Systemic therapy for hormone receptor-positive/human epidermal growth factor receptor 2-negative early stage and metastatic breast cancer

Real-world perioperative treatment patterns and economic burden of recurrence in early-stage HER2-negative breast cancer: a SEER-Medicare study

AIM

This study aimed to describe treatment patterns and quantify the economic impact of recurrence in early-stage human epidermal growth factor receptor 2 (HER2)-negative breast cancer (BC).

MATERIALS & METHODS

Medicare beneficiaries with stages I-III HER2-negative BC and lumpectomy or partial/total mastectomy were identified from SEER-Medicare data (2010-2019). Perioperative therapies were reported in the neoadjuvant and adjuvant setting. Locoregional recurrence and distant metastasis were identified using a claims-based algorithm developed with clinical input and consisting of a diagnosis-based and treatment-based indicator. All-cause and BC-related healthcare resource utilization (HRU) per-patient-month and monthly healthcare costs were estimated from the recurrence date for patients with recurrence and from an imputed index date for patients without recurrence using frequency matching. HRU and costs were compared between groups stratified by hormone receptor-positive (HR+) or triple negative BC (TNBC) using multivariable regression models.

RESULTS

Of 28,655 patients, 8.5% experienced recurrence, 90.4% had HR+ disease, and 5.6% received neoadjuvant therapy. Relative to patients without recurrence, patients with recurrence had more advanced disease (stage II/III: 73.7% vs. 34.0%) and higher-grade tumors (Grade 3/4: 40.6% vs. 18.0%) at diagnosis. Recurrence in HR+/HER2-negative BC and TNBC was associated with higher rates of all-cause hospitalizations (incidence rate ratio [IRR]: 2.84 and 3.65), emergency department (ED) visits (IRR: 1.75 and 2.00), and outpatient visits (IRR: 1.46 and 1.55; all p < 0.001). Similarly, recurrence was associated with higher rates of BC-related HRU, particularly for ED visits in HR+/HER2-negative BC (IRR: 4.24; p < 0.001) and hospitalizations in TNBC (IRR: 11.71; p < 0.001). Patients with HR+/HER2-negative BC and TNBC recurrence incurred higher monthly all-cause (cost difference [CD]: $3988 and $4651) and BC-related healthcare costs (CD: $3743 and $5819).

CONCLUSIONS

Our findings highlight the considerable economic burden of recurrence in early-stage HER2-negative BC and underscore the unmet need for optimization of therapies that reduce recurrence in this population.

Potential of natural flavonoids to target breast cancer angiogenesis (review)

Angiogenesis is the process by which new blood vessels form and is required for tumour growth and metastasis. It helps in supplying oxygen and nutrients to tumour cells and plays a crucial role in the local progression and distant metastasis of, and development of treatment resistance in, breast cancer. Tumour angiogenesis is currently regarded as a critical therapeutic target; however, anti-angiogenic therapy for breast cancer fails to produce satisfactory results, owing to issues such as inconsistent efficacy and significant adverse reactions. As a result, new anti-angiogenic drugs are urgently needed. Flavonoids, a class of natural compounds found in many foods, are inexpensive, widely available, and exhibit a broad range of biological activities, low toxicity, and favourable safety profiles. Several studies find that various flavonoids inhibit angiogenesis in breast cancer, indicating great therapeutic potential. In this review, we summarize the role of angiogenesis in breast cancer and the potential of natural flavonoids as anti-angiogenic agents for breast cancer treatment. We discuss the value and significance of nanotechnology for improving flavonoid absorption and utilization and anti-angiogenic effects, as well as the challenges of using natural flavonoids as drugs. LINKED ARTICLES: This article is part of a themed issue Natural Products and Cancer: From Drug Discovery to Prevention and Therapy. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v182.10/issuetoc.

Development and clinical evaluation of [68Ga]Ga-NODAGA-ADAPT6 as a novel HER2-targeted PET radiotracer for breast cancer imaging and treatment monitoring

PURPOSE

Accurate assessment of human epidermal growth factor receptor type 2 (HER2) expression is crucial for diagnosis, treatment planning, and monitoring of breast cancer patients. A 68Ga-labeled tracer based on the albumin-binding domain-derived affinity protein 6 (ADAPT6) was developed to evaluate HER2 expression in breast cancer.

METHODS

The gene encoding ADAPT6 was modified with N-terminal (GHEHEHEDANS) and C-terminal (GSSC) extensions to enhance its functionality. The precursor was synthesized, purified, and characterized, followed by radiolabeling with 68Ga to produce [68Ga]Ga-NODAGA-ADAPT6. In vivo metabolism and biodistribution studies were performed in HCC1954 (HER2-positive) and MDA-MB-468 (HER2-negative) tumor-bearing mice. Additionally, with ethical approval and informed consent, 22 breast cancer patients underwent [68Ga]Ga-NODAGA-ADAPT6 PET imaging to assess HER2 expression in primary and metastatic lesions.

RESULTS

The tracer was prepared with a radiochemical purity exceeding 99% and demonstrated high stability in vivo. Micro-PET/CT imaging revealed significant accumulation of the radiotracer in HCC1954 tumors, which was markedly reduced after HER2 blockade with trastuzumab. In contrast, MDA-MB-468 tumors showed minimal uptake. In the clinical study, [68Ga]Ga-NODAGA-ADAPT6 PET images displayed varying levels of radiotracer uptake in primary and metastatic lesions, which correlated well with the HER2 expression status determined by pathological analysis.

CONCLUSION

[68Ga]Ga-NODAGA-ADAPT6 exhibited excellent pharmacokinetic properties and high specificity for HER2-expressing lesions in PET imaging. These findings highlight its potential as a promising tool for distinguishing different levels of HER2 expression in breast cancer, aiding in personalized treatment strategies.

Insights on the association of anthropometric and metabolic variables with tumor features and genomic risk in luminal early breast cancer: Results of a multicentric prospective study

BACKGROUND

Hormone receptor-positive (HR+)/HER2-negative (HER2-) early-stage breast cancers (EBC) are treated with adjuvant endocrine therapy (ET), with chemotherapy (CT) reserved for high-risk cases. Obesity is linked to increased recurrence risk. The Oncotype DX® assay predicts prognosis and CT benefit. The PRO BONO study evaluated Oncotype DX test's impact on treatment decisions and explored associations between genomic risk, tumor features, and patient metabolic profiles.

MATERIALS AND METHODS

Patients with HR+ /HER2-EBC undergoing Oncotype DX testing were enrolled. Body mass index (BMI), tumor characteristics (ER, PR, Ki67, grading, size, nodal status), a large panel of metabolic analytes, and Oncotype DX Recurrence Score® (RS) results were collected. Treatment recommendations (ET vs CT-ET) were recorded pre- and post-Oncotype DX, and concordance was determined using Cohen's Kappa. Associations were tested using Chi-Square test and Spearman Correlation.

RESULTS

Of the 248 EBC patients (2019-2021), Oncotype DX testing reduced CT use by 47.7 %. Higher RS positively correlated with serum triglycerides and inversely with GIP (all p < 0.05). No significant association was found between patient BMI and RS result. Conversely, tumor size positively correlated with BMI (p = 0.0286) and with serum levels of leptin (p = 0.0079), PAI-1 (p = 0.0083), C-peptide (p = 0.0124), GIP (p = 0.0036), GLP-1 (p = 0.0476), glucagon (p = 0.0224), and insulin (p = 0.0327). A BMI≥ 30 and higher GLP-1 levels (>148.85pg/ml) were independently associated with increased odds of having larger tumor size (>2 cm).

CONCLUSIONS

Recurrence Score result significantly impacts treatment decisions in HR+ /HER2-EBC. RS result was not associated with BMI, although unfavorable metabolic profiles and obesity-related markers correlated with larger tumors. These findings highlight the need to further investigate the link between metabolic profiles and breast cancer biology.

A Systematic Review of Mechanisms, Incidence, and Management of Trastuzumab Deruxtecan Induced ILD/Pneumonitis in Solid Tumors

Trastuzumab deruxtecan (T-DXd) has been approved to treat various tumors. While most adverse events (AEs) associated with T-DXd are manageable, interstitial lung disease (ILD)/pneumonitis is a notable AE of special concern. This review describes the incidence, severity, and management of T-DXd-induced ILD/pneumonitis across different tumors. We conducted a systematic search of PubMed, Embase, Cochrane Library, and Web of Science for literature published up to 13 September 2024, regarding the use of T-DXd in the treatment of HER2-positive tumors. Studies included were clinical trials involving HER2-positive tumors with reported ILD/pneumonitis cases.The main data extracted from the full-text articles included the incidence and severity of T-DXd-induced ILD. 18 studies involving 3380 patients with various advanced solid malignancies were included in our review. The overall incidence of adjudicated drug-related ILD/pneumonitis was 12.40%. Although most ILD/pneumonitis cases were low-grade, the risk of ILD/pneumonitis-related death should not be overlooked. Given the prolonged exposure to the drug, careful monitoring and management of T-DXd-induced ILD/pneumonitis are critical. Management strategies include dose reduction, treatment interruption, discontinuation, corticosteroids, and supportive care. Further research is needed to clarify the risk factors and mechanisms underlying T-DXd-induced ILD/pneumonitis. This review highlights critical gaps in understanding the risk factors and mechanisms of T-DXd-induced ILD, underscoring the need for further research.

Primary Stereotactic Body Radiation Therapy for Breast Cancer Spinal Metastases

BACKGROUND

To present insights gained from a decade of employing stereotactic body radiation therapy (SBRT) as a primary intervention for spinal bone metastasis (SBM) originating from breast cancer (BC).

METHODS

We retrospectively examined the application of primary SBRT (the CyberKnife System) for BC SBMs between March 2012 and January 2023.

RESULTS

We recruited 47 female patients with 82 SBMs affecting 104 vertebrae. The mean age was 53.2 ± 12.7 years. The overall local control (LC) rate of primary SBRT for BC SBMs was 84.1%. The median local progression (LP) occurred at 12 (3-66) months. The LP rates were 9.7%, 13.3%, and 18.3% at 1, 3, and 5 years following SBRT. We observed a lower LC rate in White patients than that in Asian patients. Factors associated with an increased risk of LP included SBMs from invasive lobular carcinoma, and patients with lower revised Tokuhashi scores. Additionally, the 1-, 3-, and 5-year LP rates of different SFED (≥20 Gy vs. <20 Gy) were 4.3% versus 19.1%, 7.2% versus 24.0%, and 11.5% versus 28.9%. The incidence of acute local adverse events (AEs) was 24.4% and was significantly associated with advanced age and prescribed target coverage of less than 95%.

CONCLUSIONS

We have demonstrated SBRT using the CyberKnife System as an effective primary intervention for BC SBMs. Our findings underscore the importance of treatment planning to optimize outcomes and minimize AEs in patients undergoing SBRT for SBMs.

Phase I clinical trial to assess safety and efficacy of Oraxol, a novel oral paclitaxel chemotherapy agent, in patients with previously treated metastatic breast cancer

Oraxol, a novel oral paclitaxel chemotherapy agent, has emerged as a potential alternative for treating metastatic breast cancer (MBC). However, its safety and efficacy remain uncertain due to insufficient evidence supporting it. This open-label, single-arm, phase I trial was designed to assess the pharmacokinetics, safety, and preliminary antitumor activity of Oraxol in previously treated MBC. The primary objective was to investigate the pharmacokinetics of Oraxol, while secondary endpoints included assessing safety, tolerability, and antitumor activity. Twenty-four patients (median age, 53 years) were enrolled, and pharmacokinetic analysis showed consistent and reproducible absorption of Oraxol. Note that 96% patients experienced treatment-related adverse events (TRAEs) and no deaths attributed to TRAEs. The overall response rate was 34.8%, including 34.8% achieving partial response and 56.5% having stable disease. The median follow-up was 45.7 months, with median progression-free survival (PFS) of 3.41 months and median overall survival of 17.80 months. Notably, among patients with triple-negative breast cancer, the disease control rate was 100%, and the median PFS was 8.90 months, which notably exceeded the outcomes observed in other subtypes. Oraxol significantly alters metabolism and correlates with response and survival. In conclusion, Oraxol exhibited promising antitumor efficacy and manageable safety profiles in MBC patients.

Outperforming Traditional Staging: A Novel Nomogram for HR-Positive Breast Cancer

Background

Hormone receptor-positive breast cancer (HR-positive BC), the most prevalent subtype, typically has a favorable prognosis. However, treatment decision-making and survival prediction remain challenging due to the limitations of traditional staging systems like AJCC. Improved prognostic tools are needed to enhance individualized risk stratification.

Materials and Methods

Clinical information from the Surveillance, Epidemiology, and End Results (SEER) database and the First Affiliated Hospital of Nanchang University were analyzed to evaluate outcomes across HR-positive BC subtypes. Patients were divided into training and validation cohorts. A prognostic nomogram was developed using factors identified by univariate and multivariate Cox regression analyses and evaluated through C-index, Receiver Operating Characteristic (ROC) curves, calibration curves, and decision curve analysis (DCA).

Results

The study included 156,378 patients (training) and 67,016 (validation) for breast cancer-specific survival (BCSS) and 165,047 (training) and 70,732 (validation) for overall survival (OS), along with 232 external validation cases. Multivariate Cox regression analysis revealed that the ER-positive/PR-negative (HR=2.317 (2.219-2.419)) and ER-negative/PR-positive (HR=3.498 (3.143-3.894)) subtypes had worse prognosis than ER-positive/PR-positive patients. The prognosis of ER-negative/PR-positive subtype (HR=1.511 (1.686-1.351)) was also worse than that of ER-positive/PR-negative subtype. A nomogram integrating age, race, tumor size, grade, histology, bone, brain, lung, and liver metastases, tumor stage, HER2, marital status, positive lymph node numbers, and radiation therapy. The nomogram had a good C-index values and area under curve values for predicting OS and BCSS in both the training and validation set. Moreover, the DCA revealed that the nomogram performed better than the AJCC (TNM) staging system in predicting the three- and five-year OS and BCSS in both the groups.

Conclusion

This study introduces and validates a novel prognostic nomogram for HR-positive BC, providing enhanced risk stratification, particularly in regions with limited access to comprehensive genetic testing. Further validation through multicenter clinical studies is recommended to confirm its clinical utility.

Breast cancer: pathogenesis and treatments

Breast cancer, characterized by unique epidemiological patterns and significant heterogeneity, remains one of the leading causes of malignancy-related deaths in women. The increasingly nuanced molecular subtypes of breast cancer have enhanced the comprehension and precision treatment of this disease. The mechanisms of tumorigenesis and progression of breast cancer have been central to scientific research, with investigations spanning various perspectives such as tumor stemness, intra-tumoral microbiota, and circadian rhythms. Technological advancements, particularly those integrated with artificial intelligence, have significantly improved the accuracy of breast cancer detection and diagnosis. The emergence of novel therapeutic concepts and drugs represents a paradigm shift towards personalized medicine. Evidence suggests that optimal diagnosis and treatment models tailored to individual patient risk and expected subtypes are crucial, supporting the era of precision oncology for breast cancer. Despite the rapid advancements in oncology and the increasing emphasis on the clinical precision treatment of breast cancer, a comprehensive update and summary of the panoramic knowledge related to this disease are needed. In this review, we provide a thorough overview of the global status of breast cancer, including its epidemiology, risk factors, pathophysiology, and molecular subtyping. Additionally, we elaborate on the latest research into mechanisms contributing to breast cancer progression, emerging treatment strategies, and long-term patient management. This review offers valuable insights into the latest advancements in Breast Cancer Research, thereby facilitating future progress in both basic research and clinical application.

Multimodal integration using a machine learning approach facilitates risk stratification in HR+/HER2- breast cancer

Hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) breast cancer is the most common type of breast cancer, with continuous recurrence remaining an important clinical issue. Current relapse predictive models in HR+/HER2- breast cancer patients still have limitations. The integration of multidimensional data represents a promising alternative for predicting relapse. In this study, we leverage our multi-omics cohort comprising 579 HR+/HER2- breast cancer patients (200 patients with complete data across 7 modalities) and develop a machine-learning-based model, namely CIMPTGV, which integrates clinical information, immunohistochemistry, metabolomics, pathomics, transcriptomics, genomics, and copy number variations to predict recurrence risk of HR+/HER2- breast cancer. This model achieves concordance indices (C-indices) of 0.871 and 0.869 in the train and test sets, respectively. The risk population predicted by the CIMPTGV model encompasses those identified by single-modality models. Feature analysis reveals that synergistic and complementary effects exist in different modalities. Simultaneously, we develop a simplified model with a mean area under the curve (AUC) of 0.840, presenting a useful approach for clinical applications.

Clinical efficacy and therapy response prediction of neoadjuvant dalpiciclib plus letrozole in postmenopausal patients with HR+/HER2- stage II-III breast cancer (DARLING 01): a single-arm, open-label, exploratory study

BACKGROUND

Hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) breast cancer is the most common subtype of breast cancer, yet its response to traditional chemotherapy remains limited, posing a challenge in achieving optimal therapeutic outcomes. In this study, we aimed to evaluate the clinical efficacy and safety of dalpiciclib, a novel CDK4/6 inhibitor, combined with letrozole as neoadjuvant therapy (NAT) in postmenopausal patients with HR+/HER2- stage II-III breast cancer. Additionally, we explored potential predictive biomarkers for treatment response using gene analysis.

METHODS

This single-arm, open-label, exploratory phase II trial involved 35 postmenopausal women with HR+/HER2- breast cancer (ClinicalTrials.gov identifier NCT05512780). Patients received four cycles of dalpiciclib (125 mg/day for 3 weeks, followed by 1 week off) plus continuous letrozole (2.5 mg/day). The primary endpoint was objective response rate (ORR), and secondary endpoints included changes in Ki-67 expression, complete cell cycle arrest (CCCA) rate, residual cancer burden (RCB), and safety profiles. Gene expression profiling and least absolute shrinkage and selection operator (LASSO) regression were conducted to identify biomarkers predictive of response to NAT.

RESULTS

Among the 35 enrolled patients, 31 completed the full treatment course. Of the 29 patients with evaluable response data after 4 cycles, 16 achieved partial response (PR), resulting in an ORR of 55.2%. Following two weeks of treatment, the mean Ki-67 expression significantly decreased from a baseline of 17.5-1.8%, and CCCA was observed in 75% of patients. Grade ≥ 3 treatment-emergent adverse events (TEAEs) were mainly decreased neutrophil count (45.7%), with a median duration of 3 days. The NAT predictive model, developed using gene expression analysis and clinicopathological factors, achieved an area under the curve (AUC) of 0.928, indicating that TFRC, SCUBE2, and MMP11A could serve as novel predictive biomarkers for response to NAT.

CONCLUSIONS

Dalpiciclib combined with letrozole demonstrated promising antitumor activity and an acceptable safety profile in postmenopausal patients with HR+/HER2- breast cancer. The identification of TFRC, SCUBE2, and MMP11A as predictive biomarkers provides insights into the potential for personalized neoadjuvant treatment strategies.

Correlation Between Disease-Free Survival Endpoints and Overall Survival in Elderly Patients with Early-Stage HER2-Negative Breast Cancer: A SEER-Medicare Analysis

INTRODUCTION

Recent trial-level meta-analyses have established disease-free survival (DFS) as a valid surrogate for overall survival (OS) in human epidermal growth factor receptor 2-negative (HER2-) breast cancer (BC), irrespective of disease stage, and in early-stage hormone receptor-positive (HR+)/HER2- BC. To advance the understanding of the association between additional DFS endpoints and OS, this study assessed the patient-level correlations between DFS and OS, invasive DFS (IDFS) and OS, and distant DFS (DDFS) and OS in Medicare beneficiaries with early-stage HER2- BC, overall and in subgroups of patients with HR+/HER2- BC and triple-negative BC (TNBC).

METHODS

Patients with stages I-III HER2- BC aged ≥ 66 years were identified from SEER-Medicare data (2010-2019). DFS, IDFS, DDFS, and OS were assessed using Kaplan-Meier analyses. Normal scores rank correlation was estimated between each DFS endpoint and OS, overall and separately in patients with HR+/HER2- BC and TNBC.

RESULTS

Of 28,655 patients, 90.4% had HR+/HER2- BC and 9.6% had TNBC (median follow-up 4 years). Median DFS, IDFS, and DDFS were 4.5, 5.9, and 6.3 years, respectively, in HR+/HER2- BC and 3.0, 3.8, and 4.4 years, respectively, in TNBC. Median OS was not reached (5-year OS, HR+/HER2- BC 83.7%; TNBC 67.7%). A significant positive correlation was observed between each DFS endpoint and OS across cohorts, with the strongest correlation observed between DDFS and OS in HR+/HER2- BC (correlation coefficient 0.60; 95% confidence interval 0.57-0.62; p < 0.001) and in TNBC (0.69; 0.65-0.71; p < 0.001).

CONCLUSION

We observed significant positive patient-level correlations between DFS and OS, IDFS and OS, and DDFS and OS in early-stage HER2- BC. Our IDFS and DDFS findings advance the understanding of the role of these DFS endpoints as predictors of OS, and their potential utility as surrogate endpoints in clinical trials of early-stage HER2- BC, given additional validation in trial-level meta-analyses.

Hematological toxicity of cyclin-dependent kinase 4/6 inhibitors in patients with breast cancer: a network meta-analysis and pharmacovigilance study

OBJECTIVES

We aimed to evaluate and compare the risk of hematological adverse events (AEs) associated with CDK4/6 inhibitors using data from randomized controlled trials (RCTs) and Food and Drug Adverse Event Reporting System (FAERS) database.

METHODS

The PubMed, Embase, and Cochrane Library databases were searched for RCTs related to abemaciclib, palbociclib, and ribociclib. A network meta-analysis (NMA) was conducted to compare the risks of hematological AEs, and a disproportionality analysis was performed to detect signals of hematological AEs.

RESULTS

16 RCTs comprising 16,350 breast cancer patients were included. Palbociclib and ribociclib had similar risks for hematological AEs, except a higher risk of grade 3-4 leukopenia observed with palbociclib (risk ratio [RR]: 7.84, 95% confidence interval [95%CI]: 1.33-41.28). Abemaciclib had a higher risk of anemia than both ribociclib (grade 1-4: RR: 2.23, 95% CI: 1.25 - 3.96; grade 3-4: RR: 3.52, 95% CI: 1.59 - 8.11) and palbociclib (grade 1-4: RR: 1.65, 95%CI: 1.03 - 2.59), but a lower risk of grade 3-4 of both leukopenia (RR: 0.12, 95%CI: 0.02 - 0.49) and neutropenia (RR: 0.15, 95%CI: 0.04 - 0.52) compared with palbociclib. Signals indicating occurrence of leukopenia, neutropenia, anemia, and thrombocytopenia were identified for three CDK4/6 inhibitors.

CONCLUSION

Abemaciclib, palbociclib, and ribociclib showed significant but inconsistent hematological toxicity risks.

Current and Novel Treatment Options in Hormone Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Metastatic Breast Cancer

Metastatic breast cancer (mBC) remains an incurable disease, and most patients will experience disease progression during their treatment course. Although endocrine therapy remains the mainstay of treatment for hormone receptor-positive/human epidermal growth factor receptor 2-negative mBC, significant progress has been and continues to be made in the treatment of this BC subtype. The discovery of molecular markers, mutations in key cellular pathways, and genomic signatures have led to the development of novel and targeted agents, such as antibody-drug conjugates, oral selective estrogen receptor downregulators, and inhibitors of the PI3K/AKT/mTOR pathway. This has resulted in significant improvements in the survival and quality of life of patients. With the increasing number of treatment options for patients, appropriate drug sequencing remains a challenge. Treatment discussions should involve patient-physician shared decision making, with consideration of genomic data, previous lines of therapy, side effect profiles, and clinical trial enrollment.

Coagulation-Targeted TGF-β Signaling Pathway Inhibitor Nanomedicine for Inhibiting the Growth and Lung Metastasis of Breast Cancer

The transforming growth factor β (TGF-β) signaling pathway exerts a dual role in oncogenesis, acting as a suppressor in healthy and early stage neoplastic tissues while promoting malignancy and metastasis in advanced cancers. Tumor hemorrhage further exacerbates TGF-β-mediated metastasis by up-regulating its expression. Here, a coagulation-targeting peptide (A15)-decorated TGF-β inhibitor nanomedicine (A15-LY-NPs) was developed. The tumor colonization assays showed that the nanomedicine reduced 4T1-luc cell colonization in normal tissues. When combined with a vascular disrupting agent, A15-LY-NPs demonstrated three times greater drug accumulation in the tumor at 24 h compared to the control and showed a 93.7% tumor suppression rate in 4T1 tumors initiated at ∼500 mm3, significantly attenuating metastatic spread to the lungs and liver. This study presents an innovative approach for the precise and efficient delivery of TGF-β inhibitors to tumors, offering the potential to augment the efficacy of cancer therapeutics.

Machine learning Nomogram for Predicting endometrial lesions after tamoxifen therapy in breast Cancer patients

Objective Endometrial lesions are a frequent complication following breast cancer, and current diagnostic tools have limitations. This study aims to develop a machine learning-based nomogram model for predicting the early detection of endometrial lesions in patients. The model is designed to assess risk and facilitate individualized treatment strategies for premenopausal breast cancer patients. Method A retrospective study was conducted on 224 patients who underwent diagnostic curettage post-tamoxifen (TAM) therapy between November 2012 and November 2023. These patients exhibited signs of endometrial abnormalities or symptoms such as colporrhagia. Clinical data were collected and analyzed using R software (version 4.3.2) to identify factors influencing the occurrence of endometrial lesions and evaluate their predictive values. Three machine learning methods were employed to develop a risk prediction model, and their performances were compared. The best-performing model was selected to construct a nomogram of endometrial lesions. Internal validation was conducted using the bootstrap method, and the model's accuracy and fit were assessed using the concordance index (C-index) and calibration curves. Results Independent risk factors for endometrial lesions included ultrasound characteristics, duration of TAM therapy, presence of colporrhagia, and endometrial thickness (P < 0.05). Among the machine learning methods compared, the LASSO regression integrated with a multifactorial logistic regression model demonstrated strong performance, with a concordance index (C-index) of 0.874 and effective calibration (mean absolute error of conformity: 0.014). This model achieved an accuracy of 0.853 and a precision of 0.917, with a training set AUC of 0.874 (95% CI: 0.794-0.831) and a test set AUC of 0.891 (95% CI: 0.777-1.000), closely aligning the predicted risk with the actual observed risk. Conclusion The developed prediction model is effective in evaluating endometrial lesions in premenopausal breast cancer patients. This model offers a theoretical foundation for improving clinical predictions and devising tailored treatment strategies for this patient group.

Safety and pharmacokinetics of vepdegestrant in Japanese patients with ER+ advanced breast cancer: a phase 1 study

BACKGROUND

Vepdegestrant (ARV-471) is an oral PROteolysis TArgeting Chimera (PROTAC) estrogen receptor (ER) degrader.

METHODS

This phase 1 study (NCT05463952) investigated safety, pharmacokinetics, and antitumor activity of vepdegestrant in Japanese patients with ER-positive (ER+)/human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer at the 200-mg once daily (QD) recommended phase 3 dose. Eligible patients had ER+/HER2- advanced breast cancer resistant to standard therapy, with no standard therapy available, or had received two or more prior endocrine therapies in any setting. The primary endpoint was dose-limiting toxicities (DLTs) in cycle 1; secondary endpoints included safety, pharmacokinetics, and antitumor activity.

RESULTS

Six female patients (median age, 58 [range: 47-62] years) were treated. For advanced disease, three (50.0%) patients received three or more prior regimens and five (83.3%) patients received prior cyclin-dependent kinase 4/6 inhibitors. At data cutoff, median treatment duration was 9.8 (range: 6-28) weeks; two patients remained on treatment. No DLTs were observed. Four (66.7%) patients experienced adverse events; none led to dose reduction or discontinuation. Four (66.7%) patients had treatment-related adverse events; all were grade 1 except anemia (grade 2). Geometric mean maximum plasma concentration and 24-h area under the plasma concentration-time curve of vepdegestrant were 630.9 ng/mL and 10,400 ng∙hr/mL after a single dose and 1056 ng/mL and 18,310 ng∙hr/mL after multiple doses. Two (33.3%) patients demonstrated stable disease at week 24.

CONCLUSION

Vepdegestrant 200 mg QD was well tolerated in Japanese patients with ER+/HER2- advanced breast cancer with no notable differences in pharmacokinetics from Western patients.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov: NCT05463952 (date of registration: July 19, 2022).

Fasting-mimicking diet potentiates anti-tumor effects of CDK4/6 inhibitors against breast cancer by suppressing NRAS- and IGF1-mediated mTORC1 signaling

AIMS

Acquired resistance to cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) frequently emerges, and CDK4/6i-containing therapies in triple-negative breast cancer (TNBC) remain to be determined.

METHODS

RNA-sequencing, cell viability analysis, immunoblotting, siRNA transfection et al. were used to investigate and verify the resistance mechanism. BALB/c nude mice xenograft models and spontaneous MMTV-PyMT models were used to explore in vivo efficacy.

RESULTS

The mTOR pathway was activated in acquired CDK4/6i-resistant cells and inhibition of mTORC1 restored the sensitivity. While fasting-mimicking diet (FMD) enhances the activity of anticancer agents by inhibiting the mTORC1 signaling, we assessed FMD and found that FMD restored the sensitivity of CDK4/6i-resistant cells to abemaciclib and potentiated the anti-tumor activity of CDK4/6i in TNBC. The anti-tumor effects of FMD and/or CDK4/6i were accompanied by the downregulation of S6 phosphorylation. FMD cooperated with CDK4/6i to suppress the levels of IGF1 and RAS. The combination of FMD and abemaciclib also led to a potent inhibition of tumor growth in spontaneous transgenic MMTV-PyMT mouse models.

CONCLUSIONS

Our data demonstrate that FMD overcomes resistance and potentiates the anti-tumor effect of CDK4/6i by inhibiting mTORC1 signaling via lowering the levels of IGF1 and RAS, providing the rationale for clinical investigation of a potential FMD-CDK4/6i strategy in breast cancer.

Navigating precision: the crucial role of next-generation sequencing recurrence risk assessment in tailoring adjuvant therapy for hormone receptor-positive, human epidermal growth factor Receptor2-negative early breast cancer

Hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) breast cancer is the most common subtype, representing over two-thirds of new diagnoses. Adjuvant therapy, which encompasses various medications and treatment durations, is the standard approach for managing early stage HR+ HER2- breast cancer. Optimizing treatment is essential to minimize unnecessary side effects while addressing the biological variability inherent in HR+/HER2- breast cancers. Incorporating biological biomarkers into treatment decisions, alongside traditional clinical factors, is vital. Gene expression assays can identify patients unlikely to benefit from adjuvant chemotherapy, thereby refining treatment strategies and improving risk assessment. This paper reviews evidence for several genomic tests, including Oncotype DX, MammaPrint, Breast Cancer Index, RucurIndex, and EndoPredict, which assist in tailoring adjuvant therapy. Additionally, we explore the role of liquid biopsies in personalizing treatment, emphasizing the importance of considering late relapse risks and potential benefits of extended systemic therapy for HR+/HER2- breast cancer patients.

Advancements in research and clinical management of interstitial lung injury associated with ADC drugs administration in breast cancer

Antibody-drug conjugates (ADCs) represent a novel class of targeted anti-tumor medications that utilize the covalent linkage between monoclonal antibodies and cytotoxic agents. This unique mechanism combines the cytotoxic potency of drugs with the targeting specificity conferred by antigen recognition. However, it is essential to recognize that many ADCs still face challenges related to off-target toxicity akin to cytotoxic payloads, as well as targeted toxicity and other potential life-threatening adverse effects, such as treatment-induced interstitial lung injury. Currently, of the four approved ADC drugs for breast cancer, several reports have documented post-treatment lung injury-related fatalities. As a result, treatment-induced interstitial lung injury due to ADC drugs has become a clinical concern. In this review article, we delve into the factors associated with ADC-induced interstitial lung injury in patients with advanced-stage breast cancer and highlight strategies expected to decrease the incidence of ADC-related interstitial lung injury in the years ahead. These efforts are directed at enhancing treatment outcomes in both advanced and early-stage cancer patients while also providing insights into the development and innovation of ADC drugs and bolstering clinicians' understanding of the diagnosis and management of ADC-associated interstitial lung injury.

New Emerging Therapies Targeting PI3K/AKT/mTOR/PTEN Pathway in Hormonal Receptor-Positive and HER2-Negative Breast Cancer-Current State and Molecular Pathology Perspective

In hormone receptor-positive and HER2-negative breast cancers, a growing number of revolutionary personalized therapies are in clinical use or trials, such as CDK4/6 inhibitors, immune checkpoint inhibitors, and PIK3CA inhibitors. Those treatment options are largely driven by the presence or absence of genomic alterations in the tumor. Therefore, molecular profiling is often performed during disease progression. The most encountered genomic alterations are in the PI3K/AKT/mTOR/PTEN pathway. This review discusses the genetic alterations associated with the PI3K/AKT/mTOR/PTEN pathway to help clinicians understand drug selection, resistance, or interaction from a molecular pathologist's perspective.

Discovery of Thiochroman Derivatives as Potent, Oral Selective Estrogen Receptor Degraders and Antagonists for the Treatment of Endocrine-Resistant Breast Cancer

Selective estrogen receptor degraders (SERDs) deplete the ER signaling pathway via antagonism and degradation of ERα and represent a promising strategy to tackle endocrine resistance. Here, we report a new class of SERDs by pharmacological evolution of a selective estrogen receptor modulator, lasofoxifene. The structure-activity relationship study and efforts to circumvent the issue of human ether-a-go-go-related gene led to the identification of compounds 51. This bifunctional compound displayed broad activity across a vast array of cell backgrounds and was capable of effectively degrading and antagonizing wild-type ERα and clinically relevant ERα mutants. 51 exhibited favorable pharmacokinetic properties and good brain penetration, with a brain/plasma ratio of 3.05, and significantly suppressed the growth of tumor in a tamoxifen-resistant MCF-7 Tam1 xenograft model. Overall, the study demonstrates 51 as a highly potent, oral, and brain penetrant ER degrader and pure antagonist, showing a good potential in overcoming endocrine resistance.

First-Line (1L) Treatment Decision Patterns and Survival of Hormone Receptor (HR)-Positive/HER2-Negative Advanced Breast Cancer (ABC) Patients in a Latin American (LATAM) Public Institution

Advanced breast cancer is an incurable disease, with a median overall survival of 3 years, including in countries without access problems. Although chemotherapy is reserved in some cases, it is still used in many countries as a first-line therapy. The aim of our study is to evaluate the first-line treatment choices and the factors that influence therapeutic decisions. A retrospective analysis was conducted of hormone receptor (+)/HER2 (-) advanced breast cancer patients classified into three groups according to the first-line and second-line treatment received: endocrine therapy-chemotherapy, endocrine therapy-endocrine therapy and chemotherapy-endocrine therapy. Additionally, we explored the overall survival of sequencing therapy groups. First-line chemotherapy was chosen in 34% of patients. Also, around 60% of our patients met the "aggressive disease" criteria from the RIGHT Choice trial, justifying the use of chemotherapy in a population with poor prognosis. Furthermore, de novo and progressive disease were prognostic factors that influenced the use of chemotherapy as a first-line treatment. Regarding overall survival, the sequencing treatment groups in this trial saw an increase in survival compared with patients of the MONALEESA trials (endocrine therapy alone arms). No significant differences in progression-free survival or overall survival were found in the treatment sequencing groups. There was a higher use of chemotherapy as a first-line therapy, with de novo and "aggressive disease" criteria being the main factors to influence the decision.

The Analysis of Plasma Proteomics for Luminal A Breast Cancer

BACKGROUND

Breast cancer is the prevailing malignancy among women, exhibiting a discernible escalation in incidence within our nation; hormone receptor-positive (HR+) human epidermal growth factor receptor 2-negative (HER2-) breast cancer is the most common subtype. In this study, we aimed to search for a non-invasive, specific, blood-based biomarker for the early detection of luminal A breast cancer through proteomic studies.

METHODS

To explore new potential plasma biomarkers, we applied data-independent acquisition (DIA), a technique combining liquid chromatography and tandem mass spectrometry, to quantify breast cancer-associated plasma protein abundance from a small number of plasma samples in 10 patients with luminal A breast cancer, 10 patients with benign breast tumors, and 10 healthy controls.

RESULTS

The proteomes of 30 participants in all cohorts were analyzed using the DIA method, and a total of 517 proteins and 3584 peptides were quantified. We found that there were significant differences in plasma protein expression profiles between breast cancer patients and non-breast cancer patients, and breast cancer was mainly related to lipid metabolism pathways. Finally, the optimal protein combinations for the diagnosis of breast cancer were PON3, IGLV3-10, and IGHV3-73 through multi-model analysis, which had a high prediction accuracy for breast cancer (AUC = 0.92), and the model could also distinguish breast cancer from HC (AUC = 0.92) and breast cancer from benign breast tumor (AUC = 0.91).

CONCLUSIONS

The study revealed proteomic signatures of patients with luminal A breast cancer, identified multiple differential proteins, and identified three plasma proteins as potential diagnostic biomarkers for breast cancer. It provides a reference for the screening of biomarkers for breast cancer.

Dose reduction and discontinuation due to the combination of CDK4/6 inhibitors and endocrine drugs: a systematic review and meta-analysis

BACKGROUND

With the widespread use of CDK4/6 inhibitors, the number of discontinuations and reductions due to adverse events is increasing. Therefore, we examined the risk of dose reduction, discontinuation, and occurrence of serious adverse events and death due to adverse events when CDK4/6 inhibitors are combined with endocrine drugs.

METHODS

We searched English-language articles published up to February 10, 2024, using RR values (risk ratio) to indicate the risk of discontinuation, dose reduction, death, and the risk of serious adverse events.

RESULTS

When CDK4/6 inhibitors were used in combination with endocrine drugs, abemaciclib resulted in the highest risk of discontinuation, dose reduction, and serious adverse events. Ribociclib caused the highest risk of death.

CONCLUSION

When using CDK4/6 inhibitors in the clinical setting, a comprehensive evaluation should be performed to avoid dosage reductions and discontinuations and to choose the most appropriate treatment regimen.

Post-operative serum CEA predicts prognosis in HR-positive/HER2-negative early breast cancer

BACKGROUND

The prognostic role of preoperative carcinoembryonic antigen (CEA) in breast cancer is recognized, but the impact of postoperative CEA levels on survival in early breast cancer is uncertain.

RESEARCH DESIGN AND METHODS

We conducted a retrospective study of 921 non-metastatic breast cancer patients treated at anonymized. Patients were categorized as normal (CEA ≤3 µg/L) or elevated (CEA >3 µg/L).

RESULTS

Elevated postoperative CEA levels were associated with shorter disease-free survival (DFS) (median, 174.6 vs. 239.8 months; hazard ratio (HR): 1.80; 95% confidence interval (CI): 1.27-2.56; p < 0.001) and overall survival (OS) (median, 174.6 vs. 261.1 months; HR:2.34; 95% CI: 1.59-3.45; p < 0.001). Elevated CEA was associated with shorter DFS (median, 174.6 months vs. not reached (NR); HR:2.30; 95% CI: 1.03-5.19; p = 0.043) and OS (NR vs. NR; HR: 2.81; 95% CI: 1.06-7.48; p = 0.039) in stage 1, shorter DFS (median, 239. 8 vs. 141.1 months; HR: 1.95; 95% CI: 1.28-2.98; p = 0.002) and OS (median, 169 vs. 261.1 months; HR: 2.56; 95% CI: 1.6-4.12; p < 0.001) in stage 2 and shorter OS (median, 65 vs. 183.1 months; HR: 3.25; 95% CI: 1.19-8.83; p = 0.021) in stage 3.

CONCLUSIONS

Elevated postoperative CEA indicates worse DFS and OS in patients with HR-positive/HER2-negative early breast cancer.

Preclinical study and phase 2 trial of neoadjuvant pyrotinib combined with chemotherapy in luminal/HER2-low breast cancer: PILHLE-001 study

The prognosis of patients with luminal/human epidermal growth factor receptor 2 (HER2)-low early breast cancer (EBC) needs to be improved. This preclinical study and phase 2 trial (ChiCTR2100047233) aims to explore the efficacy and safety of pyrotinib (a pan-HER tyrosine kinase inhibitor) plus chemotherapy in this population. Our preclinical experiments indicate a synergistic anti-tumor effect of pyrotinib plus chemotherapy in luminal/HER2-low (immunochemistry [IHC] 2+/fluorescent in situ hybridization [FISH]-negative) breast cancer models. Furthermore, 48 women with luminal/HER2-low (IHC 2+/FISH-negative) high-risk EBC are enrolled to receive neoadjuvant pyrotinib plus chemotherapy (epirubicin-cyclophosphamide followed by docetaxel). Ultimately, 26 (54.2%; 95% confidence interval [CI] 39.2%-68.6%) patients achieve the primary endpoint (residual cancer burden [RCB] 0/I). Treatment-related adverse events of grade ≥3 occur in 21 (43.8%) patients, with the most prevalent being diarrhea (10 [20.8%]). In conclusion, neoadjuvant pyrotinib plus chemotherapy has encouraging efficacy and manageable toxicity in women with luminal/HER2-low (IHC 2+/FISH-negative) high-risk EBC. This regimen warrants to be further validated.

MAP3K1 mutations confer tumor immune heterogeneity in hormone receptor-positive HER2-negative breast cancer

Treatment for hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) breast cancer, the most common type of breast cancer, has faced challenges such as endocrine therapy resistance and distant relapse. Immunotherapy has shown progress in treating triple-negative breast cancer, but immunological research on HR+/HER2- breast cancer is still in its early stages. Here, we performed a multi-omics analysis of a large cohort of patients with HR+/HER2- breast cancer (n = 351) and revealed that HR+/HER2- breast cancer possessed a highly heterogeneous tumor immune microenvironment. Notably, the immunological heterogeneity of HR+/HER2- breast cancer was related to mitogen-activated protein kinase kinase kinase 1 (MAP3K1) mutation and we validated experimentally that a MAP3K1 mutation could attenuate CD8+ T cell-mediated antitumor immunity. Mechanistically, MAP3K1 mutation suppressed MHC-I-mediated tumor antigen presentation through promoting the degradation of antigen peptide transporter 1/2 (TAP1/2) mRNA, thereby driving tumor immune escape. In preclinical models, the postbiotic tyramine could reverse the MAP3K1 mutation-induced MHC-I reduction, thereby augmenting the efficacy of immunotherapy. Collectively, our study identified the vital biomarker driving the immunological heterogeneity of HR+/HER2- breast cancer and elucidated the underlying molecular mechanisms, which provided the promise of tyramine as what we believe to be a novel therapeutic strategy to enhance the efficacy of immunotherapy.

Efficacy and safety of RC48-ADC in HER2-positive and HER2-low metastatic breast cancer: a multicenter, real-world study

Background

A standard treatment recommendation for third-line and subsequent treatments for advanced HER2-positive breast cancer is still missing, especially for low HER2 expression. Nevertheless, there is evidence that these patients might benefits from antibody-drug conjugates (ADCs) treatment. Therefore, this study aimed to evaluate the clinical efficacy, safety, and factors affecting efficacy of Disitamab Vedotin (RC48) for treating HER2-positive and HER2-low metastatic breast cancer (MBC) in the real-world setting.

Methods

A retrospective study at five clinical sites was conducted in China, enrolling MBC patients treated with RC48 from July 01, 2021 and May 31, 2023. Patient demographics, treatment patterns, and adverse events (AEs) were recorded and analyzed.

Results

A total of 154 patients were included: 104 (67.53%) patients with HER2-positive and 50 (32.47%) patients with HER2-low MBC. The median progression-free survival (mPFS) was 5.06 months. The objective response rate (ORR) and disease control rate (DCR) were 36.36% and 68.83%, respectively. HER2-positive patients exhibited a mPFS of 5.93 and an ORR of 41.35%. In contrast, patients with low-HER2 had a mPFS of 4.28 months and an ORR of 26.00%. The most common AEs included neutropenia (54.55%), increased AST (53.25%), leukopenia (51.95%), and fatigue (43.51%), mostly graded mild to moderate (grade 1-2).

Conclusions

This extensive study in China demonstrated that RC48 has excellent therapeutic potential for both HER2-positive and HER2-low MBC with a favorable safety profile. The study also suggests that combination therapy significantly boosts efficacy beyond monotherapy, indicating a promising avenue for future ADC development.

Abemaciclib increases the risk of venous thromboembolism in breast cancer: Integrate meta-analysis, pharmacovigilance database analysis, and in vitro validation

BACKGROUND

Recently, cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) have emerged as a novel treatment strategy for breast cancer. However, increasing reports of CDK4/6i-associated venous thromboembolism (VTE) have garnered attention. This study assessed CDK4/6i-associated VTE in breast cancer, and examined the effect of CDK4/6i on platelet/coagulation function for the first time in vitro.

METHODS

PubMed and Embase databases were searched for studies published from the establishment of the database to December 31, 2022 for randomized controlled trials (RCTs) and real-world studies of CDK4/6i in patients with breast cancer, and the data obtained from the included studies were used for meta-analysis. A disproportionality analysis by extracting adverse drug reaction signals of CDK4/6i-associated VTE from the FDA Adverse Event Reporting System (FAERS) database was also conducted. Additionally, the in vitro effect of CDK4/6i on platelet function was assessed based on platelet aggregation tests and flow cytometry, and coagulation function was assessed based on the blood clotting function test.

FINDINGS

A total of 16,903 patients in 13 RCTs and 6,490 patients in 9 real-world studies were included in the meta-analysis. In RCTs, VTE occurred in 193 (2.1 %) and 55 (0.7 %) patients in the CDK4/6i and control groups, respectively. In real-world studies, the aggregate incidence rate of VTE was 4.2 % (95 % CI: 2.1, 6.3). The meta-analysis of RCTs revealed that abemaciclib (Odds ratio [OR]: 4.40 [95 % CI: 2.74,7.05], p < 0.001) and palbociclib (OR: 2.35 [95 % CI: 1.34, 4.12], p < 0.01) significantly increased the risk of VTE in patients with breast cancer compared to placebo. FAERS database analysis revealed that abemaciclib (reporting odds ratio [ROR]: 1.63 [95 % CI: 1.36, 1.97]; IC025: 0.67) and ribociclib (ROR: 1.17 [95 % CI: 1.0, 1.39]; IC025: 0.18) demonstrated a significantly increased signal of VTE. Similarly, findings from in vitro experiments demonstrated that abemaciclib enhanced agonist-induced platelet activation, especially when collagen was used as the inducer, and this effect became more prominent with increasing its concentration.

INTERPRETATION

Use of abemaciclib may increase the risk of VTE in patients with breast cancer, which may be partially attributed to the effect of abemaciclib on platelet function. Close monitoring of VTE occurrence is highly recommended while using abemaciclib, especially in patients at a high risk of VTE.

Continuation of CDK4/6 Inhibition and Switching of Hormonal Therapy After Progression on Prior CDK4/6 Inhibitors in HR+/HER2- Breast Cancer: A Systematic Review and Meta-Analysis

This study aims to determine the efficacy of maintaining cyclin-dependent kinase 4/6 (CDK4/6) inhibition and switching endocrine therapy (ET) versus ET alone after progression on prior CDK4/6 inhibitors (CDK4/6i) in patients with hormone-receptor-positive, human epidermal growth factor receptor-2-negative breast cancer. We identified phase II and III comparative randomized clinical trials through a systematic search across relevant clinical databases. A random effects model was used to determine the pooled hazard ratio (HR) for progression-free survival (PFS) according to the inverse-variance method. Heterogeneity was measured using tau2 and I2 statistics. The pooled odds ratio for the overall response rate was calculated through the Mantel-Haenszel method in a random effects model. A narrative review was done to describe treatment-related side effects. After the systematic search, we identified four trials (n=833) that accomplished the inclusion criteria. Switching ET and maintaining CDK4/6 inhibition was associated with longer PFS than switching the hormonal therapy alone (HR: 0.77; 95% CI: 0.60-0.99; p=0.04) with moderate heterogeneity among the included trials (tau2: 0.04; I2: 56%; p=0.08). Subgroup analysis identified a PFS benefit from this approach independently of the length of previous CDK4/6 inhibition. The PFS benefit was more pronounced in those individuals who received abemaciclib or ribociclib as second CDK4/6i. Continuation of CDK4/6 inhibition was associated with higher rates of grade 3 and 4 neutropenia (range: 25-40%) and anemia (range: 1.7-11%). In conclusion, switching CDK4/6i and ET conferred a statistically significant improvement of PFS in comparison to ET alone in patients with progression or recurrence on prior CDK4/6i-containing therapy.

Epidemiology of early vs late recurrence among women with early stage estrogen receptor-positive breast cancer in the Pathways Study

BACKGROUND

Relatively little is known about the differences in prognostic factors for early vs late recurrence among women with early stage estrogen receptor-positive breast cancer.

METHODS

We analyzed factors related to early (<5 years) vs late (≥5 years) recurrence in 2992 women with stage I-IIB estrogen receptor-positive breast cancer in the Pathways Study, a prospective cohort of women with breast cancer enrolled between 2006 and 2013, with ascertainment of recurrence and death through December 2021.

RESULTS

After a median follow-up of 13.3 years, 341 (13.8%) women had recurrences, including 181 (53.7%) with late recurrence. Higher stage and grade were associated with recurrence regardless of timing, whereas progesterone receptor negativity was associated with early but not late recurrence. Receipt of endocrine therapy was associated with reduced risk of overall recurrence, but the length of endocrine therapy was not statistically significant in multivariable models. Minoritized racial and ethnic groups, including Asian, Black, and Hispanic women, had higher risk of early but not late recurrence compared to non-Hispanic White women. The trend of higher risk of early recurrence among these groups remained after adjustment for clinical, demographic, and socioeconomic factors but was statistically significant only in Asian women.

CONCLUSIONS

Our study revealed potentially important distinctions for early vs late recurrence, including the associations with progesterone receptor negativity and self-identified race and ethnicity. Possible higher risk of early recurrence among Asian, Black, and Hispanic women provides novel evidence for the existence of disparities in cancer outcomes, even within the breast cancer subtype indicative of generally good prognosis.

PKMYT1 Is a Marker of Treatment Response and a Therapeutic Target for CDK4/6 Inhibitor-Resistance in ER+ Breast Cancer

Endocrine therapies (ET) with cyclin-dependent kinase 4/6 (CDK4/6) inhibition are the standard treatment for estrogen receptor-α-positive (ER+) breast cancer, however drug resistance is common. In this study, proteogenomic analyses of patient-derived xenografts (PDXs) from patients with 22 ER+ breast cancer demonstrated that protein kinase, membrane-associated tyrosine/threonine one (PKMYT1), a WEE1 homolog, is estradiol (E2) regulated in E2-dependent PDXs and constitutively expressed when growth is E2-independent. In clinical samples, high PKMYT1 mRNA levels associated with resistance to both ET and CDK4/6 inhibition. The PKMYT1 inhibitor lunresertib (RP-6306) with gemcitabine selectively and synergistically reduced the viability of ET and palbociclib-resistant ER+ breast cancer cells without functional p53. In vitro the combination increased DNA damage and apoptosis. In palbociclib-resistant, TP53 mutant PDX-derived organoids and PDXs, RP-6306 with low-dose gemcitabine induced greater tumor volume reduction compared to treatment with either single agent. Our study demonstrates the clinical potential of RP-6306 in combination with gemcitabine for ET and CDK4/6 inhibitor resistant TP53 mutant ER+ breast cancer.

Subdivision of M1 category and prognostic stage for de novo metastatic breast cancer to enhance prognostic prediction and guide the selection of locoregional therapy

BACKGROUND

Although de novo metastatic breast cancer (dnMBC) is acknowledged as a heterogeneous disease, the current staging systems do not distinguish between patients within the M1 or stage IV category. This study aimed to refine the M1 category and prognostic staging for dnMBC to enhance prognosis prediction and guide the choice of locoregional treatment.

METHODS

We selected patients with dnMBC from the SEER database (2010-2019), grouping them into training (N = 8048) and internal validation (N = 3450) cohorts randomly at a 7:3 ratio. An independent external validation cohort (N = 660) was enrolled from dnMBC patients (2010-2023) treated in three hospitals. Nomogram-based risk stratification was employed to refine the M1 category and prognostic stage, incorporating T/N stage, histologic grade, subtypes, and the location and number of metastatic sites. Both internal and external validation sets were used for validation analyses.

RESULTS

Brain, liver, or lung involvement and multiple metastases were independent prognostic factors for overall survival (OS). The nomogram-based stratification effectively divided M1 stage into three groups: M1a (bone-only involvement), M1b (liver or lung involvement only, with or without bone metastases), and M1c (brain metastasis or involvement of both liver and lung, regardless of other metastatic sites). Only subtype and M1 stage were included to define the final prognostic stage. Significant differences in OS were observed across M1 and prognostic subgroups. Patients with the M1c stage benefited less from primary tumor surgery in comparison with M1a stage.

CONCLUSION

Subdivision of the M1 and prognostic stage could serve as a supplement to the current staging guidelines for dnMBC and guide locoregional treatment.

The Experience of Patients with Endocrine Therapy for Breast Cancer: A Patient Journey Map Based on Qualitative Research

(1) Background: While there is extensive documentation on the medical experience of breast cancer, a thorough understanding of the various stages of endocrine therapy remains insufficient. The aim of this study was to map the experiences and coping styles of breast cancer patients during endocrine therapy. (2) Methods: Qualitative research was conducted to gather insights into the experiences of breast cancer patients undergoing endocrine therapy. The themes were organized through content analysis and induction. Subsequently, patients were invited for face-to-face interviews at a top-three hospital in Guangzhou to supplement and validate the findings from the literature review. The patient journey was then mapped based on both the literature review and the semi-structured interviews. (3) Results: A total of 24 studies were included that described patients' experiences and behaviors during the early, middle, and late stages of treatment, leading to the formation of a preliminary framework. Interviews were conducted with 20 patients, which confirmed and enriched the findings from the literature review. Based on these results, a stage trajectory for endocrine therapy in breast cancer was established. (4) Conclusions: The patient journey map developed in this study clearly and intuitively illustrates the thought and emotion matrix, as well as the behavior matrix, of breast cancer patients undergoing endocrine therapy. This provides a theoretical foundation for enhancing clinical services tailored to the needs of these patients.

The use of nanomaterials as drug delivery systems and anticancer agents in the treatment of triple-negative breast cancer: an updated review (year 2005 to date)

Triple-negative breast cancer (TNBC) is characterised by the lack or low expression of estrogen, progesterone, and human epidermal growth factor receptor 2 receptors. TNBC has a high recurrence rate, swiftly metastasizes, and has a high mortality rate. Subsequently, the increase in cases of TNBC has signaled the need for treatment strategies with improved drug delivery systems. New diagnostic approaches, chemical entities, formulations particular those in the nanometric range have emerged after extensive scientific research as alternative strategies for TNBC treatment. As compared to contemporary cancer therapy, nanoparticles offer peculiar tunable features namely small size, shape, electrical charge, magnetic and fluorescent properties. Specifically in targeted drug delivery, nanoparticles have been demonstrated to be highly efficient in encapsulating, functionalization, and conjugation. Presently, nanoparticles have ignited and transformed the approach in photodynamic therapy, bioimaging, use of theranostics and precision medicine delivery in breast cancer. Correspondingly, recent years have witnessed a drastic rise in literature pertaining to treatment of TNBC using nanomaterials. Subsequently, this manuscript aims to present a state-of-the-art of nanomaterials advance on TNBC treatment; the ubiquitous utility use of nanomaterials such as liposomes, dendrimers, solid lipid nanomaterials, gold nanomaterials and quantum dots as anticancer agents and drug delivery systems in TNBC.

Radiogenomics: bridging the gap between imaging and genomics for precision oncology

Genomics allows the tracing of origin and evolution of cancer at molecular scale and underpin modern cancer diagnosis and treatment systems. Yet, molecular biomarker-guided clinical decision-making encounters major challenges in the realm of individualized medicine, consisting of the invasiveness of procedures and the sampling errors due to high tumor heterogeneity. By contrast, medical imaging enables noninvasive and global characterization of tumors at a low cost. In recent years, radiomics has overcomes the limitations of human visual evaluation by high-throughput quantitative analysis, enabling the comprehensive utilization of the vast amount of information underlying radiological images. The cross-scale integration of radiomics and genomics (hereafter radiogenomics) has the enormous potential to enhance cancer decoding and act as a catalyst for digital precision medicine. Herein, we provide a comprehensive overview of the current framework and potential clinical applications of radiogenomics in patient care. We also highlight recent research advances to illustrate how radiogenomics can address common clinical problems in solid tumors such as breast cancer, lung cancer, and glioma. Finally, we analyze existing literature to outline challenges and propose solutions, while also identifying future research pathways. We believe that the perspectives shared in this survey will provide a valuable guide for researchers in the realm of radiogenomics aiming to advance precision oncology.

Role of Radiology in the Diagnosis and Treatment of Breast Cancer in Women: A Comprehensive Review

Breast cancer remains a leading cause of morbidity and mortality among women worldwide. Early detection and precise diagnosis are critical for effective treatment and improved patient outcomes. This review explores the evolving role of radiology in the diagnosis and treatment of breast cancer, highlighting advancements in imaging technologies and the integration of artificial intelligence (AI). Traditional imaging modalities such as mammography, ultrasound, and magnetic resonance imaging have been the cornerstone of breast cancer diagnostics, with each modality offering unique advantages. The advent of radiomics, which involves extracting quantitative data from medical images, has further augmented the diagnostic capabilities of these modalities. AI, particularly deep learning algorithms, has shown potential in improving diagnostic accuracy and reducing observer variability across imaging modalities. AI-driven tools are increasingly being integrated into clinical workflows to assist in image interpretation, lesion classification, and treatment planning. Additionally, radiology plays a crucial role in guiding treatment decisions, particularly in the context of image-guided radiotherapy and monitoring response to neoadjuvant chemotherapy. The review also discusses the emerging field of theranostics, where diagnostic imaging is combined with therapeutic interventions to provide personalized cancer care. Despite these advancements, challenges such as the need for large annotated datasets and the integration of AI into clinical practice remain. The review concludes that while the role of radiology in breast cancer management is rapidly evolving, further research is required to fully realize the potential of these technologies in improving patient outcomes.

Discovery of novel 1,8-naphthalimide piperazinamide based benzenesulfonamides derivatives as potent carbonic anhydrase IX inhibitors and ferroptosis inducers for the treatment of triple-negative breast cancer

A novel series of 1,8-naphthalimide piperazinamide based benzenesulfonamides derivatives were designed and synthesized as carbonic anhydrase IX (CA IX) inhibitors and ferroptosis inducers for the treatment of triple-negative breast cancer (TNBC). The representative compound 9o exhibited more potent inhibitory activity and selective against CA IX over off-target CA II, compared with positive control SLC-0111. Molecular docking study was also performed to gain insights into the binding interactions of 9o in the binding pocket of CAIX. Moreover, compound 9o exhibited superior antitumor activities against breast cancer cells under hypoxia than that of normoxia conditions. Mechanism studies revealed that compound 9o could act as DNA intercalator and effectively suppressed cell migration, arrested the cell cycle at G1/S phase and induced apoptosis in MDA-MB-231 cells, while inducing ferroptosis accompanied by the dissipation of MMP and the elevation intracellular levels of ROS. Notably, in vivo studies demonstrated that 9o effectively inhibited tumor growth and metastasis in a highly metastatic murine breast cancer 4 T1 xenograft model. Taken together, this study suggests that compound 9o represents a potent and selective CA IX inhibitor and ferroptosis inducer for the treatment of TNBC.

Practical Guidance on Abemaciclib in Combination with Adjuvant Endocrine Therapy for Treating Hormone Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative High-Risk Early Breast Cancer

The most common subtype of breast cancer is hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer, accounting for 65-70% of all breast cancer cases diagnosed in the United States. Until 2015, single-agent endocrine therapy (ET) was the recommended first-line treatment for metastatic HR-positive, HER2-negative breast cancer. However, the paradigm has since shifted, as targeted therapy is now recommended in combination with ET. The cyclin-dependent kinase (CDK) 4/6 inhibitors have revolutionized the treatment of this breast cancer subtype, and combining either palbociclib, ribociclib, or abemaciclib with ET is now the standard first-line treatment for metastatic disease. Results of clinical trials in the metastatic setting have demonstrated that treatment with the combination of a CDK4/6 inhibitor and ET rather than ET alone is associated with longer overall survival, longer progression-free survival, and better objective response rates. Each of the CDK4/6 inhibitors has been investigated in combination with ET in patients with early-stage HR-positive, HER2-negative breast cancer who are at high risk of relapse. In October 2021, abemaciclib was the first CDK4/6 inhibitor approved in combination with ET by the US Food and Drug Administration for adjuvant treatment of patients with HR-positive, HER2-negative, high-risk early breast cancer. Herein, we provide practical guidance on the use of abemaciclib in combination with ET for HR-positive, HER2-negative, high-risk early breast cancer to assist clinicians in their day-to-day practice, and we review clinically relevant topics of dosing, side effect management, sequencing and optimal timing for initiation, and patient selection.

Identification of breast cancer-associated PIK3CA H1047R mutation in blood circulation using an asymmetric PCR assay

PURPOSE

To establish a highly sensitive and specific approach for the detection of circulating PIK3CA H1047R mutation in breast cancer (BC) patients and to investigate the association between the prevalence of PIK3CA H1047R mutation and clinical presentations.

METHODS

A proper blocker was designed in an allele-specific manner and optimized for PCR-based identification of the PIK3CA H1047R mutation. The established technique was validated in cell-free DNA samples from 196 recruited BC patients.

RESULTS

The allele-specific PCR assay with a properly designed blocker was able to detect the H1047R mutant variant with 0.01%. By applying the newly established assay, 62 cases (31.6% of the total recruited cases) were found to carry a blood-circulating H1047R mutant. Wherein, the detected mutant rates increased with disease stages from 2/18 (11.1%) of stage I to 17/71 (23.9%) of stage II, 20/53 (37.7%) of stage III, and 23/31 (42.6%) of stage IV (p = 0.025), respectively. Higher frequencies of H1047R mutation were associated with late-stage (p = 0.033) or recurrence (p = 0.045) or metastatic patients (p = 0.049) as well as radiation-treated human epidermal growth factor receptor 2 (HER2) positive BC (p = 0.004). PIK3CA mutant carriers were frequently observed in patients under the age of 50 who had liver-metastasized or brain metastases or lymph node-invaded (p < 0.05).

CONCLUSION

A novel allele-specific PCR assay with high sensitivity was established successfully for the detection of the PIK3CA H1047R mutation in clinical practice.

VERITAC-2: a Phase III study of vepdegestrant, a PROTAC ER degrader, versus fulvestrant in ER+/HER2- advanced breast cancer

Vepdegestrant (ARV-471) is an oral PROTAC ER degrader that binds an E3 ubiquitin ligase and ER to directly trigger ubiquitination of ER and its subsequent proteasomal degradation. In a first-in-human Phase I/II study, vepdegestrant monotherapy was well tolerated with clinical activity in pretreated patients with ER+/HER2- advanced breast cancer. The global, randomized Phase III VERITAC-2 study compares efficacy and safety of vepdegestrant versus fulvestrant in adults with ER+/HER2- advanced breast cancer after treatment with a CDK4/6 inhibitor plus endocrine therapy. Progression-free survival by blinded independent central review (primary end point) will be assessed in the intention-to-treat population and ESR1 mutation-positive subpopulation. Secondary end points include overall survival, tumor response, safety, pharmacokinetics, patient-reported outcomes, and circulating tumor DNA biomarkers.Clinical trial registration: NCT05654623 (ClinicalTrials.gov).

M2 macrophages promote PD-L1 expression in triple-negative breast cancer via secreting CXCL1

BACKGROUND

M2 macrophages are known to play a significant role in the progression of triple-negative breast cancer (TNBC) by creating an immunosuppressive microenvironment. The aim of this study is to investigate the impact of M2 macrophages on TNBC and their correlation with programmed death-ligand 1 (PD-L1) expression.

METHODS

We employed a co-culture system to analyze the role of the mutual regulation of M2 macrophages and TNBC cells. Employing a multifaceted approach, including bioinformatics analysis, Western blotting, flow cytometry analysis, ELISA, qRT-PCR, lentivirus infection, mouse models, and IHC, we aimed to elucidate the influence and mechanism of M2 macrophages on PD-L1 expression.

RESULTS

The results showed a substantial infiltration of M2 macrophages in TNBC tissue, which demonstrated a positive correlation with PD-L1 expression. CXCL1 exhibited abnormally high expression in M2 macrophages and enhanced the expression of PD-L1 in TNBC cells. Notably, silencing CXCL1 or its receptor CXCR2 inhibited M2 macrophages-induced expression of PD-L1. Mechanistically, CXCL1 derived from M2 macrophages binding to CXCR2 activated the PI3K/AKT/NF-κB signaling pathway, resulting in increased PD-L1 expression in TNBC.

CONCLUSION

Broadly speaking, these results provide evidence for the immunosuppressive role of M2 macrophages and CXCL1 in TNBC cells, indicating their potential as therapeutic biomarkers.

Hyaluronic acid-conjugated methotrexate and 5-fluorouracil for targeted drug delivery

The delivery of chemotherapeutical drugs via nanomaterials has become a focus of pharmaceutical research over several decades due to improved drug delivery to cancer cells, decreased side effects on normal tissues, and increased therapeutic efficacy. Herein, a novel hyaluronic acid-conjugated methotrexate and 5-fluorouracil nanodrug system has been developed to address the critical limitations associated with the high toxicity and side effects of methotrexate and 5-fluorouracil. Furthermore, this nanodrug system enhances the targeting capacity of drug molecules and facilitates the potential integration of multimodal drug therapies. Concomitantly, the synergistic effects of MTX with 5-fluorouracil have been shown to improve the therapeutic index of MTX while attenuating the associated toxicities of MTX. The structure and micromorphology of the novel nanodrug can be confirmed by 1HNMR, FT-IR, UV-Vis, DLS, TEM, and AFM. Due to the ability of HA to bind to CD44 receptors activated on the surface of cancer cells and its enhanced permeability and retention (EPR) effect, the novel nanodrug we designed and synthesized can effectively target cancer cells. Cell counting Kit-8 (CCK8), flow cytometry, and live-dead staining assays in vitro showed that this nanodrug system had high targeting and antitumor activity against CD44 receptors. By using drugs to act on patient-derived colorectal, liver, and breast cancer organoids, the anticancer effect of the nanodrug was identified and verified. These results showed that the nanodrug system developed in this study may have great potential as a targeted therapy for cancer.

Efficacy and safety of neoadjuvant therapy for HR-positive/HER2-negative early breast cancer: a Bayesian network meta-analysis

BACKGROUND

Neoadjuvant treatment for hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) breast cancer is controversial and requires a comprehensive analysis for optimal therapy assessment. Therefore, a two-step Bayesian network meta-analysis (NMA) was performed to compare the efficacy and safety of different neoadjuvant regimens.

RESEARCH DESIGN AND METHODS

Phase II/III randomized clinical trials comparing various neoadjuvant therapies for HR+/HER2- breast cancer were included. NMA and pairwise meta-analyses were conducted using Stata (version 14), R (version 4.2.3), and Review Manager 5.4.

RESULTS

Twenty-eight studies (5,625 patients) were eligible. NMA of objective response rate (ORR) indicated the highest SUCRA for chemotherapy (CT) and chemotherapy with anthracycline (CT(A)). Pathologic complete response (PCR) NMA demonstrated significant PCR improvement with chemotherapy regimens containing programmed cell death protein-1 and programmed cell death ligand-1 inhibitors (PD-1i/PD-L1i) and poly ADP-ribose polymerase inhibitors (PARPi). Combined analysis considering both the ORR and safety highlighted CT(A)'s efficacy and toxicity balance.

CONCLUSIONS

CT(A) and CT showed improved ORR compared with alternative regimens. CT(A) combined with PD-1/PD-L1 or PARP inhibitors significantly increased PCR rates. Comprehensive assessment of both ORR and safety indicated that CT(A) represents an optimal neoadjuvant therapy for HR+/HER2- breast cancer, whereas AI + CDK4/6 inhibitors rank solely behind chemotherapy.

REGISTRATION

PROSPERO Registration: CRD42024538948. International Platform of Registered Systematic Review and Meta-Analysis Protocols (INPLASY) registration number INPLASY202440092.

Synthesis and Preclinical Evaluation of Novel 68Ga-DOTA-RBB as Potential PET Radiotracer for Imaging CDK4/6 in Tumors

Many malignant tumors, including breast cancer, exhibit amplification and overexpression of cyclin-dependent kinase 4 and 6 (CDK4/6). Ribociclib, approved and used in clinical treatment, acts as a highly selective CDK4/6 inhibitor for ER+/HER2- breast cancer. By modifying ribociclib with the chelator DOTA, we designed and synthesized a novel CDK4/6-positive PET imaging agent, which was radiolabeled by 68Ga for radioactive tagging. The radiotracer demonstrates high radiochemical purity, excellent stability in vitro and in vivo, and favorable pharmacokinetic characteristics. Cell uptake experiments using MCF-7 cells indicate that an excess of ribociclib (RBB) can inhibit cellular uptake of 68Ga-DOTA-RBB. Imaging and biodistribution experiments in MCF-7 tumor-bearing nude mice show significant radioactive accumulation in the tumor. However, preadministration of excess ribociclib results in a substantial reduction in radioactive accumulation within the tumor. On the basis of our explorations, 68Ga-DOTA-RBB, as a targeted imaging agent for CDK4/6-positive tumors, holds significant potential application values.

Green synthesis of zinc oxide nanoparticles using Rhus coriaria extract and their anticancer activity against triple-negative breast cancer cells

The growing interest in using plant extracts for the biogenic synthesis of zinc oxide nanoparticles (ZnO NPs) stems from their facile, eco-friendly, and biologically safe approach instead of chemical routes. For the first time, ZnO NPs were successfully biosynthesized using Rhus coriaria fruit aqueous extract as a reducing and capping agent. Characterization revealed that the biosynthesized ZnO NPs possessed a maximum absorbance of approximately 359 nm and closely resembled the hexagonal ZnO wurtzite crystalline structure, with an average crystalline size of 16.69 nm. The transmission electron microscope (TEM) showed the presence of spherical and hexagonal morphologies, with an average grain size of 20.51 ± 3.90 nm. Moreover, the elemental composition of the synthesized ZnO NPs was assessed via energy-dispersive X-ray spectrometry (EDX), and the presence of phytocompounds on their surface was subsequently verified through FT-IR analysis. The ζ-potential of ZnO NPs was recorded at - 19.9 ± 0.1663 mV. Regarding anti-cancer properties, ZnO NPs were found to possess potent anti-tumor effects on MCF-7 and MDA-MB-231 breast cancer cells. Their efficacy was dose-dependent, with IC50 values ranging from 35.04-44.86 μg/mL for MCF-7 and 55.54-63.71 µg/mL for MDA-MB-231 cells. Mechanistic studies in MDA-MB-231 cells revealed apoptosis induction, validated by DAPI staining, confocal microscopy, and Annexin V/PI staining, showing apoptosis by 12.59% and 81.57% at ½ IC50 and IC50 values, respectively. Additionally, ZnO NPs were observed to provoke S-phase arrest and inhibit colony-forming and metastatic potential by modulating apoptosis and metastasis-related genes. This study unravels new insights into how ZnO NPs provoke cancer cell death and inhibit metastasis, revealing new prospects in cancer nanotechnology.

Lasofoxifene as a potential treatment for aromatase inhibitor-resistant ER-positive breast cancer

BACKGROUND

Breast cancers treated with aromatase inhibitors (AIs) can develop AI resistance, which is often driven by estrogen receptor-alpha (ERα/ESR1) activating mutations, as well as by ER-independent signaling pathways. The breast ER antagonist lasofoxifene, alone or combined with palbociclib, elicited antitumor activities in a xenograft model of ER + metastatic breast cancer (mBC) harboring ESR1 mutations. The current study investigated the activity of LAS in a letrozole-resistant breast tumor model that does not have ESR1 mutations.

METHODS

Letrozole-resistant, MCF7 LTLT cells tagged with luciferase-GFP were injected into the mammary duct inguinal glands of NSG mice (MIND model; 6 mice/group). Mice were randomized to vehicle, lasofoxifene ± palbociclib, fulvestrant ± palbociclib, or palbociclib alone 2-3 weeks after cell injections. Tumor growth and metastases were monitored with in vivo and ex vivo luminescence imaging, terminal tumor weight measurements, and histological analysis. The experiment was repeated with the same design and 8-9 mice in each treatment group.

RESULTS

Western blot analysis showed that the MCF7 LTLT cells had lower ERα and higher HER2 expressions compared with normal MCF7 cells. Lasofoxifene ± palbociclib, but not fulvestrant, significantly reduced primary tumor growth versus vehicle as assessed by in vivo imaging of tumors at study ends. Percent tumor area in excised mammary glands was significantly lower for lasofoxifene plus palbociclib versus vehicle. Ki67 staining showed decreased overall tumor cell proliferation with lasofoxifene ± palbociclib. The lasofoxifene + palbociclib combination was also associated with significantly fewer bone metastases compared with vehicle. Similar results were observed in the repeat experiment.

CONCLUSIONS

In a mouse model of letrozole-resistant breast cancer with no ESR1 mutations, reduced levels of ERα, and overexpression of HER2, lasofoxifene alone or combined with palbociclib inhibited primary tumor growth more effectively than fulvestrant. Lasofoxifene plus palbociclib also reduced bone metastases. These results suggest that lasofoxifene alone or combined with a CDK4/6 inhibitor may offer benefits to patients who have ER-low and HER2-positive, AI-resistant breast cancer, independent of ESR1 mutations.

An oral bioactive chitosan-decorated doxorubicin nanoparticles/bacteria bioconjugates enhance chemotherapy efficacy in an in-situ breast cancer model

Breast cancer is the second leading cause of cancer-related deaths among women worldwide. Despite significant advancements in chemotherapy, its effectiveness is often limited by poor drug distribution and systemic toxicity caused by the weak targeting ability of conventional therapeutic agents. The hypoxic tumor microenvironment (TME) also plays a vital role in treatment outcomes. Oral anticancer therapeutic agents have gained popularity and show promising results due to their ease of repeated administration. This study introduces autopilot biohybrids (Bif@BDC-NPs) for the effective delivery of doxorubicin (DOX) to the tumor site. This hybrid combines albumin-encapsulated DOX nanoparticles (BD-NPs) coated with chitosan (CS) for breast cancer chemotherapy, along with anaerobic Bifidobacterium infantis (B. infantis, Bif) serving as self-propelled motors. Due to Bif's specific anaerobic properties, Bif@BDC-NPs precisely anchor hypoxic regions of tumor tissue and significantly increase drug accumulation at the tumor site, thereby promoting tumor cell death. In an in-situ mouse breast cancer model, Bif@BDC-NPs achieved 94 % tumor inhibition, significantly prolonging the median survival of mice to 62 days, and reducing the toxic side effects of DOX. Therefore, the new bacteria-driven oral drug delivery system, Bif@BDC-NPs, overcomes multiple physiological barriers and holds great potential for the precise treatment of solid tumors.

Antibody-drug conjugates transform the outcome of individuals with low-HER2-expression advanced breast cancer

Antibody-drug conjugates (ADCs)-a groundbreaking class of agents for targeted oncological therapies-consist of monoclonal antibodies with strong antigenic specificity coupled with highly active cytotoxic agents (also referred to as "payloads"). Over the past 2 decades, breast cancer research has evolved into a focal point for the research and development of ADCs, leading to several recent landmark publications. These advancements are ushering in a transformative era in breast cancer treatment and redefining conventional classifications by introducing a prospective subtype termed "HER2-low." The latest iterations of ADCs have demonstrated enhanced efficacy in disease management through the optimization of various factors, notably the incorporation of the bystander effect. These conjugates are no longer limited to the oncogenic driver human epidermal growth factor receptor 2 (HER2). Other antigens, including human epidermal growth factor receptor 3 (HER3), trophoblast cell surface antigen 2 (Trop-2), zinc transporter ZIP6 (LIV-1), and folate receptor α (FRα), have recently emerged as intriguing tumor cell surface nondriver gene targets for ADCs, each with one or more specific ADCs that showed encouraging results in the breast cancer field. This article reviews recent advances in the application of ADCs in the treatment of HER2-low breast cancer. Additionally, this review explores the underlying factors contributing to the impact of target selection on ADC efficacy to provide new insights for optimizing the clinical application of ADCs in individuals with low HER2 expression in advanced breast cancer.