Metastatic gastric cancer treatment: Second line and beyond

Integrated multi-omics analysis and machine learning developed a prognostic model based on mitochondrial function in a large multicenter cohort for Gastric Cancer

BACKGROUND

Gastric cancer (GC) is a common and aggressive type of cancer worldwide. Despite recent advancements in its treatment, the prognosis for patients with GC remains poor. Understanding the mechanisms of cell death in GC, particularly those related to mitochondrial function, is crucial for its development and progression. However, more research is needed to investigate the significance of the interaction between mitochondrial function and GC cell death.

METHODS

We employed a robust computational framework to investigate the role of mitochondria-associated proteins in the progression of GC in a cohort of 1,199 GC patients. Ten machine learning algorithms were utilized and combined into 101 unique combinations. Ultimately, we developed a Mitochondrial-related-Score (MitoScore) using the machine learning model that exhibited the best performance. We observed the upregulation of LEMT2 and further explored its function in tumor progression. Mitochondrial functions were assessed by measuring mitochondrial ATP, mitochondrial membrane potential, and levels of lactate, pyruvate, and glucose.

RESULTS

MitoScore showed significant correlations with GC immune and metabolic functions. The higher MitoScore subgroup exhibited enriched metabolic pathways and higher immune activity. Overexpression of LETM2 (leucine zipper and EF-hand containing transmembrane protein 2) significantly enhanced tumor proliferation and metastasis. LETM2 plays a role in promoting GC cell proliferation by activating the mTOR pathway, maintaining mitochondrial homeostasis, and promoting glycolysis.

CONCLUSION

The powerful machine learning framework highlights the significant potential of MitoScore in providing valuable insights and accurate assessments for individuals with GC. This study also enhances our understanding of LETM2 as an oncogene signature in GC. LETM2 may promote tumor progression by maintaining mitochondrial health and activating glycolysis, offering potential targets for diagnosis, treatment, and prognosis of GC.

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

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

Loss of NDUFS1 promotes gastric cancer progression by activating the mitochondrial ROS-HIF1α-FBLN5 signaling pathway

BACKGROUND

Recent studies suggested that NDUFS1 has an important role in human cancers; however, the effects of NDUFS1 on gastric cancer (GC) are still not fully understood.

METHODS

We confirmed that NDUFS1 is downregulated in GC cells through western blot immunohistochemistry and bioinformation analysis. The effect of NDUFS1 on GC was studied by CCK-8, colony formation, transwell assay in vitro and Mouse xenograft assay in vivo. Expression and subcellular localization of NDUFS1 and the content of mitochondrial reactive oxygen species (mROS) was observed by confocal reflectance microscopy.

RESULTS

Reduced expression of NDUFS1 was found in GC tissues and cell lines. Also, NDUFS1 overexpression inhibited GC cell proliferation, migration, and invasion in vitro as well as growth and metastasis in vivo. Mechanistically, NDUFS1 reduction led to the activation of the mROS-hypoxia-inducible factor 1α (HIF1α) signaling pathway. We further clarified that NDUFS1 reduction upregulated the expression of fibulin 5 (FBLN5), a transcriptional target of HIF1α, through activation of mROS-HIF1α signaling in GC cells.

CONCLUSIONS

The results of this study indicate that NDUFS1 downregulation promotes GC progression by activating an mROS-HIF1α-FBLN5 signaling pathway.

Nab-Paclitaxel in the Treatment of Gastrointestinal Cancers-Improvements in Clinical Efficacy and Safety

Taxanes (paclitaxel and docetaxel) are one of the most useful classes of anticancer drugs. Taxanes are highly hydrophobic; therefore, these drugs must be dissolved in organic solvents (polysorbate or Cremophor EL), which contribute to their toxicities. To reduce this toxicity and to enhance their efficacy, novel formulations have been developed. Nanoparticle albumin-bound paclitaxel (nab-paclitaxel) is an albumin-stabilized, Cremophor-free, and water-soluble nanoparticle formulation of paclitaxel. Nab-paclitaxel has better solubility and less infusion-associated toxicity compared to solvent-based paclitaxel. Additionally, nab-paclitaxel can be given at higher doses and concentrations compared with solvent-based paclitaxel. Based on its superior clinical efficacy and safety profile, nab-paclitaxel received FDA approval for metastatic breast cancer (2008) and NSCLC (2011). Among gastrointestinal cancers, it is now approved in the USA for treating patients with metastatic adenocarcinoma of the pancreas as first-line therapy in combination with gemcitabine. Furthermore, several clinical trials have suggested the potential efficacy of nab-paclitaxel as a single agent or in combination with other agents for the treatment of metastatic esophageal, gastric, bowel, and biliary tract cancers. Nab-paclitaxel has been demonstrated to have greater overall response rates (ORR) with enhanced progression-free survival (PFS), overall survival (OS) and a superior safety profile with fewer adverse effects in patients with gastrointestinal tract cancers. This review summarizes the advantages associated with nab-paclitaxel-based regimens in terms of improving clinical efficacy and the safety profile in upper gastrointestinal cancer.

HER2-Positive Gastric Cancer: The Role of Immunotherapy and Novel Therapeutic Strategies

Gastric cancer is an aggressive disease with increasing global incidence in recent years. Human epidermal growth receptor 2 (HER2) is overexpressed in approximately 10-20% of gastric cancers. The implementation of targeted therapy against HER2 as part of the standard of care treatment in metastatic disease has improved the prognosis of this subset of patients. However, gastric cancer still has high mortality rates and urgently requires new treatment strategies. The combination of immunotherapy with HER2-targeted therapies has shown synergistic effects in preclinical models, this being the rationale behind exploring this combination in clinical trials in locally advanced and metastatic settings. Additionally, the irruption of antibody-drug conjugates and other novel HER2-targeted agents has led to the development of numerous clinical trials showing promising results. This review presents the molecular mechanisms supporting the use of HER2-targeted drugs in combination with immunotherapy and provides an overview of the therapeutic scenario of HER2-positive disease. We focus on the role of immunotherapy but also summarize emerging therapies and combinations under clinical research that may change the standard treatment in HER-2 positive disease in the future.

Enhancing gastric cancer conventional chemotherapy effects by triple angiokinase inhibitor nintedanib in preclinical models

Background

Gastric adenocarcinoma (GAC) is the fourth leading cause of cancer death worldwide. Systemic chemotherapy is a preferred treatment option for advanced and recurrent GAC, but response rates and survival prolongation remain limited. Tumor angiogenesis plays a critical role in GAC growth, invasion and metastasis. We investigated the antitumor efficacy of nintedanib, a potent triple angiokinase inhibitor for VEGFR-1/2/3, PDGFR-α/β and FGFR-1/2/3, alone or in combination with chemotherapy, in preclinical models of GAC.

Methods

Animal survival studies were performed in peritoneal dissemination xenografts in NOD/SCID mice using human GAC cell lines MKN-45 and KATO-III. Tumor growth inhibition studies were performed in subcutaneous xenografts in NOD/SCID mice using human GAC cell lines MKN-45 and SNU-5. The mechanistic evaluation involved Immunohistochemistry analyses in tumor tissues obtained from subcutaneous xenografts. In vitro cell viability assays were performed using a colorimetric WST-1 reagent.

Results

In MKN-45 GAC cell-derived peritoneal dissemination xenografts, animal survival was improved by nintedanib (33%), docetaxel (100%) and irinotecan (181%), while oxaliplatin, 5-FU and epirubicin had no effect. The addition of nintedanib to docetaxel (157%) or irinotecan (214%) led to a further extension in animal survival. In KATO-III GAC cell-derived xenografts carrying FGFR2 gene amplification, nintedanib extended survival by 209%. Again, the addition of nintedanib further enhanced the animal survival benefits of docetaxel (273%) and irinotecan (332%). In MKN-45 subcutaneous xenografts, nintedanib, epirubicin, docetaxel and irinotecan reduced tumor growth (range: 68-87%), while 5-FU and oxaliplatin had a smaller effect (40%). Nintedanib addition to all chemotherapeutics demonstrated a further reduction in tumor growth. Subcutaneous tumor analysis revealed that nintedanib attenuated tumor cell proliferation, reduced tumor vasculature and increased tumor cell death.

Conclusion

Nintedanib showed notable antitumor efficacy and significantly improved taxane or irinotecan chemotherapy responses. These findings indicate that nintedanib, alone and in combination with a taxane or irinotecan, has the potential for improving clinical GAC therapy.

Prognosis value and positive association of Rab1A/IL4Rα aberrant expression in gastric cancer

Gastric cancer (GC) is the most common gastrointestinal cancer and the leading cause of worldwide cancer-associated mortality. Several GC patients are diagnosed at the advanced stage with an unsatisfactory 5-year survival rate. Rab1A was significantly associated with IL4Rα expression in non-small cell lung cancer. However, their potential correlation in expression and prognosis remains largely unknown in GC. In this study, Rab1A/IL-4Rα was significantly increased in GC than in para-cancerous tissues, and Rab1A/IL-4Rα overexpression caused poor prognosis among GC patients. Rab1A expression was significantly correlated with IL-4Rα expression in GC tissues, as determined by IHC analysis. In addition, the mRNA expression of Rab1A was closely linked with the IL-4Rα mRNA expression in GC tissue expressed by qPCR. Furthermore, the Kaplan-Meier analysis demonstrated that the group with negative Rab1A and IL-4Rα expression had longer 5-year survival rates than the other group. Besides, the group with positive Rab1A and IL-4Rα expression had a worse prognosis than the other group. Finally, nomograms revealed the overall 3 and 5-year survival determined crucial roles of Rab1A/IL-4Rα expression in predicting the prognosis of GC patients. Therefore, Rab1A/IL-4Rα is vital in GC, providing a novel perspective on targeted GC therapy.

Nivolumab with or without chemotherapy for metastatic gastroesophageal cancers and future perspectives

INTRODUCTION

Gastroesophageal cancers (GEC) are frequently found at the advanced stage. GEC treatment advancements have been limited and prognosis, therefore, remains poor. Through numerous clinical trials, the addition of immune checkpoint inhibitors, including nivolumab, to conventional therapy has demonstrated a survival benefit.

AREAS COVERED

Here, we focus on the function of nivolumab in patients with advanced GECs. We discuss the most recent trials that led to nivolumab's incorporation into therapy and pathways forward.

EXPERT OPINION

Nivolumab in combination with chemotherapy appears well tolerated, with only a small number of patients reporting severe toxicity; therefore, it may be possible to add additional biological agents to improve outcomes. A number of 'nivolumab plus other agents' is currently being investigated, and we anticipate continued advancement in GEC management in the coming years.

Augmenting Experimental Gastric Cancer Activity of Irinotecan through Liposomal Formulation and Antiangiogenic Combination Therapy

Gastric adenocarcinoma (GAC) is the third most common cause of cancer-related deaths worldwide. Combination chemotherapy remains the standard treatment for advanced GAC. Liposomal irinotecan (nal-IRI) has improved pharmacokinetics (PK) and drug biodistribution compared with irinotecan (IRI, CPT-11). Angiogenesis plays a crucial role in the progression and metastasis of GAC. We evaluated the antitumor efficacy of nal-IRI in combination with novel antiangiogenic agents in GAC mouse models. Animal survival studies were performed in peritoneal dissemination xenografts. Tumor growth and PK studies were performed in subcutaneous xenografts. Compared with controls, extension in animal survival by nal-IRI and IRI was >156% and >94%, respectively. The addition of nintedanib or DC101 extended nal-IRI response by 13% and 15%, and IRI response by 37% and 31% (MKN-45 xenografts); nal-IRI response by 11% and 3%, and IRI response by 16% and 40% (KATO-III xenografts). Retardation of tumor growth was greater with nal-IRI (92%) than IRI (71%). Nintedanib and DC101 addition tend to augment nal-IRI or IRI response in this model. The addition of antiangiogenic agents enhanced tumor cell proliferation inhibition effects of nal-IRI or IRI. The tumor vasculature was decreased by nintedanib (65%) and DC101 (58%), while nal-IRI and IRI alone showed no effect. PK characterization in GAC xenografts demonstrated that compared with IRI, nal-IRI treatment groups had higher retention, circulation time, and tumor levels of CPT-11 and its active metabolite SN-38. These findings indicate that nal-IRI, alone and in combination with antiangiogenic agents, has the potential for improving clinical GAC therapy.

5,7,2,5-tetrahydroxy-8,6-dimethoxyflavone up-regulates miR-145 expression and inhibits proliferation of gastric cancer cells

INTRODUCTION

Gastric cancer is a frequently detected malignancy, and its incidence has increased over the past decades in East Asia. The present study investigated the effect of 5,7,2, 5-tetrahydroxy-8,6-dimethoxyflavone (THDMF) on gastric cancer cells and explored the underlying mechanism. The study analysed cell viability changes, apoptotic features, and metastasis potential of treatment with THDMF.

MATERIAL AND METHODS

MTT colorimetric assay was used for measurement of MKN28, MKN45, and GES-1 cell proliferation and flow cytometry for the detection of apoptosis. Transwell and wound healing assays were used to observe the invasion and migration abilities of MKN28 cells. The expression of p21, MMP2/-9, PI3K, and c-Myc proteins was detected by western blotting.

RESULTS

The THDMF treatment significantly (p < 0.05) reduced MKN28 and MKN45 cell proliferation without changing GES-1 cell viability. A significant increase in apoptotic cell population on treatment with THDMF was observed. Treatment of MKN28 cells with THDMF increased the percentage of cells in the G1 phase. Exposure of MKN28 cells to THDMF caused a marked decrease in invasion and migration potential in comparison to control cells. The expression of miR-145 was markedly increased in MKN28 cells on treatment with THDMF. In MKN28 cells expression of c-Myc, PI3K, p-AKT, MMP-2, and MMP-9 was suppressed markedly on exposure to THDMF. The expression of p21 protein in MKN28 cells was markedly promoted on exposure to THDMF.

CONCLUSIONS

THDMF exhibits anti-cancer effect on gastric cancer cells in vitro by activation of cell apoptosis and arrest of cell cycle. In addition, THDMF promoted miR-145 expression and down-regulation of PI3K/AKT signalling pathway in MKN28 cells. Therefore, THDMF may be utilised as a potential novel therapeutic agent for the treatment of gastric cancer.

Sarcopenia assessment by new EWGSOP2 criteria for predicting chemotherapy dose-limiting toxicity in patients with gastrointestinal tract tumors

INTRODUCTION

In 2019, The EWGSOP2 group made updates on the definition and diagnosis of sarcopenia. The aim of this study is to determine the possible risk factors for chemotherapy dose-limiting toxicity (DLT).

METHODS

Newly diagnosed gastrointestinal (GI) cancer patients were included in this prospective observational study. Chemotherapy DLTs were recorded in patients receiving platinum-based therapy. The patients were divided into two groups according to the current sarcopenia criteria.

RESULTS

75 patients were included in the final analysis. Chemotherapy DLT occurred in 52% (n = 39) of all patients who received platinum-based chemotherapy. DLT rates were 78.9% and 42.9% in sarcopenic and non-sarcopenic patients, respectively (p = 0.007). According to the results of the multivariate analysis, the only sarcopenia was found as a statistically significant risk factor for DLT.

CONCLUSION

Assessment of sarcopenia evaluated with the current EWGSOP2 diagnostic criteria is useful in predicting chemotherapy DLT development in patients with a diagnosis of GI cancer. In the future, current EWGSOP2 recommendations should be considered while designing a study investigating the correlation between sarcopenia and chemotoxicity.

Blood alkaline phosphatase predicts prognosis of patients with advanced HER2-negative gastric cancer receiving immunotherapy

BACKGROUND

Immune checkpoint blockade is effective against many cancer types, but few patients achieve a complete response (OR). Therefore, effective prognostic biomarkers are needed for metastatic gastric cancer (GC) patients after immune treatment. The present study assessed the value of hematological parameters as markers of the effectiveness of immune checkpoint blockade among metastatic GC patients.

METHODS

This retrospective study included patients with metastatic GC who underwent multiline chemotherapy including at least two courses of immunotherapy between September 2018 and December 2020. Patient and tumor characteristics were tested for prognostic significance by analysis of variance or chi-square test. Kaplan-Meier and Cox analyses were performed to identify factors associated with progression-free survival (PFS).

RESULTS

Sixty-one GC patients (mean age 55.61±11.97 years, range 23-80 years, 24 females, and 37 males) were included, and 27, 9 and 25 cases had organ only, peritoneum only, and simultaneous organ and peritoneum metastasis, respectively. Gastrectomy was performed in 24 cases, and there was no operative treatment in the other 37 cases, while all patients received two or more lines of chemotherapy. After immune treatment, 13 patients achieved a partial response (PR), 16 stable disease (SD), and 32 progressive disease (PD). The median PFS was 4.93±3.47 months. An alkaline phosphatase (ALP) level >225 U/L, a lactate dehydrogenase level (LDH) >299 U/L, and a body mass index (BMI) >24 kg/m2 were associated with a short PFS (P=0.01, P=0.008, and P=0.039, respectively). A Cox multivariate proportional hazard model indicated that higher ALP level was a significant prognostic indicator for adverse PFS.

CONCLUSIONS

Our data show an ALP cutoff of 225 U/L offered good prognostic sensitivity for HER2-negative metastatic GC. ALP measurement represents a convenient, cost-effective, and relatively sensitive screening tool, and prospective studies involving its evaluation in addition to other biomarkers in metastatic GC patients are indicated.

Enhanced Vasculogenic Capacity Induced by 5-Fluorouracil Chemoresistance in a Gastric Cancer Cell Line

Chemotherapy is still widely used as a coadjutant in gastric cancer when surgery is not possible or in presence of metastasis. During tumor evolution, gatekeeper mutations provide a selective growth advantage to a subpopulation of cancer cells that become resistant to chemotherapy. When this phenomenon happens, patients experience tumor recurrence and treatment failure. Even if many chemoresistance mechanisms are known, such as expression of ATP-binding cassette (ABC) transporters, aldehyde dehydrogenase (ALDH1) activity and activation of peculiar intracellular signaling pathways, a common and universal marker for chemoresistant cancer cells has not been identified yet. In this study we subjected the gastric cancer cell line AGS to chronic exposure of 5-fluorouracil, cisplatin or paclitaxel, thus selecting cell subpopulations showing resistance to the different drugs. Such cells showed biological changes; among them, we observed that the acquired chemoresistance to 5-fluorouracil induced an endothelial-like phenotype and increased the capacity to form vessel-like structures. We identified the upregulation of thymidine phosphorylase (TYMP), which is one of the most commonly reported mutated genes leading to 5-fluorouracil resistance, as the cause of such enhanced vasculogenic ability.

Loss of DAB2IP Contributes to Cell Proliferation and Cisplatin Resistance in Gastric Cancer

Objective

Resistance to chemotherapeutic drugs, such as cisplatin, has been one of the major problems adversely affecting the clinical prognosis of patients with gastric cancer (GC). Disabled Homolog 2-Interacting Protein (DAB2IP) status is one of the major factors involved in sensitivity to chemotherapy in multiple cancer types. In the present study, we aimed to investigate the potential roles of DAB2IP in GC cell proliferation and cisplatin resistance.

Materials and Methods

DAB2IP expression was detected in human GC tissues using immunohistochemistry (IHC). The role of DAB2IP in regulating GC cell proliferation and cisplatin resistance was explored by genetic manipulation. Western blot analysis was used to determine the molecular signaling to explain the mechanism of the observed DAB2IP effects in GC.

Results

DAB2IP expression was downregulated in human GC tissues and low DAB2IP expression predicted poor prognosis. Moreover, our data provided evidence that DAB2IP upregulation impaired cell proliferation property and sensitized GC cells to cisplatin while DAB2IP depletion possessed the opposite effects. Mechanistically, we showed that DAB2IP could inhibit the phosphorylation and activation of protein kinase B (AKT) and extracellular signal-regulated kinase (ERK), and the enhanced proliferation ability induced by DAB2IP knockdown was greatly impaired after incubation with AKT or ERK inhibitor.

Conclusion

DAB2IP modulates GC cell proliferation and sensitivity to cisplatin potentially via regulation of AKT and ERK signaling pathway, indicating that DAB2IP may serve as a potential prognostic biomarker and therapeutic target for treatment of GC.

Comparison of PD-L1 immunohistochemical assays in advanced gastric adenocarcinomas using endoscopic biopsy and paired resected specimens

Immunohistochemical (IHC) assays for programmed death ligand 1 (PD-L1) expression are crucial for guiding immune checkpoint inhibitor therapies in advanced gastric adenocarcinoma (AGC). The results from clinical trials of various PD-L1 antibody clones are variable and the exchangeability of these assays is a highly sought goal. The aim of this study was to determine whether three different PD-L1 assays (SP263 and 22C3 on the Dako and Ventana platforms) are interchangeable through analysis of their concordance rate within samples between biopsy and paired resected specimens. One hundred pairs of biopsied and resected AGC specimens were collected and stained for PD-L1. The combined positive score (CPS) was used for the IHC analysis and a four tiered system was applied, i.e., <1, 1 to < 5, 5 to 50, and >50. The agreement for the different IHC assays was low across all cut-offs with the biopsied or resected specimens (biopsy, κ=0.17-0.453; resection, κ=0.02-0.311). The overall positive agreement (OPA) for the PD-L1 results from the biopsy and resection tissues was 100% (SP263, κ=1), 86% (22C3 on the Dako platform, κ=0.693) and 93% (22C3 on the Ventana platform, κ=0.82) at the CPS1 cut-off. The low concordances among the three PD-L1 IHC assays indicated that they cannot be used interchangeably in clinical practice. The results of the SP263 assay using CPS1 showed the highest agreement between the biopsy and resection specimens, suggesting SP263 may provide the most representative approach for the evaluation of PD-L1 status in gastric cancer.

Healthcare utilization and total costs of care among patients with advanced metastatic gastric and esophageal cancer

Aim: Study first-line (1L) treatment patterns and economic outcomes among patients with advanced metastatic gastric cancer (GC) and esophageal cancer (EC). Materials & methods: Newly diagnosed patients with systemic GC and EC treatments were identified between 1 January 2011 and 31 July 2017; costs were presented as per patient per month (PPPM) basis. Results: Study included 392 GC and 436 EC patients. Most frequently used 1L regimens were: 5-fluorouracil (5-FU) + oxaliplatin (22.5%) and epirubicin + cisplatin + 5-FU (ECF)/ECF modifications (21.9%) in patients with GC; and carboplatin + paclitaxel (29.6%) and 5-FU + oxaliplatin (11.5%) in EC patients. Mean all-cause costs were US$16,242 PPPM for GC, and $18,384 PPPM for EC during 1L treatment. Conclusion: GC and EC were resource intensive and costly. High costs and short treatment durations underscored a gap in care in 1L treatment.

Nivolumab in Combination with Irinotecan and 5-Fluorouracil (FOLFIRI) for Refractory Advanced Gastroesophageal Cancer

INTRODUCTION

Advanced unresectable gastroesophageal cancers continue to confer a dismal patient prognosis. Limited options remain once the cancer is refractory to cytotoxics/biologics (like irinotecan, taxane, and ramucirumab). Recently, anti-programmed death-1 (anti-PD-1) inhibitors have been used with limited efficacy in select patients with adenocarcinoma. Similarly, irinotecan-based therapy has marginal efficacy. We combined irinotecan plus a fluoropyrimidine with an anti-PD-1 antibody, nivolumab, with hopes of having a higher advantage for patients.

OBJECTIVES

Primary objective was to assess safety judged by toxicities, dose delays, or dose reductions. Secondary endpoints included the assessment of response, overall survival (OS), and progression-free survival (PFS).

METHODS

We treated 15 patients with this combination during July 2017 to April 2019. Patients were included if they had follow-up at our institution.

RESULTS

Median doses given were nivolumab 240 mg + irinotecan 120 mg/m2 + 5-FU 2,000 mg/m2 over 46-48 h (or capecitabine 1,250 mg/m2/day; 7 days on, 7 days off) given every 2 weeks. Median age of the patients was 55 years, and all patients had an ECOG performance status of 0-1. The patients had a median of 1 prior therapy. Slightly over half of the patients had PD-L1 expression. The median number of cycles was 7. Five patients (33%) had a dose delay or dose adjustment. The most common reason for dose delay or adjustment was grade 2 fatigue. Disease control (response or stability) on first scan was 73.3% (n = 11). Median PFS and OS for the entire group was 7 and 13.3 months, respectively.

CONCLUSION

In this small cohort of patients, we conclude that this combination is quite feasible and resulted in prolonged stability in some patients. Further development of this regimen is warranted.

Safety and Efficacy of Durvalumab and Tremelimumab Alone or in Combination in Patients with Advanced Gastric and Gastroesophageal Junction Adenocarcinoma

PURPOSE

This randomized, multicenter, open-label, phase Ib/II study assessed durvalumab and tremelimumab in combination or as monotherapy for chemotherapy-refractory gastric cancer or gastroesophageal junction (GEJ) cancer.

PATIENTS AND METHODS

Second-line patients were randomized 2:2:1 to receive durvalumab plus tremelimumab (arm A), or durvalumab (arm B) or tremelimumab monotherapy (arm C), and third-line patients received durvalumab plus tremelimumab (arm D). A tumor-based IFNγ gene signature was prospectively evaluated as a potential predictive biomarker in second- and third-line patients receiving the combination (arm E). The coprimary endpoints were objective response rate and progression-free survival (PFS) rate at 6 months.

RESULTS

A total of 113 patients were treated: 6 in phase Ib and 107 (arm A, 27; arm B, 24; arm C, 12; arm D, 25; arm E, 19) in phase II. Overall response rates were 7.4%, 0%, 8.3%, 4.0%, and 15.8% in the five arms, respectively. PFS rates at 6 months were 6.1%, 0%, 20%, 15%, and 0%, and 12-month overall survival rates were 37.0%, 4.6%, 22.9%, 38.8%, and NA, respectively. Treatment-related grade 3/4 adverse events were reported in 17%, 4%, 42%, 16%, and 11% of patients, respectively.

CONCLUSIONS

Response rates were low regardless of monotherapy or combination strategies. No new safety signals were identified. Including use of a tumor-based IFNγ signature and change in baseline and on-treatment circulating tumor DNA are clinically feasible and may be novel strategies to improve treatment response in this difficult-to-treat population.

Clinical efficacy of apatinib in treating metastatic gastric cancer and its effect on IL-17

Clinical efficacy of apatinib in treating metastatic gastric cancer and its effect on the levels of serum IL-17 were investigated. A retrospective analysis was performed on 129 patients who had metastatic gastric cancer after first-line chemotherapy and were treated in Xiangyang No. 1 People's Hospital from February 2012 to February 2015. Of these patients, 78 received oral apatinib and were assigned to experimental group; and 51 received oral tegafur-gimeracil-oteracil and were assigned to control group. Clinical efficacy was compared between the two groups, and the levels of serum IL-17 were measured for all the patients. The treatment response rate in the experimental group was 52.56% and in the control group 31.37%. Apparently, the treatment response rate in the experimental group was higher than that in the control group, and the difference was statistically significant (P<0.05). The incidence of adverse drug reactions in the experimental group was significantly lower than that in the control group (P<0.05). The serum level of IL-17 after one course of medication was significantly lower than that before medication in both groups (P<0.05). In comparison between groups, the serum level of IL-17 after one course of medication was clearly lower in the experimental group than that in the control group (P<0.05). Apatinib regimen was demonstrated to have less toxic side-effects in the treatment of metastatic gastric cancer than tegafur-gimeracil-oteracil regimen, indicating that apatinib has favorable safety. In addition, apatinib can downregulate IL-17 expression, which is helpful in attenuating tumor proliferation and improving the clinical efficacy. Therefore, apatinib has potential use in a wide range of clinical applications.

Effect of miR‑145 on gastric cancer cells

Gastric cancer is one of the most common malignant tumors in the world. Due to the lack of early diagnosis and effective treatment, the outcome of treatment and prognosis is poor. MicroRNA-145 (miR-145) is downregulated in various cancer types. In the present study, miR-145 expression was detected by reverse transcription-quantitative polymerase chain reaction in gastric cancer cell lines and normal gastric epithelial cells. The function of miR-145 in the gastric cancer cell line SGC-7901 was investigated. The present results demonstrated that the expression of miR-145 was downregulated in gastric cancer cells. Further analysis identified that upregulation of miR-145 significantly suppressed SGC-7901 cell proliferation, increased cellular apoptosis and blocked the cell cycle in the G₁ phase. Additionally, overexpression of miR-145 reduced SGC-7901 cell invasion and metastasis in vitro. Western blot analysis demonstrated that overexpression of miR-145 downregulated Myc proto-oncogene protein, phosphoinositide 3-kinase/protein kinase B and matrix metalloproteinase 2/9, and upregulated p21 in SGC-7901 cells. The present results revealed potential signaling pathways that miR-145 may use to regulate gastric cancer cell proliferation, apoptosis and metastasis. Collectively, the present results suggest that miR-145 is a tumor suppressor for gastric cancer and it may be a potential therapeutic target for gastric cancer treatment.

Yes-associated protein enhances proliferation and attenuates sensitivity to cisplatin in human gastric cancer cells

BACKGROUND

Yes-associated protein (YAP) is upregulated in many cancer types, and its overexpression is involved in tumor cell proliferation, metastasis and resistance to chemotherapy. In the present study, we aimed to investigate the potential role of YAP in the development and progression of gastric cancer.

METHODS

YAP levels were analyzed in human gastric cancer and adjacent normal tissues by Western blotting and immunohistochemistry. Potential roles of YAP in regulating gastric cancer cell proliferation and sensitivity to cisplatin were examined by genetic manipulation in vitro. The molecular signaling was determined to understand the mechanisms of observed YAP effects.

RESULTS

YAP level was higher in gastric cancer tissues as compared to paired normal tissues. Knockdown of YAP attenuated gastric cancer cell proliferation and enhanced sensitivity to cisplatin in vitro while YAP overexpression possessed the opposite effects. YAP regulated Epidermal growth factor receptor (EGFR) expression and its downstream AKT and extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathway in gastric cancer cells.

CONCLUSION

YAP enhances gastric cancer cell proliferation and attenuates sensitivity to cisplatin potentially through targeting the EGFR signaling, indicating that YAP/EGFR signaling axis may serve as a potential target for treatment of gastric cancer.

Evolution of checkpoint inhibitors for the treatment of metastatic gastric cancers: Current status and future perspectives

BACKGROUND

Standard treatment options for patients with advanced gastric or gastroesophageal junction cancer (GC/GEJC) are associated with limited efficacy and some toxicity. Recently, immunotherapy with antibodies that inhibit the programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) interaction has emerged as a new treatment option. This manuscript reviews early-phase and late-phase trials of immunotherapy in advanced GC/GEJC.

METHODS

Searches for studies of immunotherapy in GC/GEJC were performed using PubMed, ClinicalTrials.gov, and abstract databases for select annual congresses. Findings were interpreted based on expert opinion.

RESULTS

Monotherapy with anti-PD-1/PD-L1 antibodies, including pembrolizumab, nivolumab, avelumab, durvalumab, and atezolizumab, has shown interesting objective response rates (ORRs; 7-26%) across varying GC/GEJC populations, with ORRs potentially higher in PD-L1 + vs PD-L1 - tumors. Safety profiles compare favorably with chemotherapy, with grade ≥3 treatment-related adverse events occurring in 5-17%. Based on a large phase 2 study, pembrolizumab was approved in the United States for third-line treatment of patients with PD-L1 + GC/GEJC. In a phase 3 trial, third-line or later nivolumab increased overall survival vs placebo in an Asian population, leading to regulatory approval in Japan, although other completed phase 3 trials did not show superiority for pembrolizumab or avelumab monotherapy vs chemotherapy. Other trials in advanced GC/GEJC are assessing various anti-PD-1/PD-L1-based strategies, including administration in first-line and later-line settings and as combination (with chemotherapy or agents targeting other immune checkpoint proteins, eg, CTLA-4, LAG-3, and IDO) or switch-maintenance regimens.

CONCLUSIONS

Anti-PD-1/PD-L1 antibodies have shown encouraging clinical activity in advanced GC/GEJC. Results from ongoing phase 3 trials are needed to further evaluate the potential roles of these agents within the continuum of care.

Ramucirumab in HER-2-positive gastroesophageal adenocarcinoma: an argument for overcoming trastuzumab resistance

AIM

Patients with advanced gastric cancer have a relatively poor prognosis with few therapeutic alternatives beyond first-line therapy. The purpose of this manuscript is to highlight the potential for prolonged responses in patients with HER-2-positive disease. Patients, materials & methods: We analyzed the data of patients diagnosed with HER-2-positive-advanced gastric cancer who progressed on trastuzumab-based combination therapy and subsequently received second-line therapy consisting of ramucirumab in combination with paclitaxel.

RESULTS

Most patients had a stable disease after ramucirumab-based therapy (50%, 5/10), median duration to disease control was 8 months.

CONCLUSION

The prolonged duration of response that we observed indicates that an interaction between the EGF pathway and the angiogenesis pathway requires further clinical investigations.

Superresolution imaging of individual replication forks reveals unexpected prodrug resistance mechanism

Many drugs require extensive metabolism en route to their targets. High-resolution visualization of prodrug metabolism should therefore utilize analogs containing a small modification that does not interfere with its metabolism or mode of action. In addition to serving as mechanistic probes, such analogs provide candidates for theranostics when applied in both therapeutic and diagnostic modalities. Here a traceable mimic of the widely used anticancer prodrug cytarabine (ara-C) was generated by converting a single hydroxyl group to azide, giving "AzC." This compound exhibited the same biological profile as ara-C in cell cultures and zebrafish larvae. Using azide-alkyne "click" reactions, we uncovered an apparent contradiction: drug-resistant cells incorporated relatively large quantities of AzC into their genomes and entered S-phase arrest, whereas drug-sensitive cells incorporated only small quantities of AzC. Fluorescence microscopy was used to elucidate structural features associated with drug resistance by characterizing the architectures of stalled DNA replication foci containing AzC, EdU, γH2AX, and proliferating cell nuclear antigen (PCNA). Three-color superresolution imaging revealed replication foci containing one, two, or three partially resolved replication forks. Upon removing AzC from the media, resumption of DNA synthesis and completion of the cell cycle occurred before complete removal of AzC from genomes in vitro and in vivo. These results revealed an important mechanism for the low toxicity of ara-C toward normal tissues and drug-resistant cancer cells, where its efficient incorporation into DNA gives rise to highly stable, stalled replication forks that limit further incorporation of the drug, yet allow for the resumption of DNA synthesis and cellular division following treatment.

KIAA1199 promotes migration and invasion by Wnt/β-catenin pathway and MMPs mediated EMT progression and serves as a poor prognosis marker in gastric cancer

BACKGROUND

KIAA1199 was upregulated in diverse cancers, but the association of KIAA1199 with gastric cancer (GC), the biological role of KIAA1199 in GC cells and the related molecular mechanisms remain to be elucidated.

METHODS

KIAA1199 expression was analysed by reverse transcription-polymerase chain reaction assay (RT-PCR) and immunohistochemistry (IHC) in GC patient tissue. The small hairpin RNA (shRNA) was applied for the knockdown of endogenous KIAA1199 in NCI-N87 and AGS cells. MTT, colony formation, scratch wounding migration, transwell chamber migration and invasion assays were employed respectively to investigate the role of KIAA1199 in GC cells. The potential signaling pathway of KIAA1199 induced migration and invasion was detected.

RESULTS

KIAA1199 was upregulated in GC tissue and was an essential independent marker for poor prognosis. Knockdown KIAA1199 suppressed the proliferation, migration and invasion in GC cells. KIAA1199 stimulated the Wnt/β-catenin signaling pathway and the enzymatic activity of matrix metalloproteinase (MMP) family members and thus accelerated the epithelial-to-mesenchymal transition (EMT) progression in GC cells.

CONCLUSION

These findings demonstrated that KIAA1199 was upregulated in GC tissue and associated with worse clinical outcomes in GC, and KIAA1199 acted as an oncogene by promoting migration and invasion through the enhancement of Wnt/β-catenin signaling pathway and MMPs mediated EMT progression in GC cells.

Promising immunotherapies for esophageal cancer

INTRODUCTION

Esophageal cancer (EC) is the eighth most common cancer in the world, and the prognosis of EC is still poor. Although immunotherapy has been developed in melanoma and lung cancer, it is also expected to show efficacy in EC. Currently, several clinical trials are ongoing to evaluate the safety and efficacy of immunotherapies, immune checkpoint inhibitors, adoptive T cell transfer, and therapeutic cancer vaccines in EC. Areas covered: This review provides an overview and the status of immunotherapy in EC. Clinical significance of molecules related immune checkpoints, especially PD-1 and PD-L1 is presented and the designs, results and future directions of clinical trials using immunotherapy in EC are provided. Expert opinion: To bring immunotherapy to the forefront of treatment for EC, it is necessary to select patients who can obtain a high efficacy of immunotherapy and to also elucidate the correct timing for administration. Moreover, combination therapies of immunotherapy with existing chemotherapy or radiation or other immunotherapy with different mechanisms of action must be evaluated to achieve excellent outcomes in patients with EC.

MAGI1 inhibits migration and invasion via blocking MAPK/ERK signaling pathway in gastric cancer

OBJECTIVE

To explore the association of membrane-associated guanylate kinase inverted 1 (MAGI1) with gastric cancer (GC) and the related molecular mechanisms.

METHODS

The reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC) were utilized to measure the MAGI1 expression level in GC tissues. Quantitative real-time PCR and Western blotting were used to ensure the MAGI1 expression in GC cell lines. Small hairpin RNA (shRNA) was applied for knockdown of endogenous MAGI1 in GC cells. MTT assay and colony formation assay, scratch wounding migration assay and transwell chamber migration assay, as well as transwell chamber invasion assay were employed respectively to investigate the GC cell proliferation, migration and invasion in MAGI1-knockdown and control GC cells. The potential molecular mechanism mediated by MAGI1 was studied using Western blotting and RT- PCR.

RESULTS

RT-PCR and IHC verified MAGI1 was frequently expressed in matched adjacent noncancerous mucosa compared with GC tissues and the expression of MAGI1 was related to clinical pathological parameters. Functional assays indicated that MAGI1 knockdown significantly promoted GC cell migration and invasion. Further mechanism investigation demonstrated that one pathway of MAGI1 inhibiting migration and invasion was mainly by altering the expression of matrix metalloproteinases (MMPs) and epithelial-mesenchymal transition (EMT)-related molecules via inhibiting MAPK/ERK signaling pathway.

CONCLUSIONS

MAGI1 was associated with GC clinical pathological parameters and acted as a tumor suppressor via inhibiting of MAPK/ERK signaling pathway in GC.