Metastatic Breast Cancer Patients Research Articles

Evidence that CRISPR-Cas9 Y537S-mutant expressing breast cancer cells activate Yes-associated protein 1 to driving the conversion of normal fibroblasts into cancer-associated fibroblasts.

Endocrine therapy (ET) has improved the clinical outcomes of Estrogen receptor alpha-positive (ERɑ +) breast cancer (BC) patients, even though resistance to ET remains a clinical issue. Mutations in the hormone-binding domain of ERɑ represent an acquired intrinsic mechanism of ET resistance. However, the latter also depends on the multiple functional interactions between BC cells and the tumor microenvironment (TME). Here, we investigated how the most common Y537S-ERɑ mutation may influence the behavior of fibroblasts, the most prominent component of the TME. We conducted coculture experiments with normal human foreskin fibroblasts BJ1-hTERT (NFs), cancer-associated fibroblasts (CAFs), isolated from human BC specimens, and Y537S CRISPR-expressing MCF-7 BC cells (MCF-7YS). Mass spectrometry (MS) and Metacore analyses were performed to investigate how the functional interactions between BC cells/fibroblasts may affect their proteomic profile. The impact of fibroblasts on BC tumor growth and metastatic potential was evaluated in nude mice. Mutant BC conditioned medium (CM) affected the morphology/proliferation/migration of both NFs and CAFs. 198 deregulated proteins signed the proteomic similarity profile of NFs exposed to the YS-CM and CAFs. Among the upregulated proteins, Yes-associated protein 1 (YAP1) was the main central hub in the direct interaction network. Increased YAP1 protein expression and activity were confirmed in NFs treated with MCF-7YS-CM. However, YAP1 activation appears to crosstalk with the insulin growth factor-1 receptor (IGF-1R). Higher amount of IGF-1 were noticed in the MCF-7YS-CM cells compared to the MCF-7P, and IGF-1 immunodepletion reversed the enhanced YAP1 expression and activity. Mutant cells upon exposure to the NF- and CAF-CM exhibited an enhanced proliferation/growth/migration/invasion compared to the MCF-7P. MCF-7YS cells when implanted with CAFs showed an early relative increased tumor volume compared to YS alone. No changes were observed when MCF-7P cells were co-implanted with CAFs. Compared with that in MCF-7P cells, the metastatic burden of MCF-7YS cells was intrinsically greater, and this effect was augmented upon treatment with NF-CM and further increased with CAF-CM. YS mutant BC cells induced the conversion of fibroblasts into CAFs, via YAP, which represent a potential therapeutic target which interrupt the functional interactions between mutant cells/TME and to be implemented in the novel therapeutic strategy of a subset of metastatic BC patients carrying the frequent Y537S mutations.

Abstract A046: Development of a scoring system to classify HER2 protein expression in circulating tumor cells through immunofluorescence following isolation using Parsortix® instruments

Abstract Background. HER2 testing through immunohistochemistry (IHC) is routinely performed on tissue biopsy samples from metastatic breast cancer (MBC) patients, resulting in a HER2 score that is used in patient stratification and treatment decisions. However, tissue biopsy is invasive, with little opportunity for re-examination while liquid biopsy is minimally invasive and allows monitoring of disease progression through recurrent sample collection. This study aimed to establish an assay (Research Use Only) allowing scoring of HER2 protein expression in circulating tumor cells (CTCs), by immunofluorescence (IF) staining, using cancer cell lines of known HER2 expression. Method. Cultured cancer cell lines with HER2 expression comparable to tissue samples (i.e. HER2 0, 1+, 2+ and 3+ by IHC score) were used in this study (SKBR3 [3+], HCC1954 [3+], SKOV-3 [2+/3+], ZR-75-1 [2+], MCF-7 [0 – 1+] and Hs 578T [0]). Cultured cancer cells were spun onto CellKeep™ slides and stained with ANGLE’s Portrait HER2 IF panel, comprising a nuclear dye, an anti-HER2 antibody, epithelial, mesenchymal and leukocyte markers. Slides were imaged on a BioView Allegro Plus, a platform equipped with artificial intelligence for automated imaging, CTC candidate identification and reporting. The workflow was implemented using samples from 5 MBC patients with known HER2 IHC scores, whose blood was drawn into Streck Cell-Free DNA tubes and processed on ANGLE's Parsortix® instrument, a marker-independent microfluidic device which isolates CTCs based on size and deformability, before being stained with the Portrait HER2 assay. The cohort is being expanded and currently includes three HER2 0 and two HER2 3+ patients as diagnosed by tissue IHC. Results. By observing mean fluorescence intensity (MFI) of each cancer cell line reported to be reflective of each IHC score, thresholds were set to establish a protein scoring system. 95%, 95% and 91% of SKBR3, HCC1954 and SKOV-3, respectively, fell in the 3+ class, 83% of ZR-75-1 fell in the 2+ class, 69% of MCF-7 fell in the 1+ class and 25% and 89% of MCF-7 and Hs 578T, respectively, fell in the 0 class. ≥1 CTC were found in all 5 subjects (mean=405, median=146), with 60% donors presenting mesenchymal CTCs, 20% epithelial CTCs and 20% epithelial and mesenchymal CTCs. HER2+ CTCs were found in both HER2 3+ donors, but not in the HER2 0 donors. HER2+ CTCs from both donors fell in the 3+ class based on MFI, despite one donor receiving Herceptin treatment (1 CTC) and the other being treatment naïve (435 CTCs). Conclusion. This study showed it is possible to establish a HER2 protein scoring system using cultured cancer cell lines stained with the Portrait HER2 assay and demonstrates the potential utility of liquid biopsy in tracking HER2 status. This scoring system will be applied to CTCs isolated from an extended cohort of MBC patients with known tissue biopsy HER2 IHC results to test the robustness of the system and assess concordance of CTC and tissue biopsy scores. FISH will be performed on the samples from MBC patients to confirm results. Citation Format: Alex Young, Laila Vlietinck, Bethan Edwards, Liam Cook, Chassidy Johnson, Mariacristina Ciccioli, Anne-Sophie Pailhes-Jimenez. Development of a scoring system to classify HER2 protein expression in circulating tumor cells through immunofluorescence following isolation using Parsortix® instruments [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr A046.

Abstract B013: An mDETECT assay for monitoring treatment response in metastatic breast cancer patients

Abstract Metastatic breast cancer treatment response is currently assessed every 3-6 months and this long delay results in many patients undergoing ineffective and toxic treatments for long periods of time. We have developed the methylation DETEction of Circulating Tumour DNA (mDETECT) assay, a targeted DNA methylation-based Next Generation Sequencing liquid biopsy that detects cancer-specific patterns in all subtypes of breast cancer. The assay targets 60 differentially hypermethylated regions in breast cancer across the genome and assesses over 400 individual CpGs with an average of 8 CpGs per target amplicon. The assay has been assessed on DNA from 73 breast cancer tumour samples which on average had 40 regions hypermethylated per patient with similar rates across all subtypes. We will present results from plasma samples from locally advanced and metastatic breast cancer patients along with plasma from age-matched, healthy female controls. A prospective, multi-centre observational cohort study to monitor metastatic breast cancer patients using the mDETECT liquid biopsy as they undergo treatment is active and recruiting patients. Blood is drawn with every standard-of-care blood draw for up to 3 years. Plasma has been assessed using the mDETECT assay to determine the methylation status of the DNA at each time point. 35 patients have been enrolled to date with ongoing recruitment up to 150 patients. Patients are being monitored with the mDETECT assay for earlier detection of disease progression on a treatment. They will also be monitored through treatment changes to assess a patient’s initial response to a given treatment. Changes in mDETECT levels will be correlated with clinical response to determine if the mDETECT breast cancer assay can detect a response to treatment at an earlier timepoint. This assay could allow for improved monitoring of treatment response allowing clinicians to make informed decisions, improving outcomes and prolonging patient’s lives. Citation Format: Keira Frosst, Brooke Wilson, Katrina Cristall, Catherine Crawford-Brown, Christopher R Mueller. An mDETECT assay for monitoring treatment response in metastatic breast cancer patients [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr B013.

Abstract A001: Analytical validation of a novel multiomic metastatic breast cancer liquid biopsy test that combines ctDNA analysis with CTC HER2-ultralow and ER co-expression, as well as single-cell chromosomal instability

Abstract Background: Metastatic breast cancer (MBC) subtype characterization is critical for effective treatment. The DefineMBC™ multiomic blood biopsy clinical diagnostic combines ctDNA and circulating tumor cell (CTC) analyses to characterize MBC patients when a tissue biopsy is not feasible. Innovation in the DefineMBC 2.0 5-channel immunofluorescent (IF) CTC characterization assay now measures ultralow (UL) levels of HER2 protein expression, ER protein expression, and chromosomal instability (CI) as well as ERBB2 amplification via single- cell sequencing. Cell-level HER2/ER co-detection enables monitoring of receptor conversion during a patient’s MBC treatment journey. As trastuzumab-deruxtecan (T-DxD) has become standard of care for HER2-low disease, distinguishing HER2-UL from HER2[-] by DefineMBC’s liquid biopsy approach may identify additional patients who can benefit from such therapy. This addresses an unmet need given the known shortcomings of tissue biopsy IHC in the metastatic setting as recently noted by communications from NCCN, ASCO, and the College of American Pathologists. Methods: Assay development including analytical validation studies utilized biologically relevant cell lines of epithelial origin and known expression levels of HER2 and ER (MDA-MB-453: HER2[+] & ER[-]; MCF-7: HER2-low & ER[+]; and MCF-7/ERBB2 knockout: HER2[-]) that were spiked into healthy donor blood. Additionally, patients with various forms of MBC were characterized with the new assay. As with all samples, following red blood cell lysis, nucleated cells were deposited on glass slides at high density (∼3E6 WBC/slide). Slides underwent IF staining for cytokeratins (CK), CD31, CD45, HER2, ER, and Hoechst to localize nuclear DNA, followed by scanning and machine learning-based rare cell detection. CK[+], CD31[-]/CD45[-] cells were classified as CTC candidates and assessed for HER2/ER expression. Pathologist-selected CTCs were isolated for single-cell whole genome sequencing and analyzed using a proprietary CTC DNA copy number pipeline to detect CI and amplification at the ERBB2 locus. Results: Analytical validation studies demonstrated the limit of detection at 1 CTC per 12E6 WBC (∼1.6 mL of blood) with a linear range of 1- 300 CTCs per slide. Sensitivity, specificity, accuracy, and precision metrics of the HER2 and ER IF assays were 96%, 96%, 96%, 2% CV; 91%, 95%, 93%, 3% CV; respectively. CTC enumeration precision was validated at greater than 80% for enumeration bins of 0, 1-10, 11-50, and>50 CTCs per sample. During patient testing 7 patients previously called HER2[-] are now designated as consistent with HER2-low by the pathologist, suggesting improved test performance in future clinical validation studies is likely. Conclusions: Advancement of our comprehensive cancer profiling platform now includes ER/HER2-UL/CI co-detection on enumerated CTCs in MBC patients. Clinical studies currently in progress will reveal whether HER2-UL/HER2[+] detection on CTCs will identify patients better suited for T-DxD or trastuzumab, respectively. Citation Format: Raj Srikrishnan, Jordan Ritchie, Alessandra Cunsolo, Andrew Kunihiro, Brandon Guillory, Sara Tin, Zhuo Meng, Ernest T Lam, Bharat Annaldas, Evan Schwab, Nilesh Dharajiya, Timothy Pluard, Martin Blankfard, David Bourdon. Analytical validation of a novel multiomic metastatic breast cancer liquid biopsy test that combines ctDNA analysis with CTC HER2-ultralow and ER co-expression, as well as single-cell chromosomal instability [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr A001.

PATH-67. THE ROLE OF STATUS OF HER-2, ESTROGEN-RECEPTOR, BRCA 1, AND BRCA 2, IN THE INCIDENCE OF BRAIN METASTASIS IN BREAST CANCER

Abstract Breast cancer (BC) is the most diagnosed tumor in women and the second-leading cause of brain metastasis (BM), with a prevalence ranging from 10-36%. According to the Epidemiological Strategy and Medical Economics research program, advanced BC patients face an estimated 25% risk of developing BM within 2-3 years after the initial diagnosis. The frequency of BM is significantly increased by the primary tumor profile, including larger tumors, higher nuclear grade, HER-2 positivity, estrogen-receptor negativity, and triple-negative status. A gap remains in the classification of the BM site relative to primary tumor biomarkers, and the absence of multimodality treatment methodologies poses challenges to survival rates and quality of life in BC patients. This retrospective cross-sectional study at Aga Khan University Hospital identified 52 cases of brain metastasis secondary to breast cancer over a 10-year period. The median age of patients was 55 years, ranging from 32 to 78 years. Primary breast tumors were predominantly high-grade ductal carcinomas (65%), followed by lobular carcinomas (25%) and other rare histological types (10%). Secondary brain metastases were primarily located in the cerebrum (60%), cerebellum (25%), and brainstem (15%). Tumor profiles indicated a significant correlation between HER-2 positivity and the development of brain metastasis, with 70% of HER-2 positive patients presenting with extensive brain metastasis. Tumor progression varied, with a median time to brain metastasis of 2.5 years from the initial breast cancer diagnosis. Despite aggressive multimodality treatments, including surgery, radiation, and chemotherapy, the overall prognosis remained poor. The study found that early detection of HER-2 positive and triple-negative tumors could potentially delay the progression of brain metastasis through targeted therapies. Mortality rates in this cohort were high, with a median survival of 8 months following the diagnosis of brain metastasis. These findings underscore the need for improved diagnostic, preventive, and therapeutic strategies to manage brain metastasis in breast cancer patients.

Cost minimization analysis of treatments for metastatic HER2-positive breast cancer in Peru: Fixed-dose combination of pertuzumab and trastuzumab for subcutaneous injections.

The main objective of this study is to determine whether the employment of fixed-dose combination of pertuzumab and trastuzumab for subcutaneous injection (PH FDC SC; and Phesgo as brand name) to treat metastatic HER2-positive breast cancer patients would minimize costs compared to the traditional treatment of separate intravenous doses of pertuzumab and trastuzumab in Peru. To achieve this, we used EsSalud (the social security health insurance) data and assessed it through a mixed strategy, which consisted of a quantitative and a qualitative approach. The first one aimed to calculate the direct (non-drug consumables, drugs, and healthcare professionals) and indirect costs of both treatments to develop a comparison, whilst the second aimed to validate information and internalize the procedure in an EsSalud context. Overall, we found that the usage of PH FDC SC would be cost saving in EsSalud's context. Specifically, we found three main advantages. Firstly, PH FDC SC generates a savings of 62% in non-drug consumables, which helps alleviate the healthcare system budget constraint. Secondly, its adoption frees up 61 hours of treatment and observation time for a single patient per year, which in turn increases the attention capacity of the healthcare system in terms of nursing hours and chemotherapy couches. Thirdly, the reduction of clinic time supposes an advantage for the patient in the form of increased productivity and well-being. Hence, the adoption of this drug would improve the quality of life of patients while reducing costs and pressure on the healthcare system. This is aligned with the strategy of prioritizing the appropriate breast cancer treatment within the National Cancer Care Plan. In this regard, we also found that the savings produced from switching from the traditional intravenous treatment to the subcutaneous one would allow EsSalud to afford full annual costs of 2 additional treatments, but without increasing their budget. This would cover 7% of the gap of 29 patients who do not have access to full treatment.

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

BackgroundA 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.MethodsA 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.ResultsA 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).ConclusionsThis 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.

Mediator Subunit Med4 Enforces Metastatic Dormancy in Breast Cancer.

Long term survival of breast cancer patients is limited due to recurrence from metastatic dormant cancer cells. However, the mechanisms by which these dormant breast cancer cells survive and awaken remain poorly understood. Our unbiased genome-scale genetic screen in mice identified Med4 as a novel cancer-cell intrinsic gatekeeper in metastatic reactivation. MED4 haploinsufficiency is prevalent in metastatic breast cancer patients and correlates with poorer prognosis. Syngeneic xenograft models revealed that Med4 enforces breast cancer dormancy. Contrary to the canonical function of the Mediator complex in activating gene expression, Med4 maintains 3D chromatin compaction and enhancer landscape, by preventing enhancer priming or activation through the suppression of H3K4me1 deposition. Med4 haploinsufficiency disrupts enhancer poise and reprograms the enhancer dynamics to facilitate extracellular matrix (ECM) gene expression and integrin-mediated mechano-transduction, driving metastatic growth. Our findings establish Med4 as a key regulator of cellular dormancy and a potential biomarker for high-risk metastatic relapse.

Deep neural network provides personalized treatment recommendations for de novo metastatic breast cancer patients

Deep neural network provides personalized treatment recommendations for <i>de novo</i> metastatic breast cancer patients

Long-Term Risk of Medication-Related Osteonecrosis of the Jaw (MRONJ) After Bisphosphonates and/or Denosumab in Metastatic Breast Cancer Patients

Recently published data identified cancer patients with bone metastases receiving continuous monthly antiresorptive drugs (bisphosphonates and/or denosumab) as patients at high risk for Medication-Related Osteonecrosis of the Jaw (MRONJ), even with late onset. A retrospective multicenter study was conducted between 2000 and 2020 at all breast centers across Tyrol (Austria), screening all patients with breast cancer and bone metastases receiving antiresorptive therapy. The MRONJ incidence was found to be considerably high in patients receiving denosumab (11.6%-16.3%), with an elevated cumulative incidence at 6 years. This commentary underlines some important results of the study and proposes further evaluation of the group of patients receiving a sequence of bisphosphonates and denosumab. Furthermore, other interesting data could come from patients treated in the last decade, receiving more effective anticancer treatments but also more frequently denosumab, in comparison with patients treated in previous years.

SUMOylation regulates the aggressiveness of breast cancer-associated fibroblasts.

Cancer-associated fibroblasts (CAFs) are the most abundant stromal cellular component in the tumor microenvironment (TME). CAFs contribute to tumorigenesis and have been proposed as targets for anticancer therapies. Similarly, dysregulation of SUMO machinery components can disrupt the balance of SUMOylation, contributing to tumorigenesis and drug resistance in various cancers, including breast cancer. We explored the role of SUMOylation in breast CAFs and evaluated its potential as a therapeutic strategy in breast cancer. We used pharmacological and genetic approaches to analyse the functional crosstalk between breast tumor cells and CAFs. We treated breast CAFs with the SUMO1 inhibitor ginkgolic acid (GA) at two different concentrations and conditioned media was used to analyse the proliferation, migration, and invasion of breast cancer cells from different molecular subtypes. Additionally, we performed quantitative proteomics (SILAC) to study the differential signalling pathways expressed in CAFs treated with low or high concentrations of GA. We confirmed these results both in vitro and in vivo. Moreover, we used samples from metastatic breast cancer patients to evaluate the use of GA as a therapeutic strategy. Inhibition of SUMOylation with ginkgolic acid (GA) induces death in breast cancer cells but does not affect the viability of CAFs, indicating that CAFs are resistant to this therapy. While CAF viability is unaffected, CAF-conditioned media (CM) is altered by GA, impacting tumor cell behaviour in different ways depending on the overall degree to which SUMO1-SUMOylated proteins are dysregulated. Breast cancer cell lines exhibited a concentration-dependent response to conditioned media (CM) from CAFs. At a low concentration of GA (10µM), there was an increase in proliferation, migration and invasion of breast cancer cells. However, at a higher concentration of GA (30µM), these processes were inhibited. Similarly, analysis of tumor development revealed that at 10µM of GA, the tumors were heavier and there was a greater degree of metastasis compared to the tumors treated with the higher concentration of GA (30µM). Moreover, some of these effects could be explained by an alteration in the activity of the GTPase Rac1 and the activation of the AKT signalling pathway. The results obtained using SILAC suggest that different concentrations of GA affected cellular processes differentially, possibly influencing the secretome of CAFs. Treatment of metastatic breast cancer with GA demonstrated the use of SUMOylation inhibition as an alternative therapeutic strategy. The study highlights the importance of SUMOylation in the tumor microenvironment, specifically in cancer-associated fibroblasts (CAFs). Targeting SUMOylation in CAFs affects their signalling pathways and secretome in a concentration-dependent manner, regulating the protumorigenic properties of CAFs.

Pyrotinib combined with metronomic etoposide in heavily pretreated HER2-positive metastatic breast cancer: a single-arm, phase II study

BackgroundExploration of novel combination mode of pyrotinib and chemotherapy for heavily pretreated HER2-positive metastatic breast cancer (MBC) and how to balance survival benefits and compliance are still urgent problems in clinical practice. The current single-arm prospective phase II study aimed to evaluate the efficacy and safety of pyrotinib in combination with metronomic oral etoposide in heavily pretreated HER2-positive MBC.MethodsHER2-positive MBC patients previously treated with trastuzumab were enrolled to receive oral pyrotinib 400 mg per day and metronomic oral etoposide 50 mg per day d1-21 every 28 days, until disease progression or unacceptable toxicity. The primary endpoint was progression-free survival (PFS). The secondary endpoints were objective response rate (ORR), disease control rate (DCR), clinical benefit rate (CBR), overall survival (OS), and safety.Results22 patients were enrolled with a median of 4 prior treatment regimens for MBC. During the follow-up of 20 evaluable patients, the median PFS was 9.0 months (95% CI, 7.6–10.4 months), and the median OS was 27.0 months (95%CI, 20.9–33.1 months). The ORR was 30% (6/20), the DCR was 80% (16/20), and the CBR was 65% (13/20). The most common grade 3 adverse events (AEs) included nausea (15%), vomiting (15%), diarrhea (5%), anemia (5%), and peripheral neuropathy (5%). No grade 4 or lethal AEs were observed.ConclusionThe combination of pyrotinib with metronomic oral etoposide has achieved promising clinical benefits in heavily pretreated HER2-positive MBC, with acceptable and manageable toxicity.Trial registrationRegistry number: NCT03923179. Registered April 18, 2019.

Real-World Clinical Outcomes of Treatment With Olaparib for BRCA1/2 Mutation-Positive Metastatic Breast Cancer in Japanese Patients.

Background Olaparib is effective in the treatment of metastatic breast cancer (MBC) patients, mainly confirmed by deleterious germline BRCA mutations. However, real-world data are scarce. Methodology A total of 10 cases from our institute and 17 cases from the relevant Japanese literature were reviewed. All 27 patients had MBC with confirmed deleterious germline BRCA mutations. Tumor reduction, response duration, disease-free interval (DFI), overall survival (OS), and safety were assessed. Additionally, exploratory research was conducted on the characteristics of a subgroup of patients who had a long-term response to olaparib. Results In the 10 cases from two Juntendo hospitals who received olaparib from July 2018 to December 2021, the median age was 48 years (range = 37-63 years). The same numbers of BRCA1 and BRCA2 mutations and the same ratios of luminal and triple negative (TN) breast cancer cases were observed. The metastatic sites, mainly visceral, included the lungs (n = 4), liver (n = 5), and bone (n = 6). The median duration of drug use was four months (range = 1-36 months). The median number of treatment regimens from metastasis to olaparib administration was 2.0 (range = 1-9 regimens). The median DFI was 21 months (range = 0-106 months). The median OS was not reached (range = 16-191 months). In the subgroup analysis of six cases in which olaparib was effective for four months or more, there was a case where DFI was longer than 100 months. Treatment-related toxicities (TRTs) included neutropenia (n = 5; 50%), anemia (n = 4; 40%), thrombocytopenia (n = 2; 20%), nausea (n = 1; 10%), and fatigue (n = 1; 10%). CTCAE (version 5.0) grade ≥3 TRTs included anemia (n = 1; 10%) and neutropenia (n = 5; 50%). On the other hand, neutropenia was previously said to be as low as 27.3%, lower than anemia (40.0%), in a population including various races. We additionally examined another 17 cases from the Japanese literature. Conclusions To our knowledge, this study reports the first real-world data of Japanese patients with MBC and confirmed deleterious germline BRCA mutations. Our data showed that olaparib is effective in the real world. The incidence of neutropenia seemed higher in Japanese patients.

Diagnostic utility of ESR1 mutation detection in liquid biopsy of metastatic breast cancer patients.

Molecular analysis of circulating cell-free DNA (cfDNA) extracted from peripheral blood plasma samples of metastatic breast cancer (BC) patients is of rising interest to find optimal therapeutic strategies. Detection of emerging resistance mutations against endocrine therapy is possible with this approach. Here we present the applicability of a laboratory-developed NGS assay in molecular pathology routine diagnostic, covering four genes with therapeutic (ESR1, PIK3CA, ERBB2) and prognostic (TP53) consequences in metastatic BC. We analyzed 162 liquid biopsy samples and 25 corresponding metastases from metastatic BC patients. In the liquid biopsies, we detected ESR1 mutations in 42 cases (25.9%) and ERBB2 mutations in six cases (3.7%), arguing for a change in therapy to fulvestrant, elacestrant, or neratinib. Furthermore, 17 cases had detectable TP53 mutations, associated with resistance against endocrine therapy. We conclude that liquid biopsy testing is a noninvasive, sensitive, and helpful method to optimize therapeutic decisions in metastatic BC.

Impact of trastuzumab emtansine (T-DM1) on spleen volume in patients with HER2-positive metastatic breast cancer.

Trastuzumab emtansine (T-DM1) is a novel therapy for human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer, combining the targeted action of trastuzumab with the cytotoxic effects of emtansine. Although T-DM1 has demonstrated greater efficacy and safety compared to traditional therapies, concerns about hepatotoxicity and spleen-related complications have arisen. We conducted a retrospective study of 64 HER2-positive metastatic breast cancer patients treated with T-DM1 at our institution. Patients underwent computed tomography or magnetic resonance imaging at baseline and during treatment cycles. Spleen volume, portal vein diameter, and laboratory values were compared between baseline and 12months after T-DM1 treatment. Median spleen volume significantly increased from 201cm3 (IQR, 157-275) at baseline to 291cm3 (IQR, 215-420) after 12months of T-DM1 treatment (P<0.001). Spleen enlargement was observed in 87.5% of patients, while no significant alteration was detected in portal vein diameter. The change in spleen volume was positively correlated with changes in serum globulin levels, liver enzymes, and bilirubin levels, but did not impact survival outcomes. T-DM1 therapy in HER2-positive metastatic breast cancer leads to significant spleen enlargement and systemic biochemical changes. Future studies should focus on elucidating the long-term implications of these findings and optimizing monitoring strategies for spleen-related complications.

Could macrocytosis predict survival In advanced breast cancer patients that were treated with CDK 4–6 inhibitors?

IntroductionCyclin Dependent Kinase (CDK) 4–6 inhibitors are the recommended first-line treatment option for hormone-positive metastatic breast cancer (MBC). They show their effects by causing cell cycle arrest in G1-S phase. Neutropenia is the most common haematological side effect. In the literature, data on the association between CDK 4–6 inhibitors and macrocytosis are limited. We aimed to investigate the effect of macrocytosis on survival. MethodsWe retrospectively analysed 133 patients with de novo hormone positive MBC using CDK 4–6 inhibitors in first line treatment. Mean Corpuscular Volume (MCV) > 100 was considered macrocytosis and patients were divided into two groups; MCV<100 and MCV >100. The association of macrocytosis with clinicopathological features, Progression Free Survival (PFS) and Overall Survival (OS) were evaluated. Results42 patients were receiving palbociclib and 81 patients were receiving ribociclib. Median OS was determined as 33 months and median PFS was determined as 22 months. Macrocytosis ever rate was 45.8 % during follow-up. Macrocytosis was observed in 4.2 % of the patients in the first month, 16.7 % in the third month, 41.6 % in the sixth month and 42.2 % in the twelfth month. ER receptor level, ki-67, macrocytosis at 6–12 months and macrocytosis-ever which were found to affect OS as a result of univariate Cox regression analysis, were evaluated with multivariate Cox regression models and it was observed that they had significant effect on PFS and OS. ConclusionMacrocytosis may be a useful biomarker for the prediction of PFS and OS in MBC patients receiving CDK 4–6 inhibitors.

Pre-treatment [18F]FDG PET/CT biomarkers for the prediction of antibody-drug conjugates efficacy in metastatic breast cancer.

This study aimed to evaluate the association between pretreatment [18F]FDG PET/CT-derived biomarkers and outcomes in metastatic breast cancer (mBC) patients treated with antibody-drug conjugates (ADCs) Sacituzumab Govitecan (SG) and Trastuzumab Deruxtecan (T-DXd). A retrospective bicentric analysis was conducted on triple-negative mBC (mTNBC) patients treated with SG and HER2-low mBC patients treated with T-DXd, who underwent [18F]FDG PET/CT scans before therapy. Key biomarkers, including maximum standardized uptake value (SUVmax), total metabolic tumor volume (TMTV) and maximum tumor dissemination (Dmax), were measured. Their prognostic value for progression-free survival (PFS) and overall survival (OS) was assessed using Cox models and Kaplan-Meier curves. 128 patients were included: 71 mTNBC treated with SG and 57 HR-positive and -negative HER2-low mBC treated with T-DXd. Median follow-up was 12.9months. In the SG cohort, median PFS and OS were 4.8 and 8.9months, respectively. High Dmax (HR 2.1, 95% CI 1.1-4.3) and high TMTV (HR 2.9, 95% CI 1.2-6.6) were independently associated with shorter OS. In the T-DXd cohort, median PFS and OS were 5.8 and 9.0months, respectively. High Dmax (HR 2.1, 95% CI 1.2-3.9) and high TMTV (HR 2.4, 95% CI 1.0-6.5) independently correlated with shorter PFS and shorter OS, respectively. Pretreatment [18F]FDG PET/CT-derived biomarkers, namely TMTV and Dmax, have significant prognostic value in patients with mTNBC and HER2-low mBC treated with SG and T-DXd. These biomarkers improve prognostic prediction and may optimize treatment strategies, warranting their clinical use, but larger studies are needed to validate these findings.

Expression of histone methyltransferase WHSC1 in invasive breast cancer and its correlation with clinical and pathological data

BackgroundThe WHSC1 protein facilitates specific dimethylation of histone H3 at the K36 position, enhancing gene transcription and expression. Studies have confirmed its high expression in diverse malignant tumors. We aimed to identify novel molecular markers to assess the biological behavior of breast cancer cells. MethodsWe conducted a comprehensive analysis of mRNA expression in breast cancer and adjacent tissues based on TCGA data. We enrolled 141 breast cancer patients treated at the First Affiliated Hospital of Fujian Medical University between 2012 and 2016. Patient clinical information and pathological specimens were obtained. We utilized tissue microarray (TMA) technology. We employed the chi-square test for between-group comparisons, with p < 0.05 indicating statistical significance. Furthermore, we analyzed the associations between WHSC1 expression and clinical or pathological data. ResultsWHSC1 mRNA expression was significantly higher in breast cancer tissues than in adjacent tissues (p < 0.001). Moreover, high WHSC1 protein expression in breast cancer was associated with several important clinical parameters, such as pathological type (p = 0.007), high Ki67 expression(Ki67＞20 %) (p < 0.001), lymph node metastasis (p < 0.001), T stage (p = 0.011), N stage (p < 0.001), postoperative pathological stage (p < 0.001), premenopausal status (p = 0.004), and positive HER2 status (p < 0.001). Multivariate regression analysis showed that high WHSC1 expression, elevated Ki67 levels, and positive HER2 status were independent risk factors for axillary lymph node metastasis in breast cancer patients. ConclusionWHSC1 protein expression is upregulated in breast cancer patients and represents an independent risk factor influencing axillary lymph node metastasis, highlighting its potential significance as a strong candidate biomarker.

Real-World Evidence on Prescribing Patterns and Clinical Outcomes of Metastatic Breast Cancer Patients Treated with PARP Inhibitors: The Mayo Clinic Experience

Real-World Evidence on Prescribing Patterns and Clinical Outcomes of Metastatic Breast Cancer Patients Treated with PARP Inhibitors: The Mayo Clinic Experience

Necrosis area, Tumor Size, and Lymph Node of Breast Cancer

Background: Breast cancer is the leading cause of cancer deaths in women worldwide in 2020. The high mortality rate is often influenced by various reasons, one of which is patients's prognosis. One of the prognostic factors is necrosis area, caused by hypoxic tumor tissue that can affect tumor growth and metastasis. Therefore, this study aims to determine the relationship between necrosis area with tumor size and lymph node metastasis in breast cancer patients. Methods: This study was an observational analytic with a cross-sectional approach. This research was conducted at the Anatomical Pathology Laboratory of Dr Soedarso Pontianak General Hospital and the Microscopy Laboratory of the Faculty of Medicine Tanjungpura University from September until November 2022. The study sample was 55 slides of Formalin-Fixed Paraffin-Embedded (FFPE). The study was conducted by observing the preparations under a microscope and then analyzed using ImageJ and SPSS software. The independent variable in this study was the necrosis area in the tumor microenvironment, and the dependent variables were tumor size and lymph node metastasis in breast tissue. Results: All study samples were female patients with invasive ductal carcinoma. Breast cancer tends to occur in patients aged 48-55 years. The highest percentage of necrosis area was 21% and the most diagnosed breast tumor size and lymph node metastasis were stage T4 and stage N2. Spearman's rho correlation test showed that there was no relationship between necrosis area and tumor size (p = 0.122; r = 0.16) and lymph node metastasis (p = 0.637; r = 0.18). Conclusions: There is no correlation between necrosis area with tumor size and lymph node metastasis of breast cancer patients in the Anatomical Pathology Laboratory at Dr Soedarso Pontianak General Hospital.