Updated Molecular Testing Guideline for the Selection of Lung Cancer Patients for Treatment With Targeted Tyrosine Kinase Inhibitors: Guideline From the College of American Pathologists, the International Association for the Study of Lung Cancer, and the Association for Molecular Pathology

Clinical utility of plasma-based digital next-generation sequencing in patients with advance-stage lung adenocarcinomas with insufficient tumor samples for tissue genotyping

BACKGROUND

Approximately 30% of tumor biopsies from patients with advanced-stage lung adenocarcinomas yield insufficient tissue for successful molecular subtyping. We have analyzed the clinical utility of next-generation sequencing (NGS) of cell-free circulating tumor DNA (ctDNA) in patients with inadequate tumor samples for tissue genotyping.

PATIENTS AND METHODS

We conducted the study in a multi-institutional prospective cohort of clinically unselected patients with advanced-stage lung adenocarcinomas with insufficient tissue for EGFR, ALK or ROS1 genotyping across 12 Spanish institutions (n = 93). ctDNA NGS was carried out by Guardant Health (Guardant360, Redwood City, CA), using a hybrid-capture-based 73-gene panel. Variants were deemed actionable if they were part of the OncoKB precision oncology knowledge database and classified in four levels of actionability based on their clinical or preclinical evidence for drug response.

RESULTS

Eighty-three out of 93 patients (89%) had detectable levels of ctDNA. Potentially actionable level 1-4 genomic alterations were detected in 53 cases (57%), of which 13 (14%) had level 1-2A alterations (Food and Drug Administration-approved and standard-care biomarkers according to lung cancer guidelines). Frequencies of each genomic alteration in ctDNA were consistent with those observed in unselected pulmonary adenocarcinomas. The majority of the patients (62%), particularly those with actionable alterations (87%), had more than one pathogenic variant in ctDNA. The median turnaround time to genomic results was 13 days. Twelve patients (13%) received genotype-matched therapies based on ctDNA results, deriving the expected clinical benefit. Patients with co-occurring pathogenic alterations had a significantly shorter median overall survival as compared with patients without co-occurring pathogenic alteration (multivariate hazard ratio = 5.35, P = 0.01).

CONCLUSION

Digital NGS of ctDNA in lung cancers with insufficient tumor samples for tissue sequencing detects actionable variants that frequently co-occur with other potentially clinically relevant genomic alterations, allowing timely initiation of genotype-matched therapies.

Diagnosis and first-line treatment of non-small cell lung cancer in the era of novel immunotherapy: recommendations for clinical practice

INTRODUCTION

In the era of personalized cancer therapy, the sampling of adequate tumor tissue for histologic diagnosis and genomic profiling is crucial, not only at the initial diagnosis but also in the event of resistant and recurrent disease when sequential biopsies may be required to evaluate somatic mutations and histologic changes. Areas covered: The identification of genetic driver alterations led to the selection of patients who are most likely to benefit from epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) and rat osteosarcoma (ROS-1) tyrosine kinase inhibitors; on the other hand, in the absence of oncogenic alterations, platinum-based doublet chemotherapy regimens were the cornerstone of treatment. However, the advent of immunotherapy has widely changed the first-line treatment. Expert commentary: An Italian Experts Panel Meeting was held to discuss on recommendations for diagnosis (optimization of the cyto/histologic tumor sample issue and management of tissue to molecular evaluation) and immunotherapy as first-line treatment of patients with advanced non-small-cell lung cancer.

Molecular Profile of Advanced Non-Small Cell Lung Cancers in Octogenarians: The Door to Precision Medicine in Elderly Patients

Background: There is a pressing need to expand the evidence base in geriatric lung oncology. Most non-small cell lung cancers (NSCLCs) are diagnosed in the elderly, with approximately 15% of cases affecting octogenarians. Treatment-related decisions are challenging in this population, and the role of biologically driven therapies is still underrated. Methods: A single-institution cohort of 76 NSCLCs from octogenarian patients was submitted to molecular analysis using a next-generation sequencing (NGS) multigene panel, fluorescence in situ hybridization (FISH) analyses, and immunohistochemistry for PD-L1 assessment. Treatment and clinical outcome data were available for 33 patients. Results: Most cases (n = 66, 87%) harbored at least one genomic alteration. EGFR and KRAS mutations were detected in 18 (24%) and 20 (26%) patients, respectively. No ALK alterations were found, but in two patients ROS1 translocation was identified. Of 22 cases tested, 17 were positive for PD-L1 staining. Octogenarian patients who received tyrosine kinase inhibitors (TKIs) based on molecular analysis showed clinical benefits, with long progression-free survival as expected in TKI-treated younger cohorts. Conclusions: This study highlights the utility of molecular profiling in all advanced-stage NSCLCs, regardless of the age at diagnosis, to drive personalized treatment. The prevalence of druggable alterations and the clinical benefits obtained by biologically-driven therapies in octogenarians were comparable to those of the younger NSCLC population.

The diagnosis of non-small cell lung cancer in the molecular era

Lung carcinoma is the leading cause of cancer mortality for both genders in the United States and throughout the world. Many of these tumors are being diagnosed with minimally invasive means resulting in small samples. There is a need to extract an increasing amount of therapeutic and prognostic information from progressively smaller samples. Collaboration among clinicians and pathologists is needed to produce a comprehensive final diagnosis in patients with lung cancer. This collaboration facilitates triage of small samples for ancillary studies including molecular testing. What follows represents a review of the current required testing for lung cancer specimens, an example of an algorithm currently employed at the Cleveland Clinic so that all required tests can be performed even on the smallest of specimens and suggestions on how pathologists may approach this new era of "doing more with less".

The utilization of cytologic and small biopsy samples for ancillary molecular testing

There has recently been an increased emphasis on the utilization of cytologic samples and small biopsies for not only diagnostic purposes but also for ancillary testing. In some instances, the ancillary tests contribute to the diagnosis and in other scenarios, they provide prognostic and theranostic information for the management of patients with advanced stage cancer. These ancillary tests include immunohistochemical biomarker analysis, molecular mutation analysis, and cytogenetic tests. Despite the finite nature of the cellular material procured in cytologic and small tissue biopsies, pathologists are tasked with ordering an increasing number of tests using these limited samples. This requires the pathologists to utilize and triage these samples in an optimal fashion so that as much information can be gleaned from a given specimen. This review will focus on the pre-analytic requirements for ancillary molecular and cytogenetic tests in the context of a discussion of the various preparation methods for cytologic and small biopsy specimens. The goal will be to provide the reader with the necessary concepts that can be utilized to develop optimal specimen selection and triage strategies to maximize the chances of effectively utilizing these samples for comprehensive diagnostic and relevant ancillary testing purposes.

Biomarker Testing for Patients With Advanced Non-Small Cell Lung Cancer: Real-World Issues and Tough Choices

Over the last decade, the treatment of patients with advanced non-small cell lung cancer (NSCLC) has become reliant on tissue and/or blood biomarkers to help guide treatment decisions. There are now multiple biomarker-defined patient subgroups, with evidence showing that treatment with targeted therapies has superior clinical outcomes when compared with traditional cytotoxic chemotherapy. However, rapid change in the field of precision oncology brings with it the challenge of translating recommendations into clinical practice. In this review, we discuss the major guidelines recommending biomarker testing in NSCLC, as well the logistical challenges to applying these guidelines to patients with NSCLC both in the United States and worldwide. The techniques commonly used for biomarker testing will be discussed, both for tissue- and blood-based biomarkers. Finally, we discuss the challenge of interpreting the results of biomarker testing and using these results to guide treatment decisions.

The challenges of evaluating predictive biomarkers using small biopsy tissue samples and liquid biopsies from non-small cell lung cancer patients

The list of theranostic biomarkers for the care of patients with advanced stage or metastatic non-small cell lung cancer has lengthened considerably these last few years. Moreover, the advances in therapeutics will certainly increase the number and complexity of these tests performed in laboratories in the near future. In addition, the methods for investigation of biomarkers that require access to biological tissue are less and less invasive with the consequential increase in the use of small-sized tissue biopsies and cytological and blood samples. Thus, each laboratory must master the management of the biological samples according to the number and type of tests to be performed. This review will provide an update of the difference challenges facing pathologists and biologist in responding to the issues related to new treatments. These challenges concern: (I) the management of the pre-analytical phase; (II) the appropriate choice of the technological approach; (III) the performance of quality control; (IV) the mastering of the delay in obtaining the results; and (V) the economic model of the laboratory.

Therapeutic potential of trametinib to inhibit the mutagenesis by inactivating the protein kinase pathway in non-small cell lung cancer

Introduction:Mitogen-activated protein kinase (MAPK) pathway is known to be involved in the tumorigenesis of cancer cells including non-small cell lung cancer (NSCLC) and kinases involved in this pathway are frequently mutated. The development of new targeted therapies in cancer has led to the evaluation of MEK-inhibitors. Areas covered: This article reviews different studies using trametinib alone, in combination with other targeted therapies or associated with other non-targeted therapies in NSCLC, with a focus on KRAS mutant and BRAF mutant NSCLC. Expert commentary: Trametinib demonstrated activity in association with a BRAF inhibitor when BRAF was mutated. The combination of trametinib and dabrafenib has been approved for this population of BRAF mutant NSCLC patients. For KRAS mutant NSCLC, the combination of trametinib with chemotherapy has showed promising results and should be further assessed. Several clinical trials are ongoing, assessing trametinib in combination with other targeted therapies. In addition, preclinical studies suggest a synergistic effect of trametinib in combination with immune checkpoint inhibitors and such combinations should be studied in clinical trials.

Tumor mutational burden in non-small cell lung cancer-the pathologist's point of view

In non-small cell lung cancer (NSCLC), the pathologist has contributed to the development of personalized medicine from the determination of the right histological type to EGFR and ALK/ROS1 molecular screening for targeted therapies. With the development of immunotherapies, pathologists intervene forefront with programmed death-ligand 1 (PD-L1) immunohistochemical testing, companion test for pembrolizumab monotherapy, first line and complementary test to the other programmed cell death-1 (PD-1) PD-L1 inhibitors. Recently, tumor mutational burden has emerged as a promising tool to evaluate sensitivity to immunotherapy (IO). The pathologist has a crucial role in the setting of tumor mutational burden (TMB) testing for the selection and the preparation of the sample for high throughput molecular analysis, and in the first steps of the next-generation sequencing (NGS) workflow.

Implementing Precision Medicine Programs and Clinical Trials in the Community-Based Oncology Practice: Barriers and Best Practices

There has been a rapid uptick in the pace of oncology precision medicine advancements over the past several decades as a result of increasingly sophisticated technology and the ability to study more patients through innovative trial designs. As more precision oncology approaches are developed, the need for precision medicine trials is increasing in the community setting, where most patients with cancer are treated. However, community-based practices, as well as some academic centers, may face unique barriers to implementing precision medicine programs and trials within their communities. Such challenges include understanding the tissue needs of molecular tests (e.g., tumor, blood), identifying which molecular tests are best used and when tissue should be tested, interpreting the test results and determining actionability, understanding the role of genetic counseling and/or follow-up testing, determining clinical trial eligibility, and assessing patient attitudes and financial concerns. The purpose of this article is to provide guidance to community-based oncology practices currently conducting clinical trials who want to expand their research program to include precision medicine trials. Here, we describe the core components of precision medicine programs and offer best practices for successful implementation of precision medicine trials in community-based practices.

Molecular Diagnostic Assays and Clinicopathologic Implications of MET Exon 14 Skipping Mutation in Non-small-cell Lung Cancer

BACKGROUND

Recent studies revealed MET exon 14 skipping (METex14) as a biomarker that predicts the response to MET inhibitors in non-small-cell lung cancer (NSCLC). However, METex14 genomic alterations exhibit a highly diverse sequence composition, posing a challenge for clinical diagnostic testing. This study aimed to find a reasonable diagnostic assay for METex14 and identify its clinicopathologic implications.

MATERIALS AND METHODS

We performed a comprehensive analysis of METex14 in 414 EGFR/KRAS/ALK/ROS1-negative (quadruple negative) surgically resected NSCLCs. We used real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Sanger sequencing for the first assay, followed by next-generation sequencing (NGS; hybrid-capture targeted DNA/RNA sequencing). Clinicopathologic implications of the METex14 group were analyzed in a total of 880 NSCLCs.

RESULTS

METex14 was confirmed in 13 (3.1%) patients by DNA- and RNA-NGS. After comparison of assay results, qRT-PCR and NGS demonstrated the highest concordance rate. The mean variant allele frequency was 10.5% and 49% in DNA- and RNA-NGS, respectively. DNA-NGS revealed various lengths of indel and substitutions around and in exon 14. Moreover, METex14 was associated with adenocarcinoma (4.8%; 11/230) or sarcomatoid carcinoma (9.5%; 2/21), old age, never-smokers, and early stage of disease.

CONCLUSIONS

METex14 occurs in about 3% of NSCLCs and has characteristic clinicopathologic features. NGS should be the first assay of choice as a multiplex testing. Sanger sequencing can detect METex14, but sensitivity can be hampered by large deletions or low allele frequency. qRT-PCR, an mRNA-based method, is sensitive and specific and can be appropriate for screening METex14 as a single gene testing.

Canadian perspectives: update on inhibition of ALK-positive tumours in advanced non-small-cell lung cancer

Background

Inhibition of the anaplastic lymphoma kinase (alk) oncogenic driver in advanced non-small-cell lung carcinoma (nsclc) improves survival. In 2015, Canadian thoracic oncology specialists published a consensus guideline about the identification and treatment of ALK-positive patients, recommending use of the alk inhibitor crizotinib in the first line. New scientific literature warrants a consensus update.

Methods

Clinical trials of alk inhibitor were reviewed to assess benefits, risks, and implications relative to current Canadian guidance in patients with ALK-positive nsclc.

Results

Randomized phase iii trials have demonstrated clinical benefit for single-agent alectinib and ceritinib used in treatment-naïve patients and as second-line therapy after crizotinib. Phase ii trials have demonstrated activity for single-agent brigatinib and lorlatinib in further lines of therapy. Improved responses in brain metastases were observed for all second- and next/third-generation alk tyrosine kinase inhibitors in patients progressing on crizotinib. Canadian recommendations are therefore revised as follows:■ Patients with advanced nonsquamous nsclc have to be tested for the presence of an ALK rearrangement.■ Treatment-naïve patients with ALK-positive disease should initially be offered single-agent alectinib or ceritinib, or both sequentially.■ Crizotinib-refractory patients should be treated with single-agent alectinib or ceritinib, or both sequentially.■ Further treatments could include single-agent brigatinib or lorlatinib, or both sequentially.■ Patients progressing on alk tyrosine kinase inhibitors should be considered for pemetrexed-based chemotherapy.■ Other systemic therapies should be exhausted before immunotherapy is considered.

Summary

Multiple lines of alk inhibition are now recommended for patients with advanced nsclc with an ALK rearrangement.

ALK (D5F3) CDx: an immunohistochemistry assay to identify ALK-positive NSCLC patients

Screening for anaplastic lymphoma kinase (ALK) rearrangements is a very important process in treatment decision making for advanced non-small-cell lung cancer (NSCLC). Although fluorescent in situ hybridization (FISH) is considered the universally accepted reference standard, it is associated with technical difficulties and high costs that have made global implementation of this assay challenging. Conversely, ALK immunohistochemistry has shown high sensitivity and specificity compared to FISH and other molecular assays and is more cost-effective. In fact, the ALK (D5F3) CDx immunohistochemistry assay was approved by the US Food and Drug Administration as a standalone test for ALK rearrangements in lung cancer in 2015. In this review, we will discuss the overview of ALK rearrangements in NSCLC, various testing methods for ALK rearrangements, and the details of immunohistochemistry for ALK, in particular one with the ALK antibody clone D5F3.

CNS Metastases in Epidermal Growth Factor Receptor Mutation-Positive Non-Small-Cell Lung Cancer: Impact on Health Resource Utilization

PURPOSE

Patients with epidermal growth factor receptor (EGFR) mutation-positive (EGFRm) non-small-cell lung cancer commonly experience disease progression in the CNS. Here, we assess the impact of CNS disease on resource utilization and outcomes in patients who are EGFRm.

METHODS

We completed a retrospective review of all advanced patients who were EGFRm, referred to BC Cancer, and treated with a first- and/or second-generation EGFR tyrosine kinase inhibitor from 2010 to 2015. Baseline characteristics, systemic treatment, and CNS management were collected. We compared health resource utilization (HRU) between patients with CNS-negative disease and those with CNS metastases from the median time of CNS metastases diagnosis to death or last follow-up (9.1 months) and at 9 months preceding death or last follow-up for the CNS-negative group.

RESULTS

Four hundred ninety-nine patients were referred, of which 68% were female; 51% were of Asian ethnicity; and 57%, 37%, and 6% were exon 19, 21, or other, respectively; with a median age of 66 years. Two hundred twenty-nine (46%) of 499 patients developed CNS metastases-39% at diagnosis and 61% over the course of disease. CNS metastases were managed with surgery with or without whole-brain radiotherapy (WBRT; 13%) WBRT alone (73%), stereotactic radiosurgery with or without WBRT (5%), or no CNS-directed therapy (9%). The median time from the development of CNS metastases diagnosis to death was 9.1 months. CNS-negative patients used less HRU versus patients that were CNS-positive in the 9 months preceding death or last follow-up-in the average number of clinic visits (8.53 v 12.71, respectively; P < .001), hospitalizations (0.43 v 0.76, respectively; P < .001), CNS imaging investigations (0.52 v 2.65, respectively; P < .001), emergency room visits (0.03 v 0.14, respectively; P = .001), palliative care unit admission (8% v 10%, respectively; P = .64), and hospice admission (3% v 19%, respectively; P < .001).

CONCLUSION

The incidence of CNS metastases in patients with EGFRm is high and associated with increased HRU. Prevention or delay of CNS metastases with newer systemic therapy options may translate into lower resource utilization.

Alectinib in the treatment of ALK-positive non-small cell lung cancer: an update on its properties, efficacy, safety and place in therapy

Anaplastic lymphoma kinase (ALK) rearrangement is identified in 3–7% of advanced non-small cell lung cancer (NSCLC) cases, and ALK tyrosine kinase inhibitors (TKIs) have revolutionized the management of this subset of NSCLC patients. ALK–TKIs have been proven highly effective in ALK-rearranged advanced NSCLC patients, but after initial responses and benefit, a subsequent progression inevitably occurs. Understanding acquired-resistance mechanisms and defining an appropriate algorithm is becoming even more essential, particularly considering the availability of extremely efficacious next-generation ALK inhibitors. The aim of this review is the analysis of current data about ALK inhibition as a therapeutic strategy in ALK-rearranged NSCLC management, with a focus on a specific ALK–TKI, alectinib. Alectinib is a highly selective inhibitor of ALK and showed systemic and central nervous system (CNS) efficacy in the treatment of this particular population. The change of first-line approach, and consequently of further lines of therapy, in ALK-rearranged NSCLC patients is still a matter of debate. A summary of evidence from randomized trials evaluating alectinib will be presented in order to discuss the available clinical evidence, safety and place in therapy.

Lung Cancers: Molecular Characterization, Clonal Heterogeneity and Evolution, and Cancer Stem Cells

Lung cancer causes the largest number of cancer-related deaths in the world. Most (85%) of lung cancers are classified as non-small-cell lung cancer (NSCLC) and small-cell lung cancer (15%) (SCLC). The 5-year survival rate for NSCLC patients remains very low (about 16% at 5 years). The two predominant NSCLC histological phenotypes are adenocarcinoma (ADC) and squamous cell carcinoma (LSQCC). ADCs display several recurrent genetic alterations, including: KRAS, BRAF and EGFR mutations; recurrent mutations and amplifications of several oncogenes, including ERBB2, MET, FGFR1 and FGFR2; fusion oncogenes involving ALK, ROS1, Neuregulin1 (NRG1) and RET. In LSQCC recurrent mutations of TP53, FGFR1, FGFR2, FGFR3, DDR2 and genes of the PI3K pathway have been detected, quantitative gene abnormalities of PTEN and CDKN2A. Developments in the characterization of lung cancer molecular abnormalities provided a strong rationale for new therapeutic options and for understanding the mechanisms of drug resistance. However, the complexity of lung cancer genomes is particularly high, as shown by deep-sequencing studies supporting the heterogeneity of lung tumors at cellular level, with sub-clones exhibiting different combinations of mutations. Molecular studies performed on lung tumors during treatment have shown the phenomenon of clonal evolution, thus supporting the occurrence of a temporal tumor heterogeneity.

Analysis of a large cohort of non-small cell lung cancers submitted for somatic variant analysis demonstrates that targeted next-generation sequencing is fit for purpose as a molecular diagnostic assay in routine practice

AIMS

Targeted next-generation sequencing (tNGS) is increasingly being adopted as an alternative to single gene testing in some centres. Our aim was to assess the overall fitness and utility of tNGS as a routine clinical test in non-small cell lung cancer (NSCLC).

METHODS

All NSCLC cases submitted to a single laboratory for tNGS analysis over a 3-year period were included. Rejection/failure rates and turnaround times were calculated. For reportable cases, data relating to observed genetic changes likely to be driving tumour growth and/or contributing to therapeutic resistance were extracted. The impact of varied referral site practices (tissue processing and sample format submitted) on analytical outcomes was also considered.

RESULTS

A total of 2796 cases were submitted, of which 217 (7.8%) were rejected and 131 (5.1%) failed. The median turnaround time was seven working days. Of 2448 reported cases, KRAS, EGFR or other recognised driver mutations were observed in 35%, 17% and 5.4%, respectively. Of the remaining cases, 3.5% demonstrated significant incidental evidence of gene amplification. In 15% of EGFR-driven cases, evidence of an EGFR tyrosine kinase inhibitor resistance mechanism was observed. Potential concerns around the provision of slides or precut 'rolls' only (cf, formalin fixed paraffin embedded (FFPE) tissue blocks) as standard practice by certain referral sites were identified.

CONCLUSIONS

A tNGS panel approach is practically achievable, with acceptable success rates and turnaround times, in the context of a routine clinical service. Furthermore, it provides additional clinically and analytically relevant information, which is not available from single gene testing alone.

Computed tomography characteristics of lung adenocarcinomas with epidermal growth factor receptor mutation: A propensity score matching study

OBJECTIVES

We investigated the relationship between computed tomography (CT) characteristics and epidermal growth factor receptor (EGFR) mutations in a large Asian cohort who received surgical resection of invasive lung adenocarcinoma.

MATERIALS AND METHODS

We retrospectively included 864 patients (524 with EGFR mutation and 340 with EGFR wild-type) who received surgical resections for invasive lung adenocarcinomas. After applying propensity score matching, 312 patients with mutated EGFR were matched with 312 patients with wild-type EGFR. CT characteristics, predominant histologic subtype, and CT measurement parameters (volume and estimated diameter of the total tumor and inner solid portion and ground-glass opacity [GGO] proportion) were compared within matched pairs.

RESULTS

Tumors in the EGFR mutation group showed higher proportions of pure ground-glass nodules (4.1% vs 1.3%), GGO-predominant (23.7% vs 14.7%), and solid-predominant part-solid nodules (37.2% vs 31.7%) CT characteristics, whereas EGFR wild-type tumors predominantly presented as pure solid nodules (34.6% vs 52.2%, P < 0.0001). EGFR mutation tumors more frequently had a lepidic-predominant subtype than did EGFR wild-type tumors (20.2% and 11.9%; P < 0.0001), and showed a smaller whole tumor size and solid portion (P < 0.0001) with a higher GGO proportion (P < 0.0001). Tumors with exon 21 missense mutations showed the highest GGO proportion and the smallest inner solid portion size, followed by tumors harboring an exon 19 deletion, compared with EGFR wild-type tumors (posthoc P < 0.01).

CONCLUSION

Adenocarcinomas with EGFR mutations had a higher GGO proportion than those with wild-type EGFR after matching of clinical variables. Lesions with an exon 21 mutation had a higher GGO proportion than lesions with other mutations.

Liquid Biopsy for Advanced Non-Small Cell Lung Cancer (NSCLC): A Statement Paper from the IASLC

The isolation and analysis of circulating cell-free tumor DNA in plasma is a powerful tool with considerable potential to improve clinical outcomes across multiple cancer types, including NSCLC. Assays of this nature that use blood as opposed to tumor samples are frequently referred to as liquid biopsies. An increasing number of innovative platforms have been recently developed that improve not only the fidelity of the molecular analysis but also the number of tests performed on a single specimen. Circulating tumor DNA assays for detection of both EGFR sensitizing and resistance mutations have already entered clinical practice and many other molecular tests - such as detection of resistance mutations for Anaplastic Lymphoma Kinase (ALK) receptor tyrosine kinase rearrangements - are likely to do so in the near future. Due to an abundance of new evidence, an appraisal was warranted to review strengths and weaknesses, to describe what is already in clinical practice and what has yet to be implemented, and to highlight areas in need of further investigation. A multidisciplinary panel of experts in the field of thoracic oncology with interest and expertise in liquid biopsy and molecular pathology was convened by the International Association for the Study of Lung Cancer to evaluate current available evidence with the aim of producing a set of recommendations for the use of liquid biopsy for molecular analysis in guiding the clinical management of advanced NSCLC patients as well as identifying unmet needs. In summary, the panel concluded that liquid biopsy approaches have significant potential to improve patient care, and immediate implementation in the clinic is justified in a number of therapeutic settings relevant to NSCLC.

Latest development of liquid biopsy

Liquid biopsy provides the opportunity of detecting and analyzing cancer in various body fluids. In peripheral blood, apart from circulating cell free DNA, circulating cancer cells and other tumor-associated compounds such as extracellular vesicles are also emerging candidates for detection. Compared to conventional tissue or cytology samples, liquid biopsy is non-invasive, safe, and easy to repeat. In view of tumor heterogeneity, it is also suggested that circulating cell free DNA may be more representative of the whole tumor cells population than a biopsy or cytology sample. In addition to assisting in the initial diagnosis, liquid biopsy can also be tailored for disease monitoring, detecting resistance mutation, tumor recurrence, and perhaps for screening in the future. The accuracy of this test is greatly facilitated by the advances of molecular techniques, from PCR-based methods, DNA sequencing, Digital PCR, to the more state-of-the-art next generation sequencing technologies. Despite the tremendous potential of liquid biopsy, there are limitations and not all clinical relevant cancer biomarkers can be detected in liquid biopsy at the present moment. The clinical utility of many of the tests derived from liquid biopsy required further investigations and clinical validation. This review provides an overview of the concept of liquid biopsy, its clinical applications, and discuss the multifaceted advances in this field.

Biomarkers in the diagnosis of pleural diseases: a 2018 update

The use of biomarkers on pleural fluid (PF) specimens may assist the decision-making process and enhance clinical diagnostic pathways. Three paradigmatic examples are heart failure, tuberculosis and, particularly, malignancy. An elevated PF concentration of the amino-terminal fragment of probrain natriuretic peptide (>1500 pg/ml) is a hallmark of acute decompensated heart failure. Adenosine deaminase, interferon-γ and interleukin-27 are three valuable biomarkers for diagnosing tuberculous pleurisy, yet only the first has been firmly established in clinical practice. Diagnostic PF biomarkers for malignancy can be classified as soluble-protein based, immunocytochemical and nucleic-acid based. Soluble markers (e.g. carcinoembryonic antigen (CEA), carbohydrate antigen 15-3, mesothelin) are only indicative of cancer, but not confirmatory. Immunocytochemical studies on PF cell blocks allow: (a) to distinguish mesothelioma from reactive mesothelial proliferations (e.g. loss of BAP1 nuclear expression, complemented by the demonstration of p16 deletion using fluorescence in situ hybridization, indicate mesothelioma); (b) to separate mesothelioma from adenocarcinoma (e.g. calretinin, CK 5/6, WT-1 and D2-40 are markers of mesothelioma, whereas CEA, EPCAM, TTF-1, napsin A, and claudin 4 are markers of carcinoma); and (c) to reveal tumor origin in pleural metastases of an unknown primary site (e.g. TTF-1 and napsin A for lung adenocarcinoma, p40 for squamous lung cancer, GATA3 and mammaglobin for breast cancer, or synaptophysin and chromogranin A for neuroendocrine tumors). Finally, PF may provide an adequate sample for analysis of molecular markers to guide patients with non-small cell lung cancer to appropriate targeted therapies. Molecular testing must include, at least, mutations of epidermal growth-factor receptor and BRAF V600E, translocations of rat osteosarcoma and anaplastic lymphoma kinase, and expression of programmed death ligand 1.