Kevin Washetine

Comparative study of the PD-L1 status between surgically resected specimens and matched biopsies of NSCLC patients reveal major discordances. A potential issue for anti-PD-L1 therapeutic strategies

BACKGROUND High expression of programmed death ligand-1 (PD-L1) on tumor cells (TC) and/or on tumor-infiltrating immune cells (IC) is associated with a high response rate in patients with advanced nonsmall-cell lung cancer (NSCLC) treated with PD-L1 inhibitors. The use of a PD-L1 immunohistochemical (IHC) test in determining the responsiveness to immunotherapy has raised the question of the reliability and reproducibility of its evaluation in lung biopsies compared with corresponding resected surgical specimens. PATIENTS AND METHODS PD-L1 expression in TC and IC was assessed in 160 patients with operable NSCLC on both whole surgical tissue sections and matched lung biopsies, by using a highly sensitive SP142 IHC assay. The specimens were scored as TC 0-3 and IC 0-3 based on increasing PD-L1 expression. RESULTS PD-L1 expression was frequently discordant between surgical resected and matched biopsy specimens (the overall discordance rate = 48%; 95% confidence interval 4.64-13.24) and κ value was equal to 0.218 (poor agreement). In all cases, the biopsy specimens underestimated the PD-L1 status observed on the whole tissue sample. PD-L1-positive IC tumors were more common than PD-L1-positive TC tumors on resected specimens. The discrepancies were mainly related to the lack of a PD-L1-positive IC component in matched biopsies. CONCLUSIONS Our results indicate relatively poor association of the PD-L1 expression in TC and IC between lung biopsies and corresponding resected tumors. Although these results need to be further validated in larger cohorts, they indicate that the daily routine evaluation of the PD-L1 expression in diagnostic biopsies can be misleading in defining the sensitivity to treatment with PD-L1 targeted therapy.

Detection of circulating tumor cells from lung cancer patients in the era of targeted therapy: promises, drawbacks and pitfalls.

Interest in biomarkers in the field of thoracic oncology is focused on the search for new robust tests for diagnosis (in particular for screening), prognosis and theragnosis. These biomarkers can be detected in tissues and/or cells, but also in biological fluids, mainly the blood. In this context, there is growing interest in the detection of circulating tumor cells (CTCs) in the blood of lung cancer patients since CTC identification, enumeration and characterization may have a direct impact on diagnosis, prognosis and theragnosis in the daily clinical practice. Many direct and indirect methods have been developed to detect and characterize CTCs in lung cancer patients. However, these different approaches still hold limitations and many of them have demonstrated unequal sensitivity and specificity. Indeed, these methods hold advantages but also certain disadvantages. Therefore, despite the promises, it is currently difficult and premature to apply this methodology to the routine care of lung cancer patients. This situation is the consequence of the analysis of the methodological approaches for the detection and characterization of CTCs and of the results published to date. Finally, the advent of targeted cancer therapies in thoracic oncology has stimulated considerable interest in non-invasive detection of genomic alterations in tumors over time through the analysis of CTCs, an approach that may help clinicians to optimize therapeutic strategies for lung cancer patients. We describe here the main methods for CTC detection, the advantages and limitations of these different approaches and the potential usefulness and value of CTC characterization in the field of thoracic oncology.

Accréditation de l’activité de pathologie moléculaire selon la norme ISO 15189. Principales étapes à respecter et principaux écueils possibles

The quick emerging of the several targeted therapies and the concept of personnalized medicine underlie the necessity to develop and to well organize a molecular biology (or molecular pathology) unit of high quality, dedicated to clinical care, in order to look for tissular and cellular theragnosis biomarkers. This new and sudden area of activity for a clinical pathologist is strongly linked to the knowledge of a new medical speciality in health care institutions. Thus, the molecular pathology (or molecular biology made from cellular or tissular samples) can nicely be implemented in a clinical pathology laboratory. This new mission for a pathologist has to be done in respect with a great quality assurance which should allow obtaining in a short-term an ISO 15189 accreditation to keep going to perform this activity. The present work aims to describe the main steps to be set up in the order to get an ISO 15189 accreditation in molecular pathology. The different chapters of this norm will not be described in their exhaustivity, but in their large lines. Finally, we will describe the potential difficulties and pitfalls to be avoided before getting this accreditation.

Sense and nonsense in the process of accreditation of a pathology laboratory

The aim of accreditation of a pathology laboratory is to control and optimize, in a permanent manner, good professional practice in clinical and molecular pathology, as defined by internationally established standards. Accreditation of a pathology laboratory is a key element in fine in increasing recognition of the quality of the analyses performed by a laboratory and in improving the care it provides to patients. One of the accreditation standards applied to clinical chemistry and pathology laboratories in the European Union is the ISO 15189 norm. Continued functioning of a pathology laboratory might in time be determined by whether or not it has succeeded the accreditation process. Necessary requirements for accreditation, according to the ISO 15189 norm, include an operational quality management system and continuous control of the methods used for diagnostic purposes. Given these goals, one would expect that all pathologists would agree on the positive effects of accreditation. Yet, some of the requirements stipulated in the accreditation standards, coming from the bodies that accredit pathology laboratories, and certain normative issues are perceived as arduous and sometimes not adapted to or even useless in daily pathology practice. The aim of this review is to elaborate why it is necessary to obtain accreditation but also why certain requirements for accreditation might be experienced as inappropriate.

Article originalAccréditation de l’activité de pathologie moléculaire selon la norme ISO 15189. Principales étapes à respecter et principaux écueils possiblesAccreditation of the activity of molecular pathology according to ISO 15189: Key steps to follow and the main potential pitfalls

The quick emerging of the several targeted therapies and the concept of personnalized medicine underlie the necessity to develop and to well organize a molecular biology (or molecular pathology) unit of high quality, dedicated to clinical care, in order to look for tissular and cellular theragnosis biomarkers. This new and sudden area of activity for a clinical pathologist is strongly linked to the knowledge of a new medical speciality in health care institutions. Thus, the molecular pathology (or molecular biology made from cellular or tissular samples) can nicely be implemented in a clinical pathology laboratory. This new mission for a pathologist has to be done in respect with a great quality assurance which should allow obtaining in a short-term an ISO 15189 accreditation to keep going to perform this activity. The present work aims to describe the main steps to be set up in the order to get an ISO 15189 accreditation in molecular pathology. The different chapters of this norm will not be described in their exhaustivity, but in their large lines. Finally, we will describe the potential difficulties and pitfalls to be avoided before getting this accreditation.

Why and how immunohistochemistry should now be used to screen for the BRAFV600E status in metastatic melanoma? The experience of a single institution (LCEP, Nice, France).

Knowledge of the BRAFV600E status is mandatory in metastatic melanoma patients (MMP). Molecular biology is currently the gold standard method for status assessment.

Immunohistochimie et médecine personnalisée en oncologie pulmonaire: potentialités et limites

The concept of personalized or stratified medicine in thoracic oncology have led to the development of companion diagnostic testing in the laboratories in order to detect genomic alterations which can be targeted by therapeutic molecules. The use of these companion tests has to be associated with an optimized quality control with the aim of getting solid results before treatment administration to the patients. The great majority of these tests is based on molecular biology approach. However, since the commercial availability of different antibodies targeting genomic alterations which can be used in formalin fixed paraffin sections, an alternative method to the molecular approach is the immunohistochemistry (IHC). Some of these antibodies are or will be probably soon used in a daily routine practice (such as anti-ALK or anti-MET antibodies). Other antibodies have currently a more restricted use in thoracic oncology (such as anti-BRAF V600E, anti-ROS1 and mutation-specific anti-EGFR antibodies). In this review, we aim to detail the advantages and the limits of IHC method in thoracic oncology field for personalized medicine, in particular comparatively to the molecular biology technology. Moreover, we discuss the opportunity to provide accredited IHC tests in the context of stratified medicine for lung cancer patients.

Les biobanques : quels enjeux en 2017 ?

Resume Les biobanques ou centres de ressources biologiques (CRB) sont les maillons essentiels de la recherche translationnelle. Ces structures beneficient de financements publics recurrents afin d’etablir des collections d’echantillons biologiques utilisees dans le cadre de projets de recherche. Plus de 100 biobanques ont ete developpees sur le territoire national au sein des hopitaux universitaires et des centres de lutte contre le cancer. Le developpement de nouvelles techniques et de nouvelles methodes d’analyses dans la recherche medicale bouleversent les pratiques et soulevent de nouveaux defis scientifiques et organisationnels dans la collecte, la transformation et la conservation des echantillons. Relever ces defis devient un enjeu primordial pour les biobanques. La mise en place d’une strategie dynamique pour anticiper les besoins des utilisateurs est necessaire et repose sur de nouveaux modes de fonctionnement. Cet article decrit les enjeux a court et a moyen terme pour les biobanques francaises et propose des elements d’organisation pour y repondre.

Optimization of EGFR mutation detection by the fully-automated qPCR-based Idylla system on tumor tissue from patients with non-small cell lung cancer

Treatment with EGFR inhibitors is limited to patients with advanced/metastatic non-small cell lung cancer who have known EGFR mutations. Currently, patient care has to respond to several imperatives to make these inhibitors broadly available to all patients; fast and accurate detection of EGFR mutations by a sensitive and specific standardized cost-effective method, easy-to-implement in settings with limited expertise in molecular diagnostics. We evaluated the Idylla™ EGFR Mutation Assay (Biocartis) for the detection of EGFR mutations in archived formalin-fixed paraffin-embedded (FFPE) tumor samples from a series of 55 patients with lung adenocarcinoma and compared these results with those obtained by a pyrosequencing ISO-15189 accredited laboratory method. The comparison was made on both whole surgical tumor sections and on three artificially constructed small biopsies (∼1 mm) from the same FFPE blocks. Cost-effectiveness and turnaround time comparison between the two methods was performed. On both whole tissue sections and on biopsy cores, the Idylla™ and pyrosequencing had an agreement of 95% (52/55). The Idylla™ EGFR Assay produced results faster and more cost-effective than pyrosequencing. The Idylla™ system showed a good sensitivity and was cost-saving in our setting. Because of the easy workflow, the Idylla™ system has the potential to expand EGFR testing to more pathology laboratories in a reliable and fast manner.

Les méthodes de séquençage de « nouvelle génération » (NGS) et le cancer broncho-pulmonaire: principales technologies, applications et limites actuelles en pathologie

Resume Durant la derniere decennie, des progres spectaculaires ont ete menes dans la comprehension des mecanismes moleculaires et cellulaires gouvernant l’initiation et la progression tumorale des cancers bronchopulmonaires non a petites cellules (CBNPC). En parallele, des progres therapeutiques majeurs ont ete realises avec la decouverte de plusieurs cibles moleculaires et le developpement des therapies ciblees. Actuellement, ces approches sont parfaitement illustrees par le traitement des patients atteints de CBNPC avec des inhibiteurs de tyrosine kinase lorsque la tumeur presente une mutation activatrice sur le gene de l’ EGFR ou un rearrangement du gene ALK . La liste des biomarqueurs analyses en genetique somatique est amenee a s’accroitre a court terme en raison du nombre croissant de therapies ciblees en cours de developpement. Des avancees technologiques recentes se traduisant par le developpement du sequencage de nouvelle generation (NGS) offrent la possibilite d’interroger rapidement et de maniere exhaustive le genome des CBNPC, meme sur des biopsies de petite taille. C’est dans ce contexte que les pathologistes moleculaires doivent faire face au defi de determiner comment selectionner, interpreter et appliquer progressivement dans leur laboratoire ces nouvelles technologies de genomique. Cette revue rapporte l’etat actuel des principales technologies de NGS, leurs applications et leurs limites actuelles, en particulier dans le cadre des CBNPC.