Differential Expression Profiles of Oxidative Stress Levels, 8-oxo-dG and 4-HNE, in Barrett's Esophagus Compared to Esophageal Adenocarcinoma.

Barrett's esophagus (BE), a chronic inflammatory condition, is the leading risk factor for esophageal adenocarcinoma (EAC). In inflammation to cancer pathways, oxidative stress profiles have been linked to cancer progression. However, the relevance of oxidative stress profiles along the BE-disease sequence remains to be elucidated. In this study, markers of oxidative stress; DNA adducts (8-oxo-dG) and lipoperoxidation (4-HNE), and markers of proliferation (Ki67) were measured in patient biopsies representing the BE-disease sequence. Differences in expression of these markers in Barrett's patients with cancer-progression and non-progression were examined. Proliferation was reduced in Barrett's specialized intestinal metaplasia (SIM) compared with EAC (p < 0.035). Correcting for cell proliferation levels, a confounding factor, linked to oxidative stress profiles, SIM demonstrated increased levels of 8-oxo-dG and 4-HNE (p < 0.05) compared with EAC. Longitudinal analysis of Barrett's patients demonstrated decreased levels of 8-oxo-dG in SIM cancer progression (p < 0.05). BE is an environment of increased oxidative stress and inflammation. Patients with progressive disease demonstrated reduced oxidative stress levels in 8-oxo-dG. Perhaps these alterations facilitate Barrett's progression, whereas in non-progressive disease, cells follow the rules of increased oxidative stress ultimately triggers cell apoptosis, thereby preventing propagation and survival.

Barrett's to oesophageal cancer sequence: a model of inflammatory-driven upper gastrointestinal cancer.

Cancer-related inflammation is considered the 'seventh hallmark of cancer'; many studies show that tumours develop and progress within inflammatory diseases. This review focuses on Barrett's oesophagus, a common condition in which chronic inflammation and resulting alterations in the stroma can lead to carcinogenesis, specifically oesophageal adenocarcinoma. Changes that occur in the tissue microenvironment during development of this disease are discussed. Infiltration of immune cells facilitates tumour development through production of factors that promote carcinogenesis and by enabling tumours to evade the host immune response. Small molecules including cytokines, chemokines and growth factors play key roles in both inflammation and cancer by promoting proliferation, angiogenesis and carcinogenesis and by recruiting immune cells. The extracellular matrix is altered in inflammation, and provides structural support to developing tumours. Hypoxia is a common state in cancers and inflamed tissues which causes DNA damage and induces tumourigenic factors. Finally, tissue vasculature is a vital part of its microenvironment, supplying oxygen, nutrients and growth factors to rapidly dividing cells, and providing a mechanism for metastatic spread. The cells and molecules outlined here represent potential targets for treatment of this cancer, especially in its pre-cancerous, inflammatory stage.

Systematic Review and STARD Scoring of Renal Cell Carcinoma Circulating Diagnostic Biomarker Manuscripts.

BACKGROUND: No validated molecular biomarkers exist to help guide diagnosis of renal cell carcinoma (RCC) patients. We seek to evaluate the quality of published RCC circulating diagnostic biomarker manuscripts using the Standards for Reporting of Diagnostic Accuracy Studies (STARD) guidelines. METHODS: The phrase "(renal cell carcinoma OR renal cancer OR kidney cancer OR kidney carcinoma) AND circulating AND (biomarkers OR cell free DNA OR tumor DNA OR methylated cell free DNA OR methylated tumor DNA)" was searched in Embase, MEDLINE, and PubMed in March 2018. Relevant manuscripts were scored using 41 STARD subcriteria for a maximal score of 26 points. All tests of statistical significance were 2 sided. RESULTS: The search identified 535 publications: 27 manuscripts of primary research were analyzed. The median STARD score was 11.5 (range = 7-16.75). All manuscripts had appropriate abstracts, introductions, and distribution of alternative diagnoses. None of the manuscripts stated how indeterminant data were handled or if adverse events occurred from performing the index test or reference standard. Statistically significantly higher STARD scores were present in manuscripts reporting receiver operator characteristic curves (P < .001), larger sample sizes (P = .007), and after release of the original STARD statement (P = .005). CONCLUSIONS: Most RCC circulating diagnostic biomarker manuscripts poorly adhere to the STARD guidelines. Future studies adhering to STARD guidelines may address this unmet need.

GATA6 Expression Distinguishes Classical and Basal-like Subtypes in Advanced Pancreatic Cancer.

PURPOSE: To determine the impact of basal-like and classical subtypes in advanced pancreatic ductal adenocarcinoma (PDAC) and to explore GATA6 expression as a surrogate biomarker. EXPERIMENTAL DESIGN: Within the COMPASS trial, patients proceeding to chemotherapy for advanced PDAC undergo tumor biopsy for RNA-sequencing (RNA-seq). Overall response rate (ORR) and overall survival (OS) were stratified by subtypes and according to chemotherapy received. Correlation of GATA6 with the subtypes using gene expression profiling, in situ hybridization (ISH) was explored. RESULTS: Between December 2015 and May 2019, 195 patients (95%) had enough tissue for RNA-seq; 39 (20%) were classified as basal-like and 156 (80%) as classical. RECIST response data were available for 157 patients; 29 basal-like and 128 classical where the ORR was 10% versus 33%, respectively (P = 0.02). In patients with basal-like tumors treated with modified FOLFIRINOX (n = 22), the progression rate was 60% compared with 15% in classical PDAC (P = 0.0002). Median OS in the intention-to-treat population (n = 195) was 9.3 months for classical versus 5.9 months for basal-like PDAC (HR, 0.47; 95% confidence interval, 0.32-0.69; P = 0.0001). GATA6 expression by RNA-seq highly correlated with the classifier (P < 0.001) and ISH predicted the subtypes with sensitivity of 89% and specificity of 83%. In a multivariate analysis, GATA6 expression was prognostic (P = 0.02). In exploratory analyses, basal-like tumors, could be identified by keratin 5, were more hypoxic and enriched for a T-cell-inflamed gene expression signature. CONCLUSIONS: The basal-like subtype is chemoresistant and can be distinguished from classical PDAC by GATA6 expression.See related commentary by Collisson, p. 4715.

The microbiome and cancer for clinicians.

The human microbiome is an emerging target in cancer development and therapeutics. It may be directly oncogenic, through promotion of mucosal inflammation or systemic dysregulation, or may alter anti-cancer immunity/therapy. Microorganisms within, adjacent to and distant from tumors may affect cancer progression, and interactions and differences between these populations can influence the course of disease. Here we review the microbiome as it pertains to cancer for clinicians. The microbiota of cancers including colorectal, pancreas, breast and prostate are discussed. We examine "omics" technologies, microbiota associated with tumor tissue and tumor-site fluids such as feces and urine, as well as indirect effects of the gut microbiome. We describe roles of the microbiome in immunotherapy, and how it can be modulated to improve cancer therapeutics. While research is still at an early stage, there is potential to exploit the microbiome, as modulation may increase efficacy of treatments, reduce toxicities and prevent carcinogenesis.

Structure and Optimization of Checkpoint Inhibitors.

With the advent of checkpoint inhibitor treatment for various cancer types, the optimization of drug selection, pharmacokinetics and biomarker assays is an urgent and as yet unresolved dilemma for clinicians, pharmaceutical companies and researchers. Drugs which inhibit cytotoxic T-lymphocyte associated protein-4 (CTLA-4), such as ipilimumab and tremelimumab, programmed cell death protein-1 (PD-1), such as nivolumab and pembrolizumab, and programmed cell death ligand-1 (PD-L1), such as atezolizumab, durvalumab and avelumab, each appear to have varying pharmacokinetics and clinical activity in different cancer types. Each drug differs in terms of dosing, which becomes an issue when drug comparisons are attempted. Here, we examine the various checkpoint inhibitors currently used and in development. We discuss the antibodies and their protein targets, their pharmacokinetics as measured in various tumor types, and their binding affinities to their respective antigens. We also examine the various dosing regimens for these drugs and how they differ. Finally, we examine new developments and methods to optimize delivery and efficacy in the field of checkpoint inhibitors, including non-fucosylation, prodrug formations, bispecific antibodies, and newer small molecule and peptide checkpoint inhibitors.

Systematic review and REMARK scoring of renal cell carcinoma prognostic circulating biomarker manuscripts.

BACKGROUND: No validated molecular biomarkers exist to help guide prognosis of renal cell carcinoma (RCC) patients. We seek to evaluate the quality of published prognostic circulating RCC biomarker manuscripts using the Reporting Recommendations for Tumor Marker Prognostic Studies (REMARK) guidelines. METHODS: The phrase "(renal cell carcinoma OR renal cancer OR kidney cancer OR kidney carcinoma) AND circulating AND (biomarkers OR cell free DNA OR tumor DNA OR methylated cell free DNA OR methylated tumor DNA)" was searched in Embase, Medline and PubMed March 2018. Relevant manuscripts were scored using 48 REMARK sub-criteria for a maximal score of 20 points. RESULTS: The search identified 535 publications: 33 were manuscripts of primary research and were analyzed. The mean REMARK score was 10.6 (range 6.42-14.2). All manuscripts stated their biomarker, study objectives and method of case selection. The lowest scoring criteria: time lapse between storage of blood/serum and marker assay (n = 2) and lack of flow diagram (n = 2). REMARK scores were significantly higher in publications stating adherence to REMARK guidelines (p = 0.0307) and reporting statistically significant results (p = 0.0318). CONCLUSIONS: Most RCC prognostic biomarker manuscripts poorly adhere to the REMARK guidelines. Better designed studies and appropriate reporting are required to address this urgent unmet need.

Unusual Sites of High-Grade Neuroendocrine Carcinomas: A Case Series and Review of the Literature.

BACKGROUND Neuroendocrine tumors (NETs) encompass a diverse group of varying clinicopathological entities arising from cells of the endocrine and nervous systems. The presentation of these unique tumors can range from occult disease discovered incidentally to hyperactive, metastatic secretory tumors. NETs most commonly originate in the gastrointestinal and respiratory tract, although they may occur at any site in the body due to the wide distribution of neuroendocrine cells. Their classification system is complex and continues to evolve, and the current system uses histological grade in defining these subtypes. Neuroendocrine carcinomas (NECs), or high-grade, poorly-differentiated NETs, are the most aggressive subtype. Surgical resection remains the primary treatment modality and may be curative, thus early diagnosis is paramount. Management of advanced NETs remains both a diagnostic and therapeutic challenge; however, advances in our understanding of these unique neoplasms as well as an evolving classification system has led to the development of adjunctive therapeutic approaches aimed to minimize morbidity and improve patient outcomes. CASE REPORT We present 6 cases of unusual sites of high-grade neuroendocrine carcinomas involving the cervix, gallbladder, oesophagus, ovary, prostate, and urinary bladder. CONCLUSIONS Our case series highlights the heterogenous and aggressive nature of this subtype of NETs as well as their diagnostic and therapeutic difficulties. We also review the evolution of the NET classification system and its impact on the management of these malignancies.