Predictive molecular pathology in non-small cell lung cancer in France: The past, the present and the perspectives

Matched tissue and liquid biopsies for advanced non-small cell lung cancer patients A potentially indispensable complementary approach

The introduction of liquid biopsies (LB) has brought forth a number of therapeutic opportunities into the domain of thoracic oncology. Many of which have been adopted for care of patients presenting with advanced non-squamous non-small cell lung cancer (aNS-NSCLC). For example, one of the most frequent indications to perform a LB in these patients, at least in Europe, is for patients treated with tyrosine kinase inhibitors (TKIs) targeting EGFR and ALK genomic alterations when the tumor progresses. A tissue biopsy (TB) must then be taken, ideally from a site of a tumor that progresses, in particular if the LB does not permit detection of a mechanism of resistance to TKI. A LB from a patient with aNS-NSCLC is recommended before first-line therapy if no tissue and/or cytological material is accessible or if the extracted nucleic acid is insufficient in amount and/or of poor quality. At present a LB and a TB are rarely performed simultaneously before treatment and/or on tumor progression. This complementary/matched testing approach is still controversial but needs to be better evaluated to determine the true benefit to care of patients. This review provides an update on the complementarity of the LB and TB method for care of patients presenting with aNS-NSCLC.

Quality of cell blocks prepared from residual pleural effusion and bronchial washing samples for immunocytochemistry

INTRODUCTION

Cell blocks (CBs) enable the long-term preservation of cytological samples. The aim of this study was to analyse the quality of CBs prepared from leftover fluid from lung adenocarcinoma pleural effusion samples and residual bronchial washing sediment for immunocytochemistry.

METHODS

The residual part of 455 lung adenocarcinoma pleural effusion samples and sediment from 384 bronchial washing samples were used to prepare CBs following the agarose method. The quality of CBs was evaluated based on the quantity of malignant cells in haematoxylin and eosin-stained slides and interpreted as optimal or insufficient for immunocytochemistry. Immunocytochemistry on CBs was performed using the Dako EnVision™ FLEX detection visualisation system. The CB results for TTF-1, ALK, and PD-L1 immunocytochemistry were compared with the corresponding cytological smears.

RESULTS

Among all CBs, 202 (44.4%) from leftover pleural effusion fluid and 85 (22.1%) from residual bronchial washing sediment had an optimal number of lung adenocarcinoma cells. Eight pleural effusion CBs were stained for TTF-1. Four pleural effusion and two bronchial washing CBs were stained for ALK and PD-L1. All tested pleural effusion CBs were confirmed positive for TTF-1 and negative for ALK. The PD-L1 tumour proportion score (TPS) was ≥ 50% in two pleural effusions. ALK was confirmed negative in bronchial washing CBs. One bronchial washing CB was interpreted as PD-L1-negative while the corresponding smear was positive (TPS ≥1%; 2%).

CONCLUSION

The CB results of TTF-1, ALK, and PD-L1 corresponded to the findings for the smears. The inclusion of CBs prepared from leftover fluid from pleural effusion samples and residual bronchial washing sediment in routine cytological practice could provide a source of high-quality material for immunocytochemistry in addition to smears and cytospins.

Molecular Profiling in Non-Squamous Non-Small Cell Lung Carcinoma: Towards a Switch to Next-Generation Sequencing Reflex Testing

Molecular diagnosis of lung cancer is a constantly evolving field thanks to major advances in precision oncology. The wide range of actionable molecular alterations in non-squamous non-small cell lung carcinoma (NS-NSCLC) and the multiplicity of mechanisms of resistance to treatment resulted in the need for repeated testing to establish an accurate molecular diagnosis, as well as to track disease evolution over time. While assessing the increasing complexity of the molecular composition of tumors at baseline, as well as over time, has become increasingly challenging, the emergence and implementation of next-generation sequencing (NGS) testing has extensively facilitated molecular profiling in NS-NSCLC. In this review, we discuss recent developments in the molecular profiling of NS-NSCLC and how NGS addresses current needs, as well as how it can be implemented to address future challenges in the management of NS-NSCLC.

Precision Oncology in Canada: Converting Vision to Reality with Lessons from International Programs

Canada's healthcare system, like others worldwide, is immersed in a process of evolution, attempting to adapt conventional frameworks of health technology assessment (HTA) and funding models to a new landscape of precision medicine in oncology. In particular, the need for real-world evidence in Canada is not matched by the necessary infrastructure and technologies required to integrate genomic and clinical data. Since healthcare systems in many developed nations face similar challenges, we adopted a solutions-based approach and conducted a search of worldwide programs in personalized medicine, with an emphasis on precision oncology. This search strategy included review articles published between 1 January 2016 and 1 March 2021 and hand-searches of their reference lists for relevant publications back to 1 December 2005. Thirty-nine initiatives across 37 countries in Europe, Australasia, Africa, and the Americas had the potential to lead to real-world data (RWD) on the clinical utility of oncology biomarkers. We highlight four initiatives with helpful lessons for Canada: Genomic Medicine France 2025, UNICANCER, the German Medical Informatics Initiative, and CANCER-ID. Among the 35 other programs evaluated, the main themes included the need for collaboration and systems to support data harmonization across multiple jurisdictions. In order to generate RWD in precision oncology that will prove acceptable to HTA bodies, Canada must take a national approach to biomarker strategy and unite all stakeholders at the highest level to overcome jurisdictional and technological barriers.

Daily Practice Assessment of KRAS Status in NSCLC Patients: A New Challenge for the Thoracic Pathologist Is Right around the Corner

Simple Summary

RAS mutation is the most frequent oncogenic alteration in human cancers and KRAS is the most frequently mutated, notably in non-small cell lung carcinomas (NSCLC). Various attempts to inhibit KRAS in the past were unsuccessful in these latter tumors. However, recently, several small molecules (AMG510, MRTX849, JNJ-74699157, and LY3499446) have been developed to specifically target KRAS G12C-mutated tumors, which seems promising for patient treatment and should soon be administered in daily practice for non-squamous (NS)-NSCLC. In this context, it will be mandatory to systematically assess the KRAS status in routine clinical practice, at least in advanced NS-NSCLC, leading to new challenges for thoracic oncologists.

Abstract

KRAS mutations are among the most frequent genomic alterations identified in non-squamous non-small cell lung carcinomas (NS-NSCLC), notably in lung adenocarcinomas. In most cases, these mutations are mutually exclusive, with different genomic alterations currently known to be sensitive to therapies targeting EGFR, ALK, BRAF, ROS1, and NTRK. Recently, several promising clinical trials targeting KRAS mutations, particularly for KRAS G12C-mutated NSCLC, have established new hope for better treatment of patients. In parallel, other studies have shown that NSCLC harboring co-mutations in KRAS and STK11 or KEAP1 have demonstrated primary resistance to immune checkpoint inhibitors. Thus, the assessment of the KRAS status in advanced-stage NS-NSCLC has become essential to setting up an optimal therapeutic strategy in these patients. This stimulated the development of new algorithms for the management of NSCLC samples in pathology laboratories and conditioned reorganization of optimal health care of lung cancer patients by the thoracic pathologists. This review addresses the recent data concerning the detection of KRAS mutations in NSCLC and focuses on the new challenges facing pathologists in daily practice for KRAS status assessment.

Influence of deep-freezing and MGG staining on DNA and RNA quality in different types of lung adenocarcinoma cytological smears

BACKGROUND

Preserving the optimal quality of DNA and RNA is mandatory for molecular testing in lung adenocarcinoma cytological smears (LACSs).

METHODS

DNA and RNA were isolated from 90 frozen unstained and 46 May Grünwald Giemsa (MGG) stained LACSs prepared from bronchial washing (BW), bronchial brushing (BB), and pleural effusion (PE) samples during 3 years. Concentrations of nucleic acids in all LACSs were assessed by spectrophotometric analysis. Fragmentation of DNA and RNA was determined by PCR amplification of selected genes. Amplicons of 100, 200, 300, 400, and 600 bp were used for DNA and 108 bp-long HPRT1 transcript fragment for RNA fragmentation analysis.

RESULTS

Among 90 frozen LACSs, significantly lower DNA concentrations of BB and RNA concentrations of BW samples frozen for 6-10 months were observed in comparison with samples frozen for longer periods (p < .05). Among 46 paired LACSs, 44 (95.7%) frozen and 15 (32.6%) MGG-stained samples showed 600 bp-long DNA amplicons. Statistically significant difference (p < .05) in the fragmentation of DNA between frozen and MGG-stained LACSs was observed (p < .05), with DNA being less fragmented in frozen LACSs. In addition, 33 (71.7%) frozen and 36 (78.2%) MGG-stained LASCs showed HPRT1 gene amplicon of 108 bp. RNA was less fragmented in 3-year old MGG-stained samples than in LACSs frozen for 3 years.

CONCLUSION

DNA and RNA extracted from frozen and MGG-stained LACSs showed different results depending on the time of storage and/or type of samples, but in general all samples had adequate quantity and quality for downstream molecular testing.

EGFR Status Assessment for Better Care of Early Stage Non-Small Cell Lung Carcinoma: What Is Changing in the Daily Practice of Pathologists?

The recent emergence of novel neoadjuvant and/or adjuvant therapies for early stage (I-IIIA) non-small cell lung carcinoma (NSCLC), mainly tyrosine kinase inhibitors (TKIs) targeting EGFR mutations and immunotherapy or chemo-immunotherapy, has suddenly required the evaluation of biomarkers predictive of the efficacy of different treatments in these patients. Currently, the choice of one or another of these treatments mainly depends on the results of immunohistochemistry for PD-L1 and of the status of EGFR and ALK. This new development has led to the setup of different analyses for clinical and molecular pathology laboratories, which have had to rapidly integrate a number of new challenges into daily practice and to establish new organization for decision making. This review outlines the impact of the management of biological samples in laboratories and discusses perspectives for pathologists within the framework of EGFR TKIs in early stage NSCLC.

The roles and mechanisms of the circular RNA circ_104640 in early-stage lung adenocarcinoma: a potential diagnostic and therapeutic target

Background

In recent years, there have been increasing reports that dysregulated circular RNAs (circRNAs) play a key role in the carcinogenesis of lung adenocarcinoma (LUAC). However, the role of circRNAs in early-stage LUAC is poorly understood.

Methods

The Gene Expression Omnibus (GEO) database and qRT-PCR were used to verify the abnormal expression of circRNAs, miRNAs and genes in early-stage LUAC tissues. shRNA and miRNA inhibitor are designed and synthesized to knock down circ_104640 and microRNA (miR)-145-5p expression. CCK-8 assay, colony formation assay and flow cytometry were used to study the effect of circ_104640 on cell proliferation and apoptosis. Bioinformatics analysis, dual luciferase reporter assays and argonaute 2 (Ago2) RNA immunoprecipitation (RIP) assays were chosen to find out the potential target of circ_104640.

Results

Based on the GEO database and tissue sample from our institution, we identified that the circRNA circ_104640, the miR-145-5p, and CCL20 (C-C motif chemokine ligand 20) were abnormally expressed in the tissues of early-stage LUAC. In vitro experiments showed that circ_104640 could exist stably in the cytoplasm, and a short pin RNA that targeted circ_104640 (sh-circ) inhibited cell growth and promoted apoptosis of LUAC cells. Dual luciferase reporter assays and Ago2 (RIP) assays confirmed the Ago2-dependent interaction of circ_104640 and miR-145-5p. In terms of mechanisms, we found that circ_104640 increased the expression of CCL20 by sponging miR-145-5p.

Conclusions

Our research demonstrated that circ_104640 could accelerate the proliferation of LUAC cells, while inhibiting LUAC cell apoptosis. circ_104640 may be a potential novel biomarker and therapeutic target for early-stage LUAC.