Computational pathology in the identification of HER2-low breast cancer: Opportunities and challenges

For the past 2 decades, pathologists have been accustomed to reporting the HER2 status of breast cancer as either positive or negative, based on HER2 IHC. Today, however, there is a clinical imperative to employ a 3-tier approach to interpreting HER2 IHC that can also identify tumours categorised as HER2-low. Meeting this need for a finer degree of discrimination may be challenging, and in this article, we consider the potential for the integration of computational approaches to support pathologists in achieving accurate and reproducible HER2 IHC scoring as well as outlining some of the practicalities involved.

Early endpoints of a randomized phase II trial of preoperative chemotherapy with S-1/CDDP with or without trastuzumab followed by surgery for HER2-positive resectable gastric or esophagogastric junction adenocarcinoma with extensive lymph node metastasis: Japan Clinical Oncology Group study JCOG1301C (Trigger Study)

BACKGROUND

This randomized phase II study explored the superiority of trastuzumab plus S-1 plus cisplatin (SP) over SP alone as neoadjuvant chemotherapy (NAC) for HER2-positive resectable gastric cancer with extensive lymph node metastasis.

METHODS

Eligible patients with HER2-positive gastric or esophagogastric junction cancer and extensive lymph node metastasis were randomized to receive three or four courses of preoperative chemotherapy with SP (arm A) or SP plus trastuzumab (arm B). Following gastrectomy, adjuvant chemotherapy with S-1 was administered for 1 year in both arms. The primary endpoint was overall survival, and the sample size was 130 patients in total. The trial is registered with the Japan Registry of Clinical Trials, jRCTs031180006.

RESULTS

This report elucidates the early endpoints, including pathological findings and safety. The study was terminated early due to slow patient accruals. In total, 46 patients were allocated to arm A (n = 22) and arm B (n = 24). NAC was completed in 20 patients (91%) in arm A and 23 patients (96%) in arm B, with similar incidences of grade 3-4 hematological and non-hematological adverse events. Objective response rates were 50% in arm A and 84% in arm B (p = 0·065). %R0 resection rates were 91% and 92%, and pathological response rates (≥ grade 1b in Japanese classification) were 23% and 50% (p = 0·072) in resected patients, respectively.

CONCLUSIONS

Trastuzumab can be safely added to platinum-containing doublet chemotherapy as NAC, and it has the potential to contribute to higher antitumor activity against locally advanced, HER2-positive gastric or esophagogastric junction cancer with extensive nodal metastasis.

SLC35A2 expression is associated with HER2 expression in breast cancer

The role of SLC35A2 in breast cancer remains poorly understood, with limited available information on its significance. This study aimed to investigate the expression of SLC35A2 and clinicopathological variables in breast cancer patients. Immunohistochemical analysis of SLC35A2 protein was conductedon 40 adjacent non-neoplastic tissues and 320 breast cancer tissues. The study also assesed the association between SLC35A2 expression and breast cancer clinicopathological features of breast cancer, as well as its impact on overall survival. In comparison to adjacent non-neoplastic tissues, a significantly higher expression of SLC35A2 was observed in breast cancer tissues (P = 0.020), and this expression was found to be independently correlated with HER2 positivity (P = 0.001). Survival analysis indicated that patients with low SLC35A2 expression had a more favorable prognosis in HER2-positive subtype breast cancer (P = 0.017). These results suggest that SLC35A2 is overexpressed in breast cancer tissues compared to adjacent non-neoplastic tissues and may serve as a potential prognostic marker for HER2-positive subtype breast cancer. Furthermore, breast cancer patients with the HER2 positive subtype who exhibited decreased levels of SLC35A2 expression demonstrated improved long-term prognostic outcomes.

Discovery of novel HER2 targeting peptide-camptothecin conjugates with effective suppression for selective cancer treatment

Due to the strong selectivity and permeability of tumor tissue, anti-cancer peptide-drug conjugates (PDCs) can accumulate high concentration of toxic payloads at the target, effectively killing tumor cells. This approach holds great promise for tumor-targeted treatment. In our previous study, we identified the optimal peptide P1 (NPNWGRSWYNQRFK) targeting HER2 from pertuzumab, a monoclonal antibody that blocks the HER2 signaling pathway. Here, a series of PDCs were constructed through connecting P1 and CPT with different linkers. Among these, Z8 emerged as the optimal compound, demonstrating good antitumor activity and targeting ability in biological activity tests. Z8 exhibited IC50 values of 1.04 ± 0.24 μM and 1.91 ± 0.71 μM against HER2-positive SK-BR-3 and NCI-N87 cells, respectively. Moreover, superior antitumor activity and higher biosafety of Z8 were observed compared to the positive control CPT in vivo, suggesting a novel idea for the construction of PDCs.

Significant effect of posterior line treatment of HER2 positive advanced gastric cancer: A case report

At present, there are few options for third line and above treatment of advanced gastric cancer and the single drug effect is poor. HER2 positive gastric cancer is an important subtype of gastric cancer and has certain immune characteristics. The combination of HER2 inhibitor and PD-1 inhibitor has a synergistic effect, and anti-tumor drugs targeting HER2 can play an anti-angiogenesis role by downregulating VEGF. We report a patient with HER2-positive gastric cancer who developed post-operative tumor recurrence and metastasis after adjuvant chemotherapy and radiotherapy. Trastuzumab combined with albumin paclitaxel was used as second-line treatment with progression-free survival for 9 months. In third line treatment, we retained trastuzumab and combined it with camrelizumab and apatinib. During the treatment period, although the patient stopped taking the drugs due to the side effects of camrelizumab and apatinib, he achieved a PFS of 10.4 months. Considering the good effect of the third line treatment, we added another PD-1 inhibitor and continued to combine trastuzumab treatment. We found that the patient still benefited from the treatment and continued to survive for another 4 months. At present, the patient is treated with DisitamabVedotin (HER2-ADC) combined with PD-1 inhibitor, and no overall survival outcome has been observed.

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

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

Top advances of the year: Uterine cancer

Endometrial cancer continues to be the only gynecologic malignancy with a rising incidence and mortality, with both regional and global implications. Combination carboplatin and paclitaxel has been the recognized chemotherapy backbone for the treatment of advanced-stage or recurrent disease, with modest clinical outcomes. Over the last year, significant advances were achieved in improving oncologic outcomes by capitalizing on the molecular characterization of this heterogenous disease. These advances include incorporation of immunotherapy, identification of effective hormonal approaches, the evolution of antibody drug conjugates, and utilization of alternate targeted therapies. PLAIN LANGUAGE SUMMARY: The molecular characterization of endometrial cancer has been critical in informing novel treatment strategies. Over the past year, significant gains have been made via the incorporation of immunotherapy, hormonal combinations as well as antibody drug conjugates.

Peptide-drug conjugate designated for targeted delivery to HER2-expressing cancer cells

Targeted therapy of the highest globally incident breast cancer shall resolve the issue of off-target toxicity concurring with augmented killing of specific diseased cells. Thus, the goal of this study was to prepare a peptide-drug conjugate targeting elevated expression of HER2 receptors in breast cancer. Towards this, the rL-A9 peptide was conjugated with the chemotherapeutic drug doxorubicin (DOX) through a N-succinimidyl-4-(N-maleimidomethyl) cyclohexane-1-carboxylate (SMCC) linker. The synthesized peptide-drug conjugate, rL-A9-DOX, was characterized by mass spectrometry. Molecular docking studies, based on binding energy data, suggested a stronger interaction of rL-A9-DOX with the HER2 receptor in comparison to the unconjugated peptide, rL-A9. The cytotoxic effect of the rL-A9-DOX conjugate was observed to be higher in HER2-positive SKOV3 cells compared to HER2-negative MDA-MB-231 cells, indicating selective cell killing. Cellular internalization of the rL-A9-DOX conjugate was evident from the flow cytometry analysis, where a noticeable shift in mean fluorescent intensity (MFI) was observed for the conjugate compared to the control group. This data was further validated by confocal microscopy, where the fluorescent signal ascertained nuclear accumulation of rL-A9-DOX. The present studies highlight the promising potential of rL-A9-DOX for targeted delivery of the drug into a defined group of cancer cells.

Combined therapy of dabrafenib and an anti-HER2 antibody-drug conjugate for advanced BRAF-mutant melanoma

BACKGROUND

Melanoma is the most lethal skin cancer characterized by its high metastatic potential. In the past decade, targeted and immunotherapy have brought revolutionary survival benefits to patients with advanced and metastatic melanoma, but these treatment responses are also heterogeneous and/or do not achieve durable responses. Therefore, novel therapeutic strategies for improving outcomes remain an unmet clinical need. The aim of this study was to evaluate the therapeutic potential and underlying molecular mechanisms of RC48, a novel HER2-target antibody drug conjugate, either alone or in combination with dabrafenib, a V600-mutant BRAF inhibitor, for the treatment of advanced BRAF-mutant cutaneous melanoma.

METHODS

We evaluated the therapeutic efficacy of RC48, alone or in combination with dabrafenib, in BRAF-mutant cutaneous melanoma cell lines and cell-derived xenograft (CDX) models. We also conducted signaling pathways analysis and global mRNA sequencing to explore mechanisms underlying the synergistic effect of the combination therapy.

RESULTS

Our results revealed the expression of membrane-localized HER2 in melanoma cells. RC48 effectively targeted and inhibited the growth of HER2-positive human melanoma cell lines and corresponding CDX models. When used RC48 and dabrafenib synergically induced tumor regression together in human BRAF-mutant melanoma cell lines and CDX models. Mechanically, our results demonstrated that the combination therapy induced apoptosis and cell cycle arrest while suppressing cell motility in vitro. Furthermore, global RNA sequencing analysis demonstrated that the combination treatment led to the downregulation of several key signaling pathways, including the PI3K-AKT pathway, MAPK pathway, AMPK pathway, and FOXO pathway.

CONCLUSION

These findings establish a preclinical foundation for the combined use of an anti-HER2 drug conjugate and a BRAF inhibitor in the treatment of BRAF-mutant cutaneous melanoma.

Exploratory analysis of serum HER2 extracellular domain for HER2 positive gastric cancer treated with SOX plus trastuzumab

BACKGROUND

The aim of this study was to explore the clinical utility of serum HER2 extracellular domain (sHER2 ECD) using data from a clinical trial evaluating trastuzumab combined S-1 plus oxaliplatin (SOX) in HER2 positive gastric cancer.

METHODS

sHER2 ECD were prospectively measured at baseline and subsequent treatment courses. Based on each quantile point of baseline sHER2 ECD levels and its early changes, patients were divided into two groups and compared clinical outcomes.

RESULTS

43 patients were enrolled, and 17 patients (39.5%) were positive for baseline sHER2 ECD. Higher baseline sHER2 ECD levels tended to have lower hazard ratios (HRs). When divided into two groups by baseline sHER2 ECD of 19.1 ng/ml, median progression-free survival (PFS) and overall survival (OS) was longer in the higher group (mPFS: 16.8 vs 8.7 months, p = 0.359. mOS: 35.5 vs 20.6 months, p = 0.270), respectively. After initiation of treatment, sHER2 ECD significantly decreased up until the third cycle. Higher reduction rates of sHER2 ECD within 3 cycles also tended to have lower HRs. When divided into two groups by reduction rate of 42.5%, mPFS and mOS was longer in the higher reduced group (mPFS: 17.2 vs 8.7 months, p = 0.095. mOS: 65.0 vs 17.8 months, p = 0.047), respectively. Furthermore, higher reduction rates could surrogate higher objective response rates (ORR) (ORR: 90% vs 63.2% for 29.5%, p = 0.065. 100% vs 70% for 42.5%, p = 0.085), respectively.

CONCLUSIONS

Baseline sHER2 ECD levels and its early decline may be useful biomarkers for SOX plus trastuzumab efficacy in HER2 positive gastric cancer.

Phenotypic immune characterization of gastric and esophageal adenocarcinomas reveals profound immune suppression in esophageal tumor locations

Background

Tumors in the distal esophagus (EAC), gastro-esophageal junction including cardia (GEJAC), and stomach (GAC) develop in close proximity and show strong similarities on a molecular and cellular level. However, recent clinical data showed that the effectiveness of chemo-immunotherapy is limited to a subset of GEAC patients and that EACs and GEJACs generally benefit less from checkpoint inhibition compared to GACs. As the composition of the tumor immune microenvironment drives response to (immuno)therapy we here performed a detailed immune analysis of a large series of GEACs to facilitate the development of a more individualized immunomodulatory strategy.

Methods

Extensive immunophenotyping was performed by 14-color flow cytometry in a prospective study to detail the immune composition of untreated gastro-esophageal cancers (n=104) using fresh tumor biopsies of 35 EACs, 38 GEJACs and 31 GACs. The immune cell composition of GEACs was characterized and correlated with clinicopathologic features such as tumor location, MSI and HER2 status. The spatial immune architecture of a subset of tumors (n=30) was evaluated using multiplex immunohistochemistry (mIHC) which allowed us to determine the tumor infiltration status of CD3+, CD8+, FoxP3+, CD163+ and Ki67+ cells.

Results

Immunophenotyping revealed that the tumor immune microenvironment of GEACs is heterogeneous and that immune suppressive cell populations such as monocytic myeloid-derived suppressor cells (mMDSC) are more abundant in EACs compared to GACs (p<0.001). In contrast, GACs indicated a proinflammatory microenvironment with elevated frequencies of proliferating (Ki67+) CD4 Th cells (p<0.001), Ki67+ CD8 T cells (p=0.002), and CD8 effector memory-T cells (p=0.024). Differences between EACs and GACs were confirmed by mIHC analyses showing lower densities of tumor- and stroma-infiltrating Ki67+ CD8 T cells in EAC compared to GAC (both p=0.021).

Discussions

This comprehensive immune phenotype study of a large series of untreated GEACs, identified that tumors with an esophageal tumor location have more immune suppressive features compared to tumors in the gastro-esophageal junction or stomach which might explain the location-specific responses to checkpoint inhibitors in this disease. These findings provide an important rationale for stratification according to tumor location in clinical studies and the development of location-dependent immunomodulatory treatment approaches.

Advances in the Imaging of Esophageal and Gastroesophageal Junction Malignancies

Accurate imaging is key for the diagnosis and treatment of esophageal and gastroesophageal junction cancers . Current imaging modalities, such as computed tomography (CT) and 18F-FDG (2-deoxy-2-[18F]fluoro-D-glucose) positron emission tomography (PET)/CT, have limitations in accurately staging these cancers. MRI shows promise for T staging and residual disease assessment. Novel PET tracers, like FAPI, FLT, and hypoxia markers, offer potential improvements in diagnostic accuracy. 18F-FDG PET/MRI combines metabolic and anatomic information, enhancing disease evaluation. Radiomics and artificial intelligence hold promise for early detection, treatment planning, and response assessment. Theranostic nanoparticles and personalized medicine approaches offer new avenues for cancer therapy.

Site-specific glycosylation analysis of epidermal growth factor receptor 2 (ErbB2): exploring structure and function toward therapeutic targeting

Glycans found on receptor tyrosine kinases (RTKs) have emerged as promising targets for cancer chemotherapy, aiming to address issues such as drug resistance. However, to effectively select the target glycans, it is crucial to define the structure and function of candidate glycans in advance. Through mass spectrometric analysis, this study presents a "glycoform atlas" of epidermal growth factor receptor 2 (ErbB2), an RTK targeted for the treatment of ErbB2-positive cancers. Our analysis provides an in-depth and site-specific glycosylation profile, including both asparagine- and serine/threonine-linked glycosylation. Molecular dynamics simulations of N-glycosylated ErbB2 incorporating the identified glycan structures suggested that the N-glycan at N124 on the long flexible loop in the N-terminal region plays a role in stabilizing the ErbB2 structure. Based on the model structures obtained from the simulations, analysis employing an ErbB2 mutant deficient in N-glycosylation at N124 exhibited a significantly shorter intracellular half-life and suppressed autophosphorylation compared to wild-type ErbB2. Moreover, a structural comparison between the N-glycosylated forms of ErbB2 and its structurally homologous receptor, epidermal growth factor receptor (EGFR), demonstrated distinct variations in the distribution and density of N-glycans across these two molecules. These findings provide valuable insights into the structural and functional implications of ErbB2 glycosylation and will contribute to facilitating the establishment of glycan-targeted therapeutic strategies for ErbB2-positive cancers.

Comparative Preclinical Evaluation of HYNIC-Modified Designed Ankyrin Repeat Proteins G3 for the 99mTc-Based Imaging of HER2-Expressing Malignant Tumors

HER2 status determination is a necessary step for the proper choice of therapy and selection of patients for the targeted treatment of cancer. Targeted radiotracers such as radiolabeled DARPins provide a noninvasive and effective way for the molecular imaging of HER2 expression. This study aimed to evaluate tumor-targeting properties of three 99mTc-labeled DARPin G3 variants containing Gly-Gly-Gly-Cys (G3C), (Gly-Gly-Gly-Ser)3-Cys ((G3S)3C), or Glu-Glu-Glu-Cys (E3C) amino acid linkers at the C-terminus and conjugated to the HYNIC chelating agent, as well as to compare them with the clinically evaluated DARPin G3 labeled with 99mTc(CO)3 using the (HE)3-tag at the N-terminus. The labeling of DARPin G3-HYNIC variants provided radiochemical yields in the range of 50-80%. Labeled variants bound specifically to human HER2-expressing cancer cell lines with affinities in the range of 0.5-3 nM. There was no substantial influence of the linker and HYNIC chelator on the binding of 99mTc-labeled DARPin G3 variants to HER2 in vitro; however, [99mTc]Tc-G3-(G3S)3C-HYNIC had the highest affinity. Comparative biodistribution of [99mTc]Tc-G3-G3C-HYNIC, [99mTc]Tc-G3-(G3S)3C-HYNIC, [99mTc]Tc-G3-E3C-HYNIC, and [99mTc]Tc-(HE)3-G3 in healthy CD1 mice showed that there was a strong influence of the linkers on uptake in normal tissues. [99mTc]Tc-G3-E3C-HYNIC had an increased retention of activity in the liver and the majority of other organs compared to the other conjugates. The tumor uptake of [99mTc]Tc-G3-(G3S)3C-HYNIC and [99mTc]Tc-(HE)3-G3 in Nu/j mice bearing SKOV-3 xenografts was similar. The specificity of tumor targeting in vivo was demonstrated for both tracers. [99mTc]Tc-G3-(G3S)3C-HYNIC provided comparable, although slightly lower tumor-to-lung, tumor-to spleen and tumor-to-liver ratios than [99mTc]Tc-(HE)3-G3. Radiolabeling of DARPin G3-HYNIC conjugates with 99mTc provided the advantage of a single-step radiolabeling procedure; however, the studied HYNIC conjugates did not improve imaging contrast compared to the 99mTc-tricarbonyl-labeled DARPin G3. At this stage, [99mTc]Tc-(HE)3-G3 remains the most promising candidate for the clinical imaging of HER2-overexpressing cancers.

SIBP-03, a novel anti-HER3 antibody, exerts antitumor effects and synergizes with EGFR- and HER2-targeted drugs

HER3 (human epidermal growth factor receptor 3) acts through heterodimerization with EGFR (epidermal growth factor receptor) or HER2 to play an essential role in activating phosphoinositide 3-kinase (PI3K) and AKT signaling-a crucial pathway that promotes tumor cell survival. HER3 is a promising target for cancer therapy, and several HER3-directed antibodies have already entered into clinical trials. In this study we characterized a novel anti-HER3 monoclonal antibody, SIBP-03. SIBP-03 (0.01-10 μg/mL) specifically and concentration-dependently blocked both neuregulin (NRG)-dependent and -independent HER3 activation, attenuated HER3-mediated downstream signaling and inhibited cell proliferation. This antitumor activity was dependent, at least in part, on SIBP-03-induced, cell-mediated cytotoxicity and cellular phagocytosis. Importantly, SIBP-03 enhanced the antitumor activity of EGFR- or HER2-targeted drugs (cetuximab or trastuzumab) in vitro and in vivo. The mechanisms underlying this synergy involve increased inhibition of HER3-mediated downstream signaling. Collectively, these results demonstrated that SIBP-03, which is currently undergoing a Phase I clinical trial in China, may offer a new treatment option for patients with cancers harboring activated HER3, particularly as part of a combinational therapeutic strategy.

Comparison of an amplicon-based large panel next generation sequencing (NGS) assay with conventional testing methods for MET and HER2 amplification in lung and breast cancers

The frequency of MET and HER2 amplification being detected by next generation sequencing (NGS) is increasing due to NGS being increasingly adopted for molecular profiling of cancers. However, the accuracy of NGS in detecting these gene amplifications remains uncertain due to conflicting reports in the scientific literature. We studied the accuracy of an amplicon-based large panel NGS assay in detecting MET and HER2 amplification in lung and breast cancers, respectively, by comparing it against conventional testing methods. Amongst 48 lung cancers, four of five cancers that were MET amplified on fluorescence in situ hybridisation (FISH) were classified as amplified on NGS while 42 of the remaining 43 non-amplified cancers were classified as non-amplified on NGS, giving a sensitivity of 80%, specificity of 97.7% and overall concordance of 95.8%. Of the 46 breast cancers tested, only six of the nine cancers that were HER2-positive on immunohistochemistry (IHC)/FISH were HER2-positive on NGS, while all the remaining HER2-negative cases were negative on NGS, giving a sensitivity of 66.7%, specificity of 100% and overall concordance of 93.5%. All the false-negative cases had low level gene amplification (MET:CEP7 or HER2:CEP17 FISH ratio of <3). The low sensitivity for HER2 amplification may be confounded by the small sample size and disproportionate number of cases with low level amplification. In summary, the NGS assay has good concordance with conventional testing methods but may be less sensitive in detecting low level gene amplification.

Do HER2-Low Tumors Have a Distinct Clinicopathologic Phenotype?

BACKGROUND

Breast cancer subtypes, distinguished by hormone receptor (HR) and HER2 status, have different clinicopathologic features. With recognition of the clinical relevance of HER2-low, there is debate as to whether this is a distinct subtype. Our study aimed to determine whether HER2-low breast cancers have specific clinicopathologic features that differ from those of HER2-negative and HER2-positive cancers.

PATIENTS AND METHODS

A total of 11,072 patients undergoing upfront surgery from 1998 to 2010 were identified from a single-institution prospectively maintained database. HER2 status was classified by immunohistochemistry (IHC)/fluorescence in situ hybridization (FISH) as HER2 negative (41.2%), HER2 low (45%; IHC 1+ or 2+ with negative FISH), and HER2 positive (13.7%), and stratified by HR status. Univariate (UVA) and multivariable multinomial logistic regression analysis (MVA) were performed to determine associations among variables and subtypes.

RESULTS

Compared with HER2-negative tumors, HER2 low was associated with lymphovascular invasion [odds ratio (OR) 1.2, 95% confidence interval (CI) 1.06-1.36; p = 0.003], multifocality (OR 1.26, 95% CI 1.12-1.42; p < 0.001), nodal micrometastasis (OR 1.15, 95% CI 1.02-1.31; p = 0.024), and lower rates of ≥ 3 positive nodes (OR 0.77, 95% CI 0.66-0.90, p = 0.001). When stratified by HR expression, in both HR-positive and HR-negative tumors, age and multifocality were associated with HER2 low on UVA. On MVA, no variables were independently associated with both HR-negative and HR-positive/HER2-low tumors compared with HER2-negative tumors. In contrast, HER2-positive tumors, regardless of HR status, were associated with multifocality and an extensive intraductal component.

CONCLUSION

Clinicopathologic features of HER2-low tumors appear to be primarily related to HR status. Our findings do not support the characterization of HER2 low as a separate subtype.

Potential Role of Nrf2, HER2, and ALDH in Cancer Stem Cells: A Narrative Review

Cancer is one of the main causes of death among humans, second only to cardiovascular diseases. In recent years, numerous studies have been conducted on the pathophysiology of cancer, and it has been established that this disease is developed by a group of stem cells known as cancer stem cells (CSCs). Thus, cancer is considered a stem cell disease; however, there is no comprehensive consensus about the characteristics of these cells. Several different signaling pathways including Notch, Hedgehog, transforming growth factor-β (TGF-β), and WNT/β-catenin pathways cause the self-renewal of CSCs. CSCs change their metabolic pathways in order to access easy energy. Therefore, one of the key objectives of researchers in cancer treatment is to destroy CSCs. Nuclear factor erythroid 2-related factor 2 (Nrf2) plays an essential role in the protection of CSCs from reactive oxygen species (ROS) and chemotherapeutic agents by regulating antioxidants and detoxification enzymes. Human epidermal growth factor receptor 2 (HER2) is a member of the tyrosine kinase receptor family, which contributes to the protection of cancer cells against treatment and implicated in the invasion, epithelial-mesenchymal transition (EMT), and tumorigenesis. Aldehyde dehydrogenases (ALDHs) are highly active in CSCs and protect the cells against damage caused by active aldehydes through the regulation of aldehyde metabolism. On the other hand, ALDHs promote the formation and maintenance of tumor cells and lead to drug resistance in tumors through the activation of various signaling pathways, such as the ALDH1A1/HIF-1α/VEGF axis and Wnt/β-catenin, as well as changing the intracellular pH value. Given the growing body of information in this field, in the present narrative review, we attempted to shed light on the function of Nrf2, HER2, and ALDH in CSCs.

Noninvasive Assessment of HER2 Expression Status in Gastric Cancer Using 18F-FDG Positron Emission Tomography/Computed Tomography-Based Radiomics: A Pilot Study

Purpose: Immunohistochemistry (IHC) is the main method to detect human epidermal growth factor receptor 2 (HER2) expression levels. However, IHC is invasive and cannot reflect HER2 expression status in real time. The aim of this study was to construct and verify three types of radiomics models based on 18F-fuorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) imaging and to evaluate the predictive ability of these radiomics models for the expression status of HER2 in patients with gastric cancer (GC). Patients and Methods: A total of 118 patients with GC were enrolled in this study. 18F-FDG PET/CT imaging was performed prior to surgery. The LIFEx software package was applied to extract PET and CT radiomics features. The minimum absolute contraction and selection operator (least absolute shrinkage and selection operator [LASSO]) algorithm was used to select the best radiomics features. Three machine learning methods, logistic regression (LR), support vector machine (SVM), and random forest (RF) models, were constructed and verified. The Synthetic Minority Oversampling Technique (SMOTE) was applied to address data imbalance. Results: In the training and test sets, the area under the curve (AUC) values of the LR, SVM, and RF models were 0.809, 0.761, 0.861 and 0.628, 0.993, 0.717, respectively, and the Brier scores were 0.118, 0.214, and 0.143, respectively. Among the three models, the LR and RF models exhibited extremely good prediction performance. The AUC values of the three models significantly improved after SMOTE balanced the data. Conclusions: 18F-FDG PET/CT-based radiomics models, especially LR and RF models, demonstrate good performance in predicting HER2 expression status in patients with GC and can be used to preselect patients who may benefit from HER2-targeted therapy.

Anchoring of hyaluronan glycocalyx to CD44 reduces sensitivity of HER2-positive gastric cancer cells to trastuzumab

Trastuzumab is widely used in human epidermal growth factor receptor 2 (HER2)-positive gastric cancer (GC) therapy, but ubiquitous resistance limits its clinical application. In this study, we first showed that CD44 antigen is a significant predictor of overall survival for patients with HER2-positive GC. Next, we found that CD44 could be co-immunoprecipitated and co-localized with HER2 on the membrane of GC cells. By analyzing the interaction between CD44 and HER2, we identified that CD44 could upregulate HER2 protein by inhibiting its proteasome degradation. Notably, the overexpression of CD44 could decrease the sensitivity of HER2-positive GC cells to trastuzumab. Further mechanistic study showed that CD44 upregulation could induce its ligand, hyaluronan (HA), to deposit on the cancer cell surface, resulting in covering up the binding sites of trastuzumab to HER2. Removing the HA glycocalyx restored sensitivity of the cells to trastuzumab. Collectively, our findings suggested a role for CD44 in regulating trastuzumab sensitivity and provided novel insights into HER2-targeted therapy.

Establishment of a Novel Cancer-Specific Anti-HER2 Monoclonal Antibody H2Mab-250/H2CasMab-2 for Breast Cancers

Overexpression of human epidermal growth factor receptor 2 (HER2) in breast and gastric cancers is an important target for monoclonal antibody (mAb) therapy. All therapeutic mAbs, including anti-HER2 mAbs, exhibit adverse effects probably due to the recognition of antigens expressed in normal cells. Therefore, tumor-selective or specific mAbs can be beneficial in reducing the adverse effects. In this study, we established a novel cancer-specific anti-HER2 monoclonal antibody, named H2Mab-250/H2CasMab-2 (IgG1, kappa). H2Mab-250 reacted with HER2-positive breast cancer BT-474 and SK-BR-3 cells. Importantly, H2Mab-250 did not react with nontransformed normal epithelial cells (HaCaT and MCF 10A) and immortalized normal epithelial cells in flow cytometry. In contrast, most anti-HER2 mAbs, such as H2Mab-119 and trastuzumab reacted with both cancer and normal epithelial cells. Immunohistochemical analysis demonstrated that H2Mab-250 possesses much higher reactivity to the HER2-positive breast cancer tissues compared with H2Mab-119, and did not react with normal tissues, including heart, breast, stomach, lung, colon, kidney, and esophagus. The epitope mapping demonstrated that the Trp614 of HER2 domain IV mainly contributes to the recognition by H2Mab-250. H2Mab-250 could contribute to the development of chimeric antigen receptor-T or antibody-drug conjugates without adverse effects for breast cancer therapy.

Targeting HER2 in Gastroesophageal Adenocarcinoma: Molecular Features and Updates in Clinical Practice

Gastroesophageal adenocarcinoma (GEA) is one of the principal causes of death related to cancer globally. Human epidermal growth factor receptor 2 (HER2) is a tyrosine kinase receptor which is found to be overexpressed or amplified in approximately 20% of GEA cases. In GEA, the identification of HER2-positive status is crucial to activate a specific anti-HER2 targeted therapy. The landmark ToGA trial demonstrated the superiority of adding trastuzumab to platinum-based chemotherapy, becoming the first-line standard of treatment. However, unlike breast cancer, the efficacy of other anti-HER2 drugs, such as lapatinib, pertuzumab, and T-DM1, has failed to improve outcomes in advanced and locally advanced resectable GEA. Recently, the combination of trastuzumab with pembrolizumab, along with chemotherapy, and the development of trastuzumab deruxtecan, with its specific bystander activity, demonstrated improved outcomes, renewing attention in the treatment of this disease. This review will summarise historical and emerging therapies for the treatment of HER2-positive GEA, with a section dedicated to the HER2 molecular pathway and the use of novel blood biomarkers, such as circulating tumour DNA and circulating tumour cells, which may be helpful in the future to guide treatment decisions.

HER2-Positive Gastric Cancer and Antibody Treatment: State of the Art and Future Developments

Despite a decreasing incidence in Western countries, gastric cancer is among the most common cancer subtypes globally and is associated with one of the highest tumor-related mortality rates. Biomarkers play an increasing role in the treatment against gastric cancer. HER2 was one of the first biomarkers that found its way into clinical practice. Since the ToGA trial, trastuzumab has been part of first-line palliative chemotherapy in metastatic or unresectable gastric cancer. HER2-targeting agents, such as the tyrosine kinase inhibitor lapatinib, the antibody drug conjugate (ADC) trastuzumab-emtansine or dual HER2 inhibition (pertuzumab and trastuzumab), have been investigated in the second-line setting but led to negative study results. More recently, the ADC trastuzumab-deruxtecan was authorized after the failure of trastuzumab-based treatment. However, further improvements in HER2-directed therapy are required as resistance mechanisms and HER2 heterogeneity limit the existing treatment options. This review aims to give an overview of the current standard-of-care HER2-directed therapy in gastric cancer, as well as its challenges and future developments.

Hormone Receptor-Positive/HER2-Positive Breast Cancer: Hormone Therapy and Anti-HER2 Treatment: An Update on Treatment Strategies

Hormone receptor (HR)-positive/HER2-positive breast cancer represents a distinct subtype expressing estrogen and progesterone receptors with an overexpression of HER2. Approximately 14% of female breast cancer cases are HER2-positive, with the majority being HR-positive. These tumors show a cross-talk between the hormonal and HER2 pathways; the interaction has implications for the treatment options for the disease. In this review, we analyze the biology of HR-positive/HER2-positive breast cancer and summarize the evidence concerning the standard of care options both in neoadjuvant/adjuvant settings and in advanced disease. Additionally, we focus on new trials and drugs for HR-positive/HER2-positive breast cancer and the new entity: HER2-low breast cancer.

Advances in Human Epidermal Growth Factor Receptor 2-Targeted Therapy in Upper Gastrointestinal Cancers

The Trastuzumab for Gastric Cancer (ToGA) trial marked a pivotal moment in the adoption of trastuzumab for treating advanced human epidermal growth factor receptor 2 (HER2)-positive esophagogastric (EG) cancer. The KEYNOTE-811 trial brought to light the synergistic effect of immune modulation and HER2 targeting. Additionally, the emergence of trastuzumab deruxtecan (T-DXd) highlighted the potential of new pharmaceutical technologies to extend response, particularly for patients who have advanced beyond initial HER2-targeted therapies. This review aims to navigate through both the successes and challenges encountered historically, as well as promising current trials on innovative and transformative therapeutic strategies, including promising first-in-class and novel first-in-human agents.

Unveiling the Molecular Mechanism of Trastuzumab Resistance in SKBR3 and BT474 Cell Lines for HER2 Positive Breast Cancer

HER2-positive breast cancer is one of the most prevalent forms of cancer among women worldwide. Generally, the molecular characteristics of this breast cancer include activation of human epidermal growth factor receptor-2 (HER2) and hormone receptor activation. HER2-positive is associated with a higher death rate, which led to the development of a monoclonal antibody called trastuzumab, specifically targeting HER2. The success rate of HER2-positive breast cancer treatment has been increased; however, drug resistance remains a challenge. This fact motivated us to explore the underlying molecular mechanisms of trastuzumab resistance. For this purpose, a two-fold approach was taken by considering well-known breast cancer cell lines SKBR3 and BT474. In the first fold, trastuzumab treatment doses were optimized separately for both cell lines. This was done based on the proliferation rate of cells in response to a wide variety of medication dosages. Thereafter, each cell line was cultivated with a steady dosage of herceptin for several months. During this period, six time points were selected for further in vitro analysis, ranging from the untreated cell line at the beginning to a fully resistant cell line at the end of the experiment. In the second fold, nucleic acids were extracted for further high throughput-based microarray experiments of gene and microRNA expression. Such expression data were further analyzed in order to infer the molecular mechanisms involved in the underlying development of trastuzumab resistance. In the list of differentially expressed genes and miRNAs, multiple genes (e.g., BIRC5, E2F1, TFRC, and USP1) and miRNAs (e.g., hsa miR 574 3p, hsa miR 4530, and hsa miR 197 3p) responsible for trastuzumab resistance were found. Downstream analysis showed that TFRC, E2F1, and USP1 were also targeted by hsa-miR-8485. Moreover, it indicated that miR-4701-5p was highly expressed as compared to TFRC in the SKBR3 cell line. These results unveil key genes and miRNAs as molecular regulators for trastuzumab resistance.

Quantitative proteomic analysis of HER2 protein expression in PDAC tumors

Metastatic pancreatic adenocarcinoma (PDAC) is the third leading cause of cancer-related death in the United States, with a 5-year survival rate of only 11%, necessitating identification of novel treatment paradigms. Tumor tissue specimens from patients with PDAC, breast cancer, and other solid tumor malignancies were collected and tumor cells were enriched using laser microdissection (LMD). Reverse phase protein array (RPPA) analysis was performed on enriched tumor cell lysates to quantify a 32-protein/phosphoprotein biomarker panel comprising known anticancer drug targets and/or cancer-related total and phosphorylated proteins, including HER2Total, HER2Y1248, and HER3Y1289. RPPA analysis revealed significant levels of HER2Total in PDAC patients at abundances comparable to HER2-positive (IHC 3+) and HER2-low (IHC 1+ /2+ , FISH-) breast cancer tissues, for which HER2 screening is routinely performed. These data support a critical unmet need for routine clinical evaluation of HER2 expression in PDAC patients and examination of the utility of HER2-directed antibody-drug conjugates in these patients.

Effects of trastuzumab emtansine on canine urothelial carcinoma cells in vitro and in vivo

Urothelial carcinoma (UC) is the most common malignancy of the urinary tract in dogs and has aggressive behaviour. Although human epidermal growth factor receptor 2 (HER2) is a known therapeutic target with evidence in canine UC, the efficacy of anti-HER2 antibody drugs remains unknown. This study aimed to investigate the effects of anti-HER2 antibody drugs including trastuzumab and trastuzumab emtansine (T-DM1) on canine UC cell lines in vitro and in vivo. Four canine UC cell lines (Nene, TCCUB, Love, and Sora) were used. In western blotting, HER2 protein expression was observed in all the cell lines. Although both trastuzumab and T-DM1 showed dose-dependent growth inhibitory activity in the cell lines, T-DM1 showed much stronger activity than that of trastuzumab. In flow cytometry analyses with the canine UC cell line (Sora), T-DM1 but not trastuzumab significantly increased the percentages of early and late apoptotic cells in annexin V apoptotic assays and the sub-G1 phase fraction in cell cycle analyses. For the in vivo experiment, the canine UC cells (Sora) were subcutaneously injected into nude mice. Four days after inoculation, trastuzumab, T-DM1, or vehicle was administered intraperitoneally once a week for three times. Tumour volumes were significantly smaller in the T-DM1 group compared to the trastuzumab and vehicle control groups. These findings indicate that T-DM1 exerts a stronger antitumour effect than that of trastuzumab on canine UC cells in vitro and in vivo, possibly by inducing apoptosis due to DM1.

Universal CAR T cells targeted to HER2 with a biotin-trastuzumab soluble linker penetrate spheroids and large tumor xenografts that are inherently resistant to trastuzumab mediated ADCC

CAR T cell therapies face challenges in combating solid tumors due to their single-target approach, which becomes ineffective if the targeted antigen is absent or lost. Universal CAR T cells (UniCAR Ts) provide a promising solution by utilizing molecular tags (linkers), such as biotin conjugated to monoclonal antibodies, enabling them to target a variety of tumor antigens. Recently, we showed that conventional CAR T cells could penetrate the extracellular matrix (ECM) of ADCC-resistant tumors, which forms a barrier to therapeutic antibodies. This finding led us to investigate whether UniCAR T cells, targeted by soluble antibody-derived linkers, could similarly tackle ADCC-resistant tumors where ECM restricts antibody penetration. We engineered UniCAR T cells by incorporating a biotin-binding monomeric streptavidin 2 (mSA2) domain for targeting HER2 via biotinylated trastuzumab (BT). The activation and cytotoxicity of UniCAR T cells in the presence or absence of BT were evaluated in conventional immunoassays. A 3D spheroid coculture was set up to test the capability of UniCAR Ts to access ECM-masked HER2+ cells. For in vivo analysis, we utilized a HER2+ xenograft model in which intravenously administered UniCAR T cells were supplemented with intraperitoneal BT treatments. In vitro, BT-guided UniCAR T cells showed effective activation and distinct anti-tumor response. Upon target recognition, IFNγ secretion correlated with BT concentration. In the presence of BT, UniCAR T cells effectively penetrated HER2+ spheroids and induced cell death in their core regions. In vivo, upon intravenous administration of UniCAR Ts, circulating BT linkers immediately engaged the mSA2 domain and directed effector cells to the HER2+ tumors. However, these co-treated mice died early, possibly due to the lung infiltration of UniCAR T cells that could recognize both native biotin and HER2. Our results suggest that UniCAR T cells guided with soluble linkers present a viable alternative to conventional CAR T cells, especially for patients resistant to antibody therapy and those with solid tumors exhibiting high antigenic variability. Critical to their success, however, is the choice of an appropriate binding domain for the CAR and the corresponding soluble linker, ensuring both efficacy and safety in therapeutic applications.

Fluorescence Lifetime Imaging for Quantification of Targeted Drug Delivery in Varying Tumor Microenvironments

Rationale

Trastuzumab (TZM) is a monoclonal antibody that targets the human epidermal growth factor receptor (HER2) and is clinically used for the treatment of HER2-positive breast tumors. However, the tumor microenvironment can limit the access of TZM to the HER2 targets across the whole tumor and thereby compromise TZM's therapeutic efficacy. An imaging methodology that can non-invasively quantify the binding of TZM-HER2, which is required for therapeutic action, and distribution within tumors with varying tumor microenvironments is much needed.

Methods

We performed near-infrared (NIR) fluorescence lifetime (FLI) Forster Resonance Energy Transfer (FRET) to measure TZM-HER2 binding, using in vitro microscopy and in vivo widefield macroscopy, in HER2 overexpressing breast and ovarian cancer cells and tumor xenografts, respectively. Immunohistochemistry was used to validate in vivo imaging results.

Results

NIR FLI FRET in vitro microscopy data show variations in intracellular distribution of bound TZM in HER2-positive breast AU565 and AU565 tumor-passaged XTM cell lines in comparison to SKOV-3 ovarian cancer cells. Macroscopy FLI (MFLI) FRET in vivo imaging data show that SKOV-3 tumors display reduced TZM binding compared to AU565 and XTM tumors, as validated by ex vivo immunohistochemistry. Moreover, AU565/XTM and SKOV-3 tumor xenografts display different amounts and distributions of TME components, such as collagen and vascularity. Therefore, these results suggest that SKOV-3 tumors are refractory to TZM delivery due to their disrupted vasculature and increased collagen content.

Conclusion

Our study demonstrates that FLI is a powerful analytical tool to monitor the delivery of antibody drug tumor both in cell cultures and in vivo live systems. Especially, MFLI FRET is a unique imaging modality that can directly quantify target engagement with potential to elucidate the role of the TME in drug delivery efficacy in intact live tumor xenografts.

Targeted dual degradation of HER2 and EGFR obliterates oncogenic signaling, overcomes therapy resistance, and inhibits metastatic lesions in HER2-positive breast cancer models

AIMS

Human epidermal growth factor receptor 2 (HER2) is an oncogenic receptor tyrosine kinase amplified in approximately 20% of breast cancer (BC). HER2-targeted therapies are the linchpin of treating HER2-positive BC. However, drug resistance is common, and the main resistance mechanism is unknown. We tested the hypothesis that drug resistance results mainly from inadequate or lack of inhibition of HER2 and its family member epidermal growth factor receptor (EGFR).

METHODS

We used clinically relevant cell and tumor models to assess the impact of targeted degradation of HER2 and EGFR on trastuzumab resistance. Trastuzumab is the most common clinically used HER2 inhibitor. Targeted degradation of HER2 and EGFR was achieved using recombinant human protein PEPDG278D, which binds to the extracellular domains of the receptors. siRNA knockdown was used to assess the relative importance of EGFR and HER2 in trastuzumab resistance.

RESULTS

Both HER2 and EGFR are overexpressed in all trastuzumab-resistant HER2-positive BC cell and tumor models and that all trastuzumab-resistant models are highly vulnerable to targeted degradation of HER2 and EGFR. Degradation of HER2 and EGFR induced by PEPDG278D causes extensive inhibition of oncogenic signaling in trastuzumab-resistant HER2-positive BC cells. This is accompanied by strong growth inhibition of cultured cells, orthotopic patient-derived xenografts, and metastatic lesions in the brain and lung of trastuzumab-resistant HER2-positive BC. siRNA knockdown indicates that eliminating both HER2 and EGFR is necessary to maximize therapeutic outcome.

CONCLUSIONS

This study unravels the therapeutic vulnerability of trastuzumab-resistant HER2-positive BC and shows that an agent that targets the degradation of both HER2 and EGFR is highly effective in overcoming drug resistance in this disease. The findings provide new insights and innovations for advancing treatment of drug-resistant HER2-positive breast cancer that remains an unmet problem.

Molecular probes targeting HER2 PET/CT and their application in advanced breast cancer

PURPOSE

Human epidermal growth factor receptor 2 (HER2)-positive breast cancer cases are among the most aggressive breast tumor subtypes. Accurately assessing HER2 expression status is vital to determining whether patients will benefit from targeted anti-HER2 treatment. HER2-targeted positron emission tomography (PET/CT) is noninvasive, enabling the real-time evaluation of breast cancer patient HER2 status with accuracy.

METHODS

We summarize the research progress of PET/CT targeting HER2 in breast cancer, focusing on PET/CT molecular probes targeting HER2 and their clinical application in the management of advanced breast cancer.

RESULTS

At present, a variety of different HER2 targeted molecular probes for PET/CT imaging have been developed, including nucleolin-labeled antibodies, antibody fragments, nanobodies, and peptides of various affinities, among others. HER2-targeted PET/CT can relatively accurately evaluate HER2 expression status in advanced breast cancer patients. It has good performance in the early detection of small HER2-positive lesions, evaluation of HER2 status in lesions that cannot be readily biopsied, evaluation of the heterogeneity of multiple metastases, identification of lesions with altered HER2 status, and evaluation of the efficacy of anti-HER2 drugs.

CONCLUSION

HER2-targeted PET/CT offers a promising noninvasive approach for real-time assessment of HER2 status，which can be guide targeted treatment for HER2-positive breast cancer patients. Future prospective clinical studies will be invaluable for fully evaluating the importance of HER2-targeted molecular imaging in the management of breast cancer.

MRI-Based Machine Learning Radiomics for Preoperative Assessment of Human Epidermal Growth Factor Receptor 2 Status in Urothelial Bladder Carcinoma

BACKGROUND

The human epidermal growth factor receptor 2 (HER2) has recently emerged as hotspot in targeted therapy for urothelial bladder cancer (UBC). The HER2 status is mainly identified by immunohistochemistry (IHC), preoperative and noninvasive methods for determining HER2 status in UBC remain in searching.

PURPOSES

To investigate whether radiomics features extracted from MRI using machine learning algorithms can noninvasively evaluate the HER2 status in UBC.

STUDY TYPE

Retrospective.

POPULATION

One hundred ninety-five patients (age: 68.7 ± 10.5 years) with 14.3% females from January 2019 to May 2023 were divided into training (N = 156) and validation (N = 39) cohorts, and 43 patients (age: 67.1 ± 13.1 years) with 13.9% females from June 2023 to January 2024 constituted the test cohort (N = 43).

FIELD STRENGTH/SEQUENCE

3 T, T2-weighted imaging (turbo spin-echo), diffusion-weighted imaging (breathing-free spin echo).

ASSESSMENT

The HER2 status were assessed by IHC. Radiomics features were extracted from MRI images. Pearson correlation coefficient and the least absolute shrinkage and selection operator (LASSO) were applied for feature selection, and six machine learning models were established with optimal features to identify the HER2 status in UBC.

STATISTICAL TESTS

Mann-Whitney U-test, chi-square test, LASSO algorithm, receiver operating characteristic analysis, and DeLong test.

RESULTS

Three thousand forty-five radiomics features were extracted from each lesion, and 22 features were retained for analysis. The Support Vector Machine model demonstrated the best performance, with an AUC of 0.929 (95% CI: 0.888-0.970) and accuracy of 0.859 in the training cohort, AUC of 0.886 (95% CI: 0.780-0.993) and accuracy of 0.846 in the validation cohort, and AUC of 0.712 (95% CI: 0.535-0.889) and accuracy of 0.744 in the test cohort.

DATA CONCLUSION

MRI-based radiomics features combining machine learning algorithm provide a promising approach to assess HER2 status in UBC noninvasively and preoperatively.

EVIDENCE LEVEL

2 TECHNICAL EFFICACY: Stage 3.

Detection of HER2 expression using 99mTc-NM-02 nanobody in patients with breast cancer: a non-randomized, non-blinded clinical trial

BACKGROUND

99mTc radiolabeled nanobody NM-02 (99mTc-NM-02) is a novel single photon emission computed tomography (SPECT) probe with a high affinity and specificity for human epidermal growth factor receptor 2 (HER2). In this study, a clinical imaging trial was conducted to investigate the relationship between 99mTc-NM-02 uptake and HER2 expression in patients with breast cancer.

METHODS

Thirty patients with pathologically confirmed breast cancer were recruited and imaged with both 99mTc-NM-02 SPECT/computed tomography (CT) and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/CT. According to the treatment conditions before recruitment, patients were divided into two groups, the newly diagnosed group (n = 24) and the treated group (n = 6). The maximal standard uptake value (SUVmax) of 18F-FDG and SUVmax and mean SUV (SUVmean) of 99mTc-NM-02 in the lesions were determined to analyze the relationship with HER2 expression.

RESULTS

No meaningful relationship was observed between 18F-FDG uptake and HER2 expression in 30 patients with breast cancer. 99mTc-NM-02 uptake was positively correlated with HER2 expression in the newly diagnosed group, but no correlation was observed in the treated group. 99mTc-NM-02 uptake in HER2-positive lesions was lower in those with effective HER2-targeted therapy compared with the newly diagnosed group. 99mTc-NM-02 SPECT/CT detected brain and bone metastases of breast cancer with a different imaging pattern from 18F-FDG PET/CT. 99mTc-NM-02 showed no non-specific uptake in inflamed tissues and revealed intra- and intertumoral HER2 heterogeneity by SPECT/CT imaging in 9 of the 30 patients with breast cancer.

CONCLUSIONS

99mTc-NM-02 SPECT/CT has the potential for visualizing whole-body HER2 overexpression in untreated patients, making it a promising method for HER2 assessment in patients with breast cancer.

TRIAL REGISTRATION

NCT04674722, Date of registration: December 19, 2020.

Color Standardization and Stain Intensity Calibration for Whole Slide Image-Based Immunohistochemistry Assessment

Automated quantification of human epidermal growth factor receptor 2 (HER2) immunohistochemistry (IHC) using whole slide imaging (WSI) is expected to eliminate subjectivity in visual assessment. However, the color intensity in WSI varies depending on the staining process and scanner device. Such variations affect the image analysis results. This paper presents methods to diminish the influence of color variation produced in the staining process using a calibrator slide consisting of peptide-coated microbeads. The calibrator slide is stained along with tissue sample slides, and the 3,3'-diaminobenzidine (DAB) color intensities of the microbeads are used for calibrating the color variation of the sample slides. An off-the-shelf image analysis tool is employed for the automated assessment, in which cells are classified by the thresholds for the membrane staining. We have adopted two methods for calibrating the color variation based on the DAB color intensities obtained from the calibrator slide: (1) thresholds for classifying the DAB membranous intensity are adjusted, and (2) the color intensity of WSI is corrected. In the experiment, the calibrator slides and tissue of breast cancer slides were stained together on different days and used to test our protocol. With the proposed protocol, the discordance in the HER2 evaluation was reduced to one slide out of 120 slides.

Artemisia argyi extracts overcome lapatinib resistance via enhancing TMPRSS2 activation in HER2-positive breast cancer

Breast cancer stands as the predominant malignancy and primary cause of cancer-related mortality among females globally. Approximately 25% of breast cancers exhibit HER2 overexpression, imparting a more aggressive tumor phenotype and correlating with poor prognoses. Patients with metastatic breast cancer receiving HER2 tyrosine kinase inhibitors (HER2 TKIs), such as Lapatinib, develop acquired resistance within a year, posing a critical challenge in managing this disease. Here, we explore the potential of Artemisia argyi, a Chinese herbal medicine known for its anti-cancer properties, in mitigating HER2 TKI resistance in breast cancer. Analysis of the Cancer Genome Atlas (TCGA) revealed diminished expression of transmembrane serine protease 2 (TMPRSS2), a subfamily of membrane proteolytic enzymes, in breast cancer patients, correlating with unfavorable outcomes. Intriguingly, lapatinib-responsive patients exhibited higher TMPRSS2 expression. Our study unveiled that the compounds from Artemisia argyi, eriodictyol, and umbelliferone could inhibit the growth of lapatinib-resistant HER2-positive breast cancer cells. Mechanistically, they suppressed HER2 kinase activation by enhancing TMPRSS2 activity. Our findings propose TMPRSS2 as a critical determinant in lapatinib sensitivity, and Artemisia argyi emerges as a potential agent to overcome lapatinib via activating TMPRSS2 in HER2-positive breast cancer. This study not only unravels the molecular mechanisms driving cell death in HER2-positive breast cancer cells induced by Artemisia argyi but also lays the groundwork for developing novel inhibitors to enhance therapy outcomes.

Successful subtotal gastrectomy and hepatectomy for HER2-positive gastric cancer with liver metastasis after trastuzumab-based chemotherapy: a case report

BACKGROUND

Conversion surgery (CS) after chemotherapy is weakly recommended as a promising tool for improving prognoses in patients with unresectable gastric cancer. Moreover, several investigators have demonstrated the clinical efficacy of subtotal gastrectomy (sTG) with a small remnant stomach for the nutritional status and surgical outcome compared with total gastrectomy. Here, we report a patient with liver metastasis from human epidermal growth factor receptor 2 (HER2)-positive gastric cancer who underwent sTG and hepatectomy after trastuzumab-based chemotherapy.

CASE PRESENTATION

An 84-year-old male patient was diagnosed with HER2-positive gastric cancer with a single liver metastasis. He was treated with eight courses of trastuzumab in combination with S-1 and oxaliplatin as first-line chemotherapy. The primary tumor and liver metastasis shrank significantly. The metastatic liver lesion's reduction rate was 65%. According to the Response Evaluation Criteria in Solid Tumors, the patient had a partial response. Therefore, he underwent an sTG with D2 lymphadenectomy and partial hepatectomy of segment 2. Histopathological examination revealed a grade 3 histological response without lymph node metastases from the primary tumor. No viable cancer cells were observed in the resected liver specimens. The patient received adjuvant chemotherapy with S-1. The postoperative quality of life (QOL) evaluated using the Postgastrectomy Syndrome Assessment Scale-45 was maintained, and the patient was still alive 8 months after the CS without recurrence.

CONCLUSIONS

An sTG with a small remnant stomach might be clinically useful for preventing a decline in QOL and improving prognoses in patients with stage IV gastric cancer after chemotherapy.

HER2 evaluation for clinical decision making in human solid tumours: pearls and pitfalls

The significant clinical benefits of human epidermal growth factor receptor 2 (HER2)-targeted therapeutic agents have revolutionized the clinical treatment landscape in a variety of human solid tumours. Accordingly, accurate evaluation of HER2 status in these different tumour types is critical for clinical decision making to select appropriate patients who may benefit from life-saving HER2-targeted therapies. HER2 biomarker scoring criteria is different in different organ systems, and close adherence to the corresponding HER2 biomarker testing guidelines and their updates, if available, is essential for accurate evaluation. In addition, knowing the unusual patterns of HER2 expression is also important to avoid inaccurate evaluation. In this review, we discuss the key considerations when evaluating HER2 status in solid tumours for clinical decision making, including tissue handling and preparation for HER2 biomarker testing, as well as pathologist's readout of HER2 testing results in breast carcinomas, gastroesophageal adenocarcinomas, colorectal adenocarcinomas, gynaecologic carcinomas, and non-small cell lung carcinomas.

In ER-Positive, HER2-Negative Breast Cancers, HER2 mRNA Levels Correlate Better with Clinicopathologic Features and Oncotype DX Recurrence Score than HER2 Immunohistochemistry

With the approval of trastuzumab deruxtecan for treating advanced human epidermal growth factor receptor-2 (HER2) low breast cancer (BC), it has become increasingly important to develop more accurate and reliable methods to identify HER2-low BC. In addition, HER2 immunohistochemistry (IHC) has limitations for quantification of HER2. We explored the relationship between HER2 IHC and mRNA levels and evaluated whether HER2 IHC scores and mRNA levels are associated with clinicopathologic features and Oncotype DX Recurrence Score (RS) in estrogen receptor (ER)-positive, HER2-negative BCs. A total of 750 BCs sent for Oncotype DX (ODX) testing were included in this study, and 559 with HER2 mRNA levels were available. There were no statistically significant differences between HER2 0 and HER2-low BC in clinicopathologic variables or ODX RS using HER2 IHC. There was a significant difference in median HER2 mRNA values between HER2 0 and HER2-low (8.7 vs 9.3, P < .001); however, the HER2 mRNA distribution had substantial overlap between these 2 groups with a suboptimal area under the receiver operating characteristic curve (area under the receiver operating characteristic curve = 0.68). A HER2 mRNA value of 9.2 was generated as the optimal cutoff for distinguishing HER2 0 and HER2-low BC. Comparing ER+ BCs with HER2 mRNA high (>9.2) and low (≤9.2) revealed a statistically significant difference in most clinicopathologic variables and ODX RS. From this large cohort of ER-positive, HER2-negative BC, our results demonstrated that HER2 mRNA levels correlated better with clinicopathologic features and recurrence risk as assessed by ODX RS than HER2 IHC scores. Our findings suggest that HER2 mRNA-detecting methods could potentially serve as a quantitative and reliable method for identifying a biologically meaningful group of HER2-low BC. Further study is needed to determine whether HER2 mRNA levels could be more reliable than IHC for identifying which patients will be most likely to benefit from trastuzumab deruxtecan.

First-in-Human Evaluation of Site-Specifically Labeled 89Zr-Pertuzumab in Patients with HER2-Positive Breast Cancer

Radioimmunoconjugates targeting human epidermal growth factor receptor 2 (HER2) have shown potential to noninvasively visualize HER2-positive tumors. However, the stochastic approach that has been traditionally used to radiolabel these antibodies yields poorly defined and heterogeneous products with suboptimal in vivo performance. Here, we describe a first-in-human PET study on patients with HER2-positive breast cancer evaluating the safety, biodistribution, and dosimetry of 89Zr-site-specific (ss)-pertuzumab PET, a site-specifically labeled radioimmunoconjugate designed to circumvent the limitations of random stochastic lysine labeling. Methods: Six patients with HER2-positive metastatic breast cancer were enrolled in a prospective clinical trial. Pertuzumab was site-specifically modified with desferrioxamine (DFO) via a novel chemoenzymatic strategy and subsequently labeled with 89Zr. Patients were administered 74 MBq of 89Zr-ss-pertuzumab in 20 mg of total antibody intravenously and underwent PET/CT at 1 d, 3-4 d, and 5-8 d after injection. PET imaging, whole-body probe counts, and blood draws were performed to assess the pharmacokinetics, biodistribution, and dosimetry. Results: 89Zr-ss-pertuzumab PET/CT was used to assess HER2 status and heterogeneity to guide biopsy and decide the next line of treatment at progression. The radioimmunoconjugate was able to detect known sites of malignancy, suggesting that these tumor lesions were HER2-positive. The optimal imaging time point was 5-8 d after administration, and no toxicities were observed. Dosimetry estimates from OLINDA showed that the organs receiving the highest doses (mean ± SD) were kidney (1.8 ± 0.5 mGy/MBq), liver (1.7 ± 0.3 mGy/MBq), and heart wall (1.2 ± 0.1 mGy/MBq). The average effective dose for 89Zr-ss-pertuzumab was 0.54 ± 0.03 mSv/MBq, which was comparable to both stochastically lysine-labeled 89Zr-DFO-pertuzumab and 89Zr-DFO-trastuzumab. One patient underwent PET/CT with both 89Zr-ss-pertuzumab and 89Zr-DFO-pertuzumab 1 mo apart, with 89Zr-ss-pertuzumab demonstrating improved lesion detection and higher tracer avidity. Conclusion: This study demonstrated the safety, dosimetry, and potential clinical applications of 89Zr-ss-pertuzumab PET/CT. 89Zr-ss-pertuzumab may detect more lesions than 89Zr-DFO-pertuzumab. Potential clinical applications include real-time evaluation of HER2 status to guide biopsy and assist in treatment decisions.

Revolutionizing anti-HER2 therapies for extrahepatic cholangiocarcinoma and gallbladder cancer: Current advancements and future perspectives

Biliary tract cancers (BTCs) encompass a heterogeneous group of rare tumors, including intrahepatic cholangiocarcinoma (iCCA), extrahepatic cholangiocarcinoma (eCCA), gallbladder cancer (GBC) and ampullary cancer (AC). The present first-line palliative treatment regimen comprises gemcitabine and cisplatin in combination with immunotherapy based on two randomized controlled studies. Despite the thorough investigation of these palliative treatments, long-term survival remains low. Moving beyond conventional chemotherapies and immunotherapies, the realm of precision medicine has demonstrated remarkable efficacy in malignancies such as breast and gastric cancers, characterized by notable HER2 overexpression rates. In the context of biliary tract cancer, significant HER2 alterations are observed, particularly within eCCA and GBC, heightening the interest in precision medicine. Various anti-HER2 therapies, including trastuzumab, pertuzumab, trastuzumab-deruxtecan, zanidatamab and neratinib, have undergone investigation. The objective of this review is to summarize the current evidence and outline future directions of targeted HER2 treatment therapy in patients with biliary tract tumors, specially extrahepatic cholangiocarcinoma and gallbladder cancer.

Potent antitumor activity of anti-HER2 antibody-topoisomerase I inhibitor conjugate based on self-immolative dendritic dimeric-linker

Antibody-drug conjugates (ADCs) are a rapidly expanding class of anticancer therapeutics, with 14 ADCs already approved worldwide. We developed unique linker technologies for the bioconjugation of drug molecules with controlled-release applications. We synthesized cathepsin-cleavable ADCs using a dimeric prodrug system based on a self-immolative dendritic scaffold, resulting in a high drug-antibody ratio (DAR) with the potential to reach 16 payloads due to its dendritic structure, increased stability in the circulation and efficient release profile of a highly cytotoxic payload at the targeted site. Using our novel cleavable linker technologies, we conjugated the anti-human epidermal growth factor receptor 2 (anti-HER2) antibody, trastuzumab, with topoisomerase I inhibitors, exatecan or belotecan. The newly synthesized ADCs were tested in vitro on mammary carcinoma cells overexpressing human HER2, demonstrating a substantial inhibitory effect on the proliferation of HER2-positive cells. Importantly, a single dose of our trastuzumab-based ADCs administered in vivo to mice bearing HER2-positive tumors, showed a dose-dependent inhibition of tumor growth and survival benefit, with the most potent antitumor effects observed at 10 mg/kg, which resulted in complete tumor regression and survival of 100% of the mice. Overall, our novel dendritic technologies using the protease-cleavable Val-Cit linker present an opportunity for the development of highly selective and potent controlled-released therapeutic payloads. This strategy could potentially lead to the development of novel and effective ADC technologies for patients diagnosed with HER2-positive cancers. Moreover, our proposed ADC linker technology can be implemented in additional medical conditions such as other malignancies as well as autoimmune diseases that overexpress targets, other than HER2.

Synthesis of novel pyrimido[4,5-b]quinoline derivatives as dual EGFR/HER2 inhibitors as anticancer agents

A series of novel N-aryl-5-aryl-6,7,8,9-tetrahydropyrimido[4,5-b]quinolin-4-amines 4a-4l was synthesized as potential anticancer agents through Dimroth rearrangement reaction of intermediates 3a-3c. Pyrimido[4,5-b]quinolines 4a-4l showed promising activity against the Michigan Cancer Foundation-7 (MCF-7) cell line, compared with lapatinib as the reference drug. Compounds 4d, 4h, 4i, and 4l demonstrated higher cytotoxic activity than lapatinib, with IC50 values of 2.67, 6.82, 4.31, and 1.62 µM, respectively. Compounds 4d, 4i, and 4l showed promising epidermal growth factor receptor (EGFR) inhibition with IC50 values of 0.065, 0.116, and 0.052 µM, respectively. These compounds were subjected to human epidermal growth factor receptor 2 (HER2) inhibition and showed IC50 values of 0.09, 0.164, and 0.055 µM, respectively. Compounds 4d, 4i, and 4l are good candidates as dual EGFR/HER2 inhibitors. The most active compound, 4l, was subjected to cell-cycle analysis and induced cell-cycle arrest at the S phase. Compound 4l induced apoptosis 60-fold compared with control untreated MCF-7 cells. 4l can inhibit cancer metastasis. It reduced MCF-7 cell infiltration and metastasis by 45% compared with control untreated cells.

Novel metabolic biomarker for early detection and diagnosis to the patients with gastric cardia adenocarcinoma

BACKGROUND

Gastric cardia adenocarcinoma (GCA) is classified as Siewert type II adenocarcinoma at the esophagogastric junction in Western countries. The majority of GCA patients do not exhibit early warning symptoms, leading to over 90% of diagnoses at an advanced stage, resulting in a grim prognosis, with less than a 20% 5-year survival rate.

METHOD

Metabolic features of 276 GCA and 588 healthy controls were characterized through a widely-targeted metabolomics by UPLC-MS/MS analysis. This study encompasses a joint pathway analysis utilizing identified metabolites, survival analysis in both early and advanced stages, as well as high and negative and low expression of HER2 immunohistochemistry staining. Machine learning techniques and Cox regression models were employed to construct a diagnostic panel.

RESULTS

A total of 25 differential metabolites were consistently identified in both discovery and validation sets based on criteria of p < 0.05, (VIP) ≥ 1, and FC ≥ 2 or FC ≤ 0.5. Early-stage GCA patients exhibited a more favorable prognosis compared to those in advanced stages. HER2 overexpression was associated with a more positive outcome compared to the negative and low expression groups. Metabolite panel demonstrated a robust diagnostic performance with AUC of 0.869 in discovery set and 0.900 in validation set.

CONCLUSIONS

A total of 25 common and stable differential metabolites may hold promise as liquid non-invasive indicators for GCA diagnosis. HER2 may function as a tumor suppressor gene in GCA, as its overexpression is associated with improved survival. The downregulation of bile acid metabolism in GCA may offer valuable theoretical insights and innovative approaches for precision-targeted treatments in GCA patients.

Salivary gland carcinoma: Towards a more personalised approach

Salivary Gland carcinomas (SGCs) are rare tumors accounting for less than 1% of all cancers with 21 histologically diverse subtypes. The rarity of the disease presents a challenge for clinicians to conduct large size randomized controlled trials. Surgery and radiotherapy remain the only curative treatment for localized disease, whereas treatments for recurrent and metastatic disease remain more challenging with very disappointing results for chemotherapy. The different histological subtypes harbor various genetic alterations, some pathognomonic with a diagnostic impact for pathologists in confirming a difficult diagnosis and others with therapeutic implications regardless of the histologic subtype. Current international guidelines urge pathologists to identify androgen receptor status, HER-2 expression that could be determined by immunohistochemistry, and TRK status in patients with non-adenoid cystic salivary gland carcinoma that are eligible to initiate a systemic treatment, in order to offer them available targeted therapies or refer them to clinical trials based on their mutational profile. A more advanced molecular profiling by next generation sequencing would offer a larger panel of molecular alterations with possible therapeutic implications such as NOTCH, PI3K, BRAF, MYB, and EGFR. In the following review, we present the most common genetic alterations in SGCs as well as actionable mutations with the latest available data on therapeutic options and upcoming clinical trials.

Prognostic value of HER2DX in early-stage HER2-positive breast cancer: a comprehensive analysis of 757 patients in the Sweden Cancerome Analysis Network-Breast dataset (SCAN-B)

BACKGROUND

The HER2DX risk-score has undergone rigorous validation in prior investigations involving patients with early-stage human epidermal growth factor receptor 2 (HER2)-positive (HER2+) breast cancer. In this study, we present the outcomes of the HER2DX risk-score within the most recent release of the Sweden Cancerome Analysis Network-Breast (SCAN-B) HER2+ cohort. This updated examination benefits from a larger patient sample, an extended follow-up duration, and detailed treatment information.

MATERIALS AND METHODS

Clinical and RNAseq data from the SCAN-B dataset were retrieved from Gene Expression Omnibus (GSE81538). Among the 6600 patients, 819 had HER2+ breast cancer, with 757 individuals with research-based HER2DX risk-scores and corresponding survival outcomes. The HER2DX risk-score was evaluated (i) as a continuous variable and (ii) using predefined cut-offs. The primary endpoint for this study was overall survival (OS). The Kaplan-Meier method and Cox models were used to estimate OS and a multistate model with four states was fitted to better characterize patients' follow-up.

RESULTS

The median follow-up time was 7.5 years (n = 757). The most common systemic therapy was chemotherapy with trastuzumab (82.0%) and most tumors were classified as T1-T2 (97.1%). The HER2DX risk-score as a continuous variable was significantly associated with OS after adjustment for clinical variables and treatment regimen [hazard ratios (HR) per 10-unit increment = 1.31, 95% confidence interval (CI) 1.13-1.51, P < 0.001] as well as within predefined risk groups (high versus low; HR = 2.57, 95% CI 1.36-4.85, P < 0.001). Patients classified as HER2DX high-risk also had higher risk of (i) breast cancer recurrence and (ii) death without previous recurrence. Within the subgroup of HER2+ T1N0 tumors (n = 297), those classified as high-risk demonstrated inferior OS compared to low-risk tumors (7-year OS 77.8% versus 96.8%, P < 0.001). The HER2DX mRNA ERBB2 score was associated with clinical HER2 status (area under the receiver operating characteristic curve = 0.91).

CONCLUSIONS

In patients with early-stage HER2+ breast cancer, HER2DX risk-score provides prognostic information beyond clinicopathological variables, including treatment regimen with or without trastuzumab.

Leptomeningeal carcinomatosis and brain metastases in gastroesophageal carcinoma: a real-world analysis of clinical and pathologic characteristics and outcomes

BACKGROUND

Brain metastasis (BrM) and Leptomeningeal Carcinomatosis (LMC) are uncommon complications in gastroesophageal carcinoma (GEC) patients. These patients have a poor prognosis and are challenging to treat. We described the clinicopathologic features and outcomes in the largest cohort of Central Nervous System (CNS) metastasis in GEC patients.

METHODS

single-center retrospective study of GEC treated from 2007 to 2021. Clinicopathologic characteristics and treatment modalities were reviewed. Survival was calculated from the date of CNS diagnosis until date of death/last follow-up using the Kaplan-Meier method. A multivariable Cox proportional hazards regression model was used.

RESULTS

Of 3283 GEC patients, 100 (3.04%) were diagnosed with BrM and 20 with LMC (0.61%). Patients with known human epidermal growth factor receptor 2 (HER2) status (N = 48), 60% were HER2 positive (defined as IHC 3 + or IHC 2+/FISH+). Among LMC patients most were signet-ring subtype (85%), and only 15% (2/13) were HER2 positive. Median survival was 0.7; 3.8; and 7.7 months in BrM patients treated with best supportive care, radiation, and surgery, respectively (p < 0.001). In LMC, median survival was 0.7 month in patients who had best supportive care (7/19) and 2.8 months for those who had whole brain radiation therapy (p = 0.015). Multivariate analysis showed worse outcomes in ECOG ≥ 2 (p = 0.002), number of BrM ≥ 4 (p < 0.001) and number of metastatic sites (p = 0.009).

CONCLUSION

HER2 expression were enriched in patients with BrM, while it is uncommon in LMC. Patients treated with surgery followed by radiation had an improved OS in BrM and WBRT benefited patients with LMC.

Clinicopathological differences and survival benefit in ER+/PR+/HER2+ vs ER+/PR-/HER2+ breast cancer subtypes

INTRODUCTION

Breast cancer subtypes based on estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) expression have significant implications for prognosis. HER2-positive tumors historically demonstrated poorer survival, but anti-HER2 targeted therapy improved outcomes. However, hormone receptor (HR)-positive patients may experience reduced benefit due to HER2-HR signaling crosstalk.

METHODS

Data from two databases, the Shanghai Jiao Tong University Breast Cancer Data Base (SJTUBCDB) and the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) database, were analyzed. Propensity score adjustments were used to balance patient characteristics between ER+/PR+/HER2+ and ER+/PR-/HER2+ subtypes. Kaplan-Meier survival curves estimated disease-free survival (DFS), breast cancer-specific survival (BCSS), overall survival (OS) for these subtypes in the SJTUBCDB, while subgroup analyses using multivariable models were performed based on menstruation, pN stage, HER2-targeted therapy, and endocrinotherapy.

RESULTS

The ER+/PR+/HER2+ group showed significantly better DFS and BCSS than the ER+/PR-/HER2+ group, particularly in postmenopausal and pN0 stage patients. Survival outcomes were similar after anti-HER2 therapy or endocrine aromatase inhibitor (AI) therapy in both groups. However, among patients receiving selective estrogen receptor modulator (SERM) treatment, those in the ER+/PR-/HER2+ group had a significantly worse prognosis compared to ER+/PR+/HER2+ patients.

CONCLUSIONS

HER2-positive breast cancers with different HR statuses exhibit distinct clinicopathological features and survival outcomes. Patients in the ER+/PR+/HER2+ group generally experience better survival, particularly in postmenopausal and pN0 stage patients. Treatment strategies should consider HR status and specific modalities for better personalized management.

Lung toxicity induced by anti-HER2 antibody - drug conjugates for breast cancer

Human epidermal growth factor receptor 2 (HER2) serves as both a prognostic indicator and a therapeutic target for breast cancer. Therefore, anti-HER2 therapy plays a crucial role in the treatment of HER2-positive cancer. Antibody-drug conjugates (ADCs) are composed of a monoclonal antibody, a chemical linker and a payload, wherein their aim is to reduce the toxicity associated with chemotherapy drugs by utilizing specific antibodies. Among the anti-HER2 ADCs currently approved for clinical use, trastuzumab emtansine(T-DM1) and trastuzumab deruxtecan (T-Dxd) have demonstrated remarkable efficacy in treating HER2-positive breast cancer. However, it is essential to emphasize the occurrence of lung toxicity during the treatment process, which can be life-threatening. In this review, we provide an overview of the new epidemiological features associated with interstitial lung disease (ILD) related to anti-HER2 ADCs in breast cancer. We also summarize the potential pathogenesis and explore the diagnosis and treatment strategies within this field.

A phase 2 trial of zanidatamab in HER2-overexpressed advanced endometrial carcinoma and carcinosarcoma (ZW25-IST-2)

OBJECTIVE

HER2 overexpression is associated with decreased overall survival in metastatic endometrial cancer. Trastuzumab with chemotherapy has demonstrated efficacy for first-line management of advanced HER2+ endometrial carcinoma, but HER2-directed therapy in the recurrent setting is limited. Zanidatamab (ZW25), a humanized, bispecific antibody that simultaneously binds the 2 distinct HER2 epitopes bound by trastuzumab and pertuzumab, has demonstrated safety and activity in HER2+ tumors. Here, we report the results of a phase 2, open-label study evaluating the efficacy and safety of zanidatamab in patients with HER2+ metastatic endometrial carcinoma/carcinosarcoma who received prior treatment.

METHODS

We enrolled 16 patients with HER2+ endometrial carcinoma/carcinosarcoma after progression on ≤2 lines of therapy on a single-arm phase 2 study of zanidatamab. The primary endpoint was overall response rate (ORR; complete or partial response) by Response Evaluation Criteria in Solid Tumors version 1.1. HER2 immunohistochemistry and fluorescence in situ hybridization (FISH) were performed on pretreatment samples. Intratumor HER2 genetic heterogeneity was assessed.

RESULTS

This study did not meet its primary efficacy endpoint. Although a clinical benefit rate of 37.5% was observed by 24 weeks, only 1 patient achieved a partial response (ORR, 6.2%). Eight patients had HER2 intratumor heterogeneity or lacked HER2 amplification by FISH. Decreased HER2 expression on repeat pretreatment samples was observed in 3 (75%) of 4 patients evaluated.

CONCLUSIONS

We observed a low response rate to zanidatamab in recurrent HER2+ endometrial carcinoma/carcinosarcoma, which may be driven by downregulation of HER2 expression. Repeat HER2 testing should be considered prior to second-line HER2-directed therapy.

CLINICALTRIALS

govidentifier: NCT04513665.