Current Targeted Therapies in HER2-Positive Gastric Adenocarcinoma

Advances in targeted therapy for human epidermal growth factor receptor 2 positive in advanced gastric cancer

Emerging therapeutic methods represented by targeted therapy are effective supplements to traditional first-line chemoradiotherapy resistance. Human epidermal growth factor receptor 2 (HER2) is one of the most important targets in targeted therapy for gastric cancer. Trastuzumab combined with chemotherapy has been used as the first-line treatment for advanced gastric cancer. The safety and efficacy of pertuzumab and margetuximab in the treatment of gastric cancer have been verified. However, monoclonal antibodies, due to their large molecular weight, inability to penetrate the blood-brain barrier, and drug resistance, lead to decreased therapeutic efficacy, so it is necessary to explore the efficacy of other HER2-targeting therapies in gastric cancer. Small-molecule tyrosine kinase inhibitors, such as lapatinib and pyrrotinib, have the advantages of small molecular weight, penetrating the blood-brain barrier and high oral bioavailability, and are expected to become the drugs of choice for perioperative treatment and neoadjuvant therapy of gastric cancer after validation by large-scale clinical trials in the future. Antibo-drug conjugate, such as T-DM1 and T-DXd, can overcome the resistance of monoclonal antibodies despite their different mechanisms of tumor killing, and are a supplement for the treatment of patients who have failed the treatment of monoclonal antibodies such as trastuzumab. Therefore, after more detailed stratification of gastric cancer patients, various gastric cancer drugs targeting HER2 are expected to play a more significant role.

HER2 in Gastric Cancer: A Comprehensive Analysis Combining Meta-Analysis and DCE-MRI Radiomics

OBJECTIVE

Advanced gastric cancer (AGC) is a severe malignant tumor, and overexpression of HER2/ERBB2 may play a crucial role in its development. The purpose of this study is to investigate the overexpression of HER2/ERBB2 in gastric cancer through a meta-analysis and examine its relationship with perfusion parameters using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) technology.

METHODS

We conducted an extensive literature search and collected relevant studies for the meta-analysis. We used a random-effects model and assigned weights using the "inverse variance" method. Additionally, we included 95 AGC patients diagnosed pathologically between April 2018 and October 2021. They all underwent DCE-MRI scans, and the data were subsequently analyzed using the Omni kinetic software. HER2 expression was assessed using immunohistochemistry.

RESULTS

The meta-analysis revealed an overall odds ratio (OR) of .21 for HER2/ERBB2 overexpression in gastric cancer, with a 95% confidence interval of [.14, .30]. DCE-MRI results showed a significant association between high HER2 expression and poor tumor differentiation (P < .005). The extracellular volume fraction (Ecv) quantile, mean, relative deviation, median intensity, and difference entropy were significantly higher in the low HER2 expression group compared to the high HER2 expression group. Receiver operating characteristic (ROC) curve analysis demonstrated that the area under the curve (AUC) values of DCE-MRI radiomic parameters with significant differences were close to .7.

CONCLUSION

Overexpression of HER2/ERBB2 in gastric cancer is significantly associated with certain radiomic parameters of DCE-MRI, providing a valuable diagnostic tool for clinical practice. Furthermore, the meta-analysis further confirmed the critical role of HER2/ERBB2 in the development of gastric cancer.

Circ_0003356 suppresses gastric cancer growth through targeting the miR-668-3p/SOCS3 axis

BACKGROUND

Circular RNAs (circRNAs) have attracted extensive attention as therapeutic targets in gastric cancer (GC). Circ_0003356 is known to be downregulated in GC tissues, but its cellular function and mechanisms remain undefined.

AIM

To investigate the role of circ_0003356 in GC at the molecular and cellular level.

METHODS

Circ_0003356, miR-668-3p, and SOCS3 expression were assessed via quantitative real time-polymerase chain reaction (qRT-PCR). Wound healing, EdU, CCK-8, flow cytometry and transwell assays were used to analyze the migration, proliferation, viability, apoptosis and invasion of GC cells. The subcellular localization of circ_0003356 was monitored using fluorescence in situ hybridization. The interaction of circ_0003356 with miR-668-3p was confirmed using RIP-qRT-PCR, RNA pull-down, and dual luciferase reporter assays. We observed protein levels of genes via western blot. We injected AGS cells into the upper back of mice and performed immunohistochemistry staining for examining E-cadherin, N-cadherin, Ki67, and SOCS3 expressions. TUNEL staining was performed for the assessment of apoptosis in mouse tumor tissues.

RESULTS

Circ_0003356 and SOCS3 expression was downregulated in GC cells, whilst miR-668-3p was upregulated. Exogenous circ_0003356 expression and miR-668-3p silencing suppressed the migration, viability, proliferation, epithelial to mesenchy-mal transition (EMT) and invasion of GC cells and enhanced apoptosis. Circ_0003356 overexpression impaired tumor growth in xenograft mice. Targeting of miR-668-3p by circ_0003356 was confirmed through binding assays and SOCS3 was identified as a downstream target of miR-668-3p. The impacts of circ_0003356 on cell proliferation, apoptosis, migration, invasion and EMT were reversed by miR-668-3p up-regulation or SOCS3 down-regulation in GC cells.

CONCLUSION

Circ_0003356 impaired GC development through its interaction with the miR-668-3p/SOCS3 axis.

Accurate preoperative staging and HER2 status prediction of gastric cancer by the deep learning system based on enhanced computed tomography

Purpose

To construct the deep learning system (DLS) based on enhanced computed tomography (CT) images for preoperative prediction of staging and human epidermal growth factor receptor 2 (HER2) status in gastric cancer patients.

Methods

The raw enhanced CT image dataset consisted of CT images of 389 patients in the retrospective cohort, The Cancer Imaging Archive (TCIA) cohort, and the prospective cohort. DLS was developed by transfer learning for tumor detection, staging, and HER2 status prediction. The pre-trained Yolov5, EfficientNet, EfficientNetV2, Vision Transformer (VIT), and Swin Transformer (SWT) were studied. The tumor detection and staging dataset consisted of 4860 enhanced CT images and annotated tumor bounding boxes. The HER2 state prediction dataset consisted of 38900 enhanced CT images.

Results

The DetectionNet based on Yolov5 realized tumor detection and staging and achieved a mean Average Precision (IoU=0.5) (mAP_0.5) of 0.909 in the external validation cohort. The VIT-based PredictionNet performed optimally in HER2 status prediction with the area under the receiver operating characteristics curve (AUC) of 0.9721 and 0.9995 in the TCIA cohort and prospective cohort, respectively. DLS included DetectionNet and PredictionNet had shown excellent performance in CT image interpretation.

Conclusion

This study developed the enhanced CT-based DLS to preoperatively predict the stage and HER2 status of gastric cancer patients, which will help in choosing the appropriate treatment to improve the survival of gastric cancer patients.

Evaluation of Epidermal Growth Factor Receptor 2 Status in Gastric Cancer by CT-Based Deep Learning Radiomics Nomogram

Purpose

To explore the role of computed tomography (CT)-based deep learning and radiomics in preoperative evaluation of epidermal growth factor receptor 2 (HER2) status in gastric cancer.

Materials and methods

The clinical data on gastric cancer patients were evaluated retrospectively, and 357 patients were chosen for this study (training cohort: 249; test cohort: 108). The preprocessed enhanced CT arterial phase images were selected for lesion segmentation, radiomics and deep learning feature extraction. We integrated deep learning features and radiomic features (Inte). Four methods were used for feature selection. We constructed models with support vector machine (SVM) or random forest (RF), respectively. The area under the receiver operating characteristics curve (AUC) was used to assess the performance of these models. We also constructed a nomogram including Inte-feature scores and clinical factors.

Results

The radiomics-SVM model showed good classification performance (AUC, training cohort: 0.8069; test cohort: 0.7869). The AUC of the ResNet50-SVM model and the Inte-SVM model in the test cohort were 0.8955 and 0.9055. The nomogram also showed excellent discrimination achieving greater AUC (training cohort, 0.9207; test cohort, 0.9224).

Conclusion

CT-based deep learning radiomics nomogram can accurately and effectively assess the HER2 status in patients with gastric cancer before surgery and it is expected to assist physicians in clinical decision-making and facilitates individualized treatment planning.

Targeting the autophagy promoted antitumor effect of T-DM1 on HER2-positive gastric cancer

Trastuzumab emtansine (T-DM1), an antibody-drug conjugate consisted of the HER2-targeted monoclonal antibody trastuzumab and the tubulin inhibitor emtansine, has shown potent therapeutic value in HER2-positive breast cancer (BC). However, a clinical trial indicated that T-DM1 exerts a limited effect on HER2-positive gastric cancer (GC), but the underlying mechanism is inconclusive. Our research attempted to reveal the probable mechanism and role of autophagy in T-DM1-treated HER2-positive GC. In this study, our results showed that T-DM1 induced apoptosis and exhibited potent therapeutic efficacy in HER2-positive GC cells. In addition, autophagosomes were observed by transmission electron microscopy. Autophagy was markedly activated and exhibited the three characterized gradations of autophagic flux, consisting of the formation of autophagosomes, the fusion of autophagosomes with lysosomes, and the deterioration of autophagosomes in autolysosomes. More importantly, autophagic inhibition by the suppressors 3-methyladenine (3-MA) and LY294002 significantly potentiated cytotoxicity and apoptosis in HER2-positive GC cells in vitro, while the combined use of LY294002 and T-DM1 elicited potent anti-GC efficacy in vivo. In mechanistic experiments, immunoblot analysis indicated the downregulated levels of Akt, mTOR, and P70S6K and confocal microscopy analysis clearly showed that autophagic inhibition promoted the fusion of T-DM1 molecules with lysosomes in GC cells. In conclusion, our research demonstrated that T-DM1 induced apoptosis as well as cytoprotective autophagy, and autophagic inhibition could potentiate the antitumor effect of T-DM1 on HER2-positive GC. Furthermore, autophagic inhibition might increase the fusion of T-DM1 with lysosomes, which might accelerate the release of the cytotoxic molecule emtansine from the T-DM1 conjugate. These findings highlight a promising therapeutic strategy that combines T-DM1 with an autophagy inhibitor to treat HER-positive GC more efficiently.

Ramucirumab in Combination with Pembrolizumab in Treatment-Naïve Advanced Gastric or GEJ Adenocarcinoma: Safety and Antitumor Activity from the Phase 1a/b JVDF Trial

Simple Summary

The prognosis for gastric cancer remains poor, with a median overall survival of approximately 1 year. Ramucirumab and pembrolizumab have each demonstrated antitumor activity and a favorable safety profile as treatments for patients with advanced gastric/gastroesophageal junction (G/GEJ) cancer in the second and third-line setting respectively. However, both agents failed to demonstrate survival benefit over chemotherapy in the first-line setting. Twenty-eight treatment-naïve patients with advanced/metastatic G/GEJ adenocarcinoma were treated with ramucirumab plus pembrolizumab in this phase 1a/b trial. Our results showed that this combination was well tolerated with no unexpected toxicities, and promising durable survival results, particularly among patients with PD-ligand 1 positive tumors. The results of our study therefore support modulating the tumor microenvironment with dual inhibition of VEGFR2 and PD-1 pathways in the first-line patients with advanced G/GEJ cancer.

Abstract

Ramucirumab (anti-VEGFR2) plus pembrolizumab (anti-PD1) demonstrated promising antitumor activity and tolerability among patients with previously treated advanced cancers, supporting growing evidence that combination therapies modulating the tumor microenvironment may expand the spectrum of patients who respond to checkpoint inhibitors. Here we present the results of this combination in first-line patients with metastatic G/GEJ cancer. Twenty-eight patients (≥18 years) with no prior systemic chemotherapy in the advanced/metastatic setting received ramucirumab (8 mg/kg days 1 and 8) plus pembrolizumab (200 mg day 1) every 3 weeks as part of JVDF phase 1a/b study. The primary endpoint was safety. Secondary endpoints included progression-free survival (PFS), objective response rate (ORR), and overall survival (OS). Tumors were PD-L1-positive (combined positive score ≥ 1) in 19 and -negative in 6 patients. Eighteen patients experienced grade 3 treatment-related adverse events, most commonly hypertension (14%) and elevated alanine/aspartate aminotransferase (11% each), with no grade 4 or 5 reported. The ORR was 25% (PD-L1-positive, 32%; PD-L1-negative, 17%) with duration of response not reached. PFS was 5.6 months (PD-L1-positive, 8.6 months; PD-L1-negative, 4.3 months), and OS 14.6 months (PD-L1-positive, 17.3 months; PD-L1-negative, 11.3 months). Acknowledging study design limitations, ramucirumab plus pembrolizumab had encouraging durable clinical activity with no unexpected toxicities in treatment-naïve biomarker-unselected metastatic G/GEJ cancer, and improved outcomes in patients with PD-L1-positive tumors.

A CT-based radiomics nomogram for prediction of human epidermal growth factor receptor 2 status in patients with gastric cancer

OBJECTIVE

To develop and validate a computed tomography (CT)-based radiomics nomogram for predicting human epidermal growth factor receptor 2 (HER2) status in patients with gastric cancer.

METHODS

This retrospective study included 134 patients with gastric cancer (HER2-negative: n=87; HER2-positive: n=47) from April 2013 to March 2018, who were then randomly divided into training (n=94) and validation (n=40) cohorts. Radiomics features were obtained from the CT images showing gastric cancer. Least absolute shrinkage and selection operator (LASSO) regression analysis was utilized for building the radiomics signature. A multivariable logistic regression method was applied to develop a prediction model incorporating the radiomics signature and independent clinicopathologic risk predictors, which were then visualized as a radiomics nomogram. The predictive performance of the nomogram was assessed in the training and validation cohorts.

RESULTS

The radiomics signature was significantly associated with HER2 status in both training (P<0.001) and validation (P=0.023) cohorts. The prediction model that incorporated the radiomics signature and carcinoembryonic antigen (CEA) level demonstrated good discriminative performance for HER2 status prediction, with an area under the curve (AUC) of 0.799 [95% confidence interval (95% CI): 0.704-0.894] in the training cohort and 0.771 (95% CI: 0.607-0.934) in the validation cohort. The calibration curve of the radiomics nomogram also showed good calibration. Decision curve analysis showed that the radiomics nomogram was useful.

CONCLUSIONS

We built and validated a radiomics nomogram with good performance for HER2 status prediction in gastric cancer. This radiomics nomogram could serve as a non-invasive tool to predict HER2 status and guide clinical treatment.

The Use of Epidermal Growth Factor Receptor Type 2-Targeting Tyrosine Kinase Inhibitors in the Management of Epidermal Growth Factor Receptor Type 2-Positive Gastric Cancer: A Narrative Review

Gastric cancer (GC), including gastroesophageal junction cancer (GEJC), continues to be one of the most frequently diagnosed neoplasms globally. Moreover, GC/GEJC is a principal cause of neoplasm-related fatalities. Early-stage GC/GEJC has a favorable five-year overall survival (OS) rate with surgical resection. However, the vast majority of patients present with advanced inoperable or metastatic disease with a very unfavorable five-year OS rate. Such patients are left with very limited therapeutic options, such as systemic chemotherapy, targeted therapy, and immunotherapy, all of which can be performed as monotherapy or in various combinations. The molecular profiling of GC has revealed several personalized therapeutic vulnerabilities, one of which is the expression of epidermal growth factor receptor type 2 (EGFR2, also known as HER2). HER2 overexpression or amplification is present in a fair subset of patients with GC/GEJC and has been shown to correlate with poor clinicopathological prognostic outcomes. Generally, treatment schemes to tackle HER2 in HER2-positive GC/GEJC comprise the use of anti-HER2 monoclonal antibodies or HER2-targeting tyrosine kinase inhibitors (TKIs). In this study, we engage in a narrative review of the available phase II and III literature on the efficacy and safety of HER2-targeting TKIs in the management of HER2-positive GC/GEJC.

Therapeutic efficacy and imaging assessment of the HER2-targeting chemotherapy drug ZHER2:V2-pemetrexed in lung adenocarcinoma Xenografts

Chemotherapy has always been the first therapeutic option for patients with advanced non-small cell lung cancer (NSCLC) with untreatable oncogenic mutations. However, chemotherapy has demonstrated limited success and is associated with severe side effects. This research aimed to investigate the antitumor efficacy and cytotoxic safety of the conjugate Z_HER2:V2-pemetrexed, a novel targeted chemotherapeutic drug. In this context, human epidermal growth factor receptor 2 (HER2) + A549 lung xenografts were treated using Z_HER2:V2-pemetrexed, pemetrexed or physiological saline. Therapeutic efficacy was monitored by single photon emission computed tomography (SPECT) imaging using the ^99mTc-labeled Z_HER2:V2-pemetrexed conjugate and further confirmed by performing apoptosis assays using flow cytometry analysis and hematoxylin-eosin (H&E) staining. To evaluate the expression of HER2 in tumor tissues, immunohistochemistry was performed, accompanied by quantitative analysis using flow cytometry. A toxicological evaluation was also conducted. Imaging with ^99mTc-Z_HER2:V2-pemetrexed demonstrated that in HER2+ A549 models, Z_HER2:V2-pemetrexed showed better antineoplastic effects than pemetrexed. Compared with pemetrexed, the results from the pathological and flow cytometry analyses also revealed that Z_HER2:V2-pemetrexed exhibits high antitumor activity against A549 tumors, inducing necrosis, apoptosis and cell cycle arrest. In addition, the clinical signs of toxicity in the Z_HER2:V2-pemetrexed treated group were reduced compared with those in the pemetrexed treated group. These data revealed that the Z_HER2:V2-pemetrexed conjugate encompasses promising targeted antitumor activity against HER2-positive lung adenocarcinoma, with reduced side effects compared with pemetrexed. Thus, the Z_HER2:V2-pemetrexed conjugate may serve as a novel molecular agent with tremendous clinical breakthrough potential in the diagnosis and treatment of HER2-positive lung adenocarcinoma.

MALAT1 promotes gastric adenocarcinoma through the MALAT1/miR-181a-5p/AKT3 axis

Gastric adenocarcinoma, which originates from the gastric mucosal epithelium, has the highest incidence among various malignant tumours in China. As a crucial long non-coding RNA, metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been suggested to play an important role in many tumours. Here, we aimed to investigate the role and underlying mechanism of MALAT1 in gastric adenocarcinoma. Quantitative reverse transcription polymerase chain reaction was applied to determine the expression levels of MALAT1 in serum and cell lines. A CCK-8 assay and a clonogenic survival assay were used to examine cell proliferation and apoptosis. The protein level of RAC-γ serine/threonine-specific protein kinase (AKT3) was determined by western blot. Our results showed that MALAT1 was highly expressed in the serum of patients with gastric adenocarcinoma and in cell lines. Downregulating MALAT1 inhibited proliferation and promoted apoptosis of MGC-803 cells. In addition, MALAT1 directly targeted and decreased the expression of miR-181a-5p, which in turn upregulated the expression of AKT3. Further, overexpressing miR-181a-5p or directly inhibiting the AKT pathway with the inhibitor ipatasertib exhibited similar effects to MALAT1 knockdown. Our research proposes a novel mechanism where the role of MALAT1 is dependent on the MALAT1/miR-181a-5p/AKT3 axis. MALAT1 competes with AKT3 for miR-181a-5p binding, thereby upregulating the AKT3 protein level and ultimately promoting the growth of gastric adenocarcinoma.

Targeted literature review of the global burden of gastric cancer

Gastric cancer (GC) and gastroesophageal junction cancers (GEJCs) are the third leading cause of cancer-related death worldwide. Although several studies have evaluated the epidemiology and management of GC and GEJC, to our knowledge, no global estimates of the economic burden of GC and GEJC have yet been reported. This targeted literature review was conducted to summarise the epidemiology and management of GC and GEJC and to estimate its global economic and humanistic burden. The incidence of GC and GEJC is highest in Eastern Asia, several South and Central American countries and Central and Eastern Europe and lowest in North America and Africa. Prognosis is generally poor; the global 5-year survival rate is 5%-10% in advanced stages. Patients with GC and GEJC have more severe symptoms compared with patients with other cancers, and health-related quality of life (HRQoL) worsens as the disease progresses. Given the rapid progression of GC and GEJC at advanced stages, chemotherapy, despite its toxicity, improves HRQoL compared with best supportive care. The costs of GC/GEJC are generally higher than for other cancers; in the US, the average annual cost per patient between 1998 and 2003 was 46,501 USD, compared with 29,609 USD and 35,672 USD for colorectal and lung cancer, respectively. Based on the 2012 incidence data and average costs per patient, estimates of the annual financial burden of GC and GEJC revealed great regional differences. Japan and Iran had the highest (8,492 million USD) and lowest (27 million USD) costs for 2017, respectively, while the estimate for the US was 3,171 million USD. The overall annual cost of GC and GEJC estimated for 2017 in a geographic area including Europe (France, Germany, Italy, Spain and the UK), Asia (Iran, Japan and China), North America (Canada and the US) and Australia was 20.6 billion USD.

Her2-Targeted Therapy Induces Autophagy in Esophageal Adenocarcinoma Cells

Esophageal adenocarcinoma (EAC) is a highly lethal cancer type with an overall poor survival rate. Twenty to thirty percent of EAC overexpress the human epidermal growth factor receptor 2 (Her2), a transmembrane receptor tyrosine kinase promoting cell growth and proliferation. Patients with Her2 overexpressing breast and gastroesophageal cancer may benefit from Her2 inhibitors. Therapy resistance, however, is well documented. Since autophagy, a lysosome-dependent catabolic process, is implicated in cancer resistance mechanisms, we tested whether autophagy modulation influences Her2 inhibitor sensitivity in EAC. Her2-positive OE19 EAC cells showed an induction in autophagic flux upon treatment with the small molecule Her2 inhibitor Lapatinib. Newly generated Lapatinib-resistant OE19 (OE19 LR) cells showed increased basal autophagic flux compared to parental OE19 (OE19 P) cells. Based on these results, we tested if combining Lapatinib with autophagy inhibitors might be beneficial. OE19 P showed significantly reduced cell viability upon double treatment, while OE19 LR were already sensitive to autophagy inhibition alone. Additionally, Her2 status and autophagy marker expression (LC3B and p62) were investigated in a treatment-naïve EAC patient cohort (n = 112) using immunohistochemistry. Here, no significant correlation between Her2 status and expression of LC3B and p62 was found. Our data show that resistance to Her2-directed therapy is associated with a higher basal autophagy level, which is not per se associated with Her2 status. Therefore, we propose that autophagy may contribute to acquired resistance to Her2-targeted therapy in EAC, and that combining Her2 and autophagy inhibition might be beneficial for EAC patients.

Biomarkers of gastric cancer: Current topics and future perspective

Gastric cancer (GC) is one of the most prevalent malignant types in the world and an aggressive disease with a poor 5-year survival. This cancer is biologically and genetically heterogeneous with a poorly understood carcinogenesis at the molecular level. Although the incidence is declining, the outcome of patients with GC remains dismal. Thus, the detection at an early stage utilizing useful screening approaches, selection of an appropriate treatment plan, and effective monitoring is pivotal to reduce GC mortalities. Identification of biomarkers in a basis of clinical information and comprehensive genome analysis could improve diagnosis, prognosis, prediction of recurrence and treatment response. This review summarized the current status and approaches in GC biomarker, which could be potentially used for early diagnosis, accurate prediction of therapeutic approaches and discussed the future perspective based on the molecular classification and profiling.