Aims
The nuclear proliferation marker Ki67 assayed by immunohistochemistry has multiple potential uses in breast cancer, but an unacceptable level of interlaboratory variability has hampered its ...clinical utility. The International Ki67 in Breast Cancer Working Group has undertaken a systematic programme to determine whether Ki67 measurement can be analytically validated and standardised among laboratories. This study addresses whether acceptable scoring reproducibility can be achieved on excision whole sections.
Methods and results
Adjacent sections from 30 primary ER+ breast cancers were centrally stained for Ki67 and sections were circulated among 23 pathologists in 12 countries. All pathologists scored Ki67 by two methods: (i) global: four fields of 100 tumour cells each were selected to reflect observed heterogeneity in nuclear staining; (ii) hot‐spot: the field with highest apparent Ki67 index was selected and up to 500 cells scored. The intraclass correlation coefficient (ICC) for the global method confidence interval (CI) = 0.87; 95% CI = 0.799–0.93 marginally met the prespecified success criterion (lower 95% CI ≥ 0.8), while the ICC for the hot‐spot method (0.83; 95% CI = 0.74–0.90) did not. Visually, interobserver concordance in location of selected hot‐spots varies between cases. The median times for scoring were 9 and 6 min for global and hot‐spot methods, respectively.
Conclusions
The global scoring method demonstrates adequate reproducibility to warrant next steps towards evaluation for technical and clinical validity in appropriate cohorts of cases. The time taken for scoring by either method is practical using counting software we are making publicly available. Establishment of external quality assessment schemes is likely to improve the reproducibility between laboratories further.
The blood proteome, consisting of thousands of proteins engaged in various biological processes, acts as a valuable source of potential biomarkers for various medical applications. PROphet is a ...plasma proteomics-based test that serves as a decision-support tool for non-small cell lung cancer (NSCLC) patients, combining proteomic profiling using SomaScan technology and subsequent computational algorithm. PROphet was implemented as a laboratory developed test (LDT). Under the Clinical Laboratory Improvement Amendments (CLIA) and Commission on Office Laboratory Accreditation (COLA) regulations, prior to releasing patient test results, a clinical laboratory located in the United States employing an LDT must examine its performance characteristics with regard to analytical validity. This study describes the experimental and computational analytical validity of the PROphet test, as required by CLIA/COLA regulations. Experimental precision analysis displayed a median coefficient of variation (CV) of 3.9 % and 4.7 % for intra-plate and inter-plate examination, respectively, and the median accuracy rate between sites was 88 %. Computational precision exhibited a high accuracy rate, with 93 % of samples displaying complete concordance in results. A cross-platform comparison between SomaScan and other proteomics platforms yielded a median Spearman's rank correlation coefficient of 0.51, affirming the consistency and reliability of the SomaScan platform as used under the PROphet test. Our study presents a robust framework for evaluating the analytical validity of a platform that combines an experimental assay with subsequent computational algorithms. When applied to the PROphet test, strong analytical performance of the test was demonstrated.
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•PROphet serves as a proteomics-based decision-support tool for NSCLC patients.•Both experimental and computational analytical validity of the test were examined.•A strong experimental precision and accuracy performance was observed.•Computational precision analysis displayed high consistency for repeated samples.•Cross-platform analysis supported the reliability of the examined proteomic assay
Recent circulating tumor DNA (ctDNA) research has demonstrated its potential as a non-invasive biomarker for cancer. However, the deployment of ctDNA assays in routine clinical practice remains ...challenging owing to variability in analytical approaches and the assessment of clinical significance. A well-developed, analytically valid ctDNA assay is a prerequisite for integrating ctDNA into cancer management, and an appropriate analytical technology is crucial for the development of a ctDNA assay. Other determinants including pre-analytical procedures, test validation, internal quality control (IQC), and continual proficiency testing (PT) are also important for the accuracy of ctDNA assays. In the present review, we will focus on the most widely used ctDNA detection technologies and the key quality management measures used to assure the accuracy of ctDNA assays. The aim of this review is to provide useful information for technology selection during ctDNA assay development and assure a reliable test result in clinical practice.
The 21st century challenge is to redesign healthcare systems to be safe, efficient, effective, timely, equitable and patient-centred. Although laboratory medicine is integral to many of these ...objectives involving prevention, diagnosis, treatment, and managing disease of patients, it suffers from poor visibility as a medical discipline and as a profession and fewer rewards for educational efforts when compared to other medical disciplines. Laboratory scientists are often perceived as managing machinery and equipment, but conversely they need to take a position of shared clinical leadership, showing the role of laboratory tests to guarantee optimal care for patients. This is however challenging because of some reluctance by laboratory professionals to involve themselves in test structuring and requesting and in the inspection of work as it arrives because it is assumed that all requests are clinically necessary; there is a poor communication and integration between clinical wards and laboratory; and, importantly, there is the need for an excellent cultural and scientific background of laboratory professionals for implementing outcome research and to act as knowledge managers and skilled clinical consultants. By combining the unique talent of performing quality laboratory assays with knowledge of the pathophysiologic rationale behind the tests, laboratory professionals have the expertise to advise their clinical colleagues in regard to the appropriate test selection and interpretation of laboratory results, thereby creating opportunities to define the added value and the pivotal role of laboratory medicine on healthcare delivery.
Measures of stepping volume and rate are common outputs from wearable devices, such as accelerometers. It has been proposed that biomedical technologies, including accelerometers and their ...algorithms, should undergo rigorous verification as well as analytical and clinical validation to demonstrate that they are fit for purpose. The aim of this study was to use the V3 framework to assess the analytical and clinical validity of a wrist-worn measurement system of stepping volume and rate, formed by the GENEActiv accelerometer and GENEAcount step counting algorithm. The analytical validity was assessed by measuring the level of agreement between the wrist-worn system and a thigh-worn system (activPAL), the reference measure. The clinical validity was assessed by establishing the prospective association between the changes in stepping volume and rate with changes in physical function (SPPB score). The agreement of the thigh-worn reference system and the wrist-worn system was excellent for total daily steps (CCC = 0.88, 95% CI 0.83-0.91) and moderate for walking steps and faster-paced walking steps (CCC = 0.61, 95% CI 0.53-0.68 and 0.55, 95% CI 0.46-0.64, respectively). A higher number of total steps and faster paced-walking steps was consistently associated with better physical function. After 24 months, an increase of 1000 daily faster-paced walking steps was associated with a clinically meaningful increase in physical function (0.53 SPPB score, 95% CI 0.32-0.74). We have validated a digital susceptibility/risk biomarker-pfSTEP-that identifies an associated risk of low physical function in community-dwelling older adults using a wrist-worn accelerometer and its accompanying open-source step counting algorithm.
Context: Albendazole is used in the treatment of cysticercosis and hydatid disease, and its prolonged administration can generate adverse effects attributed to the active metabolite, albendazole ...sulfoxide (ABZSO), whose measurement requires validated methods that help monitor patients under treatment. Aims: To validate a high-performance liquid chromatography method with mass detection (HPLC-MS) for the determination of ABZSO in human plasma. Methods: HPLC-MS was performed on C18 columns (100 × 4.6 mm × 3.5 µm) and mobile phase composed of methanol, water and ammonia solution (25%) (800:200:0.1 v /v/v) at a flow rate of 0.5 mL/minute. The calibration curve was built with an albendazole standard, and detection in a triple quadrupole system. Results: The method was linear (1-1500 ng/mL, R2 = 0.999) with a detection limit of 1 ng/mL. ABZSO concentrations at 1, 5, 50, 100, 200, 500, 1000, and 1500 ng/mL had relative standard deviations of 10.4, 8.4, 7.8, 2.9, 7.4, 3.2, 3.4 and 1.3%. It was highly precise with a mean coefficient of variation of 1.411%, and accurate with a bias of -14.7; 2.8 and -0.8% in ABZSO concentrations of 5, 500 and 1000 ng/mL. The average recovery was 89.2%, and the stability of ABZSO after refrigeration had an average coefficient of variation of 2.3%. Conclusions: The HPLC-MS method is valid and reliable to determine ABZSO, and could be used in pharmacokinetic, bioequivalence, and other studies that evaluate the biological monitoring of patients receiving oral treatment with albendazole.
Multigene panel testing for breast and ovarian cancer predisposition diagnosis is a useful tool as it makes possible to sequence a considerable number of genes in a large number of individuals. More ...than 200 different multigene panels in which the two major BRCA1 and BRCA2 breast cancer predisposing genes are included are proposed by public or commercial laboratories. We review the clinical validity and clinical utility of the 26 genes most oftenly included in these panels. Because clinical validity and utility are not established for all genes and due to the heterogeneity of tumour risk levels, there is a substantial difficulty in the routine use of multigene panels if management guidelines and recommendations for testing relatives are not previously defined for each gene. Besides, the classification of variant of unknown significance (VUS) is a particular limitation and challenge. Efforts to classify VUSs and also to identify factors that modify cancer risks are now needed to produce personalised risk estimates. The complexity of information, the capacity to come back to patients when VUS are re-classified as pathogenic, and the expected large increase in the number of individuals to be tested especially when the aim of multigene panel testing is not only prevention but also treatment are challenging both for physicians and patients. Quality of tests, interpretation of results, information and accompaniment of patients must be at the heart of the guidelines of multigene panel testing.
•Multigene panel allows to sequence a high number of genes in numerous individuals.•Management and relative testing guidelines need to be defined for each gene.•Variant classification is a challenge amplified by NGS.•Quality of tests, information and accompaniment of patients are testing guidelines.•Tumour DNA is the native DNA of the patient!.
The most significant biomarkers that are included in the Alzheimer's disease (AD) research framework are amyloid-β plaques deposition, p-tau, t-tau, and neurodegeneration.Although cerebrospinal fluid ...(CSF) biomarkers are included in the most recent AD research criteria, their use is increasing in the routine clinical practice and is applied also to the preclinical phases of AD, including mild cognitive impairment. The role of these biomarkers is still unclear concerning the preclinical stage of AD diagnosis, the CSF methodology, and the costs-benefits of the biomarkers' tests. The controversies regarding the use of biomarkers in the clinical practice are related to the concepts of analytical validity, clinical validity, and clinical utility and to the question of whether they are able to diagnose AD without the support of AD clinical phenotypes.
The objective of the present work is to expose the strengths and weaknesses of the use of CSF biomarkers in the diagnosis of AD in a clinical context.
We used PubMed as main source for articles published and the final reference list was generated on the basis of relevance to the topics covered in this work.
The use of CSF biomarkers for AD diagnosis is certainly important but its indication in routine clinical practice, especially for prodromal conditions, needs to be regulated and also contextualized considering the variety of possible clinical AD phenotypes.
We suggest that the diagnosis of AD should be understood both as clinical and pathological.
A major evolution from purely clinical diagnoses to biomarker supported clinical diagnosing has been occurring over the past years in neurology. High-throughput methods, such as next-generation ...sequencing and mass spectrometry-based proteomics along with improved neuroimaging methods, are accelerating this development. This calls for a consensus framework that is broadly applicable and provides a spot-on overview of the clinical validity of novel biomarkers. We propose a harmonized terminology and a uniform concept that stratifies biomarkers according to clinical context of use and evidence levels, adapted from existing frameworks in oncology with a strong focus on (epi)genetic markers and treatment context. We demonstrate that this framework allows for a consistent assessment of clinical validity across disease entities and that sufficient evidence for many clinical applications of protein biomarkers is lacking. Our framework may help to identify promising biomarker candidates and classify their applications by clinical context, aiming for routine clinical use of (protein) biomarkers in neurology.
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