INTRODUCTION: Trastuzumab deruxtecan (T-DXd) has revolutionised treatment for metastatic breast cancer (MBC). While effective, its high cost and toxicities, such as fatigue and nausea, pose challenges. METHOD: Medical records from the Joint Breast Cancer Registry in Singapore were used to study MBC patients treated with T-DXd (February 2021-June 2024). This study was conducted to address whether reducing dose intensity and density may have an adverse effect on treatment outcomes. RESULTS: Eighty-seven MBC patients were treated with T-DXd, with a median age of 59 years. At the time of data cutoff, 32.1% of patients were still receiving T-DXd. Over half (54%) of the patients received treatment with an initial relative dose intensity (RDI) of <;85%. Overall median real-world progression-free survival (rwPFS) was 8.1 months. rwPFS was similar between RDI groups (<85%: 8.7 months, <85%: 8.1 months, P=0.62). However, human epidermal growth receptor 2 (HER2)-positive patients showed significantly better rwPFS outcomes compared to HER2-low patients (8.8 versus 2.5 months, P<0.001). Only 16% with central nervous system (CNS) involvement had CNS progressive disease on treatment. No significant progression-free survival (PFS) differences were found between patients with or without CNS disease, regardless of RDI groups. Five patients (5.7%) developed interstitial lung disease (ILD), with 3 (3.4%) having grade 3 events. Two required high-dose steroids and none were rechallenged after ILD. There were no fatalities. CONCLUSION Our study demonstrated that reduced dose intensity and density had no significant impact on rwPFS or treatment-related toxicities. Furthermore, only 5.7% of patients developed ILD. T-Dxd provided good control of CNS disease, with 82% of patients achieving CNS disease control.
Humans ; Female ; Breast Neoplasms/mortality* ; Middle Aged ; Trastuzumab/adverse effects* ; Aged ; Adult ; Singapore/epidemiology* ; Antineoplastic Agents, Immunological/adverse effects* ; Camptothecin/adverse effects* ; Immunoconjugates/adverse effects* ; Retrospective Studies ; Progression-Free Survival ; Receptor, ErbB-2/metabolism* ; Neoplasm Metastasis ; Dose-Response Relationship, Drug ; Treatment Outcome ; Registries

OBJECTIVES: To explore the mechanism by which Pulsatilla saponin D (PSD) inhibits invasion and metastasis of triple-negative breast cancer (TNBC). METHODS: The public databases were used to identify the potential targets of PSD and the invasion and metastasis targets of TNBC to obtain the intersection targets between PSD and TNBC. The "PSD-target-disease" interaction network was constructed and protein-protein interaction (PPI) analysis was performed to obtain the core targets, which were analyzed for KEGG pathway and GO functional enrichment. Molecular docking study of the core targets and PSD was performed, and the therapeutic effect and mechanism of PSD were verified using Transwell assay and Western blotting in cultured TNBC cells. RESULTS: Network pharmacology analysis identified a total of 285 potential PSD targets and 26 drug-disease intersection core targets. GO analysis yielded 175 entries related to the binding of biomolecules (protein, DNA and RNA), enzyme activities, and regulation of gene transcription. KEGG analysis yielded 46 entries involving pathways in cancer, chemical carcinogenesis-receptor activation, microRNAs in cancer, chemical carcinogenesis-reactive oxygen species, PD-L1 expression and PD-1 checkpoint pathway in cancer. Molecular docking showed high binding affinities of PSD to MTOR, HDAC2, ABL1, CDK1, TLR4, TERT, PIK3R1, NFE2L2 and PTPN1. In cultured TNBC cells, treatment with PSD significantly inhibited cell invasion and migration and lowered the expressions of MMP2, MMP9, N-cadherin and the core proteins p-mTOR, ABL1, TERT, PTPN1, HDAC2, PIK3R1, CDK1, TLR4 as well as NFE2L2 expressionin the cell nuclei. CONCLUSIONS The inhibitory effects of PSD on TNBC invasion and metastasis are mediated by multiple targets and pathways.
Humans ; Triple Negative Breast Neoplasms/metabolism* ; Saponins/pharmacology* ; Pulsatilla/chemistry* ; Female ; Molecular Docking Simulation ; Cell Line, Tumor ; Neoplasm Invasiveness ; Protein Interaction Maps ; Neoplasm Metastasis ; Signal Transduction/drug effects* ; Cell Movement/drug effects*

OBJECTIVES: To investigate the effect of downregulation of medium-chain acyl-coenzyme A dehydrogenase (ACADM) on invasion and migration of estrogen receptor-positive breast cancer cells and the underlying mechanism. METHODS: The Kaplan-Meier Plotter database was used to analyze the ACADM expression levels in breast cancer and normal tissues and their association with patient prognosis. Human breast cancer MCF-7 and T47D cell lines with lentivirus-mediated ACADM knockdown were established, and their in situ tumor formation and metastasis after tail vein injection were evaluated in nude mice. The MCF-7 and T47D cells with ACADM knockdown and their unmodified parental cells were examined with oil-red O staining assay, ROS assay, mitochondrial respiratory chain function assay before and after treatments with ROS scavenger, Elamipretide (a cardiolipin oxidation inhibitor) or SC79 (an AKT activator), and the changes in migration and invasion abilities of the treated cells were analyzed with Transwell invasion assay and Boyden chamber assay. Western blotting was used to detect protein expression levels of related signaling pathways in the treated cells. RESULTS: ACADM overexpression was associated with a significantly shorter overall survival of breast cancer patients. In MCF-7 and T47D cells, ACADM knockdown resulted in downregulation of N calnexin, vimentin, p-P13K and p-AKT proteins, increased levels of free fatty acids and reactive oxygen species, lowered activities of mitochondrial respiratory chain complex III and V, and reduced mitochondrial inner phospholipids. ACADM knockdown significantly decreased the invasive capacity of the cells, which were obviously reversed by treatment with ROS scavenger, Elamipretide, and SC79. CONCLUSIONS Down-regulation of ACADM inhibits migration and invasion ability of estrogen receptor-positive breast cancer cells by lowering lipotoxicity and impairing mitochondrial function through the ROS/PI3K/AKT pathway.
Humans ; Breast Neoplasms/metabolism* ; Female ; Mice, Nude ; Down-Regulation ; Neoplasm Invasiveness ; Animals ; Mice ; Receptors, Estrogen/metabolism* ; MCF-7 Cells ; Cell Movement ; Cell Line, Tumor ; Reactive Oxygen Species/metabolism* ; Acyl-CoA Dehydrogenase/genetics* ; Signal Transduction ; Neoplasm Metastasis ; Proto-Oncogene Proteins c-akt/metabolism*

OBJECTIVES: To investigate the role of circular RNA circ_0000437 in regulating biological behaviors of breast cancer cells and the molecular mechanism. METHODS: Breast cancer MCF-7 and MDA-MB-231 cells were transfected with sh-circ_0000437, mimics, inhibitor, si-CTPS1, or their respective negative controls. qRT-PCR was used to detect the expression levels of circ_0000437, let-7b-5p, CTPS1, Notch1, Hes1, and Numb in breast cancer cell lines and tissues. RNase R digestion was used to confirm the circular structure of circ_0000437 and its subcellular localization in the breast cancer cells was determined by cellular distribution analysis. The changes in proliferation, invasion and migration of the transfected cells were assessed using CCK-8 assay, Transwell assay and scratch assay. Dual-luciferase reporter gene and RNA immunoprecipitation assays were employed to validate binding interactions among circ_0000437, let-7b-5p, and CTPS1. The cellular expressions of CTPS1, E-cadherin, N-cadherin, and vimentin proteins were detected with Western blotting. A tumor-bearing mouse model was used to verify the oncogenic mechanism of circ_0000437 and CTPS1. RESULTS: Circ_0000437 and CTPS1 were upregulated while let-7b-5p was downregulated in breast cancer tissues and cell lines. Circ_0000437 or CTPS1 knockdown obviously suppressed breast cancer cell proliferation, invasion, migration and epithelial-mesenchymal transition (EMT). Overexpression of let-7b-5p produced similar inhibitory effects, whereas inhibition of let-7b-5p significantly enhanced malignant behaviors of the cells. In the tumor-bearing mouse models, circ_0000437 knockdown significantly suppressed tumor growth, but co-transfection of the cells with pcDNA-CTPS1 accelerated tumor growth. Binding sites were identified between circ_0000437 and let-7b-5p and between let-7b-5p and CTPS1, and circ_0000437, let-7b-5p, and CTPS1 showed functional interactions in breast cancer cells. CONCLUSIONS Circ_0000437 is upregulated in breast cancer tissues and cells, and its high expression promotes proliferation, invasion, migration and EMT of breast cancer cells through the let-7b-5p/CTPS1 axis.
Humans ; Epithelial-Mesenchymal Transition ; Cell Proliferation ; MicroRNAs/metabolism* ; RNA, Circular ; Breast Neoplasms/metabolism* ; Cell Movement ; Female ; Neoplasm Invasiveness ; Cell Line, Tumor ; MCF-7 Cells ; Animals ; Mice

OBJECTIVES: To study the molecular mechanisms of LDH-loaded si-NEAT1 for regulating paclitaxel resistance and tumor-associated macrophage (TAM) polarization in breast cancer. METHODS: qRT-PCR and Western blotting were used to detect the expression of lncRNA NEAT1, miR-133b, and PD-L1 in breast cancer SKBR3 cells and paclitaxel-resistant SKBR3 cells (SKBR3-PR). The effects of transfection with si-NEAT1 and miR-133b mimics on MRP, MCRP and PD-L1 expressions and cell proliferation, migration and apoptosis were investigated using qRT-PCR, Western blotting, scratch and Transwell assays, and flow cytometry. Rescue experiments were conducted using si-NEAT1 and miR-133b inhibitor. Human THP-1 macrophages were cultured in the presence of conditioned media (CM) derived from SKBR3 and SKBR3-PR cells with or with si-NEAT1 transfection for comparison of IL-4-induced macrophage polarization by detecting the surface markers. LDH@si-NEAT1 nanocarriers were constructed, and their effects on MRP, MCRP and PD-L1 expressions and cell behaviors of the tumor cells were examined. THP-1 cells were treated with the CM from LDH@si-NEAT1-treated tumor cells, and the changes in their polarization were assessed. RESULTS: SKBR3-PR cells showered significantly upregulated NEAT1 and PD-L1 expressions and lowered miR-133b expression as compared with their parental cells. Transfection with si-NEAT1 and miR-133b mimics inhibited viability, promoted apoptosis and enhanced MRP and BCRP expressions in SKBR3-PR cells. NEAT1 knockdown obvious upregulated miR-133b and downregulated PD-L1, MRP and BCRP expressions. The CM from SKBR3-PR cells obviously promoted M2 polarization of THP-1 macrophages, which was significantly inhibited by CM from si-NEAT1-transfected cells. Treatment with LDH@si-NEAT1 effectively inhibited migration and invasion, promoted apoptosis, and reduced MRP, BCRP and PD-L1 expressions in the tumor cells. The CM from LDH@si-NEAT1-treated SKBR3-PR cells significantly downregulated Arg-1, CD163, IL-10, and PD-L1 and upregulated miR-133b expression in THP-1 macrophages. CONCLUSIONS LDH@si-NEAT1 reduces paclitaxel resistance of breast cancer cells and inhibits TAM polarization by targeting the miR-133b/PD-L1 axis.
Humans ; MicroRNAs/genetics* ; RNA, Long Noncoding/genetics* ; Paclitaxel/pharmacology* ; Breast Neoplasms/metabolism* ; Drug Resistance, Neoplasm ; B7-H1 Antigen/metabolism* ; Cell Line, Tumor ; Female ; Tumor-Associated Macrophages ; Apoptosis ; Cell Proliferation ; Macrophages ; Cell Movement

OBJECTIVES: To investigate the association of HOTAIR gene rs920778 single nucleotide polymorphism (SNP) with breast cancer susceptibility and response to HER2-targeted therapy in a Chinese population. METHODS: TaqMan probe-based real-time quantitative PCR was used for genotyping of the rs920778 locus (chr12:54,376,218) in peripheral blood genomic DNA from 287 breast cancer patients and 260 healthy individuals from northern Anhui Province. The genotype (GG, GT and TT) and allele (G/T) distribution frequencies were compared between the two groups to evaluate their association with breast cancer risk. Multivariate logistic regression analysis was conducted to assess the relationship between SNP at this locus and aggressive clinicopathological features (including tumor size, lymph node metastasis, ER/PR/HER2 status, and molecular subtypes) of breast cancer. For the HER2-positive subgroup, the association between rs920778 genotype and responses to dual-targeted therapy (trastuzumab [6 mg/kg q3w]+pertuzumab [420 mg q3w] + docetaxel [75 mg/m²]) was analyzed. The primary endpoints included pathological complete response rate (pCR), objective response rate (ORR), and progression-free survival (PFS). RESULTS: The TT genotype of rs920778 was associated with a significantly increased breast cancer susceptibility (OR=1.54, 95% CI: 1.09-2.19; P=0.017), an advanced tumor stage (P<0.001), lymph node metastasis (P<0.001), and the triple-negative subtype (P<0.001). In HER2-positive patients, TT genotype carriers had a markedly reduced objective response rate to dual HER2-targeted therapy (33.3% vs 89.3%, P=0.001) and a lower pathological complete response rate after neoadjuvant therapy (P=0.018). CONCLUSIONS The TT genotype of HOTAIR rs920778 serves as an independent risk factor for breast cancer susceptibility and aggressive progression in Chinese population and may predict the resistance to HER2-targeted therapies, suggesting its potential as a prognostic biomarker for precision oncology.
Adult ; Aged ; Female ; Humans ; Middle Aged ; Breast Neoplasms/drug therapy* ; Case-Control Studies ; China ; Drug Resistance, Neoplasm/genetics* ; Genetic Predisposition to Disease ; Genotype ; Polymorphism, Single Nucleotide ; Receptor, ErbB-2 ; RNA, Long Noncoding/genetics* ; East Asian People/genetics*

Recurrence and metastasis remain the leading cause of death in breast cancer patients due to the lack of effective treatment. A microenvironment suitable for cancer cell growth, referred to as pre-metastatic niche (PMN), is formed in distant organs before metastasis occurs. Myeloid-derived suppressor cells (MDSCs) are a heterogenous population of immature myeloid cells with immunosuppressive effects. They can expand in large numbers in breast cancer patients and participate in the formation of PMN. MDSCs can remodel the extracellular matrix of pulmonary vascular endothelial cells and recruit cancer stem cells to promote the lung metastasis of breast cancer. Furthermore, MDSCs facilitate immune evasion of breast cancer cells to impact the efficacy of immunotherapy. It is proposed that MDSCs represent a potential therapeutic target for the inhibition of recurrence and metastasis in breast cancer. Therapeutic strategies targeting MDSCs have shown promising efficacy in preclinical studies and clinical trials. This review presents a summary of the principal factors involved in the recruitment and activation of MDSCs during the formation of PMN, and outlines MDSCs functions such as immunosuppression and the current targeted therapies against MDSCs, aiming to provide new ideas for the treatment of distant metastases in breast cancer.
Humans ; Myeloid-Derived Suppressor Cells/immunology* ; Breast Neoplasms/immunology* ; Female ; Tumor Microenvironment ; Disease Progression ; Immunotherapy/methods* ; Neoplasm Metastasis ; Neoplastic Stem Cells

OBJECTIVES: Shear wave elastography (SWE) is a novel quantitative elastography technique that can assess the hardness of different tissues. This study introduces a novel shear wave parameter-frequency of mass characteristic (f_mass)-and investigates its correlation, along with other shear wave parameters, with the histopathological features and immunohistochemical (IHC) biomarkers of invasive breast cancer (IBC). The study aims to explore whether SWE can provide useful information for IBC treatment and prognosis. METHODS: With the pathological results as the gold standard, 258 malignant breast lesions were collected, and all patients underwent conventional ultrasound and SWE examinations. The SWE parameters [maximum elastic value (E_max), minimum elastic value (E_min), mean elastic value (E_mean), standard deviation of elastic value of the whole lesion (E_sd)] and f_mass] in the transverse and longitudinal orthogonal sections were measured, and their correlations with the prognostic factors of IBC [including tumor diameters, axillary lymph node (ALN) metastasis, lymphatic vessel invasion (LVI), calcification, histological type, histological grade, and IHC biomarkers (ER, PR, HER-2, Ki-67), and molecular subtypes] were analyzed. The correlations between the SWE parameters of the transverse and longitudinal sections of the tumors with different prognostic factors and the above indicators were analyzed. At the same time, the receiver operating characteristic (ROC) curve was used to analyze the efficacy of f_mass in predicting ER and PR expression. RESULTS: E_mean, E_max, E_sd, and f_mass were correlated with tumor diameters; E_mean, E_max and E_sd were correlated with histological types and histological grades. E_max and E_sd were correlated with ALN metastasis, LVI and pathological types. In the IHC biomarker-labeled masses, f_mass was correlated with ER and PR (both P<0.05), and E_mean, E_max, and E_sd were correlated with HER-2 and Ki-67 (all P<0.05). E_mean, E_max, and f_mass were all correlated with breast cancer subtypes (all P<0.05), and E_mean and E_max were higher in Luminal B [HER-2(+)] breast cancer, while f_mass was lower in HER-2(+) and triple-negative breast cancer. Among the statistically significant prognostic factors, the P values of the transverse sections of the masses were all less than or equal to those of the longitudinal sections. The AUC of f_mass in the transverse sections of the masses for predicting ER and PR expression were 0.73 (95% CI 0.65 to 0.80) and 0.67 (95% CI 0.60 to 0.74), respectively, with the optimal cut-off values being 76.50 and 60.66, the sensitivities being 72.45% and 81.98%, the specificities being 66.13% and 45.35%, and the accuracies being 70.93% and 69.77%, respectively. The AUC of f_mass in the longitudinal sections of the masses for predicting ER and PR expression were 0.74 (95% CI 0.67 to 0.81) and 0.65 (95% CI 0.58 to 0.72), respectively, with the optimal cut-off values being 131.8 and 137.5, the sensitivities being 69.90% and 66.28%, the specificities being 72.58% and 60.47%, and the accuracies being 70.54% and 64.34%, respectively. The f_mass in the transverse sections of the masses was more statistically significant. CONCLUSIONS The poor prognosis factors of IBC are related to high E_mean, E_min, E_max, E_sd, and low f_mass. The f_mass can predict the expression of ER and PR, and the transverse cut data are more meaningful. SWE is helpful for predicting the invasiveness of IBC.
Humans ; Breast Neoplasms/metabolism* ; Female ; Elasticity Imaging Techniques/methods* ; Biomarkers, Tumor/metabolism* ; Middle Aged ; Adult ; Prognosis ; Immunohistochemistry ; Neoplasm Invasiveness ; Receptor, ErbB-2/metabolism* ; Aged ; Lymphatic Metastasis ; Receptors, Estrogen/metabolism* ; Receptors, Progesterone/metabolism* ; Ki-67 Antigen/metabolism*

Objective: To investigate the prognosis impact of adjuvant trastuzumab treatment on human epidermal growth factor receptor 2 (HER-2) positive early breast cancer patients. Methods: A retrospective study was conducted, HER-2-positive T1N0M0 stage breast cancer patients who underwent surgery in the Affiliated Tumor Hospital of Xinjiang Medical University from January 2010 to December 2019 were divided into treatment group and control group according to whether they were treated with trastuzumab or not. Propensity score matching (PSM) was used to balance the confounding bias caused by differences in baseline characteristics between the two groups. Cox proportional hazards model was used to analyze the risk factors affecting disease-free survival (DFS). The Kaplan-Meier method was used to estimate the 3- and 5-year DFS and overall survival (OS) rates of the two groups before and after PSM. Results: There were 291 patients with HER-2 positive T1N0M0 stage breast cancer, including 21 cases in T1a (7.2%), 61 cases in T1b (21.0%), and 209 cases in T1c (71.8%). Before PSM, there were 132 cases in the treatment group and 159 cases in the control group, the 5-year DFS rate was 88.5%, and the 5-year OS rate was 91.5%. After PSM, there were 103 cases in the treatment group and 103 cases in the control group, the 5-year DFS rate was 86.0%, and the 5-year OS rate was 88.5%. Before PSM, there were significant differences in tumor size, histological grade, vascular invasion, Ki-67 index, postoperative chemotherapy or not and radiotherapy between the treatment group and the control group (P<0.05). After PSM, there were no significant difference in clinicopathological features between the treatment group and the control group (P>0.05). Multivariate analysis showed that histological grade (HR=2.927, 95 CI: 1.476, 5.805; P=0.002), vascular invasion (HR=3.410, 95 CI: 1.170, 9.940; P=0.025), menstrual status (HR=3.692, 95 CI: 1.021, 13.344, P=0.046), and chemotherapy (HR=0.238, 95 CI: 0.079, 0.720; P=0.011) were independent factors affecting DFS. After PSM, the 5-year DFS rate of the treatment group was 89.2%, while that of the control group was 83.5%(P=0.237). The 5-year OS rate of the treatment group was 96.1%, while that of the control group was 84.7%(P=0.036). Conclusion: Postoperative targeted therapy with trastuzumab can reduce the risk of recurrence and metastasis in patients with HER-2-positive T1N0M0 stage breast cancer.
Humans ; Female ; Trastuzumab/therapeutic use* ; Breast Neoplasms/metabolism* ; Retrospective Studies ; Neoplasm Staging ; Chemotherapy, Adjuvant ; Receptor, ErbB-2/metabolism* ; Prognosis ; Disease-Free Survival

Humans ; Female ; Mastectomy, Segmental ; Margins of Excision ; Reoperation ; Breast Neoplasms/surgery* ; Retrospective Studies ; Carcinoma, Ductal, Breast/surgery* ; Neoplasm Recurrence, Local