Dual HER2 inhibition: mechanisms of synergy, patient selection, and resistance

HER2-targeted therapies for patients with HER2+ breast cancer are rapidly evolving, offering a range of more complex and personalized treatment options. Currently, an array of anti-HER2 monoclonal antibodies, tyrosine kinase inhibitors and antibody-drug conjugates are administered, sometimes alongside chemotherapy or endocrine therapy, both in curative and palliative contexts. However, the heterogeneous nature of HER2+ breast cancer demands a deeper understanding of disease biology and its role in responsiveness to novel HER2-targeted agents, as well as non-HER2-targeted therapies, in order to optimize patient outcomes. In this Review, we revisit the mechanisms of action of HER2-targeted agents, examine the evidence supporting the use of dual HER2 blockade in patients with HER2-amplified tumours, and explore the role of biomarkers in guiding future treatment strategies. We also discuss potential implications for the future treatment of patients with HER2+ breast cancer.

POP1 Facilitates Proliferation in Triple-Negative Breast Cancer via m6A-Dependent Degradation of CDKN1A mRNA

Triple-negative breast cancer (TNBC) is currently the worst prognostic subtype of breast cancer, and there is no effective treatment other than chemotherapy. Processing of precursors 1 (POP1) is the most substantially up-regulated RNA-binding protein (RBP) in TNBC. However, the role of POP1 in TNBC remains clarified. A series of molecular biological experiments in vitro and in vivo and clinical correlation analyses were conducted to clarify the biological function and regulatory mechanism of POP1 in TNBC. Here, we identified that POP1 is significantly up-regulated in TNBC and associated with poor prognosis. We further demonstrate that POP1 promotes the cell cycle and proliferation of TNBC in vitro and vivo. Mechanistically, POP1 directly binds to the coding sequence (CDS) region of CDKN1A mRNA and degrades it. The degradation process depends on the N6-methyladenosine (m6A) modification at the 497th site of CDKN1A and the recognition of this modification by YTH N6-methyladenosine RNA binding protein 2 (YTHDF2). Moreover, the m6A inhibitor STM2457 potently impaired the proliferation of POP1-overexpressed TNBC cells and improved the sensitivity to paclitaxel. In summary, our findings reveal the pivotal role of POP1 in promoting TNBC proliferation by degrading the mRNA of CDKN1A and that inhibition of m6A with STM2457 is a promising therapeutic strategy for TNBC.

The potential of retinoic acid receptors as prognostic biomarkers and therapeutic targets in gastric cancer

Background

Gastric cancer is a heterogeneous collection of tumors characterized by low survival rates. All-trans retinoic acid (retinoic-acid) is a clinically useful therapeutic agent belonging to the chemical family of retinoids, which consists of both natural and synthetic derivatives of vitamin-A. Retinoids are essential components of the normal diet and they regulate different physiological processes. From a therapeutic point of view, retinoic-acid is the first example of clinically useful differentiating agent. Indeed, the differentiating properties of this compound have promoted the use of retinoic-acid as a standard of care in Acute-Promyelocytic-Leukemia, a rare form of acute myeloid leukemia. In this study, we determine the RNA expression of the six isoforms of Retinoic-Acid-Receptors (RARα/RARβ/RARγ/RXRα/RXRβ/RXRγ) in view of their potential use as gastric cancer progression markers and/or therapeutic targets. In addition, we evaluate associations between the expression of these receptors and a simplified molecular classification of stomach tumors as well as the clinical characteristics of the cohort of patients analyzed. Finally, we define the prognostic value of the various Retinoic-Acid-Receptors in gastric cancer.

Methods

In this single institution and retrospective RAR-GASTRIC study, we consider 55 consecutive gastric cancer patients. We extract total RNA from the pathological specimens and we perform a NanoString Assay using a customized panel of genes. This allows us to determine the expression levels of the RAR and RXR mRNAs as well as other transcripts of interest.

Results

Our data demonstrate ubiquitous expression of the RAR and RXR mRNAs in gastric cancers. High levels of RARα, RARβ, RXRα and RXRβ show a significant association with stage IV tumors, "de novo" metastatic disease, microsatellite-stable-status, epithelial-to-mesenchymal-transition, as well as PIK3CA and TP53 expression. Finally, we observe a worse overall-survival in gastric cancer patients characterized by high RARα/RARβ/RARγ/RXRβ mRNA levels.

Conclusions

In gastric cancer, high expression levels of RARα/RARβ/RARγ/RXRβ transcripts are associated with poor clinical and molecular characteristics as well as with reduced overall-survival. Our data are consistent with the idea that RARα, RARβ, RARγ and RXRβ represent potential prognostic markers and therapeutic targets of gastric cancer.

Overall survival prediction of gastric cancer using the gene signature of CT-detected extramural venous invasion combined with M2 macrophages infiltration

BACKGROUND

CT-detected Extramural venous invasion (EMVI) is known as an independent risk factor for distant metastasis in patients with advanced gastric cancer (GC). However, the molecular basis is not clear. In colorectal cancer, M2 macrophages plays a vital role in determining EMVI. This study aimed to investigate the relationship between CT-detected EMVI and the M2 macrophages as well as prognosis predictionusing a radiogenomic approach.

METHOD

We utilized EMVI-related genes (from mRNA sequencing of 13 GC samples correlated with EMVI score by spearman analysis, P < 0.01) to overlap the co-expression genes of WGCNA module and M2 macrophages related genes (from mRNA data of 371 GC patients in TCGA database), generating a total of 136 genes. An EMVI-M2-prognosis-related hub gene signature was constructed by COX and least absolute shrinkage and selection operator (LASSO) analysis from a training cohort TCGA database (n = 371) and validated it in a validation cohort from GEO database (n = 357). High- and low-risk groups were divided by hub gene (EGFLAM and GNG11) signature-derived risk scores. We assessed its predictive ability through Kaplan-Meier (K-M) curve and COX analysis. Furthermore, we utilized ESTIMATE to detect tumor mutation burden (TMB) and evaluate sensitivity to immune checkpoint inhibitors (ICIs). Expression of hub genes was tested using western blotting and immunohistochemistry (IHC) analysis.

RESULTS

The overall survival (OS) was significantly reduced in the high-risk group (Training/Validation: AUC = 0.701/0.620; P < 0.001/0.003). Furthermore, the risk score was identified as an independent predictor of OS in multivariate COX regression analyses (Training/Validation: HR = 1.909/1.928; 95% CI: 1.225-2.974/1.308-2.844). The low-risk group exhibited significantly higher TMB levels (P = 1.6e- 07) and greater sensitivity to ICIs. Significant higher expression of hub-genes was identified on multiple GC cell lines and original samples. Hub-genes knockdown in gastric cancer cell lines inhibited their proliferation, metastatic and invasive capacity to varying degrees. In vivo experiments indicate that EGFLAM, as one of the hub genes, its high expression can serve as a biomarker for low response to immunotherapy.

CONCLUSION

Our study demonstrated EMVI-M2 gene signature could effectively predict the prognosis of GC tissue, reflecting the relationship between EMVI and M2 macrophages.

Measurement of changes in serum-based inflammatory indicators to monitor response to nivolumab monotherapy in advanced gastric cancer: a multicenter retrospective study

BACKGROUND

Nonresectable gastric cancer develops rapidly; thus, monitoring disease progression especially in patients receiving nivolumab as late-line therapy is important. Biomarkers may facilitate the evaluation of nivolumab treatment response. Herein, we assessed the utility of serum-based inflammatory indicators for evaluating tumor response to nivolumab.

METHODS

This multicenter retrospective cohort study included 111 patients treated with nivolumab monotherapy for nonresectable advanced or recurrent gastric cancer from October 2017 to October 2021. We measured changes in the C-reactive protein (CRP)-to-albumin ratio (CAR), platelet-to-lymphocyte ratio (PLR), and neutrophil-to-lymphocyte ratio (NLR) in serum from baseline to after the fourth administration of nivolumab. Furthermore, we calculated the area under the receiver operating characteristic curves (AUC ROCs) for CAR, PLR, and NLR to identify the optimal cutoff values for treatment response. We also investigated the relationship between clinicopathologic factors and disease control (complete response, partial response, and stable disease) using the chi-squared test.

RESULTS

The overall response rate (complete and partial response) was 11.7%, and the disease control rate was 44.1%. The median overall survival (OS) was 14.0 (95% CI 10.7‒19.2) months, and the median progression-free survival (PFS) was 4.1 (95% CI 3.0‒5.9) months. The AUC ROCs for CAR, PLR, and NLR before nivolumab monotherapy for patients with progressive disease (PD) were 0.574 (95% CI, 0.461‒0.687), 0.528 (95% CI, 0.418‒0.637), and 0.511 (95% CI, 0.401‒0.620), respectively. The values for changes in CAR, PLR, and NLR were 0.766 (95% CI, 0.666‒0.865), 0.707 (95% CI, 0.607‒0.807), and 0.660 (95% CI 0.556‒0.765), respectively. The cutoff values for the treatment response were 3.0, 1.3, and 1.4 for CAR, PLR, and NLR, respectively. The PFS and OS were significantly longer when the treatment response values for changes in CAR, PLR, and NLR were below these cutoff values (CAR: OS, p < 0.0001 and PFS, p < 0.0001; PLR: OS, p = 0.0289 and PFS, p = 0.0302; and NLR: OS, p = 0.0077 and PFS, p = 0.0044).

CONCLUSIONS

Measurement of the changes in CAR, PLR, and NLR could provide a simple, prompt, noninvasive method to evaluate response to nivolumab monotherapy.

TRIAL REGISTRATION

This study is registered with number K2023006.

SAFFRON-104: a phase Ib/II study of sitravatinib alone or with tislelizumab in advanced hepatocellular carcinoma and gastric cancer/gastroesophageal junction cancer

BACKGROUND

Sitravatinib is a spectrum-selective tyrosine kinase inhibitor targeting TAM (TYRO3, AXL, MER), VEGFR-2, KIT, and MET. SAFFRON-104 (NCT03941873) was a multicohort phase Ib/II study investigating sitravatinib with/without tislelizumab, an anti-programmed cell death protein 1 (PD-1) antibody, in patients with advanced hepatocellular carcinoma (HCC) or gastric cancer/gastroesophageal junction cancer (GC/GEJC).

METHODS

Eligible patients had histologically/cytologically confirmed advanced HCC or GC/GEJC. Phase I determined the recommended phase II dose (RP2D) of sitravatinib with/without tislelizumab. Phase II evaluated sitravatinib monotherapy in patients with pretreated HCC, and sitravatinib plus tislelizumab in anti-PD-(L)1-naïve or -treated HCC and anti-PD-(L)1-naïve GC/GEJC. Primary endpoints were safety/tolerability (phase I) and objective response rate (ORR) (phase II).

RESULTS

At data cutoff (March 31, 2023), 111 patients were enrolled; 102 were efficacy-evaluable (median study follow-up 9.1 months [range: 0.7-36.9]). The RP2D of sitravatinib was determined as 120 mg orally once daily. In patients receiving sitravatinib monotherapy and sitravatinib in combination with tislelizumab, grade ≥ 3 treatment-related adverse events occurred in 14 (51.9%) and 42 (50.0%) patients, respectively. The ORR was 25% (95% confidence interval [CI]: 8.7-49.1) in patients with pretreated HCC receiving sitravatinib monotherapy. In patients receiving sitravatinib with tislelizumab, the ORR was 11.5% (95% CI 2.4-30.2) with anti-PD-(L)1-naïve HCC, 9.5% (95% CI 1.2-30.4) with anti-PD-(L)1-treated HCC, and 16.1% (95% CI 5.5-33.7) in patients with anti-PD-(L)1-naïve GC/GEJC.

CONCLUSIONS

Sitravatinib with/without tislelizumab was generally well tolerated and showed preliminary antitumor activity in patients with advanced HCC and GC/GEJC.

Precision arrows: Navigating breast cancer with nanotechnology siRNA

Nanotechnology-based drug delivery systems, including siRNA, present an innovative approach to treating breast cancer, which disproportionately affects women. These systems enable personalized and targeted therapies, adept at managing drug resistance and minimizing off-target effects. This review delves into the current landscape of nanotechnology-derived siRNA transport systems for breast cancer treatment, discussing their mechanisms of action, preclinical and clinical research, therapeutic applications, challenges, and future prospects. Emphasis is placed on the importance of targeted delivery and precise gene silencing in improving therapeutic efficacy and patient outcomes. The review addresses specific hurdles such as specificity, biodistribution, immunological reactions, and regulatory approval, offering potential solutions and avenues for future research. SiRNA drug delivery systems hold promise in revolutionizing cancer care and improving patient outcomes, but realizing their full potential necessitates ongoing research, innovation, and collaboration. Understanding the intricacies of siRNA delivery mechanisms is pivotal for designing effective cancer treatments, overcoming challenges, and advancing siRNA-based therapies for various diseases, including cancer. The article provides a comprehensive review of the methods involved in siRNA transport for therapeutic applications, particularly in cancer treatment, elucidating the complex journey of siRNA molecules from extracellular space to intracellular targets. Key mechanisms such as endocytosis, receptor-mediated uptake, and membrane fusion are explored, alongside innovative delivery vehicles and technologies that enhance siRNA delivery efficiency. Moreover, the article discusses challenges and opportunities in the field, including issues related to specificity, biodistribution, immune response, and clinical translation. By comprehending the mechanisms of siRNA delivery, researchers can design and develop more effective siRNA-based therapies for various diseases, including cancer.

Case report: pathological complete response after S-1/oxaliplatin regimen combined with trastuzumab and tislelizumab in patients with locally advanced gastric cancer

Background

The efficacy of a regimen combining Tegafur, Gimeracil and Oteracil Potassium Capsules (S-1), oxaliplatin (SOX) with trastuzumab and tislelizumab chemotherapy for advanced gastric cancer (GC) has not been reported.

Case summary

A 56-year-old male was diagnosed with GC combined with peripheral lymph node metastasis. The patient received neoadjuvant chemotherapy, including SOX, tislelizumab and trastuzumab. After 4 cycles of chemotherapy, the tumor shrank significantly, and radical surgery was performed with good clinical results. To date, the patient has been followed up for 6 months with no significant side effects.

Conclusion

In this study, the patient received combination chemotherapy with SOX trastuzumab and tislelizumab and successfully underwent radical surgery with good clinical outcomes. Combined SOX with trastuzumab and tislelizumab may be an effective neoadjuvant chemotherapy regimen.

HER2 becomes a novel survival biomarker for gastric cancer patients: a pooled analysis

Background

Although anti-HER2 therapies have been widely used against gastric carcinoma, the prognostic significance of HER2 overexpression remains unclear. Previous studies failed to provide convincible evidence due to inconsistent HER2 evaluation criteria and heterogeneous clinical characteristics.

Objectives

To figure out the prognostic significance of HER2 expression in gastric cancer, we rigorously designed and conducted this study.

Design

Meta-analysis.

Data sources and methods

Record retrieval was performed by searching PubMed, Web of Science, Cochrane Library, Embase, ASCO, and ESMO meeting libraries from inception to November 2022. Cohort studies investigating overall survival comparison between HER2-positive and HER2-negative gastric cancer patients were included. Both resectable and advanced cases were separately collected while HER2 evaluation standards should be consistent across eligible studies. Newcastle-Ottawa Scale was used for quality assessment. Overall survival was the only endpoint and effect size was presented by hazard ratio (HR) with its 95% confidence interval. The pooled calculation was conducted on Review Manager 5.4.

Results

Thirty studies were eligible, including 9945 patients. Eligible studies were mostly high quality (n = 31). Regarding resectable cases (n = 22), HER2-positive groups had significantly worse prognosis than HER2-negative counterparts (HR 1.56, 95%CI 1.32-1.85, p < 0.00001). For HER2-positive patients with advanced gastric cancer (n = 10), HER2 overexpression was also an unfavorable survival indicator (HR 1.70, 95%CI 1.23-2.35, p = 0.001). Potential heterogeneous studies had been eliminated while outcomes remained stable by sensitivity analysis. Subgroup analysis suggested HER2-positive patients had a poorer prognosis in both East Asian (resectable: HR 1.56; advanced: HR 1.32) and non-East Asian countries (HR 1.58; HR 3.27).

Conclusion

As a novel survival biomarker in gastric cancer, HER2 overexpression indicates unfavorable prognosis among both resectable and advanced patients, irrespective of East Asian or non-East Asian populations.

Trial registration

PROSPERO (CRD42020168051).

Targeting HER2 in solid tumors: Unveiling the structure and novel epitopes

Human epidermal growth factor receptor-2 (HER2) is overexpressed in various solid tumor types, acting as an established therapeutic target. Over the last three decades, the fast-paced development of diverse HER2-targeted agents, notably marked by the introduction of the antibody-drug conjugate (ADC), yielding substantial improvements in survival rates. However, resistance to anti-HER2 treatments continues to pose formidable challenges. The complex structure and dynamic dimerization properties of HER2 create significant hurdles in the development of novel targeted therapeutics. In this review, we synthesize the latest insights into the structural intricacies of HER2 and present an unprecedented overview of the epitope characteristics of HER2-targeted antibodies and their derivatives. Furthermore, we delve into the correlation between anti-HER2 antibody binding epitopes and their respective functions, with a particular focus on their efficacy against resistant tumors. In addition, we highlight the potential of emerging anti-HER2 agents that target specific sites or non-overlapping epitopes, poised to transform the therapeutic landscape for HER2-positive tumors in the foreseeable future.

Enhancing antitumor efficacy of CLDN18.2-directed antibody-drug conjugates through autophagy inhibition in gastric cancer

Claudin18.2 (CLDN18.2) is overexpressed in cancers of the digestive system, rendering it an ideal drug target for antibody-drug conjugates (ADCs). Despite many CLDN18.2-directed ADCs undergoing clinical trials, the inconclusive underlying mechanisms pose a hurdle to extending the utility of these agents. In our study, αCLDN18.2-MMAE, an ADC composed of an anti-CLDN18.2 monoclonal antibody and the tubulin inhibitor MMAE, induced a dose-dependent apoptosis via the cleavage of caspase-9/PARP proteins in CLDN18.2-positive gastric cancer cells. It was worth noting that autophagy was remarkably activated during the αCLDN18.2-MMAE treatment, which was characterized by the accumulation of autophagosomes, the conversion of autophagy marker LC3 from its form I to II, and the complete autophagic flux. Inhibiting autophagy by autophagy inhibitor LY294002 remarkably enhanced αCLDN18.2-MMAE-induced cytotoxicity and caspase-mediated apoptosis, indicating the cytoprotective role of autophagy in CLDN18.2-directed ADC-treated gastric cancer cells. Combination with an autophagy inhibitor significantly potentiated the in vivo antitumoral efficacy of αCLDN18.2-MMAE. Besides, the Akt/mTOR pathway inactivation was demonstrated to be implicated in the autophagy initiation in αCLDN18.2-MMAE-treated gastric cancer cells. In conclusion, our study highlighted a groundbreaking investigation into the mechanism of the CLDN18.2-directed ADC, focusing on the crucial role of autophagy, providing a novel insight to treat gastric cancer by the combination of CLDN18.2-directed ADC and autophagy inhibitor.

Star wars against leukemia: attacking the clones

Leukemia, although most likely starts as a monoclonal genetic/epigenetic anomaly, is a polyclonal disease at manifestation. This polyclonal nature results from ongoing evolutionary changes in the genome/epigenome of leukemia cells to promote their survival and proliferation advantages. We discuss here how genetic and/or epigenetic aberrations alter intracellular microenvironment in individual leukemia clones and how extracellular microenvironment selects the best fitted clones. This dynamic polyclonal composition of leukemia makes designing an effective therapy a challenging task especially because individual leukemia clones often display substantial differences in response to treatment. Here, we discuss novel therapeutic approach employing single cell multiomics to identify and eradicate all individual clones in a patient.

Antibody-drug conjugates in gastric cancer: from molecular landscape to clinical strategies

Antibody-drug conjugates (ADCs) represent a crucial component of targeted therapies in gastric cancer, potentially altering traditional treatment paradigms. Many ADCs have entered rigorous clinical trials based on biological theories and preclinical experiments. Modality trials have also been conducted in combination with monoclonal antibody therapies, chemotherapies, immunotherapies, and other treatments to enhance the efficacy of drug coordination effects. However, ADCs exhibit limitations in treating gastric cancer, including resistance triggered by their structure or other factors. Ongoing intensive researches and preclinical experiments are yielding improvements, while enhancements in drug development processes and concomitant diagnostics during the therapeutic period actively boost ADC efficacy. The optimal treatment strategy for gastric cancer patients is continually evolving. This review summarizes the clinical progress of ADCs in treating gastric cancer, analyzes the mechanisms of ADC combination therapies, discusses resistance patterns, and offers a promising outlook for future applications in ADC drug development and companion diagnostics.

Rechallenge of Trastuzumab-based Therapy in HER2-Positive Breast Cancer Patients who Progressed Under TDM-1

Data on rechallenges of HER2 targetted agents in breast cancer patients is limited. The goal of the study was to evaluate the effectiveness of trastuzumab-based therapy in patients who progressed under trastuzumab emtansine (TDM-1). The study was designed as a retrospective observational study. Survival plots were performed with the Kaplan-Meier method. Fifteen patients were involved in the study. The average age was 45 (range, 30-66). De novo metastatic patient number was six (40%), and the average number of metastatic sites was 2 (range, 1-4) at diagnosis. Fourteen patients (92.3%) had undergone breast surgery (lumpectomy or mastectomy). All patients previously had been treated with trastuzumab-based chemotherapy and TDM-1. Also, nine (60%) patients had received endocrine therapy, and nine (60%) patients had palliative radiotherapy. After progression under TDM-1, patients received trastuzumab with chemotherapy (73.3%) or alone (26.7%). The overall response ratio was 66.7%. Median progression-free survival was 9.4 months (95% CI, 3.4-15.3). The median OS duration was 24.2 (95% CI, 13.5-34.9) months. Toxicity in all grades was observed in ten (66.7%) patients, and grade 3-4 toxicity (anemia and neutropenia) in two patients (13.3%). This study showed that rechallenge trastuzumab-based therapy was effective and good-tolerated in heavily pretreated patients who had progressed under TDM-1.

Tailor-made molecular imprints for biological event intervention

Molecular imprints, which are crosslinked architectures containing specific molecular recognition cavities for targeting compounds, have recently transitioned from in vitro diagnosis to in vivo treatment. In current application scenarios, it has become an important topic to create new biomolecular recognition pathways through molecular imprinting, thereby inhibiting the pathogenesis and regulating the development of diseases. This review starts with a pathological analysis, mainly focusing on the corresponding artificial enzymes, enzyme inhibitors and antibody mimics with enhanced functions that are created by molecular imprinting strategies. Recent advances are highlighted in the use of molecular imprints as tailor-made nanomedicines for the prevention of three major diseases: metabolic syndrome, cancer, and bacterial/viral infections.

DDR1 Drives Malignant Progression of Gastric Cancer by Suppressing HIF-1α Ubiquitination and Degradation

The extracellular matrix (ECM) has been demonstrated to be dysregulated and crucial for malignant progression in gastric cancer (GC), but the mechanism is not well understood. Here, that discoidin domain receptor 1 (DDR1), a principal ECM receptor, is recognized as a key driver of GC progression is reported. Mechanistically, DDR1 directly interacts with the PAS domain of hypoxia-inducible factor-1α (HIF-1α), suppresses its ubiquitination and subsequently strengthens its transcriptional regulation of angiogenesis. Additionally, DDR1 upregulation in GC cells promotes actin cytoskeleton reorganization by activating HIF-1α/ Ras Homolog Family Member A (RhoA)/Rho-associated protein kinase 1 (ROCK1) signaling, which in turn enhances the metastatic capacity. Pharmacological inhibition of DDR1 suppresses GC progression and angiogenesis in patient-derived xenograft (PDX) and organoid models. Taken together, this work first indicates the effects of the DDR1-HIF-1α axis on GC progression and reveals the related mechanisms, providing experimental evidence for DDR1 as a therapeutic target for GC.

Advances in the treatment of human epidermal growth factor receptor 2-positive gastric cancer

Human epidermal growth factor receptor 2 has been a pivotal biomarker for gastric cancer treatment strategies for many years. However, more than a decade after the ToGA trial demonstrated the efficacy of trastuzumab in improving survival, the development of treatments targeting human epidermal growth factor receptor 2 remains challenging. Several large-scale clinical trials of tyrosine kinase inhibitors, non-trastuzumab anti-human epidermal growth factor receptor 2 antibodies, and antibody-drug conjugates have failed to meet the primary endpoints. The concept of trastuzumab beyond progression and the complexity of resistance mechanisms to anti-human epidermal growth factor receptor 2 therapy after trastuzumab treatment presented significant obstacles, leading to trastuzumab being the sole therapy for human epidermal growth factor receptor 2-positive gastric cancer for some time. Nevertheless, the landscape has shifted in recent years, especially since the introduction of the antibody-drug conjugate trastuzumab deruxtecan in 2020. This has rekindled the interest in developing treatments targeting human epidermal growth factor receptor 2 in gastric cancer.

Immunotherapies targeting the oncogenic fusion gene CLDN18-ARHGAP in gastric cancer

The CLDN18-ARHGAP fusion gene is an oncogenic driver newly discovered in gastric cancer. It was detected in 9% (8/87) of gastric cancer patients in our center. An immunogenic peptide specifically targeting CLDN18-ARHGAP fusion gene was generated to induce neoantigen-reactive T cells, which was proved to have specific and robust anti-tumor capacity both in in vitro coculture models and in vivo xenograft gastric cancer models. Apart from the immunogenic potential, CLDN18-ARHGAP fusion gene was also found to contribute to immune suppression by inducing a regulatory T (Treg) cell-enriched microenvironment. Mechanistically, gastric cancer cells with CLDN18-ARHGAP fusion activate PI3K/AKT-mTOR-FAS signaling, which enhances free fatty acid production of gastric cancer cells to favor the survival of Treg cells. Furthermore, PI3K inhibition could effectively reverse Treg cells upregulation to enhance anti-tumor cytotoxicity of neoantigen-reactive T cells in vitro and reduce tumor growth in the xenograft gastric cancer model. Our study identified the CLDN18-ARHGAP fusion gene as a critical source of immunogenic neoepitopes, a key regulator of the tumor immune microenvironment, and immunotherapeutic applications specific to this oncogenic fusion.

High-level tumour methylation of BRCA1 and RAD51C is required for homologous recombination deficiency in solid cancers

In ovarian and breast cancer, promoter methylation of BRCA1 or RAD51C is a promising biomarker for PARP inhibitor response, as high levels lead to homologous recombination deficiency (HRD). Yet the extent and role of such methylation in other cancers is not clear. This study comprehensively investigated promoter methylation of eight homologous recombination repair genes across 23 solid cancer types. Here, we showed that BRCA1 methylated cancers were associated with reduced gene expression, loss of heterozygosity (LOH), TP53 mutations and genomic features of HRD. We identified BRCA1 methylation in 3% of the copy-number high subtype of endometrial cancer, and as a rare event in six other cancer types, including lung squamous cell, pancreatic, bladder and stomach cancer. RAD51C promoter methylation was widespread across multiple cancer types, but HRD features were only observed for cases which contained high-level tumour methylation and LOH of RAD51C. While RAD51C methylation was frequent in stomach adenocarcinoma (6%) and low-grade glioma (2.5%), it was mostly detected at a low tumour level, suggestive of heterozygous methylation, and was associated with CpG island methylator phenotype. Our findings indicate that high-level tumour methylation of BRCA1 and RAD51C should be explored as a PARP inhibitor biomarker across multiple cancers.

Efficacy of Lapatinib Plus Capecitabine After TDM-1 in HER2-Positive Metastatic Breast Cancer Patients

Different targeted therapy options exist for treating HER2-positive metastatic breast cancer patients. This study evaluated the efficacy and tolerability of the lapatinib plus capecitabine combination after TDM-1 in HER2-positive metastatic breast cancer patients. We retrospectively evaluated the HER2-positive metastatic breast cancer patients' data. The patients who progressed after trastuzumab-based chemotherapy and TDM-1 were included in the study. We used the Kaplan-Meier for survival analysis. Eighteen patients were involved in the study. The average age was 48 (range 31-65). De novo metastatic patient's number was 5 (27.8%). The most common metastatic sites were liver (50%), lung (44.4%), and brain (44.4%), respectively. All patients were previously treated with trastuzumab + chemotherapy and TDM-1. Also, seven (38.9%) patients received hormonotherapy and twelve (66.7%) patients received palliative radiotherapy. The complete response ratio was 5.6%, partial response 11.8%, and stable response 29.4%. Median progression-free survival was found as 5.5 (95% CI, 3.2-7.7) months. The hematological and non-hematological toxicity ratio was 41.2% and 52.9%, respectively. Grade 3-4 toxicity (diarrhea, anemia, and mucositis) was observed in four (22.2%) patients. The median OS duration was 8.2 months (95% CI, 4.3-12.0). Treatment options are limited in heavily pretreated HER2-positive breast cancer patients. Despite a small number of patients, this study showed that the lapatinib plus capecitabine combination was effective and well-tolerated in heavily pretreated HER2-positive breast cancer patients after TDM-1.

Predictive biomarkers for response to TGF- β inhibition in resensitizing chemo(radiated) esophageal adenocarcinoma

Epithelial-mesenchymal transition (EMT) has been identified as a driver of therapy resistance, particularly in esophageal adenocarcinoma (EAC), where transforming growth factor beta (TGF-β) can induce this process. Inhibitors of TGF-β may counteract the occurrence of mesenchymal, resistant tumor cell populations following chemo(radio)therapy and improve treatment outcomes in EAC. Here, we aimed to identify predictive biomarkers for the response to TGF-β targeting. In vitro approximations of neoadjuvant treatment were applied to publicly available primary EAC cell lines. TGF-β inhibitors fresolimumab and A83-01 were employed to inhibit EMT, and mesenchymal markers were quantified via flow cytometry to assess efficacy. Our results demonstrated a robust induction of mesenchymal cell states following chemoradiation, with TGF-β inhibition leading to variable reductions in mesenchymal markers. The cell lines were clustered into responders and non-responders. Genomic expression profiles were obtained through RNA-seq analysis. Differentially expressed gene (DEG) analysis identified 10 positively- and 23 negatively-associated hub genes, which were bioinformatically identified. Furthermore, the correlation of DEGs with response to TGF-β inhibition was examined using public pharmacogenomic databases, revealing 9 positively associated and 11 negatively associated DEGs. Among these, ERBB2, EFNB1, and TNS4 were the most promising candidates. Our findings reveal a distinct gene expression pattern associated with the response to TGF-β inhibition in chemo(radiated) EAC. The identified DEGs and predictive markers may assist patient selection in clinical studies investigating TGF-β targeting.

Neoadjuvant Docetaxel, Oxaliplatin, and S-1 Plus Surgery and Adjuvant S-1 for Resectable Advanced Gastric Cancer: Updated Overall Survival Outcomes From Phase III PRODIGY

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.The phase III PRODIGY study demonstrated that neoadjuvant chemotherapy with docetaxel, oxaliplatin, and S-1 (DOS) followed by surgery and adjuvant S-1 chemotherapy (CSC) improved progression-free survival (PFS) compared with surgery followed by adjuvant S-1 (SC) for patients with resectable locally advanced gastric cancer (LAGC) with clinical T2-3N+ or T4Nany disease. The primary end point was PFS. Overall survival (OS) was the secondary end point. We herein report the long-term follow-up outcomes, including OS, from this trial. A total of 238 and 246 patients were randomly assigned to the CSC and SC arms, respectively, and were treated (full analysis set). As of the data cutoff (September 2022), the median follow-up duration of the surviving patients was 99.5 months. Compared with SC, CSC significantly increased the OS (adjusted hazard ratio [HR], 0.72; stratified log-rank P = .027) with an 8-year OS rate of 63.0% and 55.1% for the CSC and SC arms, respectively. CSC also significantly improved the PFS (HR, 0.70; stratified log-rank P = .016). In conclusion, neoadjuvant DOS chemotherapy, as part of perioperative chemotherapy, prolonged the OS of Asian patients with LAGC relative to patients treated with surgery and adjuvant S-1. It should be considered one of the standard treatment options for patients with LAGC in Asia.

Adenoid cystic carcinoma: insights from molecular characterization and therapeutic advances

Adenoid cystic carcinoma (ACC) is a malignant tumor primarily originating from the salivary glands, capable of affecting multiple organs. Although ACC typically exhibits slow growth, it is notorious for its propensity for neural invasion, local recurrence, and distant metastasis, making it a particularly challenging cancer to treat. The complexity of ACC's histological and molecular features poses significant challenges to current treatment modalities, which often show limited effectiveness. Recent advancements in single-cell RNA-sequencing (scRNA-seq) have begun to unravel unprecedented insights into the heterogeneity and subpopulation diversity within ACC, revealing distinct cellular phenotypes and origins. This review delves into the intricate pathological and molecular characteristics of ACC, focusing on recent therapeutic advancements. We particularly emphasize the insights gained from scRNA-seq studies that shed light on the cellular landscape of ACC, underscoring its heterogeneity and pathobiology. Moreover, by integrating analyses from public databases, this review proposes novel perspectives for advancing treatment strategies in ACC. This review contributes to the academic understanding of ACC by proposing novel therapeutic approaches informed by cutting-edge molecular insights, paving the way for more effective, personalized therapeutic approaches for this challenging malignancy.

Impact of chemotherapy delay on long-term prognosis of laparoscopic radical surgery for locally advanced gastric cancer: a pooled analysis of four randomized controlled trials

BACKGROUND

Adjuvant chemotherapy following curative surgery for locally advanced gastric cancer (AGC) significantly improves long-term patient prognosis. However, delayed chemotherapy (DC), in which patients are unable to receive timely treatment, is a common phenomenon in clinical practice for various reasons. This study aimed to investigate the impact of DC on the prognosis of patients with stage II-III locally AGC and explore the associated risk factors.

METHODS

Data from four prospective studies were included in the pooled analysis. The planned chemotherapy (PC) group was defined as the time interval between surgery and the first chemotherapy ≤ 49 d, while the DC group was defined as the time interval between surgery and chemotherapy > 49 d. The prognosis, recurrence, and risk factors were compared, and a nomogram for predicting DC was established.

RESULTS

In total, 596 patients were included, of whom 531 (89.1%) had PC and 65 (10.9%) had DC. Survival analysis revealed that the 5-year overall survival (OS) and disease-free survival (DFS) were significantly lower in the DC group than those in the PC group (log-rank P < 0.001). Cox univariable and multivariable analyses showed that DC was an independent risk factor for OS and DFS in stage II-III patients (P < 0.05). Based on the significant factors for DC, a prediction model was established that had a good fit, high accuracy (AUC = 0.780), and clinical applicability in both the training and validation sets.

CONCLUSION

Delayed chemotherapy after gastrectomy is associated with poor long-term prognosis in patients with locally advanced stage II-III GC disease. But standardized, full-cycle adjuvant chemotherapy after surgery may play a remedial role, and can to a certain extent compensate the poor effects caused by delayed chemotherapy.

Quantitative Measurement of HER2 Expression in Non-Small Cell Lung Cancer With a High-Sensitivity Assay

Recently, low human epidermal growth factor receptor 2 (HER2) protein expression has been proposed as a predictive biomarker for response to the antibody-drug conjugate trastuzumab deruxtecan (T-DXd) in metastatic breast cancer. HER2 expression in non-small cell lung cancer (NSCLC) patients has never been carefully measured, and little is known about the frequency of cases with unamplified but detectable levels of the protein. Although some HER2-targeted therapies have been studied in NSCLC patients, they have been restricted to those with genomic ERBB2 gene alterations, which only represent relatively rare cases of NSCLC. Still, emerging investigations of T-DXd in NSCLC have shown promise in patients with unamplified HER2. Taken together, we hypothesize that there may be many cases of NSCLC with levels of HER2 protein expression comparable with levels seen in breast cancer that benefit from T-DXd. Here, we used a previously validated, analytic, quantitative immunofluorescence (QIF) assay that is more sensitive than legacy clinical HER2 immunohistochemistry assays. We measured HER2 protein levels in NSCLC cases to determine the proportion of cases with detectable HER2 expression. Using cell line calibration microarrays alongside our QIF method enabled us to convert HER2 signal into units of attomoles per mm2. We found that over 63% of the 741 analyzed NSCLC cases exhibited HER2 expression above the limit of detection, with more than 17% of them exceeding the lower limit of quantification. Although the threshold for response to T-DXd in breast cancer is still unknown, many cases of NSCLC have expression in a range comparable to breast cancer cases with immunohistochemistry scores of 1+ or 2+. Our assay could potentially select NSCLC cases with a detectable target (ie, HER2) that might benefit from HER2 antibody-drug conjugates, irrespective of ERBB2 genomic alterations.

Improving individualised therapies in localised gastro-oesophageal adenocarcinoma

Despite our increased understanding of the biological and molecular aspects of gastro-oesophageal tumourigenesis, the identification of prognostic or predictive factors remains challenging. Patients with resectable gastric and oesophageal adenocarcinoma are often treated similarly after surgical resection, regardless of their tumour biology, clinical characteristics, and histological treatment response. Substantial progress has been made in the past 5 years in managing patients with gastric or oesophageal adenocarcinoma, including the use of immune checkpoint inhibitors and new targeted therapies, leading to substantial improvements in clinical outcomes. These advancements have primarily been established in advanced and metastatic disease, while the management framework for local and locoregional disease is just beginning to shift. We provide an overview of existing data on biomarkers and tumour-related and host-related factors that are relevant to stratify patients into low-risk and high-risk recurrence groups, both before and after surgery, paving the way for more personalised treatment approaches.

HER2-low gastric cancer: is the subgroup targetable?

Therapeutic developments in the targeting of human epidermal growth factor receptor 2 (HER2)-expressing gastric cancer have followed the dramatic success of HER2-expressing breast cancer treatment, which has facilitated the expansion of indications for anti-HER2 agents to include not only conventional HER2-positive breast cancer, but also HER2-low and HER2-ultralow subgroups. The targetability of HER2-low gastric cancer, however, has yet to be established. Hence, further studies are needed to comprehensively understand the clinicopathological features, specific gene alterations, and distinct tumor immune microenvironment of HER2-low gastric cancer and compare them with those for HER2-positive or -negative gastric cancer. Antibody-drug conjugates for HER2 play an important role in making HER2-low gastric cancer targetable. In this context, a deeper understanding of the novel anti-HER2 agents, including antibody-drug conjugates, bispecific T-cell engager antibodies, and a combination of these agents, as well as new forms of immunomodulatory agents are also required. Redefining and re-categorizing HER2 status through not only immunohistochemistry/fluorescence in situ hybridization but also evaluating ERRB2 copy number gain or protein overexpression levels measured using DNA or RNA sequencing might be helpful for identifying populations with HER2-expressing tumors who would ideally benefit from anti-HER2 treatment. The current paper reviewed recent clinical trials, focusing particularly on HER2-low gastric cancer together with basic/translational findings, and discuss perspectives on further therapeutic development in the treatment of this distinct subgroup.

The mechanism of RGS5 regulating gastric cancer mismatch repair protein

The incidence and mortality rates of gastric cancer (GC) remain alarmingly high worldwide, imposing a substantial healthcare burden. In this study, we utilized data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. A 4-gene prognostic model was developed to predict patient prognosis, and its accuracy was validated across multiple datasets. Patients with a low-risk score exhibited improved prognosis, elevated tumor mutation burden, heightened sensitivity to both immunotherapy and conventional chemotherapy. Notably, our investigation revealed that the key gene RGS5 positively modulates the expression of mismatch repair proteins via c-Myc. Furthermore, co-immunoprecipitation (COIP) assays demonstrated the interaction between RGS5 and c-Myc. Additionally, we confirmed that RGS5 regulates c-Myc through the ubiquitin-proteasome pathway. Moreover, RGS5 was identified as a positive regulator of PD-L1 expression and exhibited a negative correlation with the majority of immune cells. These findings underscore the potential of RGS5 as a novel biomarker and therapeutic target in the context of GC.

Current status of neoadjuvant immunotherapy for the treatment of gastric cancer

Gastric cancer is one of the most prevalent malignant tumors worldwide, characterized by high incidence and mortality rates. At present, comprehensive surgical treatment has enhanced the prognosis of locally advanced gastric cancer patients significantly. However, the postoperative recurrence rate remains high, and the long-term survival for patients is sub-optimal. In recent years, immunotherapy has garnered extensive attention as an innovative approach to the treatment of gastric cancer. Indeed, multiple studies have validated its therapeutic effects in advanced gastric cancer patients, leading to its incorporation into treatment guidelines. Currently, researchers are exploring the application of immunotherapy in the neoadjuvant setting globally in order to further adjust and refine neoadjuvant immunotherapy regimens for gastric cancer. This article summarizes the research progress and controversies associated with neoadjuvant immunotherapy in gastric cancer, aiming to optimize clinical benefits for gastric cancer patients undergoing this treatment approach. The retrieval methods of this study encompassed databases such as PubMed, Google Scholar, Web of Science, clinicaltrials.gov, etc. The retrieved articles included guidelines, consensus, meta-analyses, clinical trials, and reviews related to locally advanced gastric cancer published up to January 2024.

Mechanisms of resistance to tyrosine kinase inhibitor-targeted therapy and overcoming strategies

Tyrosine kinase inhibitor (TKI)-targeted therapy has revolutionized cancer treatment by selectively blocking specific signaling pathways crucial for tumor growth, offering improved outcomes with fewer side effects compared with conventional chemotherapy. However, despite their initial effectiveness, resistance to TKIs remains a significant challenge in clinical practice. Understanding the mechanisms underlying TKI resistance is paramount for improving patient outcomes and developing more effective treatment strategies. In this review, we explored various mechanisms contributing to TKI resistance, including on-target mechanisms and off-target mechanisms, as well as changes in the tumor histology and tumor microenvironment (intrinsic mechanisms). Additionally, we summarized current therapeutic approaches aiming at circumventing TKI resistance, including the development of next-generation TKIs and combination therapies. We also discussed emerging strategies such as the use of dual-targeted antibodies and PROteolysis Targeting Chimeras. Furthermore, we explored future directions in TKI-targeted therapy, including the methods for detecting and monitoring drug resistance during treatment, identification of novel targets, exploration of dual-acting kinase inhibitors, application of nanotechnologies in targeted therapy, and so on. Overall, this review provides a comprehensive overview of the challenges and opportunities in TKI-targeted therapy, aiming to advance our understanding of resistance mechanisms and guide the development of more effective therapeutic approaches in cancer treatment.

The Landscape and Prognosis of Microsatellite Stable (MSS) Esophageal, Gastro-Esophageal Junction and Gastric Adenocarcinomas with High Tumor Mutation Burden (TMB)

BACKGROUND

A minority of patients with MSS tumors present a high tumor mutation burden (TMB) without underlying MMR defects.

METHODS

Publicly available genomic series were assessed for identification of patients with MSS gastric gastroesophageal junction, and esophageal adenocarcinomas and a high TMB, defined as more than 10 mutations per Mb. These were compared with MSS cancers and a low TMB for genetic alterations and for survival outcomes.

RESULTS

Patients with MSS cancers with high TMB in the MSK series were older but did not differ in other clinicopathologic parameters compared with MSS patients with low TMB. Mutations in tumor suppressors TP53 and APC and oncogenes KRAS and ERBB4 as well as amplifications of ERBB2 were more prevalent in the high TMB group of MSS cancers. Mutations in DDR associated genes, in epigenetic modifiers and in genes associated with immune response were more prevalent in the hIgh TMB group patients. However, high TMB was not associated with an improved survival in MSS gastric/gastroesophageal junction/esophageal adenocarcinomas (Log Rank p = 0.5).

CONCLUSION

MSS Gastric/gastroesophageal junction/esophageal adenocarcinomas with TMB above 10 mutations per Mb possess a genomic landscape with increased alteration frequencies in common gastroesophageal cancer genes and pathways.

HER2-targeted therapies beyond breast cancer - an update

The receptor tyrosine-kinase HER2 (also known as ErbB2) is a well-established therapeutic target in patients with breast or gastric cancer selected on the basis of HER2 overexpression on immunohistochemistry and/or ERBB2 amplification on in situ hybridization. With advances in cancer molecular profiling and increased implementation of precision medicine approaches into oncology practice, actionable HER2 alterations in solid tumours have expanded to include ERBB2 mutations in addition to traditional HER2 overexpression and ERBB2 amplification. These various HER2 alterations can be found in solid tumour types beyond breast and gastric cancer, although few HER2-targeted therapeutic options have been established for the other tumour types. Nevertheless, during the 5 years since our previous Review on this topic was published in this journal, obvious and fruitful progress in the development of HER2-targeted therapies has been made, including new disease indications, innovative drugs with diverse mechanisms of action and novel frameworks for approval by regulatory authorities. These advances have culminated in the recent histology-agnostic approval of the anti-HER2 antibody-drug conjugate trastuzumab deruxtecan for patients with HER2-overexpressing solid tumours. In this new Review, we provide an update on the current development landscape of HER2-targeted therapies beyond breast cancer, as well as anticipated future HER2-directed treatment strategies to overcome resistance and thereby improve efficacy and patient outcomes.

Gastrointestinal Cancer Therapy and Cardiotoxicity

OPINION STATEMENT

Gastrointestinal cancers are a heterogenous group of cancers that share common risk factors with cardiovascular disease. Therapy for gastrointestinal cancers have improved cancer-specific outcomes at the cost of cardiotoxicity. The most common cardiotoxic therapies utilized in gastrointestinal cancers include conventional chemotherapy (including fluoropyrimidines and anthracyclines), targeted therapies including anti-vascular endothelial growth factor (VEGF) therapy and tyrosine kinase inhibitors (TKI), and immunotherapy. It is important for clinicians managing patients with gastrointestinal cancers to be aware of potential cardiotoxicity associated with these agents.

Folic acid modified precision nanocarriers: charting new frontiers in breast cancer management beyond conventional therapies

Breast cancer presents a significant global health challenge, ranking highest incidence rate among all types of cancers. Functionalised nanocarriers offer a promising solution for precise drug delivery by actively targeting cancer cells through specific receptors, notably folate receptors. By overcoming the limitations of passive targeting in conventional therapies, this approach holds the potential for enhanced treatment efficacy through combination therapy. Encouraging outcomes from studies like in vitro and in vivo, underscore the promise of this innovative approach. This review explores the therapeutic potential of FA (Folic acid) functionalised nanocarriers tailored for breast cancer management, discussing various chemical modification techniques for functionalization. It examines FA-conjugated nanocarriers containing chemotherapeutics to enhance treatment efficacy and addresses the pharmacokinetic aspect of these functionalised nanocarriers. Additionally, the review integrates active targeting via folic acid with theranostics, photothermal therapy, and photodynamic therapy, offering a comprehensive management strategy. Emphasising rigorous experimental validation for practical utility, the review underscores the need to bridge laboratory research to clinical application. While these functionalised nanocarriers show promise, their credibility and applicability in real-world settings necessitate thorough validation for effective clinical use.

Global prevalence of claudin 18 isoform 2 in tumors of patients with locally advanced unresectable or metastatic gastric or gastroesophageal junction adenocarcinoma

BACKGROUND

Limited data exist for global prevalence of claudin 18 isoform 2 (CLDN18.2) positivity and association of CLDN18.2 status with clinical and tumor characteristics in patients with locally advanced (LA) unresectable or metastatic gastric or gastroesophageal junction (mG/GEJ) adenocarcinoma. We report prevalence of CLDN18.2 positivity (phase 3; SPOTLIGHT, NCT03504397; GLOW, NCT03653507) and concordance of CLDN18.2 status between a subset of pair-matched tumor samples (phase 2, ILUSTRO, NCT03505320; phase 1, NCT03528629) from clinical studies of zolbetuximab.

METHODS

Tumor samples from patients with LA unresectable or mG/GEJ adenocarcinoma were tested for CLDN18.2 status by immunohistochemistry. Human epidermal growth factor receptor 2 (HER2) expression was tested per central or local assessment.

RESULTS

Across SPOTLIGHT and GLOW, the prevalence of CLDN18.2 positivity (≥ 75% of tumor cells demonstrating moderate-to-strong membranous CLDN18 staining) was 38.4%. Prevalence was similar in gastric versus GEJ adenocarcinoma samples and regardless of collection method (biopsy versus resection) or collection site (primary versus metastatic). CLDN18.2 positivity was most prevalent in patients with diffuse-type tumors. In ILUSTRO and the phase 1 study, concordance of CLDN18.2 positivity was 61.1% between archival (i.e., any time before treatment) and baseline (i.e., ≤ 3 months before first treatment) samples, and concordance of any CLDN18 staining (≥ 1% of tumor cells demonstrating moderate-to-strong membranous CLDN18 staining) was 88.9%.

CONCLUSIONS

CLDN18.2 was a highly prevalent biomarker in patients with HER2-negative, LA unresectable or mG/GEJ adenocarcinoma. CLDN18.2 positivity remained relatively stable over time in many patients. Biomarker testing for CLDN18.2 should be considered in standard clinical practice in these patients.

The current status of immunotherapy and future horizon in the treatment of metastatic and locally advanced gastroesophageal adenocarcinoma

INTRODUCTION

Immunochemotherapy with PD-1 blockade has been established as the current standard first-line therapy for patients with mGEA. Reviewing the history of clinical trials offers valuable insight into the evolution of immune oncology in mGEA, paving the way for future advancements in this field.

AREAS COVERED

This review summarizes the findings of previous clinical trials related to immunotherapy for patients with GEA in the metastatic and locally advanced setting. We also introduce ongoing clinical trials to address the current challenging issues in clinical practice.

EXPERT OPINION

In general, GEA exhibits intermediate immunogenic characteristics with heterogeneous expressions, and responders to anti-PD-(L)1 therapy are mostly enriched to patients with specific genomic profiles such as MSI-H, high PD-L1 expression, high TMB, and EBV-associated type. Co-administration with anti-angiogenic agents or simultaneous blockade of immune checkpoint molecules is being explored to offer benefit of immunotherapy for more patients. We hope that CLDN18.2 and upcoming targets like FGFR2b will complement the treatment niche of immunotherapy in the field of mGEA. Bispecific antibodies, antibody drug conjugates, CAR-T, and vaccine are anticipated to enhance efficacy and expand the scope of immunotherapy.

Antibody-drug conjugates in solid tumors: a new frontier

PURPOSE OF REVIEW

Antibody-drug conjugates (ADCs) are designed to carry cytotoxic payloads and deliver them to specific molecular targets within tumor cells. Several ADCs are already approved with many more in development across several disease types. In this review, we will provide an overview of the ADCs currently approved and those under investigation in solid tumors.

RECENT FINDINGS

Currently there are dozens of ADCs under clinical study evaluation of a variety of solid tumors, and preliminary results are promising. Multiple ADCs have received regulatory approval in disease such as breast cancer, non-small cell lung cancer, and bladder cancer. While some are approved in biomarker selected settings with disease specific indication (e.g. breast cancer), others have been approved irrespective of biomarker expression (urothelial carcinoma) and pan-cancer indications in biomarker selected patients (HER2 3+ expression).

SUMMARY

Cytotoxic chemotherapy has been the mainstay of systemic treatment for patients with various solid tumors. ADCs offer the advantage of carrying the cytotoxic payload onto a specific molecular receptor, thereby inducing a more selective response. Optimizing selection of target antigen, payload delivery and investigating biomarkers of response will be crucial for further expanding the therapeutic benefit of ADCs across solid tumors.

HER-2 directed therapies across gastrointestinal tract cancers - A new frontier

Gastrointestinal (GI) cancers are common and in the metastatic setting they have a poor prognosis. The current mainstay of treatment of GI cancers is chemotherapy; however, the biomarker-directed treatment landscape is evolving. HER-2 is overexpressed in a portion of GI cancers and is an emerging target for therapy, with recent FDA tumor agnostic approval for trastuzumab deruxtecan. Testing for HER-2 expression is not standardized across GI cancers, methodology requires further optimization and standardization as HER-2 targeted therapy emerges into the treatment landscape. There is established rationale for use of HER-2 targeted therapy in first line treatment of metastatic gastric cancer, and emerging evidence with variable benefit in bile duct, pancreatic and colorectal cancers.

Fructose-1, 6-Bisphosphate Aldolase B Suppresses Glycolysis and Tumor Progression of Gastric Cancer

OBJECTIVE

Gastric cancer (GC) is believed to be one of the most common digestive tract malignant tumors. However, mounting evidence indicates a link between the glycolysis and tumorigenesis, including gastric cancer.

METHODS

Our research identified 5508 differently expressed mRNAs in gastric cancer. Then, the genes highly associated with tumorigenesis were identified through weighted correlation network analysis (WGCNA). Bioinformatics analysis observed that these hub genes were significantly linked to the regulation of cell cycle, drug metabolism, and glycolysis. Among these hub genes, there is a critical gene involved in glycolysis regulation, namely fructose-bisphosphate B (ALDOB).

RESULTS

Analysis based on The Cancer Genome Atlas (TCGA) and three Gene Expression Omnibus (GEO) datasets revealed that ALDOB was significantly downregulated in GC compared with normal tissues. In addition, cell viability assay confirmed that ALDOB acted as a tumor suppressor. Finally, drug sensitivity analysis revealed that ALDOB increased the sensitivity of gastric cancer cells to most antitumor drugs, especially talazoparib, XAV939, and FTI-277. Our results showed that the expression of ALDOB was significantly lower in GC tissues than in normal tissues. And ALDOB significantly inhibited proliferation and migration, delayed glycolysis in GC cells. Consequently, our study suggests that ALDOB may be a potential target for the clinical treatment of gastric cancer.

Management of esogastric cancer in older patients

Although esogastric cancers often affect patients over 75, there are no specific age-related guidelines for the care of these patients. Esogastric cancers have a poor prognosis and require multimodal treatment to obtain a cure. The morbidity and mortality of these multimodal treatments can be limited if care is optimized by selecting patients for neoadjuvant treatment and surgery. This can include a geriatric assessment, prehabilitation, renutrition, and more extensive use of minimally invasive surgery. Denutrition is frequent in these patients and is particularly harmful in older patients. While older patients may be provided with neoadjuvant chemotherapy or radiotherapy, it must be adapted to the patient's status. A reduction in the initial dose of palliative chemotherapy should be considered in patients with metastases. These patients tolerate immunotherapy better than systemic chemotherapy, and a strategy to replace chemotherapy with immunotherapy whenever possible should be evaluated. Finally, better supportive care is needed in patients with a poor performance status. Prospective studies are needed to improve the care and prognosis of elderly patients.

Impact of clonal TP53 mutations with loss of heterozygosity on adjuvant chemotherapy and immunotherapy in gastric cancer

BACKGROUND

This study aimed to reveal the effect of TP53 status on clinical outcomes and underlying mechanism in gastric cancer (GC) patients.

METHODS

TP53 status was divided into three groups according to genome sequencing, namely clonal mutations with LOH (C-LOH), clonal diploid or subclonal mutations (CD-SC), and wild type (WT). The p53 protein activity was divided into over-expression (OE), Null and WT according to immunohistochemical staining. Four cohorts, including the TCGA, SMC, ZSHS and FUSCC cohort, were analyzed for association between TP53 mutation status and clinical outcomes and the underlying mechanism.

RESULTS

In TCGA cohort, TP53 CD-SC were associated with superior overall survival compared to TP53 C-LOH cases. GC patients could benefit from ACT only in TP53 CD-SC/ p53 OE and TP53/ p53 WT subgroups, and TP53 C-LOH subgroup demonstrated the worst response to pembrolizumab among three subgroups. Genomic and immunophenotypic deconvolution revealed that TP53 C-LOH, CD-SC and WT differed for genomic and immune-related features.

CONCLUSIONS

TP53 C-LOH GCs with genomic instability and immune evasion phenotype have poor clinical outcomes in patients treated with ACT or immunotherapy.

The efficacy and safety of PI3K and AKT inhibitors for patients with cancer: A systematic review and network meta-analysis

BACKGROUND

Inhibiting PI3K/AKT pathway activation may hinder the occurrence and progression of cancer. The aim of this study was to evaluate the efficacy and safety of the PI3K/AKT inhibitors and determine the most appropriate inhibitor for different cancer types.

METHODS

Electronic databases up to June 2024 were used to examine the efficacy and safety of PI3K inhibitors (alpelisib, copanlisib, duvelisib, and idelalisib) and AKT inhibitors (capivasertib, ipatasertib and MK-2206) for the treatment of cancer. Data was assessed with a random-effect pairwise and network meta-analysis. Randomized controlled trials and retrospective studies were eligible if they compared PI3K or AKT inhibitors with non-PI3K/AKT controls with no restriction.

RESULTS

The results were based on 34 studies from 34 published articles and 6 online registration trials (6710 patients). According to pairwise meta-analysis, PI3K/AKT inhibitors showed to be highly effective, especially for treating mutant cancers, but had poor safety profiles. According to our network meta-analysis, PI3K/AKT inhibitors, especially the AKT inhibitor capivasertib, are effective for treating solid cancers such as breast cancer (BC). Moreover, PI3K inhibitors, especially idelalisib, were effective for treating hematologic cancers such as chronic lymphocytic leukemia (CLL).

CONCLUSIONS

The PI3K/AKT inhibitors are effective in patients with genetic mutations. For solid cancers such as BC, capivasertib was efficacy and safety. For hematological cancers represented by CLL, idelalisib was efficacy and safety. The above studies can be used when recommending appropriate targeted therapies for patients with different cancer types.

Comprehensive landscape of gastric cancer-targeted therapy and identification of CSNK2A1 as a potential target

Objective

To conduct a comprehensive analysis of the landscape of gastric cancer (GC)-targeted therapy clinical trials and identify potential therapeutic targets.

Methods

A systematic search and analysis of the Cochrane Central Register of Controlled Trials (CENTRAL) was performed to retrieve all GC clinical trials published up to June 30, 2022. Approved therapeutic targets for 11 common cancers were compiled and analyzed. The role of CSNK2A1 in GC was investigated using bioinformatics tools such as GEPIA, KMPLOT, SangerBox, STRING, ACLBI, and TIMER. Four gastric cancer cell lines (AGS, HGC, MGC, BGC) and one normal gastric mucosa cell line (GES-1) were utilized to assess the sensitivity to the CSNK2A1 inhibitor CX-4945. Quantitative real-time polymerase chain reaction (qPCR) was employed to quantify the cellular expression of CSNK2A1. Cellular apoptosis was evaluated using flow cytometry and Western blot analysis.

Results

The failure rate of GC randomized controlled clinical trials (RCTs) was strikingly high, accounting for 74.29 % (26/35) of the trials. Among the 35 approved targets in 11 different cancers, 13 targets were rigorously evaluated and identified as potential therapeutic targets for GC. Bioinformatics analysis revealed that CSNK2A1 is closely associated with multiple biological characteristics in GC, and its increased expression correlated significantly with enhanced sensitivity to CX-4945 treatment. Flow cytometry and Western blot analysis consistently demonstrated concentration-dependent apoptosis induced by CX-4945 in GC cell lines.

Conclusions

The high failure rate of GC clinical trials highlights the need for a more scientific and precise approach in target identification and clinical trial design. CSNK2A1 emerges as a promising therapeutic target for GC, and its expression level could potentially serve as a biomarker for predicting sensitivity to CX-4945 treatment. Further research is warranted to elucidate the underlying molecular mechanisms and validate the clinical significance of CSNK2A1 in GC therapy.

Bispecific killer cell engagers employing species cross-reactive NKG2D binders redirect human and murine lymphocytes to ErbB2/HER2-positive malignancies

NKG2D is an activating receptor expressed by natural killer (NK) cells and other cytotoxic lymphocytes that plays a pivotal role in the elimination of neoplastic cells through recognition of different stress-induced cell surface ligands (NKG2DL). To employ this mechanism for cancer immunotherapy, we generated NKG2D-engaging bispecific antibodies that selectively redirect immune effector cells to cancer cells expressing the tumor-associated antigen ErbB2 (HER2). NKG2D-specific single chain fragment variable (scFv) antibodies cross-reactive toward the human and murine receptors were derived by consecutive immunization of chicken with the human and murine antigens, followed by stringent screening of a yeast surface display immune library. Four distinct species cross-reactive (sc) scFv domains were selected, and reformatted into a bispecific engager format by linking them via an IgG4 Fc domain to a second scFv fragment specific for ErbB2. The resulting molecules (termed scNKAB-ErbB2) were expressed as disulfide-linked homodimers, and demonstrated efficient binding to ErbB2-positive cancer cells as well as NKG2D-expressing primary human and murine lymphocytes, and NK-92 cells engineered with chimeric antigen receptors derived from human and murine NKG2D (termed hNKAR and mNKAR). Two of the scNKAB-ErbB2 molecules were found to compete with the natural NKG2D ligand MICA, while the other two engagers interacted with an epitope outside of the ligand binding site. Nevertheless, all four tested scNKAB-ErbB2 antibodies were similarly effective in redirecting the cytotoxic activity of primary human and murine lymphocytes as well as hNKAR-NK-92 and mNKAR-NK-92 cells to ErbB2-expressing targets, suggesting that further development of these species cross-reactive engager molecules for cancer immunotherapy is warranted.

HER2 amplification subtype intrahepatic cholangiocarcinoma exhibits high mutation burden and T cell exhaustion microenvironment

OBJECTIVE

This study aimed to establish a uniform standard for the interpretation of HER2 gene and protein statuses in intrahepatic cholangiocarcinoma (ICC). We also intended to explore the clinical pathological characteristics, molecular features, RNA expression and immune microenvironment of HER2-positive ICC.

METHODS

We analyzed a cohort of 304 ICCs using immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) to identify HER2 status. Comprehensive analyses of the clinicopathological, molecular genetic, and RNA expression characterizations of ICCs with varying HER2 statuses were performed using next-generation sequencing. We further investigated the tumor microenvironment of ICCs with different HER2 statuses using IHC and multiplex immunofluorescence staining.

RESULTS

HER2/CEP17 ratio of ≥ 2.0 and HER2 copy number ≥ 4.0; or HER2 copy number ≥ 6.0 were setup as FISH positive criteria. Based on this criterion, 13 (4.27%, 13/304) samples were classified as having HER2 amplification. The agreement between FISH and IHC results in ICC was poor. HER2-amplified cases demonstrated a higher tumor mutational burden compared to non-amplified cases. No significant differences were observed in immune markers between the two groups. However, an increased density of CD8 + CTLA4 + and CD8 + FOXP3 + cells was identified in HER2 gene-amplified cases.

CONCLUSION

FISH proves to be more appropriate as the gold standard for HER2 evaluation in ICC. HER2 gene-amplified ICCs exhibit poorer prognosis, higher mutational burden, and T cell exhaustion and immune suppressed microenvironment.

WYC-209 suppresses gastric cancer by down-regulating FGF18 via inactivating the STAT3 signaling pathway

BACKGROUND

Gastric cancer (GC) is regarded as a major health burden all over the world. WYC-209 inhibits the growth and metastasis of tumor-repopulating cells (TRCs). However, its effectiveness on GC was unexplored. Herein, this study aims to investigate the effect of WYC-209 on GC and elucidate its underlying mechanism.

METHODS

We examined the effects of WYC-209 on cell survival, migration, invasion, and colony-forming capacities of two GC cell lines (AGS and HGC-27). Subsequently, RNA-seq and enrichment analyses were performed to screen the differentially expressed genes (DEGs) and the enriched signaling pathways. To further explore the underlying mechanism, loss- and gain-function experiments, Chromatin immunoprecipitation, and luciferase reporter were conducted. Finally, xenograft models were constructed to examine the effects of WYC-209 in vivo.

RESULTS

WYC-209 significantly inhibited cell motility in vitro and tumor growth in vivo. RNA-seq performed in AGS cells after WYC-209 treatment revealed that the inhibition effect of WYC-209 on GCs may be associated with the down-regulation of fibroblast growth factor-18 (FGF18), and pleasantly, FGF18 overexpression abrogated the suppression effect of the drug. In addition, we found that WYC-209 attenuated the activation of the Signal Transducer and Activator of Transcription 3 (STAT3) signaling pathway, and impeded the FGF18 levels expressed in GCs. Importantly, the WYC-209 treatment circumvented the binding of STAT3 to the FGF18 promoter, suggested that WYC-209 down-regulated FGF18 expression via the STAT3 signaling pathway.

CONCLUSION

Together, our findings presented the promise of WYC-209 in suppressing GC by down-regulating FGF18 expression through inactivating the STAT3 signaling pathway.

Comparison of treatment strategies based on clinical and pathological nodal status in resectable gastric adenocarcinoma

BACKGROUND

To determine the optimal multimodal treatment strategy between perioperative chemotherapy (PEC), postoperative chemoradiation therapy (POCR), and postoperative chemotherapy (POC) in resected gastric cancer (GC) patients based on nodal status.

METHODS

In this retrospective analysis, the National Cancer Database was used to identify resected non-metastatic GC (2006-2016). Patients were stratified by clinical nodal status-negative (cLN-) and positive (cLN+). In patients with cLN- disease who underwent upfront resection and were upstaged to pathological LN+, overall survival (OS) was compared between POC and POCR. In patients with cLN- and cLN+ disease, OS was compared between PEC, POCR, and POC. Kaplan-Meier survival estimate, log-rank test, and multivariable Cox proportional hazards analysis were performed.

RESULTS

We identified 7827 patients (cLN- 4828; cLN+ 2999). On multivariable analysis in patients with cLN- disease who underwent upfront resection (n = 4314) and were upstaged to pLN+ disease (70%), POCR (n = 2300, aHR 0.78, 95% CI 0.70-0.87, p < 0.001) was associated with improved OS compared to POC (n = 907). No significant difference was noted between POCR (n = 766, aHR 1.11, 95% CI 0.88-1.40, p = 0.39) and POC (n = 341) in patients with pLN- disease. On multivariable analysis in all patients with cLN- disease, POCR (n = 3066) was significantly associated with improved OS (aHR 0.84, 95% CI 0.75-0.92, p < 0.01) compared to POC (n = 1248). No significant difference was noted between POCR (aHR 1.0, 95% CI 0.70-1.01, p = 0.958) and PEC (n = 514). These results remained consistent in patients with cLN+ disease (POCR = 1602, POC = 720, PEC = 677).

CONCLUSION

Postoperative chemoradiation is associated with improved survival in GC patients upstaged from clinically node-negative disease to pathologically node-positive disease. Negative clinical nodal disease status is not a reliable indicator of pathological nodal disease.

The Impact of Pembrolizumab as a Salvage Therapy Based on HER2 Expression in Advanced Gastric Cancer

Immune checkpoint inhibitors (ICIs) are used as salvage treatments for advanced gastric cancer (AGC) regardless of HER2 status. This study assessed the efficacy of ICIs based on HER2 expression in AGC patients who received pembrolizumab as salvage monotherapy at Samsung Medical Center from November 2017 to March 2023. HER2 status was determined via immunohistochemistry, and tumor response and survival outcomes were compared accordingly. Among the 113 patients analyzed, with a median age of 61 years and 64.6% being male, 12 patients (10.6%) were HER2-positive, and 101 patients (89.4%) were HER2-negative. Of 92 evaluable patients, none had a complete response. However, 50% of HER2-positive patients had a partial response, compared to 4.9% of HER2-negative patients (p < 0.001). The disease control rate was 70% in HER2-positive and 37.8% in HER2-negative patients (p = 0.086). Median progression-free survival was 5.53 months for HER2-positive patients versus 1.81 months for HER2-negative patients (p = 0.037). Pembrolizumab as a salvage chemotherapy for the treatment of AGC demonstrated superior effectiveness in HER2-positive patients compared with HER2-negative patients.

Predicting gastric cancer response to anti-HER2 therapy or anti-HER2 combined immunotherapy based on multi-modal data

The sole use of single modality data often fails to capture the complex heterogeneity among patients, including the variability in resistance to anti-HER2 therapy and outcomes of combined treatment regimens, for the treatment of HER2-positive gastric cancer (GC). This modality deficit has not been fully considered in many studies. Furthermore, the application of artificial intelligence in predicting the treatment response, particularly in complex diseases such as GC, is still in its infancy. Therefore, this study aimed to use a comprehensive analytic approach to accurately predict treatment responses to anti-HER2 therapy or anti-HER2 combined immunotherapy in patients with HER2-positive GC. We collected multi-modal data, comprising radiology, pathology, and clinical information from a cohort of 429 patients: 310 treated with anti-HER2 therapy and 119 treated with a combination of anti-HER2 and anti-PD-1/PD-L1 inhibitors immunotherapy. We introduced a deep learning model, called the Multi-Modal model (MuMo), that integrates these data to make precise treatment response predictions. MuMo achieved an area under the curve score of 0.821 for anti-HER2 therapy and 0.914 for combined immunotherapy. Moreover, patients classified as low-risk by MuMo exhibited significantly prolonged progression-free survival and overall survival (log-rank test, P < 0.05). These findings not only highlight the significance of multi-modal data analysis in enhancing treatment evaluation and personalized medicine for HER2-positive gastric cancer, but also the potential and clinical value of our model.