Towards precision oncology for HER2 blockade in gastroesophageal adenocarcinoma.

Gastroesophageal adenocarcinoma (GEA) represents a very heterogeneous disease and patients in advanced stages have a very poor prognosis. Although several molecular classifications have been proposed, precision medicine for HER2-amplified GEA patients still represents a challenge. Despite improvement in clinical outcomes obtained by adding trastuzumab to first-line platinum-based chemotherapy, no other anti-HER2 agents used first-line or beyond progression have demonstrated any benefit. Several factors contribute to this failure. Among them, variable HER2 amplification assessment, tumour heterogeneity, molecular mechanisms of resistance and microenvironmental factors could limit the effectiveness of anti-HER2 blockade. Identifying the factors responsible for both primary and acquired resistance is a priority for providing an improved, personalised approach. In this review, we examine current treatments for HER2-amplified GEA, their potential mechanisms of resistance and the ways to overcome them, investigating the most relevant translational studies with anti-HER2 agents in GEA, as well as novel agents under development in this field.

Targeted next-generation sequencing of circulating-tumor DNA for tracking minimal residual disease in localized colon cancer.

BACKGROUND: A high percentage of patients diagnosed with localized colon cancer (CC) will relapse after curative treatment. Although pathological staging currently guides our treatment decisions, there are no biomarkers determining minimal residual disease (MRD) and patients are at risk of being undertreated or even overtreated with chemotherapy in this setting. Circulating-tumor DNA (ctDNA) can to be a useful tool to better detect risk of relapse. PATIENTS AND METHODS: One hundred and fifty patients diagnosed with localized CC were prospectively enrolled in our study. Tumor tissue from those patients was sequenced by a custom-targeted next-generation sequencing (NGS) panel to characterize somatic mutations. A minimum variant allele frequency (VAF) of 5% was applied for variant filtering. Orthogonal droplet digital PCR (ddPCR) validation was carried out. We selected known variants with higher VAF to track ctDNA in the plasma samples by ddPCR. RESULTS: NGS found known pathological mutations in 132 (88%) primary tumors. ddPCR showed high concordance with NGS (r = 0.77) for VAF in primary tumors. Detection of ctDNA after surgery and in serial plasma samples during follow-up were associated with poorer disease-free survival (DFS) [hazard ratio (HR), 17.56; log-rank P = 0.0014 and HR, 11.33; log-rank P = 0.0001, respectively]. Tracking at least two variants in plasma increased the ability to identify MRD to 87.5%. ctDNA was the only significantly independent predictor of DFS in multivariable analysis. In patients treated with adjuvant chemotherapy, presence of ctDNA after therapy was associated with early relapse (HR 10.02; log-rank P < 0.0001). Detection of ctDNA at follow-up preceded radiological recurrence with a median lead time of 11.5 months. CONCLUSIONS: Plasma postoperative ctDNA detected MRD and identified patients at high risk of relapse in localized CC. Mutation tracking with more than one variant in serial plasma samples improved our accuracy in predicting MRD.

Complications of hyperglycaemia with PI3K-AKT-mTOR inhibitors in patients with advanced solid tumours on Phase I clinical trials.

BACKGROUND: PI3K-AKT-mTOR inhibitors (PAMi) are promising anticancer treatments. Hyperglycaemia is a mechanism-based toxicity of these agents and is becoming increasingly important with their use in larger numbers of patients. METHODS: Retrospective case-control study comparing incidence and severity of hyperglycaemia (all grades) between a case group of 387 patients treated on 18 phase I clinical trials with PAMi (78 patients with PI3Ki, 138 with mTORi, 144 with AKTi and 27 with PI3K/mTORi) and a control group of 109 patients treated on 10 phase I clinical trials with agents not directly targeting the PAM pathway. Diabetic patients were excluded in both groups. RESULTS: The incidence of hyperglycaemia was not significantly different between cases and controls (86.6% vs 80.7%, respectively, P=0.129). However, high grade (grade 3-4) hyperglycaemia was more frequent in the PAMi group than in controls (6.7% vs 0%, respectively, P=0.005). The incidence of grade 3-4 hyperglycaemia was greater with AKT and multikinase inhibitors compared with other PAMi (P<0.001). All patients with high-grade hyperglycaemia received antihyperglycemic treatment and none developed severe metabolic complications (diabetic ketoacidosis or hyperosmolar hyperglycemic nonketotic state). High-grade hyperglycaemia was the cause of permanent PAMi discontinuation in nine patients. CONCLUSIONS: PI3K-AKT-mTOR inhibitors are associated with small (6.7%) but statistically significant increased risk of high-grade hyperglycaemia compared with non-PAM targeting agents. However, PAMi-induced hyperglycaemia was not found to be associated with severe metabolic complications in this non-diabetic population of patients with advanced cancers.

The new method of ZnIn2S4 synthesis on the titania nanotubes substrate with enhanced stability and photoelectrochemical performance.

In this work, ZnIn2S4 layers were obtained on fluorine doped tin oxide (FTO) glass and TiO2 nanotubes (TiO2NT) using a hydrothermal process as photoanodes for photoelectrochemical (PEC) water splitting. Then, samples were annealed and the effect of the annealing temperature was investigated. Optimization of the deposition process and annealing of ZnIn2S4 layers made it possible to obtain an FTO-based material generating a photocurrent of 1.2 mA cm-2 at 1.62 V vs. RHE in a neutral medium. In contrast, the highest photocurrent in the neutral electrolyte obtained for the TiO2NT-based photoanode reached 0.5 mA cm-2 at 1.62 V vs. RHE. In addition, the use of a strongly acidic electrolyte allowed the generated photocurrent by the TiO2NT-based photoanode to increase to 3.02 mA cm-2 at 0.31 V vs. RHE. Despite a weaker photoresponse in neutral electrolyte than the optimized FTO-based photoanode, the use of TiO2NT as a substrate allowed for a significant increase in the photoanode's operating time. After 2 h of illumination, the photocurrent response of the TiO2NT-based photoanode was 0.21 mA cm-2, which was 42% of the initial value. In contrast, the FTO-based photoanode after the same time generated a photocurrent of 0.02 mA cm-2 which was only 1% of the initial value. The results indicated that the use of TiO2 nanotubes as a substrate for ZnIn2S4 deposition increases the photoanode's long-term stability in photoelectrochemical water splitting. The proposed charge transfer mechanism suggested that the heterojunction between ZnIn2S4 and TiO2 played an important role in improving the stability of the material by supporting charge separation.

Sequencing paired tumor DNA and white blood cells improves circulating tumor DNA tracking and detects pathogenic germline variants in localized colon cancer.

BACKGROUND: In the setting of localized colon cancer (CC), circulating tumor DNA (ctDNA) monitoring in plasma has shown potential for detecting minimal residual disease (MRD) and predicting a higher risk of recurrence. With the tumor-only sequencing approach, however, germline variants may be misidentified as somatic variations, precluding the possibility of tracking in up to 11% of patients due to a lack of known somatic mutations. In this study, we assess the potential value of adding white blood cells (WBCs) to tumor tissue sequencing to enhance the accuracy of sequencing results. PATIENTS AND METHODS: A total of 148 patients diagnosed with localized CC were prospectively recruited at the Hospital Clínico Universitario in Valencia (Spain). Employing a custom 29-gene panel, sequencing was conducted on tumor tissue, plasma and corresponding WBCs. Droplet digital PCR and amplicon-based NGS were performed on plasma samples post-surgery to track MRD. Oncogenic somatic variants were identified by annotating with COSMIC, OncoKB and an internal repository of pathogenic mutations database. A variant prioritization analysis, mainly characterized by the match of oncogenic mutations with the evidence levels defined in OncoKB, was carried out to select specific targeted therapies. RESULTS: Utilizing paired tumor and WBCs sequencing, we identified somatic mutations in all patients (100%) within our cohort, compared to 89% using only tumor tissue. Consequently, the top 10 most frequently mutated genes for plasma monitoring were altered. The sequencing of WBCs identified 9% of patients with pathogenic mutations in the germline, with APC and TP53 being the most frequently mutated genes. Additionally, mutations in genes related to clonal hematopoiesis of indeterminate potential were detected in 27% of the cohort, with TP53, KRAS, and KMT2C being the most frequently altered genes. There were no observed differences in the sensitivity of monitoring MRD using ddPCR or amplicon-based NGS (p = 1). Ultimately, 41% of the patients harbored potentially targetable alterations at diagnosis. CONCLUSION: The germline testing method not only enhanced sequencing results and raised the proportion of patients eligible for plasma monitoring, but also uncovered the existence of pathogenic germline variations, thereby aiding in the identification of patients at a higher risk of hereditary cancer syndromes.

The role of tumor-associated macrophages in gastric cancer development and their potential as a therapeutic target.

Gastric cancer (GC) represents the fifth cause of cancer-related death worldwide. Molecular biology has become a central area of research in GC and there are currently at least three major classifications available to elucidate the mechanisms that drive GC oncogenesis. Further, tumor microenvironment seems to play a crucial role, and tumor-associated macrophages (TAMs) are emerging as key players in GC development. TAMs are cells derived from circulating chemokine- receptor-type 2 (CCR2) inflammatory monocytes in blood and can be divided into two main types, M1 and M2 TAMs. M2 TAMs play an important role in tumor progression, promoting a pro-angiogenic and immunosuppressive signal in the tumor. The diffuse GC subtype, in particular, seems to be strongly characterized by an immuno-suppressive and pro-angiogenic phenotype. No molecular targets in this subgroup have yet been identified. There is an urgent need to understand the molecular pathways and tumor microenvironment features in the GC molecular subtypes. The role of anti-angiogenics and checkpoint inhibitors has recently been clinically validated in GC. Both ramucirumab, a fully humanized IgG1 monoclonal anti-vascular endothelial growth factor receptor 2 (VEGFR2) antibody, and checkpoint inhibitors in Epstein Bar Virus (EBV) and Microsatellite Instable (MSI) subtypes, have proved beneficial in advanced GC. Nevertheless, there is a need to identify predictive markers of response to anti-angiogenics and immunotherapy in clinical practice for a personalized treatment approach. The importance of M2 TAMs in development of solid tumors is currently gaining increasing interest. In this literature review we analyze immune microenvironment composition and signaling related to M1 and M2 TAMs in GC as well as its potential role as a therapeutic target.

EPDR1 up-regulation in human colorectal cancer is related to staging and favours cell proliferation and invasiveness.

The finding of novel molecular markers for prediction or prognosis of invasiveness in colorectal cancer (CRC) constitutes an appealing challenge. Here we show the up-regulation of EPDR1 in a prospective cohort of 101 CRC patients, in a cDNA array of 43 patients and in in silico analyses. EPDR1 encodes a protein related to ependymins, a family of glycoproteins involved in intercellular contacts. A thorough statistical model allowed us to conclude that the gene is significantly up-regulated in tumour tissues when compared with normal mucosa. These results agree with those obtained by the analysis of three publicly available databases. EPDR1 up-regulation correlates with the TNM staging parameters, especially T and M. Studies with CRC cell lines revealed that the methylation of a CpG island controls EPDR1 expression. siRNA knocking-down and overexpression of the gene following transient plasmid transfection, showed that EPDR1 favours cell proliferation, migration, invasiveness and adhesion to type I collagen fibres, suggesting a role in epithelial to mesenchymal transition. Both statistical and functional analysis correlated EPDR1 overexpression with invasiveness and dissemination of tumour cells, supporting the inclusion of EPDR1 in panels of genes used to improve molecular subtyping of CRC. Eventually, EPDR1 may be an actionable target.

Characterization of Epstein-Barr virus-infected cells in benign lymphadenopathy of patients seropositive for human immunodeficiency virus.

The authors investigated 25 benign lymph nodes in patients infected with the human immunodeficiency virus (HIV) by in situ hybridization (ISH) and immunohistochemistry (IHC) to detect and characterize the Epstein-Barr virus (EBV)-infected cells. After ISH, 22 lymph nodes were found to contain various numbers of Epstein-Barr-encoded RNA (EBER)-positive cells. Most of these cells were B cells. In six lymph nodes with numerous EBV-infected cells, EBNA2-positive/LMP1-positive lymphoblastoid cells were detected by IHC. Exceptional cells (in two specimens) were positively labeled with antigen-Z Epstein-Barr replicative activator (ZEBRA) antibody or BamHI Left Frame 1/Not I (BHLF1/Not I) probes, indicating that EBV replication is not enhanced in the lymphocytes. In normal conditions (healthy individuals), small lymphocytes that express a restricted pattern of viral genes do escape immune response, whereas lymphoblastoid cells do not. Thus, impaired immune system may account for the late proliferation of lymphoblastoid cells (Epstein-Barr nuclear antigen [EBNA]2positive/latent membrane protein [LMP]1 positive) in HIV-infected patients, and could explain why EBV-driven, acquired immunodeficiency syndrome (AIDS)-related, non-Hodgkin's lymphoma occur more frequently in patients with low CD4-positive T cells.

[Detection of residual disease in follicular lymphomas using the PCR technique: importance of clono-specific probes]. / Détection de la maladie résiduelle dans les lymphomes folliculaires par la technique de PCR: intérêt des sondes clono-spécifiques.

Follicular lymphoma constitutes 30-40% of non-Hodgkin's lymphomas. Most patients have widespread disease at diagnosis. The clinical course is generally indolent, and it is not usually curable with available treatment. The source of relapse in patients who achieve complete clinical remission is residual neoplastic cells that are present below the limits of detection using standard techniques. With the development of PCR technology, the presence of these residual malignant cells [Minimal Residual Disease (MRD)] has been demonstrated clearly. Recently, an association of high-dose chemotherapy with autologous bone marrow or peripheral blood progenitor cell autograft appeared promising in the treatment of these lymphomas. In the search of clonal markers for the detection of MRD in follicular lymphomas, two strategies can be used. In the cases associated with the t(14;18) (q32;q21) chromosomal translocation, the bcl-2/JH junctional regions are amplified by PCR in approximately equal to 50% of cases and then sequenced in order to synthesize an anti-junction oligonucleotide probe specific for each patient's malignant clone (clonospecific probe). In the cases negative for this translocation, an alternative strategy consists in the amplification of immunoglobulin high chain (IgH) gene rearrangement (approximately equal to 75% of cases). The present review highlights the value of molecular markers such as bcl-2/JH and VH/JH rearrangements to follow the neoplastic clone and to detect MRD in patients with follicular lymphomas.

Current questions for the treatment of advanced gastric cancer.

BACKGROUND: Gastric cancer remains a major health problem worldwide. Treatment of advanced gastric cancer is controversial and there is no standard regimen for first- or second-line chemotherapy (CT). This review aims to give an overview of the hot topics concerning treatment, prognostic factors and new strategies in advanced gastric cancer. MATERIAL AND METHODS: Seven questions of special clinical interest have been formulated previously to the literature review. With the aim of answering each of these questions, a specific search of the relevant trials and meta-analyses published or communicated from 1990 to date was performed. RESULTS: Patients treated with CT have a survival benefit over those treated with only best supportive care (BSC). Such active cytotoxic drugs as cisplatin or docetaxel and targeted agents as trastuzumab showed superiority in randomized trials. Other agents such as oxaliplatin, oral fluoropyrimidines and irinotecan showed non-inferiority or less toxic results, positioning them as valuable alternatives to classical schedules. Combination regimens seem to be an improvement over single agent therapy. However, increased toxicity of some regimens makes their general use difficult. Second-line CT is of value for selected patients with good performance status. Trastuzumab is the only targeted agent showing better survival when added to chemotherapy in HER2-driven tumors. CONCLUSIONS: With the introduction of new agents, management of advanced gastric cancer has experienced important changes. First and second-line CT improve survival in patients with good performance status. Future trials should address how to better select patients for new, targeted agents, based upon validated predictive biomarkers.

Kaposi's sarcoma-associated herpesvirus (KSHV) in bone marrow biopsies of patients with Waldenstrom's macroglobulinaemia.

Kaposi's sarcoma-associated herpesvirus (KSHV) is suspected to play a role in the aetiology of multiple myeloma. Because of similarities in the pathophysiology of multiple myeloma and Waldenstrom's macroglobulinaemia (WM), we investigated DNA samples from 20 bone marrow biopsies with WM for the detection of KSHV by PCR (KS330/ORF26). We performed two rounds of amplification and found that only 1/20 of the DNA samples obtained from biopsies had a detectable KSHV sequence. The positive patient was also infected by the human immunodeficiency virus (HIV). Our data provide evidence that KSHV cannot be implicated in the pathogenesis of WM.