Project description:Pembrolizumab is a monoclonal antibody directed against PD-1 that is US FDA approved for treatment of advanced PD-L1 positive gastric and gastroesophageal junction adenocarcinoma in patients who have progressed on at least two prior lines of chemotherapy. This article summarizes the clinical evidence regarding safety, tolerability and efficacy of pembrolizumab in this setting. In addition, this article describes the investigational use of pembrolizumab as first- and second-line therapy and in combination with other treatments. Finally, this review compares other checkpoint inhibitors to pembrolizumab for the treatment of this disease, and explores predictive biomarkers of response to PD-1 blockade.
Project description:ObjectiveEsophageal adenocarcinoma (EAC) continues to be a disease associated with high mortality. Among the factors leading to poor outcomes are innate resistance to currently available therapies, advanced stage at diagnosis, and complex biology. Platinum and ionizing radiation form the backbone of treatment for the majority of patients with EAC. Of the multiple processes involved in response to platinum chemotherapy or ionizing radiation, deoxyribonucleic acid (DNA) repair has been a major player in cancer sensitivity to these agents. DNA repair defects have been described in various malignancies. The purpose of this study was to determine whether alterations in DNA repair are present in EAC compared with normal gastroesophageal tissues.MethodsWe analyzed the expression of genes involved in homologous recombination (HR), nonhomologous end-joining, and nucleotide excision repair (NER) pathways in 12 EAC tumor samples with their matched normal counterparts. These pathways were chosen because they are the main pathways involved in the repair of platinum- or ionizing-radiation-induced damage. In addition, abnormalities in these pathways have not been well characterized in EAC.ResultsWe identified increased expression of at least one HR gene in eight of the EAC tumor samples. Alterations in the expression of EME1, a structure-specific endonuclease involved in HR, were the most prevalent, with messenger (m)RNA overexpression in six of the EAC samples. In addition, all EAC samples revealed decreased expression of at least one of numerous NER genes including XPC, XPA, DDB2, XPF, and XPG.ConclusionOur study identified DNA repair dysregulation in EAC involving two critical pathways, HR and NER, and is the first demonstration of EME1 upregulation in any cancer. These DNA repair abnormalities have the potential to affect a number of processes such as genomic instability and therapy response, and the consequences of these defects deserve further study in EAC.
Project description:Tumors of the upper gastrointestinal tract are increasing in incidence; yet, approaches to the treatment of advanced gastric and/or gastroesophageal junction cancer vary widely, with no internationally agreed first-line regimens. Recent clinical trials have shown that second-line treatment is now possible for selected patients with advanced disease, and current data suggest that the combination of ramucirumab plus paclitaxel may become a standard of care in the second-line setting for metastatic gastric cancer. Several prognostic factors have been identified for overall survival in the second-line setting; this emphasizes the need for careful sequencing of all treatments to ensure that individual patients receive optimum care. This article reviews published data on the treatment of advanced gastric cancer, with a particular emphasis on second-line chemotherapy, and suggests treatment sequences based on current understanding.
Project description:Recently, the global incidence of gastric/gastroesophageal junction (G/GEJ) cancer has remained high. China is also a large country with a high gastric cancer (GC) incidence rate, where the cases of GC account for 40% of all cases worldwide. More than 90% of GEJ cancers are the adenocarcinoma pathological type. Patients with early-stage G/GEJ adenocarcinoma may have a better prognosis after surgery. In contrast, patients with advanced metastatic G/GEJ adenocarcinoma usually choose comprehensive treatment based on systemic pharmacotherapy, but the subsequent long-term survival is not optimistic. The discovery of various biomarkers, especially microsatellite instability (MSI), programmed cell death-ligand 1 (PD-L1), human epidermal growth factor receptor 2 (HER2), tumor mutational burden (TMB) and Epstein-Barr virus (EBV), has led to the identification of an increasing number of targeted populations and has greatly improved the clinical efficacy of treatments for G/GEJ adenocarcinoma. The ToGA trial added trastuzumab to standard chemotherapy, showed improved survival of patients with HER2-positive advanced G/GEJ adenocarcinoma and brought these patients into a new era of HER2-targeted therapy. Moreover, many HER2-targeted agents have been developed and studied in patients with advanced HER2-positive G/GEJ adenocarcinoma who have demonstrated excellent clinical outcomes. However, many patients experience disease progression with HER2-targeted therapy; hence, new anti-HER2 drugs keep being developed, significantly reducing HER2 resistance. This paper reviews HER2-targeted drugs for advanced metastatic G/GEJ adenocarcinoma, potential resistance mechanisms and future directions.
Project description:The poor survival of adenocarcinomas of the gastroesophageal junction (GEJ) makes them clinically important. Discovery of host genetic factors that affect outcome may guide more individualized treatment. This study tests whether constitutional genetic variants in matrix metalloproteinases (MMP) and tissue inhibitors of metalloproteinases (TIMP) genes are associated with outcome of GEJ adenocarcinoma. Single nucleotide polymorphisms (SNPs) at four TIMP (TIMP1-4) and three MMP genes (MMP2, MMP7 and MMP9) were genotyped in DNA samples from a prospective cohort of patients with primary adenocarcinoma of the GEJ admitted to the British Columbia Cancer Agency. Cox proportional hazards regression, with adjustment for patient, disease and treatment variables, was used to estimate the association of SNPs with survival. Genotypes for 85 samples and 48 SNPs were analyzed. Four SNPs across TIMP3, (rs130274, rs715572, rs1962223 and rs5754312) were associated with survival. Interaction analyses revealed that the survival associations with rs715572 and rs5754312 are specific and significant for 5FU+cisplatin treated patients. Sanger sequencing of the TIMP3 coding and promoter regions revealed an additional SNP, rs9862, also associated with survival. TIMP3 genetic variants are associated with survival and may be potentially useful in optimizing treatment strategies for individual patients.
Project description:Current guidelines recommend two-drug cytotoxic chemotherapy with a fluoropyrimidine (fluorouracil or capecitabine) and a platinum-based agent (oxaliplatin or cisplatin) as first-line treatment for advanced gastric cancer. Pembrolizumab monotherapy has demonstrated durable antitumor activity in patients with advanced programmed death ligand 1-positive (combined positive score ≥1) gastric/gastroesophageal junction adenocarcinoma. Accumulating evidence indicates that combining pembrolizumab with standard-of-care chemotherapy for the treatment of advanced or metastatic cancer improves clinical outcomes. We describe the rationale for and the design of the randomized, double-blind, placebo-controlled, Phase III KEYNOTE-859 study, which is investigating pembrolizumab in combination with chemotherapy as first-line treatment for patients with human epidermal growth factor receptor 2-negative advanced unresectable or metastatic gastric/gastroesophageal junction adenocarcinoma. The planned sample size is 1542 patients, and the primary end point is overall survival. Clinical trial registration: NCT03675737 (ClinicalTrials.gov).
Project description:Background and aims: The aim of this study was to analyze the molecular characteristics of adenocarcinoma of the gastroesophageal junction (AGEJ) compared to esophageal (EAC) and gastric adenocarcinomas (GCFB) from The Cancer Genome Atlas (TCGA) and Seoul National University (SNU) cohorts using next-generation sequencing. Methods: Based on mRNA expression of EAC (n=78) and GCFB (n=102) from the TCGA cohort, a molecular classification model using the Bayesian compound covariate predictor classified AGEJ/cardia (n=48) from the TCGA cohort and AGEJ/upper third gastric adenocarcinoma (n=46) from the SNU cohort into the EAC-like or GCFB-like groups. The molecular characteristics between the EAC-like and GCFB-like groups were compared.
Project description:Gastric cancer is a leading cause of cancer-related death worldwide. Recent evidence suggests that gastric cancer is a complex and heterogenous disease with emerging subtypes shown to affect response to treatment and survival. Immunotherapy is an advancing field and immune checkpoint inhibitors have become standard treatment options in numerous tumor types. In this review, we discuss the current and evolving use of checkpoint blockade, focusing on the anti-PD-1 inhibitor, pembrolizumab, for use in advanced gastric and gastroesophageal cancers.
Project description:Opinion statementGastric and gastroesophageal junction (GEJ) cancers represent the third leading cause of malignancy-associated death worldwide. Approximately 15-20% of these adenocarcinomas overexpress the human epidermal growth factor receptor 2 (HER2), a pro-proliferative receptor tyrosine kinase that has been therapeutically exploited in other disease contexts. The landmark ToGA trial demonstrated that trastuzumab, an anti-HER2 antibody, could improve overall survival for patients with HER2 overexpressing advanced gastric and GEJ adenocarcinomas. In the ensuing decade, great effort has been made to refine and expand this therapeutic strategy through a variety of avenues including optimization of chemotherapy backbones, identifying potential synergy with immune checkpoint inhibition, deployment of alternative HER2-targeted antibodies, use of small molecule inhibitors, and development of HER2-directed antibody drug conjugates. While the results of these efforts have had variable success, they have led to a greater understanding of the mechanisms of both primary and acquired resistance to HER2-directed therapies, laying the groundwork for future investigations. Recently, KEYNOTE-811 and DESTINY-Gastric01 have led to the FDA approvals of pembrolizumab in combination with trastuzumab and chemotherapy in the 1st-line advanced setting and trastuzumab deruxtecan (fam-trastuzumab deruxtecan-nxki) in the 2nd-line setting, respectively. Herein, we review these significant works as well as discuss the ongoing investigations they have inspired, which aim to find and utilize additional means for targeting HER2 in gastric and GEJ cancers.