Current status and future perspectives in HER2 positive advanced gastric cancer

Molecular Classifications in Gastric Cancer: A Call for Interdisciplinary Collaboration

Gastric cancer (GC) is a heterogeneous disease, often diagnosed at advanced stages, with a 5-year survival rate of approximately 20%. Despite notable technological advancements in cancer research over the past decades, their impact on GC management and outcomes has been limited. Numerous molecular alterations have been identified in GC, leading to various molecular classifications, such as those developed by The Cancer Genome Atlas (TCGA) and the Asian Cancer Research Group (ACRG). Other authors have proposed alternative perspectives, including immune, proteomic, or epigenetic-based classifications. However, molecular stratification has not yet transitioned into clinical practice for GC, and little attention has been paid to alternative molecular classifications. In this review, we explore diverse molecular classifications in GC from a practical point of view, emphasizing their relationships with clinicopathological factors, prognosis, and therapeutic approaches. We have focused on classifications beyond those of TCGA and the ACRG, which have been less extensively reviewed previously. Additionally, we discuss the challenges that must be overcome to ensure their impact on patient treatment and prognosis. This review aims to serve as a practical framework to understand the molecular landscape of GC, facilitate the development of consensus molecular categories, and guide the design of innovative molecular studies in the field.

Identification of gastric cancer types based on hyperspectral imaging technology

Gastric cancer is becoming the second biggest cause of death from cancer. Treatment and prognosis of different types of gastric cancer vary greatly. However, the routine pathological examination is limited to the tissue level and is easily affected by subjective factors. In our study, we examined gastric mucosal samples from 50 normal tissue and 90 cancer tissues. Hyperspectral imaging technology was used to obtain spectral information. A two-classification model for normal tissue and cancer tissue identification and a four-classification model for cancer type identification are constructed based on the improved deep residual network (IDRN). The accuracy of the two-classification model and four-classification model are 0.947 and 0.965. Hyperspectral imaging technology was used to extract molecular information to realize real-time diagnosis and accurate typing. The results show that hyperspectral imaging technique has good effect on diagnosis and type differentiation of gastric cancer, which is expected to be used in auxiliary diagnosis and treatment.

The Effect of an Educational Intervention Based on the Health Belief Model (HBM) on Nutritional Performance Related to Gastric Cancer in Rural Women in Northern Regions of Iran

Gastric cancer is a common cause of cancer death in the world. This study examined 120 rural women. The educational program included four sessions for each group based on the health belief model. The mean age of the women was 34.51 ± 9.16. The mean score of the perceived barriers significantly decreased in the experimental group (11.08 ± 0.37) compared to the control group (14.92 ± 0.42) (P < .001), and the mean score of knowledge, performance and HBM constructs, increased significantly 2 months after the education (P < .001).It is recommended that educational interventions be designed by HBM to improve nutritional behaviors related to GC in the female population.

Trastuzumab Deruxtecan Dosing in Human Epidermal Growth Factor Receptor 2-Positive Gastric Cancer: Population Pharmacokinetic Modeling and Exposure-Response Analysis

This study evaluated the benefit/risk of trastuzumab deruxtecan (T-DXd) 6.4 mg/kg in patients with human epidermal growth factor receptor 2 (HER2)-positive gastric cancer using pharmacometrics. A population pharmacokinetic (PopPK) model was developed using data from patients with gastric cancer, breast cancer, or other tumors in T-DXd clinical trials, primarily conducted in Asia. Post hoc model-estimated pharmacokinetic metrics were used in exposure-efficacy (objective response rates, ORRs) and exposure-safety analyses. The PopPK analysis included 808 patients (217 with gastric cancer, 512 with breast cancer, and 79 with other cancers). In gastric cancer, the T-DXd 6.4 mg/kg steady-state exposure metrics were lower compared with 6.4 mg/kg in breast cancer, but were similar to 5.4 mg/kg in breast cancer. Tumor type was selected as a significant covariate on T-DXd clearance. In exposure-efficacy analysis among 160 patients with gastric cancer, the T-DXd steady-state minimum concentration was associated with a confirmed ORR in univariate logistic regression analysis (P = .023). The model-predicted confirmed ORRs in gastric cancer were 36.0% (90%CI 29.3% to 43.7%) with 5.4 mg/kg and 40.0% (90%CI 33.1% to 47.6%) with 6.4 mg/kg. Among 808 patients in the exposure-safety analyses, the model-predicted estimates for the rates of any-grade interstitial lung disease (ILD) over a period of 180 days were 10.2% (90%CI 8.7% to 12.8%) with 6.4 mg/kg in gastric cancer and 9.7% (90%CI 8.2% to 11.8%) with 5.4 mg/kg in breast cancer. In gastric cancer, the efficacy of T-DXd was higher at 6.4 mg/kg than at 5.4 mg/kg. Exposure and ILD rates were comparable between 6.4 mg/kg in gastric cancer and 5.4 mg/kg in breast cancer. This study identified T-DXd 6.4 mg/kg as the recommended dose in HER2-positive gastric cancer.

GHRL as a prognostic biomarker correlated with immune infiltrates and progression of precancerous lesions in gastric cancer

Objective

Ghrelin is a protein that regulate appetite and energy balance in the human body, which is encoded by the ghrelin prepropeptide gene (GHRL). GHRL is linked with carcinogenesis and immune regulation. However, the correlation of GHRL to prognosis and tumor-infiltrating lymphocytes in gastric cancer (GC) remains unclear.

Methods

In this study, we assessed the transcriptional expression, prognosis, and different clinicopathological features about GHRL and the correlation between GHRL and tumor infiltration immune cells in GC patients based on the data published in the following databases: TIMER, GEPIA, GEO, STRING, UALCAN, TISIDB, and Kaplan-Meier Plotter. Furthermore, R software analysis for GC Correa' cascade was also provided. Finally, GHRL expression in GC tissues was assayed using quantitative real-time polymerase chain reaction and immunohistochemistry.

Results

We found that GHRL expression in GC samples was lower than in normal samples and verified by quantitative PCR (qPCR) and immunohistochemistry. However, sample type, cancer stage, and worse survival were correlated to high GHRL expression. We also found that the expression of GHRL in dysplasia was significantly lower than that in CNAG and in GC. High GHRL expression was connected with immunomodulators, chemokines, and infiltrating levels of B cells, CD8+ T cells, CD4+ T cells, macrophages, neutrophils, and dendritic cells in GC.

Conclusions

GHRL is a prognostic biomarker for GC patients, and it is correlated with progression of precancerous lesions in GC. It might lead to poor prognosis by regulating tumor immune microenvironment. Studies are important to explore therapeutic targeting GHRL in the future.

Site-specific protein biomarkers in gastric cancer: a comprehensive review of novel biomarkers and clinical applications

INTRODUCTION

Gastric cancer (GC) is the fifth most common cancer and the fourth leading cause of cancer-related death worldwide, thus representing a significant global health burden. Early detection and monitoring of GC are essential to improve patient outcomes. While traditional cancer biomarkers such as carcinoembryonic antigen, carbohydrate antigen (CA) 19-9, and CA 72-4 are widely used, their limited sensitivity and specificity necessitate the exploration of alternative biomarkers.

AREAS COVERED

This review comprehensively analyzes the landscape of GC protein biomarkers identified from 2019 to 2022, with a focus on tissue, blood, urine, saliva, gastric juice, ascites, and exhaled breath as sample sources. We address the potential clinical applications of these biomarkers in early diagnosis, monitoring recurrence, and predicting survival and therapeutic response of GC patients.

EXPERT OPINION

The discovery of novel protein biomarkers holds great promise for improving the clinical management of GC. However, further validation in large, diverse cohorts is needed to establish the clinical utility of these biomarkers. Integrating these biomarkers with existing diagnostic and monitoring approaches will likely lead to improved personalized treatment plans and patient outcomes.

Assessment of the Impact of Alternative Fixatives on HER2 Detection in Breast Cancer and Gastric Cancer Tumor Specimens

The type of fixative used for preserving tumor specimens can significantly impact the performance of the immunohistochemistry and in situ hybridization assays used for assessing human epidermal growth factor receptor 2 (HER2) status. This study reports the prevalence of the use of alternative fixatives other than the guideline-recommended 10% neutral buffered formalin (NBF) during HER2 testing in a real-world setting. The effects of alternative fixatives [20% NBF and 10% unbuffered formalin (UBF) fixatives] on HER2 testing of breast cancer (BC) and gastric cancer (GC) cell lines and tissues are also assessed. Overall, 117,636 tumor samples received at a central laboratory from >8000 clinical trial sites across 60 countries were reviewed to determine the prevalence of alternative fixative usage. To investigate the impact of alternative fixatives, 27 cell lines (21 BC and 6 GC) and 76 tumor tissue samples (50 BC and 26 GC) were fixed in 10% NBF, 20% NBF, or 10% UBF, and evaluated for HER2 status by immunohistochemistry and in situ hybridization. Real-world data showed that 9195 (7.8%) tumor samples were preserved using an alternative fixative. In cell lines, overall percentage agreement, negative percentage agreement, and positive percentage agreement among the 3 fixatives were 100%. In tumor tissues, the agreement among 10% NBF, 20% NBF, and 10% UBF ranged between 94.7% and 96.6% for negative percentage agreement and 90.9% for overall percentage agreement compared with a range of 58.3% to 66.7% for positive percentage agreement. These results suggest that alternative fixatives may have the potential to convert HER2 status in tissues from positive to negative.

Cuproptosis-Mediated Patterns Characterized by Distinct Tumor Microenvironment and Predicted the Immunotherapy Response for Gastric Cancer

Cuproptosis is a newly discovered programmed cell death process, and several cuproptosis-related genes have been reported to regulate cancer cell proliferation and progression. The association between cuproptosis and tumor microenvironment in gastric cancer (GC) remains unclear. This study aimed to explore multiomics characteristics of cuproptosis-related genes regulating tumor microenvironment and provide strategies for prognosis and prediction of immunotherapy response in GC patients. We collected 1401 GC patients from the TCGA and 5 GEO data sets and identified three different cuproptosis-mediated patterns, each of which shared a distinct tumor microenvironment and different overall survival. The GC patients with high cuproptosis levels were enriched in CD8+ T cells and had a better prognosis. Whereas, the low cuproptosis level patients were associated with inhibitory immune cell infiltration and had the worst prognosis. In addition, we constructed a 3-gene (AHCYL2, ANKRD6 and FDGFRB) cuproptosis-related prognosis signature (CuPS) via Lasso-Cox and multivariate Cox regression analysis. The GC patients in the low-CuPS subgroup had higher TMB levels, MSI-H fractions, and PD-L1 expression, which suggests a better immunotherapy response. Therefore, the CuPS might have the potential value for predicting prognosis and immunotherapy sensitivity in GC patients.

Role of IL-6/STAT3 Axis in Resistance to Cisplatin in Gastric Cancers

Gastric cancer, the second most common cause of death worldwide, is characterized by poor prognosis and low responsiveness to chemotherapy. Indeed, multidrug resistance, based mainly on cellular and molecular factors, remains one of the most limiting factors of the current approach to gastric cancer (GC) therapy. We employed a comprehensive gene expression analysis through data mining of publicly available databases to assess the role of the signal transducer and activator of transcription 3 (STAT3) in gastric cancer drug efficiency. It has been proposed that gastric cancer cells are less sensitive to these drugs because they develop resistance to these agents through activating alternative signalling pathways responsible for overcoming pharmacological inhibition. Our study evaluated the hypothesis that activating STAT3 signalling in response to cisplatin reduces the reaction to the drug. Consistent with this hypothesis, inhibition of interleukin 6 (IL-6)/STAT3 in combination therapy with cisplatin prevented both STAT3 activation and more lethality than induction by a single agent. The data suggest that the IL-6/STAT3 axis block associated with cisplatin treatment may represent a strategy to overcome resistance.

Challenges and future of HER2-positive gastric cancer therapy

Gastric cancer is the fifth most common cancer worldwide, and the treatment of advanced gastric cancer has relatively little progress. With the continuous development of molecularly targeted therapy for tumors, it has been discovered that human epidermal growth factor receptor 2 (HER2) contributes to the poor prognosis and pathogenesis of various cancers. In order to treat HER2-positive advanced gastric cancer, Trastuzumab has emerged as the first first-line targeted medication used in conjunction with chemotherapy. The consequent trastuzumab resistance has become an important issue, and various new HER2-targeted gastric cancer drugs are emerging to address this challenge. This review's primary concern is the drug mechanism of various HER2-positive gastric cancer targeted therapy and fresh techniques of detection.

Predictive biomarkers in gastric cancer

Predictive biomarkers are the mainstay of precision medicine. This review summarizes the advancements in tissue-based diagnostic biomarkers for gastric cancer, which is considered the leading cause of cancer-related deaths worldwide. A disease seen in the elderly, it is often diagnosed at an advanced stage, thereby limiting therapeutic options. In Western countries, neoadjuvant/perioperative (radio-)chemotherapy is administered, and adjuvant chemotherapy is administered in the East. The morpho-molecular classification of gastric cancer has opened novel avenues identifying Epstein-Barr-Virus (EBV)-positive, microsatellite instable, genomically stable and chromosomal instable gastric cancers. In chromosomal instable tumors, receptor tyrosine kinases (RKTs) (e.g., EGFR, FGFR2, HER2, and MET) are frequently overexpressed. Gastric cancers such as microsatellite instable and EBV-positive types often express immune checkpoint molecules, such as PD-L1 and VISTA. Genomically stable tumors show alterations in claudin 18.2. Next-generation sequencing is increasingly being used to search for druggable targets in advanced palliative settings. However, most tissue-based biomarkers of gastric cancer carry the risk of a sampling error due to intratumoral heterogeneity, and adequate tissue sampling is of paramount importance.

Natural compounds targeting glycolysis as promising therapeutics for gastric cancer: A review

Gastric cancer, a common malignant disease, seriously endangers human health and life. The high mortality rate due to gastric cancer can be attributed to a lack of effective therapeutic drugs. Cancer cells utilize the glycolytic pathway to produce energy even under aerobic conditions, commonly referred to as the Warburg effect, which is a characteristic of gastric cancer. The identification of new targets based on the glycolytic pathway for the treatment of gastric cancer is a viable option, and accumulating evidence has shown that phytochemicals have extensive anti-glycolytic properties. We reviewed the effects and mechanisms of action of phytochemicals on aerobic glycolysis in gastric cancer cells. Phytochemicals can effectively inhibit aerobic glycolysis in gastric cancer cells, suppress cell proliferation and migration, and promote apoptosis, via the PI3K/Akt, c-Myc, p53, and other signaling pathways. These pathways affect the expressions of HIF-1α, HK2, LDH, and other glycolysis-related proteins. This review further assesses the potential of using plant-derived compounds for the treatment of gastric cancer and sheds insight into the development of new drugs.

Colorectal Cancer Heterogeneity and the Impact on Precision Medicine and Therapy Efficacy

Novel targeted therapies for metastatic colorectal cancer are needed to personalize treatments by guiding specific biomarkers selected on the genetic profile of patients. RAS and BRAF inhibitors have been developed for patients who become unresponsive to standard therapies. Sotorasib and adagrasib showed promising results in phase I/II basket trial and a phase III trial was planned with a combination of these RAS inhibitors and anti-EGFR monoclonal antibodies. Encorafenib and binimetinib were administered in phase II clinical trials for BRAF mutated patients. Pembrolizumab is now recommended in patients exhibiting microsatellite instability. Larotrectinib and entrectinib showed a fast and durable response with few and reversible adverse events in cases with NTRK fusions. Trastuzumab and trastuzumab deruxtecan exhibited promising and durable activity in HER-2-positive patients. In this review, the reasons for an extension of the molecular profile of patients were assessed and placed in the context of the advancements in the understanding of genetics. We highlight the differential effect of new targeted therapies through an ever-deeper characterization of tumor tissue. An overview of ongoing clinical trials is also provided.