. Regardless of genotype, more women opted for aromatase inhibitors. Overall, 80% of women completed 5 years of hormonal therapy. Five women developed recurrence, 3 contralateral breast cancer, 5 died, and 1 was diagnosed with a second primary cancer. Five-year recurrence-free and overall survival were slightly better in women with the extensive or ultra metabolizer phenotype compared to those with the IM phenotype, though not statistically significant [P = 0.743, hazard ratio (HR): 1.441, 95% confidence interval (CI): 0.191 to 10.17 and P = 0.798, HR: 1.327, 95%CI: 0.172 to 9.915, respectively]. Women receiving aromatase inhibitors also appeared to have a better, but also nonsignificant, 5-year recurrence-free and overall survival (P = 0.253, HR: 0.368, 95%CI: 0.031 to 0.258 and P = 0.292, HR: 0.252, 95%CI: 0.005 to 4.951, respectively).

CONCLUSION

The IM phenotype was highly prevalent but was not associated with clinical outcome.

Impact of Endocrine Therapy Adherence on Outcomes in Elderly Women with Early-Stage Breast Cancer Undergoing Lumpectomy Without Radiotherapy

BACKGROUND

National Comprehensive Center Network guidelines recommend radiotherapy (RT) omission in women age ≥ 70 years with estrogen receptor-positive (ER+), cN0, T1 tumors post-lumpectomy if they receive endocrine therapy (ET). However, little is known about the impact of poor adherence on locoregional recurrence (LRR) in elderly women forgoing RT.

METHODS

Women age ≥ 70 years with pT1-2 ER+ breast cancer undergoing lumpectomy without RT from 2004 to 2019 were identified from a prospectively maintained database. ET adherence, calculated as treatment duration over follow-up time up to 5 years, was determined by chart review. We compared clinicopathologic characteristics and rates of LRR between women with high adherence (≥ 80%), low adherence (< 80%), and no ET.

RESULTS

Of 968 women (27 bilateral cancers), adherence was high in 676 (70%) and low in 162 (17%); 130 (13%) took no ET. Younger age and use of aromatase inhibitor were associated with high adherence. On multivariable analysis, tumor size (hazard ratio [HR] 1.67, 95% confidence interval [CI] 1.03-2.68, p = 0.04) and high adherence (HR 0.13, 95% CI 0.07-0.26, p < 0.001) were significantly associated with LRR. At 53 months median follow-up, the 5-year rate of LRR was 3.1% (95% CI 2.4-3.9%) with high adherence, 14.7% (95% CI 11.7-17.7%) with low adherence, and 17.9% (95% CI 13.9-21.8%) with no ET (p < 0.01).

CONCLUSIONS

Although adherence to ET was high overall, in the 30% of women with low adherence or no ET, LRR rates were significantly increased. Counseling regarding the distinct toxicities of ET and RT can help patients choose the therapy to which they will likely adhere to.

Accelerating drug development in breast cancer: New frontiers for ER inhibition

The estrogen receptor (ER) is an important driver in the proliferation, tumorigenesis, and progression of breast cancers, and targeting ER signaling at different levels is a successful strategy in the control of hormone receptor positive (HR+) breast cancer. Endocrine therapy has been the treatment of choice for HR+ breast cancer in the early and advanced stages with multiple agents, including selective estrogen receptor modulators (SERMS), selective estrogen receptor degraders (SERDs), and aromatase inhibitors (AIs), which vary in their mechanisms of action and pharmacokinetics. Combination strategies also employ cyclin dependent kinase 4 and 6 and phosphatidylinositol 3-kinase to maximize the benefits of endocrine therapy. This paper reviews the clinical development of SERDs and other novel ER inhibitors, as well as combination strategies to overcome mechanisms of ER pathway escape. It also assesses the advantages of newer oral ER inhibitors with increased bioavailability, improved therapeutic index, better administration, and increased efficacy, as well as discussing future directions in the field.

Influence of the anti-oestrogens tamoxifen and letrozole on thyroid function in women with early and advanced breast cancer: A systematic review

INTRODUCTION

Breast cancer (BC) is a common type of cancer in women. Advances in therapy options have resulted in higher overall survival rates but side effects of cancer treatment are increasingly in the spotlight. The beneficial effects of anti-oestrogen therapy with tamoxifen and letrozole in the prevention of BC recurrence are well documented. While the most common side-effects of this therapy are well-defined, less is known about its effects on thyroid function. In women treated for early BC, an average of 1-5 kg weight gain has been observed after treatment with chemotherapy/anti-oestrogens. We aim to evaluate the current knowledge on the side effects of tamoxifen and letrozole treatments on thyroid function, followed by its potential influence on the observed weight gain.

METHODS

We searched PubMed and found 16 publications on thyroid function and tamoxifen treatment in pre- and post-menopausal women with early- and advanced BC, whereas five publications on letrozole treatment in post-menopausal women with advanced BC.

RESULTS

According to the current literature, there is an overall tendency towards a mild and transient thyroid dysfunction, that is, subclinical hypothyroidism in tamoxifen-treated patients. Only one publication reported further significant changes in thyroid hormones beyond one year of tamoxifen treatment. No significant changes in thyroid function have been observed among letrozole-treated patients.

CONCLUSION

Tamoxifen-treated patients can develop mild and transient thyroid dysfunction within the first 12 months, yet further significant changes in thyroid function beyond one year of tamoxifen treatment have been reported in a single study. There is no evidence of thyroid dysfunction in letrozole-treated patients. Current literature does not focus on subclinical hypothyroidism as a possible cause of weight gain in patients with BC. Subgrouping of BC patients and studies with a longer observation of thyroid hormones and weight changes during and after anti-oestrogen treatment are needed to further elucidate how anti-oestrogens affect thyroid function.

Update on prognostic and predictive biomarkers of breast cancer

Breast cancer represents a heterogeneous group of human cancer at both histological and molecular levels. Estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) are the most commonly used biomarkers in clinical practice for making treatment plans for breast cancer patients by oncologists. Recently, PD-L1 testing plays an important role for immunotherapy for triple-negative breast cancer. With the increased understanding of the molecular characterization of breast cancer and the emergence of novel targeted therapies, more potential biomarkers are needed for the development of more personalized treatments. In this review, we summarized several main prognostic and predictive biomarkers in breast cancer at genomic, transcriptomic and proteomic levels, including hormone receptors, HER2, Ki67, multiple gene expression assays, PD-L1 testing, mismatch repair deficiency/microsatellite instability, tumor mutational burden, PIK3CA, ESR1 andNTRK and briefly introduced the roles of digital imaging analysis in breast biomarker evaluation.

Promising Therapeutic Impact of a Selective Estrogen Receptor Downregulator, Fulvestrant, as Demonstrated In Vitro upon Low-Grade Serous Ovarian Carcinoma Cell Lines

Few studies have reported hormonal agent use in the treatment of low-grade serous ovarian carcinomas (LGSOCs), which are chemoresistant. Considering the need for novel effective therapies, we investigated the hormone receptor expression and hormonal inhibition efficacy in LGSOCs. Using immunohistochemistry, we assessed the estrogen receptor (ER) expression status in 33 cases of histologically confirmed serous ovarian tumors, including 10, 11, and 12 cases of LGSOCs, serous borderline tumors (SBTs), and serous cystadenomas (SCAs), respectively. The genetic background reported in our previous study was used in the current study. MPSC1 cells, which were established from LGSOCs, were used in cell proliferation assays. We observed a higher ER expression in LGSOCs and SBTs than in SCAs (70%, 81%, and 50%, respectively). Thus, LGSOCs and SBTs exhibit higher ER expression than SCAs. Moreover, the PIK3CA mutation positively correlated with ER expression in LGSOCs (p = 0.0113). MPSC1 cells showed low ER expression on Western blotting. MPSC1 cell proliferation was significantly inhibited by fulvestrant (a selective ER downregulator). The activation of ER and PI3K/AKT signaling pathways may play an important role in LGSOC carcinogenesis. ER downregulation with fulvestrant or combination therapy with PI3K inhibitors is a possible novel treatment for patients with LGSOCs.

Aromatase Inhibitors and Risk of Metabolic and Cardiovascular Adverse Effects in Breast Cancer Patients-A Systematic Review and Meta-Analysis

Aromatase inhibitors (AIs) have been considered first-line therapy for patients with hormone-dependent breast cancer due to their high efficacy and good tolerability. However, AIs are not free of adverse events, and studies show that therapy with AIs is associated with an increased risk of cardiovascular events and the development of insulin resistance and diabetes. We searched the Cochrane Central Register of Controlled Trials, PubMed and EMBASE up to 27 October 2020 for the prevalence of cardiovascular and/or metabolic adverse effects during treatment with AIs in postmenopausal women with breast cancer. A meta-analysis was performed using a random effects model. Odds ratios and 95% confidence intervals were calculated and illustrated using forest plot charts. We performed separate analyses depending on trial design. Twenty two studies met the inclusion criteria. AIs were associated with a higher risk of cardiovascular events, especially when we compared study arms in which AIs were used (alone or in sequence with TAM) with the arms in which TAM was used alone (OR = 1.16; 95%CI 1.04-1.30) or when comparing patients taking AIs alone to patients taking TAM alone or in sequence with AIs (OR = 1.24; 95%CI 1.11-1.38). A pooled analysis of five trials comparing adjuvant AIs to TAM showed the odds for arterial hypertension being 1.31 times higher for patients taking AIs; however, this did not reach statistical significance (OR = 1.31; 95%CI 0.47-3.65). We have not shown an increased risk of dyslipidemia or weight gain with the use of AIs. Our results suggest that postmenopausal women with breast cancer treated with AIs have an increased risk of cardiovascular events in comparison with TAM, potentially due more to a cardioprotective effect of the latter than the cardiotoxicity of AIs. We were unable to prove a similar association for hypertension, dyslipidemia, hyperglycemia or weight gain. Further high-quality RCTs and post-marketing safety observational studies are needed to definitively evaluate the impact of AIs on metabolic disorders in breast cancer patients.

Efficacy and Safety of Initial 5 Years of Adjuvant Endocrine Therapy in Postmenopausal Hormone Receptor-Positive Breast Cancer: A Systematic Review and Network Meta-Analysis

Purpose: To identify the optimal initial 5 years of adjuvant endocrine therapy for hormone receptor-positive postmenopausal early breast cancer (EBC) patients.

Methods: We conducted a systematic search of the PubMed, Web of Science, and EMBASE to obtain relevant studies published between January 2000 and January 2022. Randomized clinical trials assessing the efficacy and safety of initial 5 years of adjuvant endocrine therapy were included. The primary outcomes were disease-free survival and overall survival and the secondary outcome was severe adverse effects (SAEs). A Bayesian network meta-analysis was carried out to indirectly compare all regimens and the value of surface under the cumulative ranking curve (SUCRA) was used to obtain rankings.

Results: Eleven studies with 49,987 subjects were included. For DFS, exemestane (EXE) [hazard ratio (HR) 0.91, 95% confidence interval (95%CI) 0.87–0.96], anastrozole (ANA) (0.94, 0.90–0.97), letrozole (LET) (0.93, 0.89–0.97), tamoxifen (TAM) followed by EXE (0.91, 0.87–0.96), and TAM followed by ANA (0.92, 0.87–0.98) were more favorable than TAM, with TAM followed by EXE ranking as the first of SUCRA. For OS, only TAM followed by ANA showed significant superiority than TAM (HR 0.91, 95%CI 0.86–0.97) and ranked as the first of SUCRA. For SAEs, EXE (HR 1.72, 95%CI 1.04–2.98), ANA (1.58, 1.03–2.43), and LET (1.63, 1.02–2.57) showed greater associations with bone fracture than TAM. However, no significant difference in the incidences of cardiac events, thromboembolic events, and cerebrovascular events was found among all comparisons.

Conclusion: The sequential use of aromatase inhibitors, which has the best curative effects and relatively mild side effects, may be the optimal treatment mode for hormone receptor-positive postmenopausal EBC patients. In addition, the three kinds of aromatase inhibitors achieved roughly equal efficacy, but caused different types of SAEs.

Systematic Review Registration: [website], identifier [registration number].

The History of Early Breast Cancer Treatment

“The story of cancer is the story of human ingenuity, resilience, and perseverance, but also of hubris, paternalism, and misperception” (Siddhartha Mukherjee). The present review discusses the evolution of early breast cancer (BC) treatment philosophy in the last 50 years and the shift from an emphasis on local therapy to an emphasis on systemic precision treatment options.

Oncological Treatment-Related Fatigue in Oncogeriatrics: A Scoping Review

Simple Summary

Fatigue in older patients has multiple etiologies, as this symptom may be cancer-related, treatment-related, age-related, or part of frailty syndrome. Physicians need to identify this symptom and understand its risk factors but also evaluate the risk/benefit ratio of cancer treatments considering the risk of impairing the patient’s quality of life. This scoping review was aimed to present the level of information currently available on any-grade fatigue and grade 3 or more fatigue for each cancer treatment regimen, either in general or in older populations, for the most prevalent tumors.

Abstract

Fatigue is a highly prevalent symptom in both cancer patients and the older population, and it contributes to quality-of-life impairment. Cancer treatment-related fatigue should thus be included in the risk/benefit assessment when introducing any treatment, but tools are lacking to a priori estimate such risk. This scoping review was designed to report the current evidence regarding the frequency of fatigue for the different treatment regimens proposed for the main cancer indications, with a specific focus on age-specific data, for the following tumors: breast, ovary, prostate, urothelium, colon, lung and lymphoma. Fatigue was most frequently reported using the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE) versions 3 to 5. A total of 324 regimens were analyzed; data on fatigue were available for 217 (67%) of them, and data specific to older patients were available for 35 (11%) of them; recent pivotal trials have generally reported more fatigue grades than older studies, illustrating increasing concern over time. This scoping review presents an easy-to-understand summary that is expected to provide helpful information for shared decisions with patients regarding the anticipation and prevention of fatigue during each cancer treatment.

Using population-based data to evaluate the impact of adherence to endocrine therapy on survival in breast cancer through the web-application BreCanSurvPred

We show how the use and interpretation of population-based cancer survival indicators can help oncologists talk with breast cancer (BC) patients about the relationship between their prognosis and their adherence to endocrine therapy (ET). The study population comprised a population-based cohort of estrogen receptor positive BC patients (N = 1268) diagnosed in Girona and Tarragona (Northeastern Spain) and classified according to HER2 status (+ / −), stage at diagnosis (I/II/III) and five-year cumulative adherence rate (adherent > 80%; non-adherent ≤ 80%). Cox regression analysis was performed to identify significant prognostic factors for overall survival, whereas relative survival (RS) was used to estimate the crude probability of death due to BC (P_BC). Stage and adherence to ET were the significant factors for predicting all-cause mortality. Compared to stage I, risk of death increased in stage II (hazard ratio [HR] 2.24, 95% confidence interval [CI]: 1.51–3.30) and stage III (HR 5.11, 95% CI 3.46–7.51), and it decreased with adherence to ET (HR 0.57, 95% CI 0.41–0.59). P_BC differences were higher in non-adherent patients compared to adherent ones and increased across stages: stage I: 6.61% (95% CI 0.05–13.20); stage II: 9.77% (95% CI 0.59–19.01), and stage III: 22.31% (95% CI 6.34–38.45). The age-adjusted survival curves derived from this modeling were implemented in the web application BreCanSurvPred (https://pdocomputation.snpstats.net/BreCanSurvPred). Web applications like BreCanSurvPred can help oncologists discuss the consequences of non-adherence to prescribed ET with patients.

Cardiac Toxicity From Adjuvant Targeting Treatment for Breast Cancer Post-Surgery

Breast cancer is one of the most prevalent types of cancers worldwide, especially for females. Surgery is the preferred treatment for breast cancer, and various postoperative adjuvant therapies can be reasonably used according to different pathological characteristics, especially traditional radiotherapy, chemotherapy, and endocrine therapy. In recent years, targeting agent therapy has also become one of the selective breast cancer treatment strategies, including anti-HER-2 drugs, CDK4/6 inhibitor, poly ADP-ribose polymerase inhibitor, PI3K/AKT/mTOR pathway inhibitor, ER targeting drugs, and aromatase inhibitor. Because of the different pathologic mechanisms of these adjuvant therapies, each of the strategies may cause cardiotoxicity in clinic. The cardiac adverse events of traditional endocrine therapy, radiotherapy, and chemotherapy for breast cancer have been widely detected in clinic; however, the targeting therapy agents have been paid more attention with the extension of application. This review will summarize the cardiac toxicity of various adjuvant therapies for breast cancer, especially for targeting drug therapy.

Effect of concomitant statin treatment in postmenopausal patients with hormone receptor-positive early-stage breast cancer receiving adjuvant denosumab or placebo: a post hoc analysis of ABCSG-18

Background

Statins are cholesterol-lowering drugs prescribed for the prevention and treatment of cardiovascular disease. Moreover, statins may possess anticancer properties and interact with receptor activator of nuclear factor κB ligand expression. We aimed at evaluating a hypothetical synergistic effect of statins with denosumab in early-stage breast cancer (BC) patients from the Austrian Breast and Colorectal Cancer Study Group (ABCSG) trial 18.

Patients and methods

ABCSG-18 (NCT00556374) is a prospective, randomized, double-blind, phase III study; postmenopausal patients with hormone receptor-positive BC receiving a nonsteroidal aromatase inhibitor were randomly assigned to denosumab or placebo. In this post hoc analysis, we investigated the effects of concomitant statin therapy on recurrence risk (RR) of BC, fracture risk and bone mineral density (BMD).

Results

In the study population (n = 3420), statin therapy (n = 824) was associated with worse disease-free survival (DFS) [hazard ratio (HR) 1.35, 95% confidence interval (CI) 1.04-1.75; P = 0.023]. While no significant effect of lipophilic statins (n = 710) on RR was observed (HR 1.30, 95% CI 0.99-1.72; P = 0.062), patients on hydrophilic statins (n = 87) had worse DFS compared with patients not receiving any statins (HR 2.00, 95% CI 1.09-3.66; P = 0.026). This finding was mainly driven by the effect of hydrophilic statins on DFS in the denosumab arm (HR 2.63, 95% CI 1.21-5.68; P = 0.014). However, this effect subsided after correction for confounders in the sensitivity analysis. No association between statin use and fracture risk or osteoporosis was observed.

Conclusion

According to this analysis, hydrophilic statins showed a detrimental effect on DFS in the main model, which was attenuated after correction for confounders. Our data need to be interpreted with caution due to their retrospective nature and the low number of patients receiving hydrophilic statins.

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Statin co-medication was initially associated with a worse DFS in hormone receptor-positive early-stage BC patients.

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This effect was mainly driven by patients on hydrophilic statins.

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However, this effect subsided after correction for confounders in the sensitivity analysis.

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No association between statin use and fracture risk or osteoporosis was observed.