HER2 gene assessment in liquid biopsy of gastric and esophagogastric junction cancer patients qualified for surgery

Circulating miRNA and circulating tumor DNA application as liquid biopsy markers in gastric cancer

Liquid biopsy has been investigated as a novel method to overcome the numerous challenges in gastric cancer (GC) management. This non-invasive, feasible, and easy-to-repeat method has been shown to be cost-effective and capable of increasing diagnostic sensitivity and prognostic assessment. Additionally, it is potentially accurate to aid decision-making and personalized treatment planning. MicroRNA (miRNA) and circulating tumor DNA (ctDNA) markers can enhance GC management in various aspects, including diagnosis (mainly earlier diagnosis and the ability to perform population-based screening), prognosis (more precise stratification of prognosis), and treatment (including more accurate prediction of treatment response and earlier detection of resistance to the treatment). Concerning the treatment-related application, miRNAs' mimics and antagonists (by using two main strategies of restoring tumor suppressor miRNAs and inhibiting oncogene miRNAs) have been shown to be effective therapeutic agents. However, these need to be further validated in clinical trials. Furthermore, novel delivery systems, such as lipid-based vectors, polymeric-based vectors, and exosome-based delivery, have been developed to enhance the performance of these agents. Moreover, this paper explores the current detection and measuring methods for these markers. These approaches are categorized into direct methods (e.g., Chem-NAT, HTG EdgeSeq, and Multiplex Circulating Fireplex) and indirect methods (e.g., Reverse transcription-quantitative polymerase chain reaction (RT-qPCR), qPCR, microarray, and NGS) for miRNA detection. For ctDNA measurement, main core technologies like NGS, digital PCR, real-time PCR, and mass spectrometry are suggested.

Comprehensive genomic profiling of small bowel adenocarcinoma by tissue and plasma biopsy

Small bowel adenocarcinoma (SBA) is a rare and aggressive malignancy with limited treatment options and poor prognosis. The molecular landscape and immunological characteristics of SBA are poorly understood. Here, we performed comprehensive mutation profiling of tissue and plasma biopsies from 143 and 42 patients with SBA. Analysis showed that SBA had a distinct mutation spectrum from left- and right-sided colorectal carcinoma. Plasma biopsy had high concordance with tissue biopsy for single nucleotide variants and structural variants, but low concordance for copy number variations, which showed that plasma biopsy can be an alternative to tissue biopsy. Moreover, we analyzed the association of TMB with clinical and molecular features, and found that TMB was significantly higher in tumors with DNA damage response alterations. Our findings provide valuable insights into the molecular and immunological features of SBA and demonstrate the potential of plasma biopsy as a non-invasive method for SBA diagnosis and treatment.

Perspective on receptor-associated immune response to Candida albicans single and mixed infections: Implications for therapeutics in oropharyngeal candidiasis

Oropharyngeal candidiasis (OPC), commonly known as 'thrush', is an oral infection that usually dismantles oral mucosal integrity and malfunctions local innate and adaptive immunities in compromised individuals. The major pathogen responsible for the occurrence and progression of OPC is the dimorphic opportunistic commensal Candida albicans. However, the incidence induced by non-albicans Candida species including C. glabrata, C. tropicalis, C. dubliniensis, C. parapsilosis, and C. krusei are increasing in company with several oral bacteria, such as Streptococcus mutans, S. gordonii, S. epidermidis, and S. aureus. In this review, the microbiological and infection features of C. albicans and its co-contributors in the pathogenesis of OPC are outlined. Since the invasion and concomitant immune response lie firstly on the recognition of oral pathogens through diverse cellular surface receptors, we subsequently emphasize the roles of epidermal growth factor receptor, ephrin-type receptor 2, human epidermal growth factor receptor 2, and aryl hydrocarbon receptor located on oral epithelial cells to delineate the underlying mechanism by which host immune recognition to oral pathogens is mediated. Based on these observations, the therapeutic approaches to OPC comprising conventional and non-conventional antifungal agents, fungal vaccines, cytokine and antibody therapies, and antimicrobial peptide therapy are finally overviewed. In the face of newly emerging life-threatening microbes (C. auris and SARS-CoV-2), risks (biofilm formation and interconnected translocation among diverse organs), and complicated clinical settings (HIV and oropharyngeal cancer), the research on OPC is still a challenging task.

Targeted and Immunotherapy Approaches in HER2-Positive Gastric and Gastroesophageal Junction Adenocarcinoma: A New Era

HER2-targeted therapy with the HER2 monoclonal antibody trastuzumab has achieved impressive outcomes in the first-line settings of patients with advanced gastric and gastroesophageal junction (GEJ) adenocarcinoma overexpressing HER2. However, considering that a substantial proportion of those patients eventually relapses, as well as the relatively limited performance of those agents in second-line settings, a deeper understanding of resistance mechanisms is needed for enhanced guidance for patients' therapeutic selection in the second-line setting and beyond. In this review, we highlight trastuzumab's (HER2-targeting agent) performance in patients with gastric or GEJ cancer, with insight into mechanisms of resistance. We also discuss the new integration of PD-1 inhibitor pembrolizumab into the trastuzumab for gastric cancer frontline regimen, the latest addition of trastuzumab deruxtecan to the treatment armamentarium, and the potential of pipeline HER2-targeting approaches and combinations in patients with gastric or GEJ adenocarcinoma.

Validation of the Labcorp Plasma Focus Test to Facilitate Precision Oncology Through Cell-Free DNA Genomic Profiling of Solid Tumors

Genomic profiling is critical for precision oncology to guide treatment decisions. Liquid biopsy testing is a complementary approach to tissue testing, particularly when tissue is not readily available. The Labcorp Plasma Focus test is a circulating cell-free DNA genomic profiling test that identifies actionable variants in solid cancers, including non-small-cell lung, colorectal, melanoma, breast, esophageal, gastroesophageal junction, and gastric cancers. This study highlights the analytical validation of the test, including accuracy compared with orthogonal methods, as well as sensitivity, specificity, precision, reproducibility, and repeatability. Concordance with orthogonal methods showed percent positive agreement of 98.7%, 89.3%, and 96.2% for single nucleotide variants (SNVs), insertion/deletions (indels), and copy number amplifications (CNAs), respectively, and 100.0% for translocations and microsatellite instability (MSI). Analytical sensitivity revealed a median limit of detection of 0.7% and 0.6% for SNVs and indels, 1.4-fold for CNAs, 0.5% variant allele frequency for translocations, and 0.6% for MSI. Specificity was >99% for SNVs/indels and 100% for CNAs, translocations, and MSI. Average positive agreement from precision, reproducibility, and repeatability experiments was 97.5% and 88.9% for SNVs/indels and CNAs, and 100% for translocations and MSI. Taken together, these data show that the Labcorp Plasma Focus test is a highly accurate, sensitive, and specific approach for cell-free DNA genomic profiling to supplement tissue testing and inform treatment decisions.

Circulating Tumor DNA in Gastric Adenocarcinoma: Future Clinical Applications and Perspectives

Gastric cancer (GC) is still one of the most aggressive cancers with a few targetable alterations and a dismal prognosis. A liquid biopsy allows for identifying and analyzing the DNA released from tumor cells into the bloodstream. Compared to tissue-based biopsy, liquid biopsy is less invasive, requires fewer samples, and can be repeated over time in order to longitudinally monitor tumor burden and molecular changes. Circulating tumor DNA (ctDNA) has been recognized to have a prognostic role in all the disease stages of GC. The aim of this article is to review the current and future applications of ctDNA in gastric adenocarcinoma, in particular, with respect to early diagnosis, the detection of minimal residual disease (MRD) following curative surgery, and in the advanced disease setting for treatment decision choice and therapeutic monitoring. Although liquid biopsies have shown potentiality, pre-analytical and analytical steps must be standardized and validated to ensure the reproducibility and standardization of the procedures and data analysis methods. Further research is needed to allow the use of liquid biopsy in everyday clinical practice.

Novel biomarkers for early detection of gastric cancer

Gastric cancer (GC) remains a leading cause of cancer-related death worldwide. Less than half of GC cases are diagnosed at an advanced stage due to its lack of early symptoms. GC is a heterogeneous disease associated with a number of genetic and somatic mutations. Early detection and effective monitoring of tumor progression are essential for reducing GC disease burden and mortality. The current widespread use of semi-invasive endoscopic methods and radiologic approaches has increased the number of treatable cancers: However, these approaches are invasive, costly, and time-consuming. Thus, novel molecular noninvasive tests that detect GC alterations seem to be more sensitive and specific compared to the current methods. Recent technological advances have enabled the detection of blood-based biomarkers that could be used as diagnostic indicators and for monitoring postsurgical minimal residual disease. These biomarkers include circulating DNA, RNA, extracellular vesicles, and proteins, and their clinical applications are currently being investigated. The identification of ideal diagnostic markers for GC that have high sensitivity and specificity would improve survival rates and contribute to the advancement of precision medicine. This review provides an overview of current topics regarding the novel, recently developed diagnostic markers for GC.

The Role of ctDNA in Gastric Cancer

Simple Summary

DNA release from tumour cells (call circulating tumour DNA) into the blood stream can be found in patients with gastric cancer through a blood test call a liquid biopsy. This less invasive test can assess the genetic make-up of tumours to provide important information on the mechanisms of cancer development, identify mutations which can be targeted with drugs and could be used to screen for patients with gastric cancer. This article will review the current and future uses of liquid biopsies in gastric cancer.

Abstract

Circulating tumour DNA (ctDNA) has potential applications in gastric cancer (GC) with respect to screening, the detection of minimal residual disease (MRD) following curative surgery, and in the advanced disease setting for treatment decision making and therapeutic monitoring. It can provide a less invasive and convenient method to capture the tumoural genomic landscape compared to tissue-based next-generation DNA sequencing (NGS). In addition, ctDNA can potentially overcome the challenges of tumour heterogeneity seen with tissue-based NGS. Although the evidence for ctDNA in GC is evolving, its potential utility is far reaching and may shape the management of this disease in the future. This article will review the current and future applications of ctDNA in GC.

Circulating Natural Autoantibodies to HER2-Derived Peptides Performed Antitumor Effects on Oral Squamous Cell Carcinoma

Natural autoantibodies play a crucial role in destruction of malignant tumors due to immune surveillance function. Epidermal growth factor receptor 2 (HER2) has been found to be highly expressed in a variety of epithelial tumors including oral squamous cell carcinoma (OSCC). The present study was thus undertaken to investigate the effect of anti-HER2 natural autoantibodies on OSCC. Compared with cancer-adjacent tissues, cancer tissues from OSCC patients exhibited higher HER2 expression especially in those with middle & advanced stage OSCC. Plasma anti-HER2 IgG levels examined with an enzyme-linked immunosorbent assay (ELISA) developed in-house showed differences between control subjects, individuals with oral benign tumor and patients with OSCC. In addition, anti-HER2 IgG-abundant plasma was screened from healthy donors to treat OSCC cells and to prepare for anti-HER2 intravenous immunoglobulin (IVIg). Both anti-HER2 IgG-abundant plasma and anti-HER2 IVIg could significantly inhibit proliferation and invasion of OSCC cells by inducing the apoptosis, and also regulate apoptosis-associated factors and epithelial-mesenchymal transition (EMT), respectively. Besides, the complement-dependent cytotoxicity (CDC) pathway was likely to contribute to the anti-HER2 IgG mediated inhibition of OSCC cells. After the HER2 gene was knocked down with HER2-specific siRNAs, the inhibitory effects on OSCC cell proliferation and apoptotic induction faded away. In conclusion, human plasma IgG, or IVIg against HER2 may be a promising agent for anti-OSCC therapy.

Clinical Applications of Liquid Biopsy in Gastric Cancer

Liquid biopsy represents an exciting new area in the field of cancer diagnosis and management, offering a less invasive and more convenient approach to obtain a time-point image of the tumor burden and its genomic profile. Samples collected from several body fluids, mostly blood, can be used to gain access to circulating tumor cells and DNA, non-coding RNAs, microRNAs, and exosomes, at any moment, offering a dynamic picture of the tumor. For patients with GC, the use of blood-based biopsies may be particularly beneficial since tissue biopsies are difficult to obtain and cause real distress to the patient. With advantages such as repeatability and minimal invasion, it is no wonder that the field of liquid biopsy has received tremendous attention. However, the abundance of studies, involving a wide range of assays with different principles, prevented for the moment the reproducibility of the results and therefore the translation into the clinic of liquid biopsy. In this review, we present the latest technical development and data on circulating biomarkers available through liquid biopsy in gastric cancer with an emphasis on their clinical utility in areas such as cancer screening, prognostic stratification, and therapeutic management.