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Recent advancements in medical imaging have greatly enhanced the application of computational techniques in digital pathology, particularly for the classification of breast cancer using in situ hybridization (ISH) imaging. HER2 amplification, a key prognostic marker in 20–25% of breast cancers, can be assessed through alterations in gene copy number or protein expression. However, challenges persist due to the heterogeneity of nuclear regions and complexities in cancer biomarker detection. This review examines semi-automated and fully automated computational methods for analyzing ISH images with a focus on HER2 gene amplification. Literature from 1997 to 2023 is analyzed, emphasizing silver-enhanced in situ hybridization (SISH) and its integration with image processing and machine learning techniques. Both conventional machine learning approaches and recent advances in deep learning are compared. The review reveals that automated ISH analysis in combination with bright-field microscopy provides a cost-effective and scalable solution for routine pathology. The integration of deep learning techniques shows promise in improving accuracy over conventional methods, although there are limitations related to data variability and computational demands. Automated ISH analysis can reduce manual labor and increase diagnostic accuracy. Future research should focus on refining these computational methods, particularly in handling the complex nature of HER2 status evaluation, and integrate best practices to further enhance clinical adoption of these techniques. [ABSTRACT FROM AUTHOR]

Antibody–drug conjugates (ADCs) have demonstrated effectiveness in treating various cancers, particularly exhibiting specificity in targeting human epidermal growth factor receptor 2 (HER2)‐positive breast cancer. Recent advancements in phase 3 clinical trials have broadened current understanding of ADCs, especially trastuzumab deruxtecan, in treating other HER2‐expressing malignancies. This expansion of knowledge has led to the US Food and Drug Administration's approval of trastuzumab deruxtecan for HER2‐positive and HER2‐low breast cancer, HER2‐positive gastric cancer, and HER2‐mutant nonsmall cell lung cancer. Concurrent with the increasing use of ADCs in oncology, there is growing concern among health care professionals regarding the rise in the incidence of interstitial lung disease or pneumonitis (ILD/p), which is associated with anti‐HER2 ADC therapy. Studies on anti‐HER2 ADCs have reported varying ILD/p mortality rates. Consequently, it is crucial to establish guidelines for the diagnosis and management of ILD/p in patients receiving anti‐HER2 ADC therapy. To this end, a panel of Chinese experts was convened to formulate a strategic approach for the identification and management of ILD/p in patients treated with anti‐HER2 ADC therapy. This report presents the expert panel's opinions and recommendations, which are intended to guide the management of ILD/p induced by anti‐HER2 ADC therapy in clinical practice. Antihuman epidermal growth factor receptor 2 antibody–drug conjugate therapies offer significant benefits for treating human epidermal growth factor receptor 2‐positive cancers but carry risks of interstitial lung disease/pneumonitis, which, although generally manageable, requires strict adherence to evaluation and treatment guidelines to mitigate severe outcomes. This consensus from Chinese experts provides strategic recommendations for managing such risks, aiming to enhance real‐world adverse event management and improve the therapeutic safety profile of these agents. [ABSTRACT FROM AUTHOR]

In this study, we aimed to assess the concordance between HER2 positivity, defined as scores of 2+ or 3+ by immunohistochemistry (IHC), and HER2 gene amplification results obtained by fluorescence in situ hybridization (FISH) and gene panel testing (GPT). A total of 45 breast cancer patients with sufficient biopsy, breast-conserving surgery, or mastectomy specimens collected between 2018 and 2024 at Hokuto Hospital were included in the study. HER2 status was defined as HER2+ in cases with scores of 3+ on IHC staining, HER2-FISHamp in cases with scores of 2+ on IHC staining plus FISH amplification. FISH amplification was defined as a ratio of HER2 to the amplification of the chromosome 17 centromere ≥2.0. Next-generation sequencing (NGS) for these genes was conducted using MiSeq. The criterion for ERBB2 amplification requires gene amplification of more than 2 standard deviations (SD) above the average of the panel genes and CN ≥4. HER2+ correlated with the presence of NGS amplification of ERBB2 (p<0.001). NGS amplification was significantly more detectable in HER2+ than in HER2-FISHamp. HER2-FISHamp correlated with larger tumor size (p=0.009) and the presence of lymph node metastases (p<0.001). No correlations were observed between the HER2 status and other parameters such as age, histological grade, stage histological type, recurrence, treatment response evaluation, and breast cancer mortality. To achieve a comprehensive diagnosis, it is crucial to integrate GPT findings with other diagnostic approaches and to have a though understanding of the characteristics and limitations of each method. [ABSTRACT FROM AUTHOR]

Aims: Human epidermal growth factor receptor 2 (HER2) expression is an important biomarker in breast cancer (BC). Most BC cases categorised as HER2‐negative (HER2−) express low levels of HER2 [immunohistochemistry (IHC) 1+ or IHC 2+/in‐situ hybridisation not amplified (ISH−)] and represent a clinically relevant therapeutic category that is amenable to targeted therapy using a recently approved HER2‐directed antibody–drug conjugate. A group of practising pathologists, with expertise in breast pathology and BC biomarker testing, outline best practices and guidance for achieving consensus in HER2 IHC scoring for BC. Methods and results: The authors describe current knowledge and challenges of IHC testing and scoring of HER2‐low expressing BC and provide best practices and guidance for accurate identification of BCs expressing low levels of HER2. These expert pathologists propose an algorithm for assessing HER2 expression with validated IHC assays and incorporate the 2023 American Society of Clinical Oncology and College of American Pathologist guideline update. The authors also provide guidance on when to seek consensus for HER2 IHC scoring, how to incorporate HER2‐low into IHC reporting and present examples of HER2 IHC staining, including challenging cases. Conclusions: Awareness of BC cases that are negative for HER protein overexpression/gene amplification and the related clinical relevance for targeted therapy highlight the importance of accurate HER2 IHC scoring for optimal treatment selection. [ABSTRACT FROM AUTHOR]

Human epidermal growth factor receptor 3 (HER3) is the only family member of the EGRF/HER family of receptor tyrosine kinases that lacks an active kinase domain (KD), which makes it an obligate binding partner with other receptors for its oncogenic role. When HER3 is activated in a ligand-dependent (NRG1/HRG) or independent manner, it can bind to other receptors (the most potent binding partner is HER2) to regulate many biological functions (growth, survival, nutrient sensing, metabolic regulation, etc.) through the PI3K-AKT-mTOR pathway. HER3 has been found to promote tumorigenesis, tumor growth, and drug resistance in different cancer types, especially breast and non-small cell lung cancer. Given its ubiquitous expression across different solid tumors and role in oncogenesis and drug resistance, there has been a long effort to target HER3. As HER3 cannot be targeted through its KD with small-molecule kinase inhibitors via the conventional method, pharmaceutical companies have used various other approaches, including blocking either the ligand-binding domain or extracellular domain for dimerization with other receptors. The development of treatment options with anti-HER3 monoclonal antibodies, bispecific antibodies, and different combination therapies showed limited clinical efficiency for various reasons. Recent reports showed that the extracellular domain of HER3 is not required for its binding with other receptors, which raises doubt about the efforts and applicability of the development of the HER3-antibodies for treatment. Whereas HER3-directed antibody-drug conjugates showed potentiality for treatment, these drugs are still under clinical trial. The currently understood model for dimerization-induced signaling remains incomplete due to the absence of the crystal structure of HER3 signaling complexes, and many lines of evidence suggest that HER family signaling involves more than the interaction of two members. This review article will significantly expand our knowledge of HER3 signaling and shed light on developing a new generation of drugs that have fewer side effects than the current treatment regimen for these patients.

Purpose: Many patients with early breast cancer (eBC) undergoing neoadjuvant chemotherapy do not achieve pathological complete response (pCR), which is a prognostic factor. We examined the role of HER2-low expression in predicting pCR and prognosis in HER2-negative eBC. Methods: We evaluated patients with stage I-III HER2-negative BC, treated between 2013 and 2023 at The Royal Marsden NHS Foundation Trust, London. Tumors were classified based on estrogen receptor (ER) status and into HER2-low and HER2-zero subgroups. We analyzed pCR rates, relapse-free survival (RFS) and overall survival (OS). Results: 754 patients were included in the analysis. pCR rate was 8.9% in the ER+ /HER2-low, 16.5% in the ER+ /HER2-zero, 38.9% in the ER- ER-/HER2-low and 35.9% in the ER-/HER2-zero eBC (p < 0.001). Multivariable analysis showed a significantly lower pCR rate in HER2-low compared to HER2-zero BC in the ER+ subgroup. At a median follow-up of 63.8 months (59.9–67.4), we observed longer OS in HER2-low compared to HER2-zero patients in the overall and in the ER+ population. There was no predictive or prognostic impact of HER2-low status in the ER- population. Conclusion: This study supports the interpretation of HER2 status as a possible prognostic and predictive biomarker for HER2-negative eBC, especially among patients with ER+ disease. [ABSTRACT FROM AUTHOR]

Positron emission tomography (PET) plays a crucial role in breast cancer management. This review addresses the role of PET imaging in breast cancer care. We focus primarily on the utility of 18F-fluorodeoxyglucose (FDG) PET in staging, recurrence detection, and treatment response evaluation. Furthermore, we delve into the growing interest in precision therapy and the development of novel radiopharmaceuticals targeting tumor biology. This includes discussing the potential of PET/MRI and artificial intelligence in breast cancer imaging, offering insights into improved diagnostic accuracy and personalized treatment approaches. [ABSTRACT FROM AUTHOR]

Fam-trastuzumab deruxtecan (T-DXd) has demonstrated substantial antitumor activity and durable responses in patients with human epidermal growth factor receptor 2 positive (HER2+) metastatic breast cancer. We report here the treatment outcomes of T-DXd in a patient with HER2+ breast cancer with brain metastases that repeatedly recurred and progressed after two lines of salvage therapy. In 2016, a 23-year-old G0P0 female with risk factors including menarche at age 9 years, Li-Fraumeni syndrome, and a strong family history of cancer was diagnosed with bilateral, triple-positive breast cancer. She received chemotherapy, HER2-targeted therapies, total mastectomy, and locoregional radiotherapy, but a brain metastasis in the left parieto-occipital lobe was detected in 2020. After receiving capecitabine, lapatinib, gonadotropin-releasing hormone (GnRH) agonist, and tamoxifen, multiple new lesions appeared in the brain after 14 months. The patient then received capecitabine, neratinib, GnRH agonist, and letrozole; however, her brain metastases still progressed after 7 months. In 2022, she started T-DXd treatment. Good response to treatment was observed 4 months later, including a continuous decrease in the cancer antigen 15-3 level, a reduction in the size of the major brain tumor, and the absence of new lesions. Now aged 30, the patient is continuing to receive T-DXd treatment to prevent recurrence. We conclude that T-DXd was effective for the treatment of brain metastases in this young patient with triple-positive metastatic breast cancer who had multiple risk factors and had received several anti-HER2 therapies prior to T-DXd.

Breast cancer is the most common diagnosed cancer, and the second cause of cancer death among women, worldwide. HER2 overexpression occurred in approximately 15% to 20% of breast cancers. Invasive biopsy method has been used for detection of HER2 overexpression. HER2-targeted imaging via an appropriate radionuclide is a promising method for sensitive and accurate identification of HER2+ primary and metastatic lesions. 99mTc-anti-HER2 scFv can specifically target malignancies and be used for diagnosis of the cancer type and metastasis as well as treatment of breast cancer. We radiolabeled anti-HER2 scFv that was expressed in Escherichia coli and purified through Ni-NTA resin under native condition with 99mTc-tricarbonyl formed from boranocarbonate. HER2-based ELISA, BCA, TLC, and HPLC were used in this study. In the current study, anti-HER2 scFv was lyophilized before radiolabeling. It was found that freeze-drying did not change the binding activity of anti-HER2 scFv to HER2. Results demonstrated direct anti-HER2 scFv radiolabeling by 99mTc-tricarbonyl to hexahistidine sequence (His-tag) without any changes in biological activity and radiochemical purity of around 98%. Stability analysis revealed that 99mTc-anti-HER2 scFv is stable for at least 24 h in PBS buffer, normal saline, human plasma proteins, and histidine solution. [ABSTRACT FROM AUTHOR]

The treatment landscape for patients affected by gastric and colorectal cancer (G&CRC) has significantly broadened over the past decade. Molecular diagnostic methods have improved with a precision oncology-driven approach to the development of treatment options tailored to specific molecular targets, including the human epidermal growth factor 2 (HER2). While scientific evidence on the role of HER2 in G&CRC has improved, there has been a lag in general understanding and applications of testing for HER2+ G&CRC and resulting targeting treatment in the wider oncology community. To better understand and address the root causes of this gap, a needs assessment deployed among 85 oncology care providers was conducted and informed the development of an accredited online educational program entitled "GetSMART." The program consisted of four modules developed and narrated by experts in gastrointestinal oncology. The educational content and assessment metrics were guided by a confidence-based assessment (CBA) model and the Moore, Green, and Gallis outcomes framework. Assessment methods consisted of quantitative pre- and post-activity tests, an evaluation embedded within the education (n = 163), and semi-structured interviews (n = 5) post-activity completion. Findings indicated that "GetSMART" enhanced participants' knowledge, confidence, and intent to change practice in relation to their (1) identification of HER2 aberrations, (2) selection of appropriate treatments for HER2+ G&CRC, and (3) ability to engage patients in shared decision-making and management of adverse events. "GetSMART" can therefore be a valuable educational resource for oncology HCPs caring for patients affected by HER2+ metastatic G&CRC, offering strategies to ensure an optimal team and patient-centered approach to the care being delivered. [ABSTRACT FROM AUTHOR]

AbstractThis study aimed to compare the efficacy of pyrotinib, trastuzumab combined with chemotherapy with different lines therapy in human epidermal growth factor receptor 2- (HER2-) positive advanced breast cancer (ABC) and analyze the factors affecting the prognosis. A total of 84 patients with median age of 49 year-old. The mPFS of patients receiving first-line pyrotinib plus trastuzumab and chemotherapy was the longest (11 months) compared with second- and third line patients (p = 0.106). The objective response rate (ORR) and disease control rate (DCR) of the total population were 33.3% and 82.1% respectively. Subgroup analysis suggested that using pyrotinib plus trastuzumab and Albumin-bound paclitaxel was not inferior to combine with Vinorelbine in regards of PFS. Histological grade (OR: 0.233[0.069 ∼ 0.781], p = 0.018) and tumor location (OR: 0.286[0.087 ∼ 0.942], p = 0.040) were independent factors influencing the ORR. Multivariate cox analysis showed that Ki-67 was independently associated with increased risk of progression (HR: 1.843[1.044-3.254], p = 0.035). The most common adverse events were diarrhea (17.9%) and neutropenia (11.9%). In the first-, second- and third-line treatment, pyrotinib plus trastuzumab and chemotherapy is effective and safe. Pyrotinib and trastuzumab combined with Albumin-bound paclitaxel may be a potential ideal treatment plan for HER2-positive advanced breast cancer. [ABSTRACT FROM AUTHOR]

Background: With the largest sample size to date, the authors' objective was to investigate the incidence of primary‐to‐metastatic human epidermal growth factor 2 (HER2) conversion and the predictors for such conversion. Moreover, no previous studies have evaluated the prognosis of patients who have negative HER2 expression (HER2‐0) versus low HER2 expression (HER2‐low) when HER2 status was assessed based on all recurrent/metastatic lesions. Methods: The authors included 1299 patients who had available HER2 status of primary breast tumors and paired recurrent/metastatic lesions at Fudan University Shanghai Cancer Center and West China Hospital. Results: In total, 370 patients (28.5%) experienced primary‐to‐metastatic HER2 conversion. Intrapatient intermetastasis spatial heterogeneity and temporal heterogeneity of HER2 were detected. When assessing HER2 based on recurrent/metastatic tumors, patients who had HER2‐0 tumors had significantly shorter overall survival than those who had HER2‐low tumors in the overall population and in the estrogen receptor (ER)‐negative subgroup. However, when assessing HER2 based on primary tumors, there was no difference in overall survival between patients who had HER2‐0 versus HER2‐low tumors. Moreover, patients who had tumors that converted from HER2‐0 to HER2‐low had longer overall survival than those who had consistent HER2‐0 status in the ER‐negative subgroup. By combining four predictors (ER status, Ki67 index, biopsy site, and disease‐free interval), the authors established the first prediction tool to estimate the probability of HER2‐0 tumors converting to HER2‐low/positive tumors. Conclusions: Intrapatient primary‐to‐metastatic and intermetastatic HER2 heterogeneity were observed in this large‐scale cohort study. When evaluating HER2 based on recurrent/metastatic tumors, an overall survival difference was observed between patients who had HER2‐0 versus HER2‐low, recurrent/metastatic breast tumors. The developed prediction tool might help clinicians screen out patients with primary HER2‐0 tumors that have a high probability of HER2 status conversion and recommend them for re‐biopsy, thus helping to screen out candidate patients for trastuzumab deruxtecan treatment. Intrapatient primary‐to‐metastatic and intermetastatic HER2 heterogeneity was observed in this large‐scale cohort study. The prediction tool developed by the authors might help clinicians screen out patients with primary HER2‐negative tumors who have a high probability of HER2 status conversion and recommend them for re‐biopsy, thus helping to screen out candidate patients for trastuzumab deruxtecan treatment. [ABSTRACT FROM AUTHOR]

Simple Summary: In advanced, unresectable and metastatic gastric and gastroesophageal junction adenocarcinoma (GA/GEJA), Human Epidermal Growth Factor Receptor 2 (HER2) and programmed death-ligand 1 (PD-L1) expression play an important role in treatment selection. However, their potential clinical application in earlier stages of disease remains unexplored. The aim of this study was to evaluate the expression patterns of HER2 and PD-L1 in a curative-intent GA/GEJA cohort. Furthermore, we analyzed the association between HER2 expression and clinicopathological features. Among 107 patients, 8.4% were HER2-positive and seven of these also had a PD-L1 combined positive score of ≥1. HER2 status was not statistically significantly associated with survival outcomes. A pathologist-guided, region-specific analysis revealed that PD-L1 expression rarely overlaps with HER2-positive tumor areas. These novel findings indicate that combinatorial strategies targeting HER2 and PD-L1 might be directed toward distinct tumor subclones. These different biomarker expression patterns may have important therapeutic and prognostic implications. Gastric and gastroesophageal junction adenocarcinomas (GA/GEJA) are associated with a poor prognosis, primarily due to late disease diagnosis. Human Epidermal Growth Factor Receptor 2 (HER2) overexpression and programmed death-ligand 1 (PD-L1) expression are important biomarkers for treatment selection in locally advanced unresectable and metastatic GA/GEJA, and there is increasing interest in their role in earlier stages of disease. In this study, we aimed to evaluate HER2 and PD-L1 expression in a curative-intent GA/GEJA cohort to describe their expression patterns and analyze the association between HER2 expression and clinicopathological features. HER2 expression was evaluated in surgical and endoscopic submucosal dissection tumor samples, and PD-L1 was evaluated in HER2-positive cases. The clinical cohort included 107 patients, with 8.4% testing positive for HER2 (seven of whom also exhibited a PD-L1 combined positive score of ≥1. HER2 status was not significantly associated with survival outcomes. A pathologist-guided, region-specific analysis revealed that PD-L1 expression rarely overlaps with HER2-positive tumor areas. While the therapeutic implications of these observations remain unknown, these findings suggest that combination strategies targeting HER2 and PD-L1 might be directed toward distinct tumor subclones. The herein disclosed region-specific biomarker expression patterns may have important therapeutic and prognostic impacts, warranting further evaluation. [ABSTRACT FROM AUTHOR]

Abstract Background Accurate classification of breast cancer molecular subtypes is crucial in determining treatment strategies and predicting clinical outcomes. This classification largely depends on the assessment of human epidermal growth factor receptor 2 (HER2), estrogen receptor (ER), and progesterone receptor (PR) status. However, variability in interpretation among pathologists pose challenges to the accuracy of this classification. This study evaluates the role of artificial intelligence (AI) in enhancing the consistency of these evaluations. Methods AI-powered HER2 and ER/PR analyzers, consisting of cell and tissue models, were developed using 1,259 HER2, 744 ER, and 466 PR-stained immunohistochemistry (IHC) whole-slide images of breast cancer. External validation cohort comprising HER2, ER, and PR IHCs of 201 breast cancer cases were analyzed with these AI-powered analyzers. Three board-certified pathologists independently assessed these cases without AI annotation. Then, cases with differing interpretations between pathologists and the AI analyzer were revisited with AI assistance, focusing on evaluating the influence of AI assistance on the concordance among pathologists during the revised evaluation compared to the initial assessment. Results Reevaluation was required in 61 (30.3%), 42 (20.9%), and 80 (39.8%) of HER2, in 15 (7.5%), 17 (8.5%), and 11 (5.5%) of ER, and in 26 (12.9%), 24 (11.9%), and 28 (13.9%) of PR evaluations by the pathologists, respectively. Compared to initial interpretations, the assistance of AI led to a notable increase in the agreement among three pathologists on the status of HER2 (from 49.3 to 74.1%, p

Recent advancements in medical imaging have greatly enhanced the application of computational techniques in digital pathology, particularly for the classification of breast cancer using in situ hybridization (ISH) imaging. HER2 amplification, a key prognostic marker in 20–25% of breast cancers, can be assessed through alterations in gene copy number or protein expression. However, challenges persist due to the heterogeneity of nuclear regions and complexities in cancer biomarker detection. This review examines semi-automated and fully automated computational methods for analyzing ISH images with a focus on HER2 gene amplification. Literature from 1997 to 2023 is analyzed, emphasizing silver-enhanced in situ hybridization (SISH) and its integration with image processing and machine learning techniques. Both conventional machine learning approaches and recent advances in deep learning are compared. The review reveals that automated ISH analysis in combination with bright-field microscopy provides a cost-effective and scalable solution for routine pathology. The integration of deep learning techniques shows promise in improving accuracy over conventional methods, although there are limitations related to data variability and computational demands. Automated ISH analysis can reduce manual labor and increase diagnostic accuracy. Future research should focus on refining these computational methods, particularly in handling the complex nature of HER2 status evaluation, and integrate best practices to further enhance clinical adoption of these techniques.

Background: Accurate classification of breast cancer molecular subtypes is crucial in determining treatment strategies and predicting clinical outcomes. This classification largely depends on the assessment of human epidermal growth factor receptor 2 (HER2), estrogen receptor (ER), and progesterone receptor (PR) status. However, variability in interpretation among pathologists pose challenges to the accuracy of this classification. This study evaluates the role of artificial intelligence (AI) in enhancing the consistency of these evaluations. Methods: AI-powered HER2 and ER/PR analyzers, consisting of cell and tissue models, were developed using 1,259 HER2, 744 ER, and 466 PR-stained immunohistochemistry (IHC) whole-slide images of breast cancer. External validation cohort comprising HER2, ER, and PR IHCs of 201 breast cancer cases were analyzed with these AI-powered analyzers. Three board-certified pathologists independently assessed these cases without AI annotation. Then, cases with differing interpretations between pathologists and the AI analyzer were revisited with AI assistance, focusing on evaluating the influence of AI assistance on the concordance among pathologists during the revised evaluation compared to the initial assessment. Results: Reevaluation was required in 61 (30.3%), 42 (20.9%), and 80 (39.8%) of HER2, in 15 (7.5%), 17 (8.5%), and 11 (5.5%) of ER, and in 26 (12.9%), 24 (11.9%), and 28 (13.9%) of PR evaluations by the pathologists, respectively. Compared to initial interpretations, the assistance of AI led to a notable increase in the agreement among three pathologists on the status of HER2 (from 49.3 to 74.1%, p < 0.001), ER (from 93.0 to 96.5%, p = 0.096), and PR (from 84.6 to 91.5%, p = 0.006). This improvement was especially evident in cases of HER2 2+ and 1+, where the concordance significantly increased from 46.2 to 68.4% and from 26.5 to 70.7%, respectively. Consequently, a refinement in the classification of breast cancer molecular subtypes (from 58.2 to 78.6%, p < 0.001) was achieved with AI assistance. Conclusions: This study underscores the significant role of AI analyzers in improving pathologists' concordance in the classification of breast cancer molecular subtypes. [ABSTRACT FROM AUTHOR]

Background: Gene mutations play a crucial role in the occurrence and development of tumors, particularly in breast cancer (BC). Neoadjuvant therapy (NAT) has shown greater clinical benefit in HER2‐positive breast cancer. However, further clinical investigation is needed to fully understand the correlation between genetic mutations and NAT efficacy and the long‐term prognosis in HER2‐positive BC. Methods: This was a retrospective cohort study of 222 patients receiving NAT between 2017 and 2021 in the Department of Breast Surgery of Fudan University Shanghai Cancer Center. Tumor samples from these patients were subjected to Next Generation Sequencing (NGS) to analyze mutations in 513 cancer‐related genes. This study aimed to investigate the association between these genetic mutations and postoperative pathological complete response (pCR), as well as their impact on disease‐free survival (DFS). Results: In total, 48.65% patients reached pCR, ER‐negative status (p < 0.001), PR‐negative status (p < 0.001), Ki67 ≥ 20 (p = 0.011), and dual‐targeted therapy (p < 0.001) were all associated with enhanced pCR rates. The frequency of somatic alterations in TP53 (60%), PIK3CA (15%), and ERBB2 (11%) was highest. In the HER2+/HR‐ cohort, patients who achieved pCR had a significant benefit in prognosis (HR = 3.049, p = 0.0498). KMT2C (p = 0.036) and TP53 (p = 0.037) mutations were significantly increased in patients with DFS events. Moreover, TP53 mutations had prognostic significance in HER2‐positive BC patients with HR‐negative (HR = 3.712, p = 0.027) and pCR (HR = 6.253, p = 0.027) status and who received herceptin‐only targeted therapy (HR = 4.145, p = 0.011). Conclusions: The genetic mutation profiles of Chinese HER2+ patients who received NAT were discrepant with respect to HR status or DFS events. TP53 mutations have significant prognostic value in patients with NAT for HER2‐positive BC and patients benefit differently depending on HR status, the neoadjuvant regimen and response, which highlights the significance of genetic factors in treatment customization based on individual genetic and clinical characteristics. [ABSTRACT FROM AUTHOR]

In recent decades, there has been a surge in the approval of monoclonal antibodies for treating a wide range of hematological and solid malignancies. These antibodies exhibit exceptional precision in targeting the surface antigens of tumors, heralding a groundbreaking approach to cancer therapy. Nevertheless, monoclonal antibodies alone do not show sufficient lethality against cancerous cells compared to chemotherapy. Consequently, a new class of anti-tumor medications, known as antibody-drug conjugates (ADCs), has been developed to bridge the divide between monoclonal antibodies and cytotoxic drugs, enhancing their therapeutic potential. ADCs are chemically synthesized by binding tumor-targeting monoclonal antibodies with cytotoxic payloads through linkers that are susceptible to cleavage by intracellular proteases. They combined the accurate targeting of monoclonal antibodies with the potent efficacy of cytotoxic chemotherapy drugs while circumventing systemic toxicity and boasting superior lethality over standalone targeted drugs. The human epidermal growth factor receptor (HER) family, which encompasses HER1 (also known as EGFR), HER2, HER3, and HER4, plays a key role in regulating cellular proliferation, survival, differentiation, and migration. HER2 overexpression in various tumors is one of the most frequently targeted antigens for ADC therapy in HER2-positive cancers. HER2-directed ADCs have emerged as highly promising treatment modalities for patients with HER2-positive cancers. This review focuses on three approved anti-HER2 ADCs (T-DM1, DS-8201a, and RC48) and reviews ongoing clinical trials and failed trials based on anti-HER2 ADCs. Finally, we address the notable challenges linked to ADC development and underscore potential future avenues for tackling these hurdles.

Abstract Background Considering the recent advancements in the treatment of breast cancer with low expression of human epidermal growth factor receptor 2 (HER2), we aimed to examine inter-laboratory variability in the assessment of HER2-low breast cancer across all Danish pathology departments. Methods From the Danish Breast Cancer Group, we obtained data on all women diagnosed with primary invasive breast cancer in 2007–2019 who were subsequently assigned for curatively intended treatment. Results Of 50,714 patients, HER2 score and status were recorded for 48,382, among whom 59.2% belonged to the HER2-low group (score 1+ or 2+ without gene amplification), 26.8% had a HER2 score of 0, and 14.0% were HER2 positive. The proportion of HER2-low cases ranged from 46.3 to 71.8% among pathology departments (P

ObjectivePyrotinib and pertuzumab are effective treatment options for HER2-positive metastatic breast cancer (HER2+ MBC). Our study was to directly compare the efficacy and safety of pyrotinib plus trastuzumab (PyroH) and pertuzumab plus trastuzumab (HP) in patients with HER2+ MBC.MethodsWe conducted a retrospective examination of HER2+ MBC patients who received PyroH plus chemotherapy or HP plus chemotherapy between 2017 and 2022 at five institutions in China. Our primary endpoint was progression-free survival (PFS).ResultsThis study involved 333 patients, among which 161 received PyroH and 172 received HP. The utilization of PyroH as a first-line therapy for MBC was more prevalent among older patients, those with a shorter duration of disease-free interval, or those who had previously been treated with trastuzumab. Although in the first-line advanced treatment HP cohort showed numerically longer PFS (median PFS: 14.46 vs. 22.90 months, p=0.057), in the second-line or later treatments, there was no significant difference in PFS between the PyroH and HP groups (median PFS: 8.67 vs. 7.92 months, p=0.286). Despite HP showing a longer PFS in the overall cohort (median PFS: 9.30 vs. 13.01 months, p=0.005), it did not serve as an independent predictor of PFS in the multivariate analysis (HR 1.134, 95% CI 0.710-1.811, p=0.598). Without taxane, PyroH demonstrated a longer PFS than HP (median PFS: 10.12 vs. 8.15 months, p=0.017). PyroH group displayed a numerically longer median PFS in patients with brain metastases compared to the HP group, though not statistically significant (median PFS: 9.03 vs. 8.15 months, p=0.976). PyroH had higher incidence of grade 3/4 diarrhea (34.3% vs. 3.0%) but similar overall adverse events.ConclusionIn conclusion, PyroH is comparable in second-line or later treatment and during brain metastasis, even having superior efficacy without taxane in real-world setting. Toxicities were tolerable in both groups. (ClinicalTrials.gov: NCT05572645)

Background: Considering the recent advancements in the treatment of breast cancer with low expression of human epidermal growth factor receptor 2 (HER2), we aimed to examine inter-laboratory variability in the assessment of HER2-low breast cancer across all Danish pathology departments. Methods: From the Danish Breast Cancer Group, we obtained data on all women diagnosed with primary invasive breast cancer in 2007–2019 who were subsequently assigned for curatively intended treatment. Results: Of 50,714 patients, HER2 score and status were recorded for 48,382, among whom 59.2% belonged to the HER2-low group (score 1+ or 2+ without gene amplification), 26.8% had a HER2 score of 0, and 14.0% were HER2 positive. The proportion of HER2-low cases ranged from 46.3 to 71.8% among pathology departments (P < 0.0001) and from 49.3 to 65.6% over the years (P < 0.0001). In comparison, HER2 positivity rates ranged from 11.8 to 17.2% among departments (P < 0.0001) and from 12.6 to 15.7% over the years (P = 0.005). In the eight departments with the highest number of patients, variability in HER2-low cases increased from 2011 to 2019, although the same immunohistochemical assay was used. By multivariable logistic regression, the examining department was significantly related to both HER2 score 0 and HER2 positivity (P < 0.0001) but showed greater dispersion in odds ratios in the former case (range 0.25–1.41 vs. 0.84–1.27). Conclusions: Our data showed high inter-laboratory variability in the assessment of HER2-low breast cancer. The findings cast doubt on whether the current test method for HER2 is robust and reliable enough to select HER2-low patients for HER2-targeted treatment in daily clinical practice. [ABSTRACT FROM AUTHOR]

Background: As the implementation of trastuzumab, several studies have investigated new agents and regimens to treat human epidermal growth factor 2-positive (HER2+) metastatic breast cancer (MBC). However, long-term survival analyses from HER2-targeted therapies are lacking. This is a 20-year follow-up study of a phase II trial that evaluated the activity and safety of docetaxel in combination with carboplatin and trastuzumab (TCH) in patients with HER2+ MBC. Materials and Methods: This is a follow-up of a phase II, single-arm, open-label study. The primary objective was the activity from the combination of TCH in terms of response rate (RR). Secondary objectives included the activity from TCH in terms of response duration (RD), time to progression (TTP), overall survival (OS), and percent one-year survival. Results: Between 11/1999 and 10/2002, 40 women were enrolled. Most patients (67.5%) had visceral metastasis on enrollment. After 2 decades and 3 months from first enrollment, there were 4 (10%) survivors (median follow-up of 3.2 years). The RR for complete response (CR) or partial response (PR) was 72.5%. The RR for CR was 42.5%. RD was 8 months. Median TTP was 10.8 months. Participants achieved a median OS of 39.8 months. Percent one-year survival was 92.5%. Conclusion: A subset of patients (10%) receiving trastuzumab in the metastatic setting have achieved long-term survival beyond 20 years. Long-term survival analyses of HER2-targeted therapies are lacking. This is a 20-year follow-up study of a phase II trial that evaluated the activity and safety of docetaxel in combination with carboplatin and trastuzumab in patients with HER2+ metastatic breast cancer. [ABSTRACT FROM AUTHOR]

Although single-chain variable fragment (scFv) is recognized as a highly versatile scaffold of recombinant antibody fragment molecules, its overexpression in Escherichia coli often leads to the formation of inclusion bodies. To address this issue, we devised and tested four different constructs, named v21, v22, v23 and v24, for producing anti-human epidermal growth factor receptor 2 (HER2) scFv. Among them, the v24 construct obtained from N-terminal fusion of maltose-binding protein (MBP) and subsequent tobacco etch virus protease (TEV) was identified as the most efficient construct for the production of anti-HER2 scFv. Aided by an MBP tag, high-yield soluble expression was ensured and soluble scFv was liberated in cells via autonomous proteolytic cleavage by endogenously expressed TEV. The isolated scFv containing a C-terminal hexahistidine tag was purified through a one-step purification via nickel-affinity chromatography. The purified scFv exhibited a strong (nanomolar Kd) affinity to HER2 both in vitro and in cells. Structural and functional stabilities of the scFv during storage for more than one month were also assured. Given the great utility of anti-HER2 scFv as a basic platform for developing therapeutic and diagnostic agents for cancers, the v24 construct and methods presented in this study are expected to provide a better manufacturing system for producing anti-HER2 scFv with various industrial applications. [ABSTRACT FROM AUTHOR]

Perforated gastric adenocarcinoma is a rare and challenging complication of gastric cancer, which can lead to intra‐abdominal abscesses and other complications. Management of perforated gastric adenocarcinoma with an intra‐abdominal abscess requires a multidisciplinary approach, including empiric antibiotic therapy and fluid resuscitation, partial gastrectomy with Roux‐en‐Y reconstruction, and image‐guided drainage. This case report highlights the complex and challenging nature of managing perforated gastric adenocarcinoma with intra‐abdominal abscesses. Prompt recognition and timely intervention are essential for favorable outcomes. Postoperative care and close follow‐up are also important. [ABSTRACT FROM AUTHOR]

Abstract Perforated gastric adenocarcinoma is a rare and challenging complication of gastric cancer, which can lead to intra‐abdominal abscesses and other complications. Management of perforated gastric adenocarcinoma with an intra‐abdominal abscess requires a multidisciplinary approach, including empiric antibiotic therapy and fluid resuscitation, partial gastrectomy with Roux‐en‐Y reconstruction, and image‐guided drainage. This case report highlights the complex and challenging nature of managing perforated gastric adenocarcinoma with intra‐abdominal abscesses. Prompt recognition and timely intervention are essential for favorable outcomes. Postoperative care and close follow‐up are also important.

Purpose: The aim of this study was to estimate the Italian burden of incident breast cancer (BC) by subtypes, according to the distribution of hormonal receptor (HR) status and expression of human epidermal growth factor 2 (HER2). Methods: Female breast cancers incidence in the Romagna Unit of the Emilia-Romagna registry (n. 10,711) were grouped into: HR+ /HER2–, HR+ /HER2+ , HR–/HER2+ , HR–/HER2– and missing, and by age: < 50, 50–69 and 70+ years. Data were compared with other published Italian population-bases series before using them for national estimates. We used national and regional numbers of expected breast cancers published by the Italian network of cancer registries considering the age- and geographic-specific variation of the Italian population. Results: Overall, 70.7% of incident BC cases are expected to be HR+ /HER2-, 8.5% HR+ /HER2+ , 7.5% HR-/HER2-, 4.1% HR-/HER2+ and 9.3% missing. The global ranking is similar across age-groups but with age-specific differences. The proportion of missing was around 3-times lower than in the other Italian published population-based series and similar to the SEER one. In Italy, are estimated 38,841 HR+ /HER2- breast cancer cases, 4665 HR+ /HER2+ , 4098 HR-/HER2-, 2281 HR-/HER2+ , and 5092 not specified. Numbers by age-group were provided. Conclusions: The present estimates relied on high-quality population-based data and provide a clinically relevant information on the burden of breast cancer subtypes. These data will support the planning of therapy needs for oncologists, decision-makers, and all other stakeholders. [ABSTRACT FROM AUTHOR]

Background: The optimal treatment strategy for patients with small human epidermal growth factor receptor 2 (HER2)‐positive tumors is based on nodal status. The authors' objective was to evaluate pathologic nodal disease (pathologic lymph node‐positive [pN‐positive] and pathologic lymph node‐positive after preoperative systemic therapy [ypN‐positive]) rates in patients who had clinical T1–T2 (cT1–cT2)N0M0, HER2‐positive breast cancer treated with upfront surgery or neoadjuvant chemotherapy (NAC). Methods: Two databases were queried for patients who had cT1–cT2N0M0, HER2‐positive breast cancer: (1) the Dana‐Farber Brigham Cancer Center (DF/BCC) from February 2015 to October 2020 and (2) the Hospital Clinic of Barcelona and the Hospital Clinico of Valencia (HCB/HCV) from January 2012 to September 2021. The pN‐positive/ypN‐positive and axillary lymph node dissection (ALND) rates were compared between patients who underwent upfront surgery versus those who received NAC. Results: Among 579 patients from the DF/BCC database, 368 underwent upfront surgery, and 211 received NAC; the rates of nodal positivity were 19.8% and 12.8%, respectively (p =.021). The pN‐positive rates increased by tumor size (p <.001), reaching 25% for those with cT1c tumors. The ypN‐positive rates did not correlate with tumor size. NAC was associated with decreased nodal positivity (odds ratio, 0.411; 95% confidence interval, 0.202–0.838), but the ALND rates were similar (22 of 368 patients [6.0%] who underwent upfront surgery vs. 18 of 211 patients [8.5%] who received NAC; p =.173). Among 292 patients from the HCB/HCV database, 119 underwent upfront surgery, and 173 received NAC; the rates of nodal positivity were 21% and 10.4%, respectively (p =.012). The pN‐positive rates increased with tumor size (p =.011). The ALND rates were equivalent by treatment strategy (23 of 119 patients [19.3%] who underwent upfront surgery vs. 24 of 173 patients [13.9%] who received NAC; p =.213). Conclusions: Among patients who had cT1–cT2N0M0, HER2‐positive breast cancer, approximately 20% who underwent upfront surgery were pN‐positive, and the rate reached 25% for those with cT1c tumors. Given the opportunity for tailored therapy among lymph node‐positive, HER2‐positive patients, these data provide rationale for future analyses investigating the utility of routine axillary imaging in patients with HER2‐positive breast cancer. Data from patients with clinical T1–T2N0, human epidermal growth factor receptor 2‐positive breast cancer who either underwent upfront surgery or received neoadjuvant chemotherapy were extracted from two institutional databases. Nodal positivity rates were >20% at upfront surgery; neoadjuvant chemotherapy decreased nodal positivity rates, but axillary lymph node dissection rates were equivalent. [ABSTRACT FROM AUTHOR]

Abstract Near‐infrared photoimmunotherapy (NIR‐PIT) is a novel form of cancer treatment using conjugates of antibody against overexpressed antigens in cancers and photoabsorber IRDye700DX. HER2 is overexpressed in various cancers, for which molecular targeted therapy such as trastuzumab has been developed. The present study investigated the efficacy potential of HER2‐targeted NIR‐PIT using trastuzumab‐IRDye700DX conjugate (Tra‐IR700) in HER2‐positive breast cancer. We first examined the reactivity of Tra‐IR700 and the cytotoxicity of NIR‐PIT in vitro. HER2‐positive BT‐474 and SK‐BR‐3 cells and HER2‐negative BT‐20 cells were used. Tra‐IR700 fluorescence was only observed in HER2‐positive breast cancer cell lines, and the fluorescence was localized to the cell surface. Furthermore, HER2‐positive breast cancer cell lines treated with NIR‐PIT showed swelling and blebbing shortly after irradiation, and eventually increased PI‐positive dead cells. Next, tumor accumulation of Tra‐IR700 and tumor damage by NIR‐PIT were examined in vivo. Tra‐IR700 was administered intravenously to a xenograft model in which BT‐474 cells were implanted subcutaneously in BALB/c nude mice. Tra‐IR700 fluorescence was the highest in tumor tissue 1 day after administration, and the fluorescence was localized to the cell membrane of tumor cells. At this time point, NIR‐PIT resulted in diffuse necrosis of tumor tissues 1 day after irradiation. These results suggest that NIR‐PIT with Tra‐IR700 induces a highly selective therapeutic effect in a HER2‐positive breast cancer model. NIR‐PIT using Tra‐IR700 is expected to be a novel treatment for HER2‐positive cancers, including breast cancer.

Abstract Background Breast cancer is the leading cause of cancer-related mortality in women. Human epidermal growth factor receptor 2 (HER2) overexpression is seen in 20 out of 100 invasive breast cancers. Among HER2+ patients, two distinct hormone receptor (HR) subtypes can be defined: HR-positive (HR+) and HR-negative (HR−) each of which with unique therapeutic response and survival pattern. Contrast-enhanced spectral mammography (CESM) is an emerging novel imaging modality that offers diagnostic performance comparable to contrast-enhanced MRI. The purpose of this retrospective study was to describe the CESM features of HER2+ breast cancers according to hormone receptor status and to assess whether specific mammographic and CESM imaging features can differentiate between HER2+/HR+ and HER2+/HR− breast cancers potentially aiding treatment planning in HER2+ breast cancer patients. Results A total of 61 patients were included. Twenty-nine cases (47.5%) were HER2+/HR+ and 32 cases (52.5%) were HER2+/HR−. No statistically significant difference was found between mammographic imaging presentations and hormonal status. HR- were more likely to be multifocal (P 0.018), rounded or oval (P 0.008), circumscribed (P 0.004), and with associated non-mass enhancement (NME) (P

Objectives Extensive application of anti-HER2 targeted therapy improves significantly the HER2-positive advanced breast cancer (BC) prognosis, however, it is still difficult to treat brain metastasis. In current study, we explored effective approaches via combining pyrotinib to treat brain metastasis in patients with HER2-positive advanced BC based upon clinical data.Materials and methods Current study included 61 HER2-positive BC patients with brain metastases (BM) who were treated by pyrotinib-based regimens. The systemic regimens included pyrotinib combined with capecitabine, pyrotinib combined with nab-paclitaxel, and pyrotinib combined with vinorelbine. Patients’ progression-free survival (PFS), overall survival (OS), clinical benefit rate (CBR) and objective response rate (ORR), as well as drug-related adverse events (AEs) in regard of each combination regimen were analyzed.Results Pyrotinib-based systemic therapy resulted in 8.6 months median PFS (mPFS) and 18.0 months median OS (mOS) among the BM patients. Regarding different regimens, the combination of pyrotinib with nab-paclitaxel was superior to the combination with capecitabine and vinorelbine with respect to PFS and OS. The central nervous system (CNS) ORR did not showcase significant difference among 3 regimens, however, nab-paclitaxel combined regimen obtained the best peripheral ORR (84.6%) (p ≤ .05).Conclusions Pyrotinib-based combination therapy is safe for HER2-positive brain metastasis treatment. Compared with vinorelbine or capecitabine, pyrotinib combined with nab-paclitaxel is more effective with less toxicity, which is the preferable regimen for HER2-positive brain metastasis.KEY MESSAGESPresent investigation investigated effective methods through combining pyrotinib to treat brain metastasis with HER2-positive advanced brain cancer. The outcomes verified that pyrotinib-based combination therapy was safe and efficient to treat HER2-positive brain metastasis. Therefore, it is effective to treat brain metastasis applying anti-HER2 targeted therapies although pyrotinib showcases efficiency regarding its treatments for the metastasis.

Simple, fast, selective, and reliable detection of human epidermal growth factor receptor 2 (HER2) is of utmost importance in the early diagnosis of breast cancer to prevent its high prevalence and mortality. Molecularly imprinted polymers (MIPs), also known as artificial antibodies, have recently been used as a specific tool in cancer diagnosis and therapy. In this study, a miniaturized surface plasmon resonance (SPR)-based sensor was developed using epitope-mediated HER2-nanoMIPs. The nanoMIP receptors were characterized using dynamic light scattering (DLS), zeta potential, Fourier-transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), and fluorescent microscopy. The average size of the nanoMIPs was determined to be 67.5 ± 12.5 nm. The proposed novel SPR sensor provided superior selectivity to HER2 with a detection limit (LOD) of 11.6 pg mL−1 in human serum. The high specificity of the sensor was confirmed by cross-reactivity studies using P53, human serum albumin (HSA), transferrin, and glucose. The sensor preparation steps were successfully characterized by employing cyclic and square wave voltammetry. The nanoMIP–SPR sensor demonstrates great potential for use in the early diagnosis of breast cancer as a robust tool with high sensitivity, selectivity, and specificity. [ABSTRACT FROM AUTHOR]

Propose: Human epidermal growth factor receptor 2 (HER2) is overexpressed on the surface of some kinds of cancer cells including breast cancer. In this study, we designed and produced a novel immunotoxin consisting anti-HER2 single-chain Fv (scFv) from pertuzumab and a modified form of Pseudomonas exotoxin (PE35KDEL). Methods: The three-dimensional (3D) structure of the fusion protein (anti-HER IT) was predicted by MODELLER 9.23 and its interaction with HER2 receptor was assessed using HADDOCK web server. Anti-HER2 IT, anti-HER2 scFv, and PE35KDEL proteins were expressed by Escherichia coli BL21 (DE3). After purification of the proteins using Ni2+ affinity chromatography and refolding through dialysis, the cytotoxicity of proteins against breast cancer cell lines was examined by MTT assay. Results: In-silico studies showed that (EAAAK)2 linker can efficiently prevent the formation of salt bridges between two functional domains and the constructed fusion protein has a high affinity to HER2 receptor. The optimum condition of anti-HER2 IT expression was 25 °C and 1 mM IPTG. The protein was successfully purified and refolded by dialysis with a final yield of 45.7 mg per 1 L of bacterial culture. The cytotoxicity results showed that anti-HER2 IT was much more toxic on HER2-overexpressing cells, BT-474 (IC50 ~ 95 nM) compared with HER2-negative cells, MDA-MB-23 (IC50 ˃ 200 nM). Conclusion: This novel immunotoxin has the potential to be applied as a therapeutic candidate for HER2-targeted cancer therapy. However further in vitro and in vivo evaluations are still required to confirm the efficacy and safety of this protein. [ABSTRACT FROM AUTHOR]

A screen-printed carbon electrode was used to develop a biosensor with an improved response and selectivity for detecting human epidermal growth factor receptor 2 (HER2). To investigate the performance of the biosensor, electrochemical characterizations such as impedance spectroscopy, differential pulse and cyclic voltammetry were used, in addition to Fourier transform infrared spectroscopy and atomic force microscopy. The biosensor responds in a quick manner, taking only 5 min to bind to the target protein. Furthermore, the results show that the nano-biosensor has a detection limit of 4.4 Pg/ml. The findings suggest that the biosensor can be used as a potential analytical tool for HER2 detection, particularly at low concentrations, which can be a tool used in the early detection of breast cancer.

Near‐infrared photoimmunotherapy (NIR‐PIT) is a novel form of cancer treatment using conjugates of antibody against overexpressed antigens in cancers and photoabsorber IRDye700DX. HER2 is overexpressed in various cancers, for which molecular targeted therapy such as trastuzumab has been developed. The present study investigated the efficacy potential of HER2‐targeted NIR‐PIT using trastuzumab‐IRDye700DX conjugate (Tra‐IR700) in HER2‐positive breast cancer. We first examined the reactivity of Tra‐IR700 and the cytotoxicity of NIR‐PIT in vitro. HER2‐positive BT‐474 and SK‐BR‐3 cells and HER2‐negative BT‐20 cells were used. Tra‐IR700 fluorescence was only observed in HER2‐positive breast cancer cell lines, and the fluorescence was localized to the cell surface. Furthermore, HER2‐positive breast cancer cell lines treated with NIR‐PIT showed swelling and blebbing shortly after irradiation, and eventually increased PI‐positive dead cells. Next, tumor accumulation of Tra‐IR700 and tumor damage by NIR‐PIT were examined in vivo. Tra‐IR700 was administered intravenously to a xenograft model in which BT‐474 cells were implanted subcutaneously in BALB/c nude mice. Tra‐IR700 fluorescence was the highest in tumor tissue 1 day after administration, and the fluorescence was localized to the cell membrane of tumor cells. At this time point, NIR‐PIT resulted in diffuse necrosis of tumor tissues 1 day after irradiation. These results suggest that NIR‐PIT with Tra‐IR700 induces a highly selective therapeutic effect in a HER2‐positive breast cancer model. NIR‐PIT using Tra‐IR700 is expected to be a novel treatment for HER2‐positive cancers, including breast cancer. [ABSTRACT FROM AUTHOR]

Triple‐negative breast cancer (TNBC) has higher molecular heterogeneity and metastatic potential and the poorest prognosis. Because of limited therapeutics against TNBC, irradiation (IR) therapy is still a common treatment option for patients with lymph nodes or brain metastasis. Thus, it is urgent to develop strategies to enhance the sensitivity of TNBC tumors to low‐dose IR. Here, the authors report that E3 ubiquitin ligase Ring finger protein 126 (RNF126) is important for IR‐induced ATR‐CHK1 pathway activation to enhance DNA damage repair (DDR). Mechanistically, RNF126 physically associates with the MRE11‐RAD50‐NBS1 (MRN) complex and ubiquitinates MRE11 at K339 and K480 to increase its DNA exonuclease activity, subsequent RPA binding, and ATR phosphorylation, promoting sustained DDR in a homologous recombination repair‐prone manner. Accordingly, depletion of RNF126 leads to increased genomic instability and radiation sensitivity in both TNBC cells and mice. Furthermore, it is found that RNF126 expression is induced by IR activating the HER2‐AKT‐NF‐κB pathway and targeting RNF126 expression with dihydroartemisinin significantly improves the sensitivity of TNBC tumors in the brain to IR treatment in vivo. Together, these results reveal that RNF126‐mediated MRE11 ubiquitination is a critical regulator of the DDR, which provides a promising target for improving the sensitivity of TNBC to radiotherapy. [ABSTRACT FROM AUTHOR]

Background: Trastuzumab, the first humanized antibody approved for therapeutic use has shown promising results for the treatment of patients with human epidermal growth factor receptor 2 (HER2)-positive cancers. The aim of this study was to formulate immunoPET agents based on trastuzumab fragments and demonstrate their potential for early diagnosis of HER2-positive tumors. Materials and Methods: F(ab')2 and F(ab') fragments of trastuzumab were prepared by enzymatic digestion and conjugated with chelator NOTA for labeling with 68Ga. For comparison, intact trastuzumab was also radiolabeled. In vitro stability, immunoreactivity, and binding affinity of radio formulations toward HER2 receptors were evaluated by performing in vitro studies in cancer cell lines. Biodistribution and PET imaging studies were performed in animal model bearing tumors. Results:68Ga-NOTA-F(ab')-trastuzumab, 68Ga-NOTA-F(ab')2-trastuzumab, and 68Ga-NOTA-trastuzumab could be prepared with >98% radiochemical purity (% RCP) and were found to be stable when studied up to 4 h. In vitro binding studies revealed high affinity and specificity of formulations toward HER2 receptors. Specific tumor uptake of 68Ga-NOTA-F(ab')-trastuzumab and 68Ga-NOTA-F(ab')2-trastuzumab in HER2-positive tumors was observed in biodistribution and PET imaging studies. Conclusions: This study describes optimization of protocol for the formulation of 68Ga-NOTA-F(ab')-trastuzumab and 68Ga-NOTA-F(ab')2-trastuzumab for targeting HER2-overexpressing tumors. Further studies with these radioformulations are warranted to confirm their potential as immunoPET agents for management of HER2-positive breast and other solid tumors. [ABSTRACT FROM AUTHOR]

Background: The molecular subtyping of breast cancer is related to estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2). The present study aimed to systematically analyze the expression, function, and prognostic value of ER, PR, HER2, and their prevalence in different ethnic groups and among Bangladeshi breast cancer (BC) patients. Method: This study included 25 BC patients and 25 healthy controls, aged between 25 and 70 years. The study characteristics were compared using the ANOVA and Chi-square tests. Also, the multi-Omics dataset of 775 BC patients from TCGA was analyzed for ER, PR, and HER2 in breast cancer subtypes and compared among different ethnicities. Results: For most BD breast cancer cases, the age at diagnosis was ⩾40 years, had only a histopathological diagnosis (P -value.004), and no history of mammography or other pathological tests. For treatment, had only chemotherapy (P -value.004) and no hormone therapy (P -value <.001). The majority of patients (>60%) were of stage-II cancer and TNBC (40%) subtype. The BC ethnicity-stratified data of ER, PR, and HER2 indicated a strong correlation across all ethnicities (P -value 4.99e−35; P -value 3.79e−18). The subtypes stratified data indicated a higher percentage of Luminal A (58.3%) in Caucasians whereas Luminal B (24.3%) and HER2 (25.2%) subtypes were found higher in Asians and TNBC (36.0%) were found in Africans. However, a significantly higher frequency of TNBC (52.2%) compared to Asians (14.8%) was found in BD patients (P -value <.001). The overall survival analysis of BC subtypes demonstrated that Luminal B (P -value.005) and HER2 enriched (P -value.015) were significantly more aggressive and were dominant in the Asian population. Conclusion: A significant association was found between BC subtypes with different ethnicities and Bangladeshi women and these findings might aid in the prevention, management, and raising of awareness against risk factors in the near future. [ABSTRACT FROM AUTHOR]

Purpose: A substantial need for effective and safe treatment options is still unmet for patients with heavily pre-treated human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC). Herein, we assessed the efficacy and safety of pyrotinib plus trastuzumab and chemotherapy in patients with heavily treated HER2-positive MBC. Methods: In this single-arm exploratory phase II trial, patients with HER2-positive MBC previously treated with trastuzumab plus lapatinib or pertuzumab, received pyrotinib plus trastuzumab and chemotherapy. The primary end point was progression-free survival (PFS) in the total population (TP). Secondary end points included PFS in the subgroup with brain metastases (Sub-BrM), confirmed objective response rate (ORR), clinical benefit rate (CBR), disease control rate (DCR), exploration of predictive factors of PFS, and safety. Results: Between November 1, 2018, and March 31, 2021, 40 patients were eligible for this study. The median PFS reached 7.5 months (95% confidence interval [CI] 4.7 to 9.9 months) and 9.4 months (95% CI 6.6 to 12.1 months) in the TP and Sub-BrM, respectively. ORR was 50.5% (20/40). CBR was 75.5% (30/40) and DCR reached 97.5% (39/40). Cox univariate and multivariate analyses demonstrated that liver or/and lung metastases was the significant adverse prognostic factor for PFS (p = 0.018; p = 0.026; respectively). The most frequent grade 3 or 4 treatment-related adverse events were diarrhea, neutropenia and leukopenia. No new safety signals were observed. Conclusion: Pyrotinib plus trastuzumab and chemotherapy offered a promising option with manageable safety profile for heavily pre-treated HER2-positive MBC, especially for those without liver or/and lung metastases. [ABSTRACT FROM AUTHOR]

Background: Breast cancer is the leading cause of cancer-related mortality in women. Human epidermal growth factor receptor 2 (HER2) overexpression is seen in 20 out of 100 invasive breast cancers. Among HER2+ patients, two distinct hormone receptor (HR) subtypes can be defined: HR-positive (HR+) and HR-negative (HR−) each of which with unique therapeutic response and survival pattern. Contrast-enhanced spectral mammography (CESM) is an emerging novel imaging modality that offers diagnostic performance comparable to contrast-enhanced MRI. The purpose of this retrospective study was to describe the CESM features of HER2+ breast cancers according to hormone receptor status and to assess whether specific mammographic and CESM imaging features can differentiate between HER2+/HR+ and HER2+/HR− breast cancers potentially aiding treatment planning in HER2+ breast cancer patients. Results: A total of 61 patients were included. Twenty-nine cases (47.5%) were HER2+/HR+ and 32 cases (52.5%) were HER2+/HR−. No statistically significant difference was found between mammographic imaging presentations and hormonal status. HR- were more likely to be multifocal (P 0.018), rounded or oval (P 0.008), circumscribed (P 0.004), and with associated non-mass enhancement (NME) (P < 0.001). HR+ cancers showed a tendency for irregular shape (P 0.008), spiculated outline (P 0.004), and heterogeneous (P 0.021) or ring (P 0.046) enhancement. Conclusions: HER2+ tumors have different demographic, pathologic and imaging features according to the hormone receptor status. Because the two subtypes of HER2 breast cancer have different clinical outcomes, CESM imaging features can potentially enhance patient outcome by accelerating the diagnosis and treatment. [ABSTRACT FROM AUTHOR]

Extensive application of anti-HER2 targeted therapy improves significantly the HER2-positive advanced breast cancer (BC) prognosis, however, it is still difficult to treat brain metastasis. In current study, we explored effective approaches via combining pyrotinib to treat brain metastasis in patients with HER2-positive advanced BC based upon clinical data. Current study included 61 HER2-positive BC patients with brain metastases (BM) who were treated by pyrotinib-based regimens. The systemic regimens included pyrotinib combined with capecitabine, pyrotinib combined with nab-paclitaxel, and pyrotinib combined with vinorelbine. Patients' progression-free survival (PFS), overall survival (OS), clinical benefit rate (CBR) and objective response rate (ORR), as well as drug-related adverse events (AEs) in regard of each combination regimen were analyzed. Pyrotinib-based systemic therapy resulted in 8.6 months median PFS (mPFS) and 18.0 months median OS (mOS) among the BM patients. Regarding different regimens, the combination of pyrotinib with nab-paclitaxel was superior to the combination with capecitabine and vinorelbine with respect to PFS and OS. The central nervous system (CNS) ORR did not showcase significant difference among 3 regimens, however, nab-paclitaxel combined regimen obtained the best peripheral ORR (84.6%) (p ≤.05). Pyrotinib-based combination therapy is safe for HER2-positive brain metastasis treatment. Compared with vinorelbine or capecitabine, pyrotinib combined with nab-paclitaxel is more effective with less toxicity, which is the preferable regimen for HER2-positive brain metastasis. Present investigation investigated effective methods through combining pyrotinib to treat brain metastasis with HER2-positive advanced brain cancer. The outcomes verified that pyrotinib-based combination therapy was safe and efficient to treat HER2-positive brain metastasis. Therefore, it is effective to treat brain metastasis applying anti-HER2 targeted therapies although pyrotinib showcases efficiency regarding its treatments for the metastasis. [ABSTRACT FROM AUTHOR]

Abstract Background HER2-low breast cancers were reported to have distinct clinicopathological characteristics from HER2-zero; however, the difference in their genetic features remains unclear. This study investigated the clinical and molecular features of breast tumors according to HER2 status. Methods We analyzed the clinicopathological and genomic data of 523 Chinese women with breast cancer. Genomic data was generated by targeted next-generation sequencing (NGS) of breast tumor samples using a commercial 520 gene panel. The cohort was stratified according to HER2 status as HER2-zero (n = 90), HER2-low (n = 231), and HER2-positive (n = 202) according to their immunohistochemistry and fluorescence in situ hybridization results. Results HER2-low breast tumors were enriched with hormone receptor-positive tumors, and who had lower Ki67 expression levels. Genes were differentially mutated across HER2 subgroups. HER2-low tumors had significantly more mutations involved in PI3K-Akt signaling than HER2-positive (p < 0.001) and HER2-zero breast tumors (p < 0.01). HER2-zero tumors had more mutations in checkpoint factors (p < 0.01), Fanconi anemia (p < 0.05), and p53 signaling and cell cycle pathway (p < 0.05) compared to HER2-low breast tumors. Compared with HER2-zero tumors, HER2-low tumors had significantly lower pathological complete response rates after neoadjuvant therapy (15.9% vs. 37.5%, p = 0.042) and proportion of relapsed/progressed patients across follow-up time points (p = 0.031), but had comparable disease-free survival (p = 0.271). Conclusion Our results demonstrate the distinct clinical and molecular features and clinical outcomes of HER2-low breast tumors.

[Display omitted] • Two novel peptide-based PET tracers targeting HER2-positive CRC were developed. • [68Ga]Ga-ES-02 demonstrated high binding affinity (24.29 ± 4.95 nM) toward HER2-positive HT-29 CRC cell line. • [68Ga]Ga-ES-02 showed hydrophilicities, rapid pharmacokinetic properties and excellent stabilities. Colorectal cancer (CRC) is among the most lethal and prevalent malignancies in the world. Human epidermal growth factor receptor 2 (HER2) is a promising target for the diagnosis and treatment of CRC. In this study, we aimed to design, synthesize and label peptide-based positron emission tomography (PET) tracers targeting HER2-positive CRC, namely [68Ga]Ga-ES-01 and [68Ga]Ga-ES-02. The results show that [68Ga]Ga-ES-01 and [68Ga]Ga-ES-02 possessed hydrophilicity, rapid pharmacokinetic properties and excellent stabilities. [68Ga]Ga-ES-02 demonstrated higher binding affinity (K d = 24.29 ± 4.95 nM) toward the HER2 in CRC. In HER2-positive HT-29 CRC xenograft mouse model, PET study showed specific tumor uptake after injection of [68Ga]Ga-ES-02 (SUV 15min max = 0.87 ± 0.03; SUV 30min max = 0.64 ± 0.02). In biodistribution study, the T/M ratios of 68Ga-ES-02 at 30 min after injection reached a maximum of 4.07 ± 0.34. In summary, we successfully synthesized and evaluated two novel peptide-based PET tracers. Our data demonstrate that [68Ga]Ga-ES-01/02 is capable of HER2-positive colorectal cancer, with [68Ga]Ga-ES-02 showing superior imaging effect, enhanced targeting, and increased specificity. [ABSTRACT FROM AUTHOR]

Although single-chain variable fragment (scFv) is recognized as a highly versatile scaffold of recombinant antibody fragment molecules, its overexpression in Escherichia coli often leads to the formation of inclusion bodies. To address this issue, we devised and tested four different constructs, named v21, v22, v23 and v24, for producing anti-human epidermal growth factor receptor 2 (HER2) scFv. Among them, the v24 construct obtained from N-terminal fusion of maltose-binding protein (MBP) and subsequent tobacco etch virus protease (TEV) was identified as the most efficient construct for the production of anti-HER2 scFv. Aided by an MBP tag, high-yield soluble expression was ensured and soluble scFv was liberated in cells via autonomous proteolytic cleavage by endogenously expressed TEV. The isolated scFv containing a C-terminal hexahistidine tag was purified through a one-step purification via nickel-affinity chromatography. The purified scFv exhibited a strong (nanomolar Kd) affinity to HER2 both in vitro and in cells. Structural and functional stabilities of the scFv during storage for more than one month were also assured. Given the great utility of anti-HER2 scFv as a basic platform for developing therapeutic and diagnostic agents for cancers, the v24 construct and methods presented in this study are expected to provide a better manufacturing system for producing anti-HER2 scFv with various industrial applications.

Abstract Due to the overexpression or amplification of human epidermal growth factor receptor 2 (HER2) with poor prognosis in a myriad of human tumors, recent studies have focused on HER2-targeted therapies. Deregulation in HER2 signaling pathways is accompanied by sustained tumor cells growth concomitant with their migration and also tumor angiogenesis and metastasis by stimulation of proliferation of a network of blood vessels. A large number of studies have provided clear evidence that the emerging HER2-directed treatments could be the outcome of patients suffering from HER2 positive breast and also gastric/gastroesophageal cancers. Thanks to its great anti-tumor competence, immunotherapy using HER2-specific chimeric antigen receptor (CAR) expressing immune cell has recently attracted increasing attention. Human T cells and also natural killer (NK) cells can largely be found in the tumor microenvironment, mainly contributing to the tumor immune surveillance. Such properties make them perfect candidate for genetically modification to express constructed CARs. Herein, we will describe the potential targets of the HER2 signaling in tumor cells to clarify HER2-mediated tumorigenesis and also discuss recent findings respecting the HER2-specific CAR-expressing immune cells (CAR T and CAR NK cell) for the treatment of HER2-expressing tumors.

Background: Systemic chemotherapy has been the mainstay treatment for locally advanced or metastatic urothelial carcinoma (UC). In the past few years, novel immune checkpoint inhibitors (ICIs) and antibody-drug conjugates (ADCs) have improved the treatment of advanced UC. Case presentation: Here, we report systemic therapy of a 68-year-old male diagnosed with HER2 positive (immunohistochemistry 3+), programmed cell death ligand 1(PD-L1) negative metastatic UC, and renal insufficiency. He had encountered numerous metastases and failed first-line platinum-based chemotherapy and second-line treatment with pembrolizumab and trastuzumab. During third-line treatment with RC48 (a HER2 targeting ADC) combined with pembrolizumab, he achieved a rapid partial response (PR) in the first evaluation and subsequent complete response (CR) on PET/CT and longterm progression-free survival (>12 months) at the last follow-up on 25 August 2022. There are no grade 3 or 4 adverse events or aggravations of renal insufficiency during the third-line therapy. Discussion: RC48 combined with pembrolizumab demonstrated outstanding efficacy and safety in this HER2-positive metastatic UC patient. ADC combined with ICI is a promising anti-tumor strategy that deserves further exploration in advanced UC. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to evaluate the effect of chemotherapy and trastuzumab on invasive disease-free survival (iDFS) and overall survival (OS) in patients with human epidermal growth factor receptor 2 (HER2) positive, T1abN0 breast cancer. Methods: In the Danish Breast Cancer Group database, patients with HER2-positive, T1abN0 tumors diagnosed between 2007 and 2016 were identified. Cox proportional hazards analysis was performed to analyze the association between adjuvant chemotherapy and trastuzumab and iDFS and OS. Results: Of 605 patients included in the analyses, 465 patients received chemotherapy and trastuzumab and 140 patients did not. Chemotherapy and trastuzumab did not improve iDFS or OS significantly in adjusted analyses. 5-year iDFS was 92.3% vs. 89.9%, Hazard ratio (HR) 1.01 (p = 0.98), and 5-year OS was 97.4% vs. 94.3%, HR 0.60 (p = 0.15), chemotherapy and trastuzumab vs. no chemotherapy/trastuzumab. In unadjusted analyses, significant treatment benefit on OS was found in patients with T1b tumors. The largest absolute treatment benefits were found in patients with T1b tumors and estrogen receptor (ER) negative tumors, respectively, whereas treatment effects in patients with T1a tumors and ER-positive tumors, respectively, were limited. Conclusion: Adjuvant chemotherapy and trastuzumab did not improve OS or iDFS significantly in patients with HER2-positive, T1abN0 breast cancers in adjusted analyses. In unadjusted analyses, significant OS benefit was found in patients with T1b tumors. The largest absolute benefit was observed in patients with T1b tumors and ER-negative tumors, respectively, whereas the effect was limited in patients with T1a tumors and ER-positive tumors, respectively. [ABSTRACT FROM AUTHOR]

Breast cancer is the second most common cancer worldwide. There are four main subtypes of breast cancer, one of which involves positivity for human epidermal growth factor receptor 2 (HER2). Here, we present a case series of unusually long survival in three patients with HER2-positive metastatic breast cancer. All cases involved post-menopausal women with bone-only metastases undergoing treatment with the HER2-targeted therapy trastuzumab and the receptor activator of nuclear factor kappa-Β ligand (RANK-L) inhibitor denosumab. Our three patients survived for 17, 13, and 11 years, respectively, from the time of metastasis. The patients who survived for 17 and 13 years both presented with metastatic disease at diagnosis, while the patient who survived for 11 years with metastatic disease was known to have non-metastatic breast cancer for four years prior. We also report the development of foot fractures from minor trauma, as low as walking, despite a bone density reported as normal in the patient with 17 years of treatment. These unusually long survival times and the unusual location of the fractures are questioned to be secondary to the long duration of treatment with HER2-targeted therapy and RANK-L inhibitor therapy. Our case series is the first to describe the use of trastuzumab and denosumab in HER2-positive metastatic breast cancer. All three reported cases had no clinical or radiographic disease progression at the time of reporting. Furthermore, our case of survival for 17 years represents the longest survival time reported yet, raising the possibility of a synergistic relationship between RANK-L inhibitors and HER2-targeted therapy in the long-term control of HER2-positive metastatic breast cancer. This manuscript discusses evidence from primary studies on HER2 and receptor activator of nuclear factor kappa-Β (RANK) signalling and drug responses and hypothesizes on possible mechanisms of synergism. Given that treatment of HER2-positive breast cancer has historically not involved RANK-L inhibition, this study may outline future areas of research in improving treatment algorithms, especially for bone-only metastatic disease., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Western Health Sciences Research Ethics Board issued approval (approval number not applicable). The HSREB classified our study as a case report since it involved less than five patients, and therefore, no formal application was required under our institution's policy. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Ladak et al.)