Biomarker testing in oncology - Requirements for organizing external quality assessment programs to improve the performance of laboratory testing: revision of an expert opinion paper on behalf of IQNPath ABSL

A novel proficiency test to assess the animal diagnostic investigation process in identifying an unknown toxicant

Participation in Proficiency Tests (PTs) is an important component of quality assurance in testing laboratories. In a typical chemistry PT, blind-coded samples are sent to participants for analysis of specific chemical agents, and results are compared to a pre-determined key (e.g., expected concentrations) to assess proficiency. In the animal diagnostic PT presented here, organizers evaluated not only the analytical component of the diagnostic investigation but also the entire investigative process as a multi-step, holistic multidisciplinary approach. Fourteen veterinary diagnostic laboratories (VDLs) participated in an exercise to identify the root cause of a simulated case of lead (Pb) toxicosis. VDLs received a case description outlining neurological signs in cattle, a digitized brain histology slide, and liver and brain tissue samples for optional chemistry analysis. Thirteen of 14 VDLs successfully diagnosed lead toxicosis by completing the following stages: (a) correctly identifying histological abnormalities, (b) providing three adequate differential diagnoses, (c) selecting adequate chemistry analyses to rule in or rule out possible causes, (d) accurately detecting lead concentration in the liver, and (e) interpreting the diagnostic significance of their results correctly. Importantly, participants first had to determine which chemistry analyses were appropriate and then to accurately quantify the target analytes. This approach provided greater confidence in the diagnostic capability of the laboratory by reducing the bias associated with being given a known chemical contaminant for which to test, typical of most chemistry PTs, and may therefore be of interest to PT providers and accreditation committees.

Behind the scenes of EQA-characteristics, capabilities, benefits and assets of external quality assessment (EQA)

The main stakeholders in external quality assessment (EQA) programs are the participants, in whose interests these challenges are ultimately organised. EQA schemes in the medical field contribute to improving the quality of patient care by evaluating the analytical and diagnostic quality of laboratory and point-of-care tests (POCT) by independent third parties and, if necessary, pointing out erroneous measurement results and analytical or diagnostic improvement potential. Other benefits include the option of using EQA samples for other important laboratory procedures, such as the verification or validation of in vitro diagnostic medical devices (IVD-MDs), a contribution to the estimation of measurement uncertainty, a means of training and educating laboratory staff through educational EQA programmes or samples, or even for independent and documented monitoring of staff competence, such as on samples with unusual or even exceptional characteristics. Participation in an EQA scheme for beneficiaries like medical, microbiological and histo- and molecular pathology laboratories, users of POCT and self-testing systems as well as National Metrology Institutes, calibration laboratories and reference laboratories that are dedicated to specific tasks and have particular expectations of the EQA scheme are presented here.

Best-Practice Biomarker Testing of Oesophago-Gastric Cancer in the UK: Expert Consensus Recommendations Developed Using a Modified Delphi

AIMS

Oesophago-gastric cancers (OGCs) are amongst the most commonly diagnosed malignancies worldwide and are associated with high disease-related mortality. Predictive biomarkers are molecules that can be objectively measured and used to indicate a likely response to therapeutic intervention, thus facilitating individualised cancer therapy. However, there remains variation in uptake and implementation of biomarker testing across the UK.

MATERIALS AND METHODS

We conducted a modified Delphi study to formulate consensus recommendations for best-practice biomarker testing of OGC in the UK. We employed two rounds of online questionnaires followed by a virtual consensus meeting. Biomarkers for discussion included HER2, MSI/MMR, and PD-L1. Topics comprised the overall biomarker pathway, pre-analytical, analytical, and post-analytical considerations, including challenges in current practice.

RESULTS

Twenty-six and eighteen participants completed the first and second round Delphi questionnaire, respectively, with an even split of pathologists and oncologists from across the UK. There was consensus (>80% agreement) across several topics, including the requirements for standardisation of the pathway, which must include coordination throughout the tissue journey, requirements for a quality-assured process to ensure accuracy and validity of testing, plus the need for clear, detailed information on the pathology report to support treatment decisions. There was consensus amongst oncologists regarding reflex testing of all biomarkers depending on histology; however, concerns over capacity in relation to workload and availability of pathologists were evident among the pathologists. Overall, participants were in the opinion that reflex testing improves the speed of treatment decisions and improves patient care.

CONCLUSION

The recommendations reflect best-practices and should be implemented to support rapid multidisciplinary team decision-making within oesophago-gastric cancer. Results reflect the need for standardisation and demonstrate the challenges faced in clinical practice by those requesting and testing biomarkers for oesophago-gastric cancer, suggesting significant concerns relating to pathologist capacity.

High success rate of first proficiency testing for RET fusions and RET mutations in lung and thyroid cancer samples by various methods

This study describes the external quality assessment (EQA) scheme for molecular testing of RET alterations in non-small cell lung cancer (NSCLC), medullary thyroid carcinomas (MTC), and non-MTC. The lead panel institute and Quality Assurance Initiative in Pathology (Qualitätssicherungs-Initiative Pathologie [QuIP] GmbH) selected formalin-fixed paraffin-embedded (FFPE) tissue from MTC for RET mutation testing by next-generation sequencing (NGS) methods and FFPE tissue from NSCLC and non-MTC for RET gene fusion testing using either in situ hybridisation (ISH) or NGS methods, forming 3 sub-schemes of the EQA scheme. Tissue material underwent an internal validation phase followed by an external testing phase. The internal validation phase served as a cross-validation step conducted by panel institutes. In the external testing phase, the number of participating institutes in the RET point mutation sub-scheme, RET fusion (ISH) sub-scheme, and RET fusion (NGS) sub-scheme was 32, 24, and 38, respectively. The reported success rates for external testing were 96.0%, 89.5%, and 93.5% for the RET point mutation, the ISH RET fusion, and the NGS RET fusion EQA sub-schemes, respectively. These findings confirm the reliability of the NGS method in detecting RET alterations and align with current screening recommendations. Overall, 31 institutes were certified for RET point mutation testing by NGS methods, 22 institutes were certified for RET fusion testing by ISH, and 36 institutes were certified for RET fusion testing by NGS methods. Results can be employed to inform real-world diagnostic decisions in Germany, Austria, and Switzerland.

PIK3CA testing in hormone receptor-positive/HER2-negative metastatic breast cancer: real-world data from Italian molecular pathology laboratories

Introduction: PIK3CA gene mutations occur in approximately 40% of hormone receptor-positive/HER2-negative (HR+/HER2-) metastatic breast cancers (MBCs), electing them to targeted therapy. Testing PIK3CA status is complex due to selection of biological specimen and testing method. Materials & methods: This work investigates real-life experience on PIK3CA testing in HR+/HER2- MBC. Clinical, technical and molecular data on PIK3CA testing were collected from two referral laboratories. Additionally, the results of a nationwide PIK3CA survey involving 116 institutions were assessed. Results: Overall, n = 35 MBCs were PIK3CA-mutated, with mutations mostly occurring in exons 9 (n = 19; 51.4%) and 20 (n = 15; 40.5%). The nationwide survey revealed significant variability across laboratories in terms of sampling methodology, technical assessment and clinical report signing healthcare figures for PIK3CA molecular testing in diagnostic routine practice. Conclusion: This study provides insights into the real-world routine of PIK3CA testing in HR+/HER2- MBC and highlights the need for standardization and networking in predictive pathology.

Improving practice in PD-L1 testing of non-small cell lung cancer in the UK: current problems and potential solutions

AIMS

Programmed cell death ligand 1 (PD-L1) expression, used universally to predict response of non-small cell lung cancer (NSCLC) to immune-modulating drugs, is a fragile biomarker due to biological heterogeneity and challenges in interpretation. The aim of this study was to assess current PD-L1 testing practices in the UK, which may help to define strategies to improve its reliability and consistency.

METHODS

A questionnaire covering NSCLC PD-L1 testing practice was devised and members of the Association of Pulmonary Pathologists were invited to complete this online.

RESULTS

Of 44 pathologists identified as involved in PD-L1 testing, 32 (73%) responded. There was good consistency in practice and approach, but there was wide variability in the distribution of PD-L1 scoring. Although the proportions of scores falling into the three groups (negative, low and high) defined by the 1% and 50% 'cut-offs' (38%, 33% and 27%, respectively) reflect the general experience, the range within each group was wide at 23-70%, 10-60% and 15-36%, respectively.

CONCLUSIONS

There is inconsistency in the crucial endpoint of PD-L1 testing of NSCLC, the expression score that guides management. Addressing this requires formal networking of individuals and laboratories to devise a strategy for its reduction.

Critical Factors in the Analytical Work Flow of Circulating Tumor DNA-Based Molecular Profiling

BACKGROUND

Liquid biopsy testing, especially molecular tumor profiling of circulating tumor DNA (ctDNA) in cell-free plasma, has received increasing interest in recent years as it serves as a reliable alternative for the detection of tumor-specific aberrations to guide treatment decision-making in oncology. Many (commercially available) applications have been developed, however, broad divergences in (pre)analytical work flows and lack of universally applied guidelines impede routine clinical implementation. In this review, critical factors in the blood-based ctDNA liquid biopsy work flow are evaluated.

CONTENT

In the preanalytical phase, several aspects (e.g., blood collection tubes [BCTs], plasma processing, and extraction method) affect the quantity and quality of the circulating cell-free DNA (ccfDNA) applicable for subsequent molecular analyses and should meet certain standards to be applied in diagnostic work flows. Analytical considerations, such as analytical input and choice of assay, might vary based on the clinical application (i.e., screening, primary diagnosis, minimal residual disease [MRD], response monitoring, and resistance identification). In addition to practical procedures, variant interpretation and reporting ctDNA results should be harmonized. Collaborative efforts in (inter)national consortia and societies are essential for the establishment of standard operating procedures (SOPs) in attempts to standardize the plasma-based ctDNA analysis work flow.

SUMMARY

Development of universally applicable guidelines regarding the critical factors in liquid biopsy testing are necessary to pave the way to clinical implementation for routine diagnostics.

Circulating lung cancer biomarkers: From translational research to clinical practice

Fundamental studies on biomarkers as well as developed assays for their detection can provide valuable information facilitating clinical decisions. For patients with lung cancer, there are established circulating biomarkers such as serum progastrin-releasing peptide (ProGRP), neuron-specific enolase (NSE), squamous cell carcinoma antigen (SCC-Ag), carcinoembryonic antigen (CEA), and cytokeratin-19 fragment (CYFRA21-1). There are also molecular biomarkers for targeted therapy such as epidermal growth factor receptor (EGFR) gene, anaplastic lymphoma kinase (ALK) gene, KRAS gene, and BRAF gene. However, there is still an unmet need for biomarkers that can be used for early detection and predict treatment response and survival. In this review, we describe the lung cancer biomarkers that are currently being used in clinical practice. We also discuss emerging preclinical and clinical studies on new biomarkers such as omics-based biomarkers for their potential clinical use to detect, predict, or monitor subtypes of lung cancer. Additionally, between-method differences in tumor markers warrant further development and improvement of the standardization and harmonization for each assay.

Lessons Learned, Challenges Taken, and Actions Made for "Precision" Immunohistochemistry. Analysis and Perspectives From the NordiQC Proficiency Testing Program

Immunohistochemistry (IHC) has for decades been an integrated method within pathology applied to gain diagnostic, prognostic, and predictive information. However, the multimodality of the analytical phase of IHC is a challenge to ensure the reproducibility of IHC, which has been documented by external quality assessment (EQA) programs for many biomarkers. More than 600 laboratories participate in the Nordic immunohistochemical Quality Control EQA program for IHC. In the period, 2017-2021, 65 different biomarkers were assessed and a total of 31,967 results were evaluated. An overall pass rate of 79% was obtained being an improvement compared with 71% for the period, 2003-2015. The pass rates for established predictive biomarkers (estrogen receptor, progesterone receptor, and HER2) for breast carcinoma were most successful showing mean pass rates of 89% to 92%. Diagnostic IHC biomarkers as PAX8, SOX10, and different cytokeratins showed a wide spectrum of pass rates ranging from 37% to 95%, mean level of 75%, and attributed to central parameters as access to sensitive and specific antibodies but also related to purpose of the IHC test and validation performed accordingly to this. Seven new diagnostic biomarkers were introduced, and all showed inferior pass rates compared with the average level for diagnostic biomarkers emphasizing the challenge to optimize, validate, and implement new IHC biomarkers. Nordic immunohistochemical Quality Control operates by "Fit-For-Purpose" EQA principles and for programmed death-ligand 1, 2 segments are offered aligned to the "3-dimensional" approach-bridging diagnostic tests, drugs to be offered, and diseases addressed. Mean pass rates of 65% and 79% was obtained in the 2 segments for programmed death-ligand 1.

[New update to the guidelines on testing predictive biomarkers in non-small-cell lung cancer: a National Consensus of the Spanish Society of Pathology and the Spanish Society of Medical Oncology]

Non-small cell lung cancer (NSCLC) presents the greatest number of identified therapeutic targets, some of which have therapeutic utility. Currently, detecting EGFR, BRAF, KRAS and MET mutations, ALK, ROS1, NTRK and RET translocations, and PD-L1 expression in these patients is considered essential. The use of next-generation sequencing (NGS) facilitates precise molecular diagnosis and allows the detection of other emerging mutations, such as the HER2 mutation and predictive biomarkers for immunotherapy responses. In this consensus, a group of experts in the diagnosis and treatment of NSCLC selected by the Spanish Society of Pathology (SEAP) and the Spanish Society of Medical Oncology (SEOM) have evaluated currently available information and propose a series of recommendations to optimize the detection and use of biomarkers in daily clinical practice.

New update to the guidelines on testing predictive biomarkers in non-small-cell lung cancer: a National Consensus of the Spanish Society of Pathology and the Spanish Society of Medical Oncology

Non-small cell lung cancer (NSCLC) presents the greatest number of identified therapeutic targets, some of which have therapeutic utility. Currently, detecting EGFR, BRAF, KRAS and MET mutations, ALK, ROS1, NTRK and RET translocations, and PD-L1 expression in these patients is considered essential. The use of next-generation sequencing facilitates precise molecular diagnosis and allows the detection of other emerging mutations, such as the HER2 mutation and predictive biomarkers for immunotherapy responses. In this consensus, a group of experts in the diagnosis and treatment of NSCLC selected by the Spanish Society of Pathology and the Spanish Society of Medical Oncology have evaluated currently available information and propose a series of recommendations to optimize the detection and use of biomarkers in daily clinical practice.

Access and quality of biomarker testing for precision oncology in Europe

BACKGROUND

Predictive biomarkers are essential for selecting the best therapeutic strategy in patients with cancer. The International Quality Network for Pathology, the European Cancer Patient Coalition and the European Federation of Pharmaceuticals Industries and Associations evaluated the access to and quality of biomarker testing across Europe.

METHODS

Data sources included surveys of 141 laboratory managers and 1.665 patients, and 58 in-depth interviews with laboratory managers, physicians and payers. Four access metrics (laboratory access, test availability, test reimbursement, test order rate) and three quality metrics (quality scheme participation, laboratory accreditation, test turnaround time) were applied to rank the results.

RESULTS

The access to precision medicines is higher in countries with public national reimbursement processes in place. Lack of diagnostic laboratory infrastructure, inefficient organization and/or insufficient public reimbursement narrow the access to single biomarker tests in many European countries. In countries with limited public reimbursement, pharma and patients' out of pocket were the primary funding sources for testing. Uptake of multi-biomarker next generation sequencing (NGS) is highly varied, ranging from 0% to >50%. Financial constraints, a lack of NGS testing capabilities and the failure to include NGS testing in the guidelines represent the main barriers to NGS implementation. The quality of biomarker testing is highest in Western and Northern Europe, with more than 90% of laboratories participating in quality assurance schemes.

CONCLUSIONS

Our data clearly indicate the need for a call to action to ensure the clinical implementation of precision medicine in Europe.

[Interlaboratory comparisons-a central means of external quality assurance]

The precise performance of immunohistochemical and molecular examinations of diagnostic and predictive markers is essential for the further therapy of patients. Due to the increasing number of biomarkers and their detection at the immunohistochemical and molecular level in patient tissue, the pathology has a direct influence on the therapy of patients, which increases the value of external quality assurance (EQA). In pathology, various forms are available for this purpose, such as proficiency tests. The standards of both the certification and accreditation procedures of pathology require regular participation in EQA and a statement on the EQA policy of the institutes. The quality of an EQA depends on the scientific concept, the adequate selection of material, the evaluation concept, and the communication of results.

Expert opinion on NSCLC small specimen biomarker testing - Part 2: Analysis, reporting, and quality assessment

The diagnostic work-up for non-small cell lung cancer (NSCLC) requires biomarker testing to guide therapy choices. This article is the second of a two-part series. In Part 1, we summarised evidence-based recommendations for obtaining and processing small specimen samples (i.e. pre-analytical steps) from patients with advanced NSCLC. Here, in Part 2, we summarise evidence-based recommendations relating to analytical steps of biomarker testing (and associated reporting and quality assessment) of small specimen samples in NSCLC. As the number of biomarkers for actionable (genetic) targets and approved targeted therapies continues to increase, simultaneous testing of multiple actionable oncogenic drivers using next-generation sequencing (NGS) becomes imperative, as set forth in European Society for Medical Oncology guidelines. This is particularly relevant in advanced NSCLC, where tissue specimens are typically limited and NGS may help avoid tissue exhaustion compared with sequential biomarker testing. Despite guideline recommendations, significant discrepancies in access to NGS persist across Europe, primarily due to reimbursement constraints. The use of increasingly complex testing methods also has implications for the reporting of results. Molecular testing reports should include clinical interpretation with additional commentary on sample adequacy as appropriate. Molecular tumour boards are recommended to facilitate the interpretation of complex genetic information arising from NGS, and to collaboratively determine the optimal treatment for patients with NSCLC. Finally, whichever testing modality is employed, it is essential that adequate internal and external validation and quality control measures are implemented.

The Significance of External Quality Assessment Schemes for Molecular Testing in Clinical Laboratories

Simple Summary

Patients and clinicians often rely on the outcome of laboratory tests, but can we really trust these test results? Good quality management is key for laboratories to guarantee reliable test results. This review focusses on external quality assessment (EQA) schemes which are a tool for laboratories to examine and improve the quality of their testing routines. In this review, an overview of the role and importance of EQA schemes for clinical laboratories is given, and different types of EQA schemes and EQA providers available on the market are discussed, as well as recent developments in the EQA landscape.

Abstract

External quality assessment (EQA) schemes are a tool for clinical laboratories to evaluate and manage the quality of laboratory practice with the support of an independent party (i.e., an EQA provider). Depending on the context, there are different types of EQA schemes available, as well as various EQA providers, each with its own field of expertise. In this review, an overview of the general requirements for EQA schemes and EQA providers based on international guidelines is provided. The clinical and scientific value of these kinds of schemes for clinical laboratories, clinicians and patients are highlighted, in addition to the support EQA can provide to other types of laboratories, e.g., laboratories affiliated to biotech companies. Finally, recent developments and challenges in laboratory medicine and quality management, for example, the introduction of artificial intelligence in the laboratory and the shift to a more individual-approach instead of a laboratory-focused approach, are discussed. EQA schemes should represent current laboratory practice as much as possible, which poses the need for EQA providers to introduce latest laboratory innovations in their schemes and to apply up-to-date guidelines. By incorporating these state-of-the-art techniques, EQA aims to contribute to continuous learning.

Cancer Biomarkers in the era of precision oncology: Addressing the needs of patients and health systems

Cancer Biomarkers are the key to unlocking the promise of precision oncology, selecting which patients will respond to a more personalised treatment while sparing non-responders the therapy-related toxicity. In this paper, we highlight the primacy of cancer biomarkers, but focus on their importance to patients and to health systems. We also highlight how cancer biomarkers represent value for money. We emphasise the need for cancer biomarkers infrastructure to be embedded into European health systems. We also highlight the need to deploy multiple biomarker testing to deliver the optimal benefit for patients and health systems and consider cancer biomarkers from the perspective of cost, value and regulation. Cancer biomarkers must also be situated in the context of the upcoming In Vitro Diagnostics Regulation, which may pose certain challenges (e.g. non-compliance of laboratory developed tests, leading to cancer biomarker shortages and increased costs) that need to be overcome. Cancer biomarkers must be embedded in the real world of oncology delivery and testing must be implemented across Europe, with the intended aim of narrowing, not widening the inequity gap for patients. Cancer patients must be placed firmly at the centre of a cancer biomarker informed precision oncology care agenda.

Causes behind error rates for predictive biomarker testing: the utility of sending post-EQA surveys

External quality assessment (EQA) schemes assess the performance of predictive biomarker testing in lung and colorectal cancer and have previously demonstrated variable error rates. No information is currently available on the underlying causes of incorrect EQA results in the laboratories. Participants in EQA schemes by the European Society of Pathology between 2014 and 2018 for lung and colorectal cancer were contacted to complete a survey if they had at least one analysis error or test failure in the provided cases. Of the 791 surveys that were sent, 325 were completed including data from 185 unique laboratories on 514 incorrectly analyzed or failed cases. For the digital cases and immunohistochemistry, the majority of errors were interpretation-related. For fluorescence in situ hybridization, problems with the EQA materials were reported frequently. For variant analysis, the causes were mainly methodological for lung cancer but variable for colorectal cancer. Post-analytical (clerical and interpretation) errors were more likely detected after release of the EQA results compared to pre-analytical and analytical issues. Accredited laboratories encountered fewer reagent problems and more often responded to the survey. A recent change in test methodology resulted in method-related problems. Testing more samples annually introduced personnel errors and lead to a lower performance in future schemes. Participation to quality improvement projects is important to reduce deviating test results in laboratories, as the different error causes differently affect the test performance. EQA providers could benefit from requesting root cause analyses behind errors to offer even more tailored feedback, subschemes, and cases.

Managing Deviating EQA Results: A Survey to Assess the Corrective and Preventive Actions of Medical Laboratories Testing for Oncological Biomarkers

Laboratories testing predictive biomarkers in lung and colorectal cancer are advised to participate in external quality assessment (EQA) schemes. This study aimed to investigate which corrective actions were taken by laboratories if predetermined performance criteria were not met, to ultimately improve current test practices. EQA participants from the European Society of Pathology between 2014 and 2018 for lung and colorectal cancer were contacted, if they had at least one analysis error or test failure in the provided cases, to complete a survey. For 72.4% of 514 deviating EQA results, an appropriate action was performed, most often including staff training (15.2%) and protocol revisions (14.6%). Main assigned persons were the molecular biologist (40.0%) and pathologist (46.5%). A change in test method or the use of complex techniques, such as next-generation sequencing, required more training and the involvement of dedicated personnel to reduce future test failures. The majority of participants adhered to ISO 15189 and implemented suitable actions by designated staff, not limited to accredited laboratories. However, for 27.6% of cases (by 20 laboratories) no corrective action was taken, especially for pre-analytic problems and complex techniques. The surveys were feasible to request information on results follow-up and further recommendations were provided.