The Biomarker Toolkit - an evidence-based guideline to predict cancer biomarker success and guide development.

BACKGROUND: An increased number of resources are allocated on cancer biomarker discovery, but very few of these biomarkers are clinically adopted. To bridge the gap between Biomarker discovery and clinical use, we aim to generate the Biomarker Toolkit, a tool designed to identify clinically promising biomarkers and promote successful biomarker translation. METHODS: All features associated with a clinically useful biomarker were identified using mixed-methodology, including systematic literature search, semi-structured interviews, and an online two-stage Delphi-Survey. Validation of the checklist was achieved by independent systematic literature searches using keywords/subheadings related to clinically and non-clinically utilised breast and colorectal cancer biomarkers. Composite aggregated scores were generated for each selected publication based on the presence/absence of an attribute listed in the Biomarker Toolkit checklist. RESULTS: Systematic literature search identified 129 attributes associated with a clinically useful biomarker. These were grouped in four main categories including: rationale, clinical utility, analytical validity, and clinical validity. This checklist was subsequently developed using semi-structured interviews with biomarker experts (n=34); and 88.23% agreement was achieved regarding the identified attributes, via the Delphi survey (consensus level:75%, n=51). Quantitative validation was completed using clinically and non-clinically implemented breast and colorectal cancer biomarkers. Cox-regression analysis suggested that total score is a significant driver of biomarker success in both cancer types (BC: p>0.0001, 95.0% CI: 0.869-0.935, CRC: p>0.0001, 95.0% CI: 0.918-0.954). CONCLUSIONS: This novel study generated a validated checklist with literature-reported attributes linked with successful biomarker implementation. Ultimately, the application of this toolkit can be used to detect biomarkers with the highest clinical potential and shape how biomarker studies are designed/performed.

Sublethal effects of bio-plastic microparticles and their components on the behaviour of Daphnia magna.

Bioplastics arise as an alternative to plastic production delinked from fossil resources. However, as their demand is increasing, there is a need to investigate their environmental fingerprint. Here we study the toxicity of microplastics (MPLs) of two widely used materials, the polylactic acid (PLA) and the polyhydroxybutyrate (PHB) on the environmental aquatic model species Daphnia magna. The study was focused on sublethal behavioural and feeding endpoints linked to antipredator scape responses and food intake. The study aimed to test that MPLs from single-use household comercial items and among them bioplastics should be more toxic than those obtained from standard plastic polymers and fossil plastic materials due to the greater amount of plastic additives, and that MPLs should be more toxic than plastic extracts due to the contribution of both particle and plastic additive toxicity. MPLs were obtained by cryogenic grinding and sea-sand erosion to obtain irregular particles. MPL included standard polymers and nine comercial items of PLA and PHB and one fossil-based material of high-density polyethylene (HDPE). The additive content in commercial items was characterised by liquid chromatography coupled with high-resolution mass spectrometry. D. magna juveniles were exposed for 24 h to particles and their plastic extracts. Results indicated that the toxicity of bioplastic particles was five times higher than the effects produced by exposure to the content of the additives alone, that bioplastic particles were more toxic than fossil ones and that particles obtained from commercial items were more toxic than those obtained from PLA, PHB or HDPE polymer standards. Predicted toxicity from the measured plastic additives in the studied commercially available household items, however, was poorly related with the observed behavioural and feeding effects. Further research on unknown chemical components together with physical factors is need it to fully understand the mechanisms of toxicity of bioplastic materials.

Cytotoxicity assessment and suspected screening of PLASTIC ADDITIVES in bioplastics of single-use household items.

Bioplastics made of renewable sources provide an excellent alternative to fossil-based materials. However, similar or greater quantities of plastic additives than fossil-based plastics are used in the formulations of bioplastics to improve their performance and barrier properties. Nowadays, there is an increasing concern about sources of chemical exposure. However, there is an important knowledge gap regarding complex additive mixtures, particularly in bio-based materials. In this study, we have characterised the presence of plastic additives in single-use materials (collected from retail shops in Spain), which are made of the most common bio-based biodegradable materials, poly(lactic acid) (PLA) and poly(hydroxybutyrate) (PHB), in contrast with a fossil-based plastic material that is extensively made from high-density polyethylene (HDPE). The approach consisted of the pulverization of material in the nano-micro range (100 nm-10 µm), with the materials being extracted using different solvents and ultrasonic-assisted solvent extraction (UASE). 100% of the additives in the material cannot be extracted, but since they were performed in the same condition for all materials can inform about the fingerprint of primary organics and the relative abundances between the different materials. The extracts were analysed by high-performance liquid chromatography coupled with high-resolution mass spectrometry equipped with a heated electrospray ionisation source operated in positive and negative ionisation conditions (HPLC-HESI(+/-)-HRMS), separately, using a suspect screening approach. A total number of 203 additives were tentatively identified (confidence level 2) in the bioplastics items of this study. An average of 123 plastic additives were found in PLA items and 121 in PHB items. Plasticisers were the most abundant additives; the phthalates group was the most commonly found, while 63 plastic additives were confirmed by standards and quantified. In parallel, the cytotoxicity of plastic particles in terms of cell viability and oxidative stress was studied using A549 alveolar basal epithelial cells, and the toxicity of the different extracts was also established using HepG2 adenocarcinoma cells. The main results of this study demonstrate that the plastic particles did not show a significant reduction in cell viability, but oxidative stress was significant, with PLA being the material that showed the highest effect. On the other hand, extracts of plastic particles did not show inhibition of cell viability except for HDPE extract, but the different extracts produced oxidative stress, with PLA showing the highest effect. Although the item showing the highest concentrations of additives was the extract of PLA material while also showing the most elevated oxidative stress, the low migration of toxicants from plastic materials ensures their safe use. However, this also supports the idea that bioplastics can contain many toxic substances in their formulations, some of which are unknown and should be studied in more depth.

Progress with Metabolomic Blood Tests for Gastrointestinal Cancer Diagnosis-An Assessment of Biomarker Translation.

There is an urgent need for cost-effective, non-invasive tools to detect early stages of gastrointestinal cancer (colorectal, gastric, and esophageal cancers). Despite many publications suggesting circulating metabolites acting as accurate cancer biomarkers, few have reached the clinic. In upper gastrointestinal cancer this is critically important, as there is no test to complement gold-standard endoscopic evaluation in patients with mild symptoms that do not meet referral criteria. Therefore, this study aimed to describe and solve this translational gap. Studies reporting diagnostic accuracy of metabolomic blood-based gastrointestinal cancer biomarkers from 2007 to 2020 were systematically reviewed and progress of each biomarker along the discovery-validation-adoption pathway was mapped. Successful biomarker translation was defined as a composite endpoint, including patent protection/FDA approval/recommendation in national guidelines. The review found 77 biomarker panels of gastrointestinal cancer, including 25 with an AUROC >0.9. All but one was stalled at the discovery phase, 9.09% were patented and none were clinically approved, confirming the extent of biomarker translational gap. In addition, there were numerous "re-discoveries," including histidine, discovered in 7 colorectal studies. Finally, this study quantitatively supports the presence of a translational gap between discovery and clinical adoption, despite clear evidence of highly performing biomarkers with significant potential clinical value.

Assessment of Health Related Quality of Life and Digestive Symptoms in Long-term, Disease Free Survivors After Esophagectomy.

OBJECTIVE: The aim of this study was to investigate long-term HRQOL and symptom evolution in disease free patients up to 20 years after esophagectomy. BACKGROUND: Esophagectomy has been associated with decreased HRQOL and persistent gastrointestinal symptoms. METHODS: The study cohort was identified from 2 high volume centers for the management of esophageal cancer. Patients completed HRQOL and symptom questionnaires, including: Digestive Symptom Questionnaire, EORTC QLQ-C30, EORTC QLQ-OG25 Euro QoL 5D, and SF36. Patients were assessed in 3 cohorts: <1 year; 1-5 years, and; >5 years after surgery. RESULTS: In total 171 of 222 patients who underwent esophagectomy between 1991 and 2017 who met inclusion criteria and were contactable, responded to the questionnaires, corresponding to a response rate of 77%. Median age was 66.2 years, and median time from operation to survey was 5.6 years (range 0.3-23.1). Early satiety was the most commonly reported symptom in all patients irrespective of timeframe (87.4%; range 82%-92%). Dysphagia was seen to decrease over time (58% at <2 years; 28% at 2-5 years; 20% at >5 years; P = 0.013). Weight loss scores demonstrated nonstatistical improvement over time. All other symptom scores including heartburn, regurgitation, respiratory symptoms, and pain scores remained constant over time. Average HRQOL did not improve from levels 1 year after surgery compared to patients up to 23 years after esophagectomy. CONCLUSION: With the exception of dysphagia, which improved over time, esophagectomy was associated with decreased HRQOL and lasting gastrointestinal symptoms up to 20 years after surgery. Pertinently however long-term survivors after oesophagectomy demonstrated comparable to improved HRQOL compared to the general population. The impact of esophagectomy on gastrointestinal symptoms and long-term HRQOL should be considered when counseling and caring for patients undergoing esophagectomy.

Screening of suspected micro(nano)plastics in the Ebro Delta (Mediterranean Sea).

This is the first work reporting the use of a double suspect-screening to assess most common polymers and additives in micro(nano)plastics (NPLs/MPLs) found in environmental waters. The method consisted of water filtration followed by ultrasonic-assisted extraction with toluene and analysis employing size exclusion chromatography using an advanced polymer chromatography column coupled to high-resolution mass spectrometry with an atmospheric pressure photoionisation source by negative ionisation conditions (LC(APC)-APPI(-)-HRMS). The identification of NPL/MPLs polymers has been based on increasing confirmation level, including the monomers characterisation by the Kendrick Mass Defect and confirmation and quantification when standards were available. In parallel, the identification of main additives in NPL/MPLs composition, as well organic contaminants adsorbed onto the plastic particles were carried out by analysis of the extracts by LC(C18)-APPI (+/-)-HRMS. To assess the impact of plastic pollution it is necessary to assess the composition in terms of polymers but also the additives. This screening approach has been employed to study composition of NPL/MPLs in the Ebro Delta. Two sampling campaigns including freshwater and seawater samples have been investigated to assess plastic composition in the top 5 cm. Polystyrene (PS), polyethylene (PE), polyisoprene (PI), polybutadiene (PBD), polypropylene (PP) and polysiloxanes were the most detected polymers and PP and PE, sizing between < 1000 and 2000 Da, were found at concentrations reaching up to 7000 ng/L in some areas. The pentadecanoic acid, 1,2,3-benzotriazoles, 2-ethylhexanoic acid (2-EHA), and phthalates such as dimethyl phthalate, mono(2-ethylhexyl) phthalate (MEHP) and the phthalimide were more frequently detected plastic additives. Finally, series of organic contaminants were as well detected in the particulate fraction. These organic contaminants cannot be associated to plastic compositions but can be associated to their adsorption to the particulate matter, in particular to NPL/MPLs, due to their non-polar character. Among these organic contaminants, the more frequently detected were pharmaceutical compounds, food additives and pesticides.