EGFR Testing in Advanced Non–Small-Cell Lung Cancer, A Mini-Review

Safety and effectiveness of CIMAvax-EGF administered in community polyclinics

In spite of the advances in immunotherapy and targeted therapies, lung cancer continues to be the leading cause of cancer-related death. The epidermal growth factor receptor is an established target for non-small cell lung cancer (NSCLC), and its overactivation by the ligands can induce accelerated proliferation, angiogenesis, and metastasis as well as proinflammatory or immunosuppressive signals. CIMAvax-EGF is an epidermal growth factor (EGF)-depleting immunotherapy that is approved for the treatment of NSCLC patients in Cuba. The study was designed as a phase IV trial to characterize the safety and effectiveness of CIMAvax-EGF in advanced NSCLC patients treated in 119 community polyclinics and 24 hospitals. CIMAvax-EGF treatment consisted of four bi-weekly doses followed by monthly boosters. Overall, 741 NSCLC patients ineligible for further cancer-specific treatment were enrolled. CIMAvax-EGF was safe, and the most common adverse events consisted of mild-to-moderate injection site reactions, fever, chills, tremors, and headache. For patients completing the loading doses, the median survival was 9.9 months. For individuals achieving at least stable disease to the frontline and completing vaccination induction, the median survival was 12 months. Most of the functional activities and symptoms evaluated through the European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 questionnaire improved over time. In conclusion, this real-world trial demonstrated that CIMAvax-EGF was safe and effective in patients who were vaccinated in the maintenance scenario. A larger effect was seen in subjects with poor prognosis like those with squamous tumors and high EGF levels. Remarkably, this community-based intervention was very important because it demonstrated the feasibility of treating advanced lung cancer patients with active immunotherapy in primary care institutions. In addition to CIMAvax-EGF, patients received supportive care at the community clinic. Vaccine administration by the family doctors at the polyclinics reduced the patients' burden on the medical oncology services that continued providing chemotherapy and other complex therapies. We conclude that community polyclinics constitute the optimal scenario for administering those cancer vaccines that are safe and require prolonged maintenance in patients with advanced cancer, despite the continuous deterioration of their general condition.

Clinical trial registration

https://rpcec.sld.cu/trials/RPCEC00000205-En, identifier RPCEC00000205.

EGFR exon 19 insertion EGFR-K745_E746insIPVAIK and others with rare XPVAIK amino-acid insertions: Preclinical and clinical characterization of the favorable therapeutic window to all classes of approved EGFR kinase inhibitors

BACKGROUND

The epidermal growth factor receptor (EGFR)-K745_E746insIPVAIK and others with XPVAIK amino-acid insertions are exon 19 insertion mutations, which, at the structural modeling level, resemble EGFR tyrosine kinase inhibitor (TKI)-sensitizing mutants. An important unmet need is the characterization of therapeutic windows plus clinical outcomes of exon 19 XPVAIK amino-acid insertion mutations to available EGFR TKIs.

METHODS

We used preclinical models of EGFR-K745_E746insIPVAIK and more typical EGFR mutations (exon 19 deletion, L858R, L861Q, G719S, A763_Y764insFQEA, other exon 20 insertion mutations) to probe representative 1st (erlotinib), 2nd (afatinib), 3rd generation (osimertinib), and EGFR exon 20 insertion active (mobocertinib) TKIs. We also compiled outcomes of EGFR exon 19 insertion mutated lung cancers-from our institution plus the literature-treated with EGFR TKIs.

RESULTS

Exon 19 insertions represented 0.3-0.8% of all EGFR kinase domain mutation in two cohorts (n = 1772). Cells driven by EGFR-K745_E746insIPVAIK had sensitivity to all classes of approved EGFR TKIs when compared to cells driven by EGFR-WT in proliferation assays and at the protein level. However, the therapeutic window of EGFR-K745_E746insIPVAIK driven cells was most akin to those of cells driven by EGFR-L861Q and EGFR-A763_Y764insFQEA than the more sensitive patterns seen with cells driven by an EGFR exon 19 deletion or EGFR-L858R. The majority (69.2%, n = 26) of patients with lung cancers harboring EGFR-K745_E746insIPVAIK and other mutations with rare XPVAIK amino-acid insertions responded to clinically available EGFR TKIs (including icotinib, gefitinib, erlotinib, afatinib and osimertinib), with heterogeneous periods of progression-free survival. Mechanisms of acquired EGFR TKI resistance of this mutant remained underreported.

CONCLUSIONS

This is the largest preclinical/clinical report to highlight that EGFR-K745_E746insIPVAIK and other mutations with exon 19 XPVAIK amino-acid insertions are rare but sensitive to clinically available 1st, 2nd, and 3rd generation as well as EGFR exon 20 active TKIs; in a pattern that mostly resembles the outcomes of models with EGFR-L861Q and EGFR-A763_Y764insFQEA mutations. These data may help with the off-label selection of EGFR TKIs and clinical expectations of outcomes when targeted therapy is deployed for these EGFR mutated lung cancers.

Non-small Cell Lung Cancer with EGFR or HER2 Exon 20 Insertion Mutations: Diagnosis and Treatment Options

Molecular testing is performed upon diagnosis of non-small cell lung cancer (NSCLC) because of the large success of targeted therapies for oncogenic mutations. Epidermal growth factor receptor (EGFR) mutations are the most commonly identified mutation in NSCLC, and EGFR exon 20 insertion mutations (exon20ins) are the third most common mutation in EGFR following EGFR exon 19 deletions and exon 21 L858R mutations. EGFR exon20ins have regularly demonstrated resistance to classical EGFR inhibition. Two treatments-mobocertinib and amivantamab-have recently been the first drugs to be approved by the US Food and Drug Administration (FDA) for treatment of lung cancers with these mutations following platinum-based therapy. Research surrounding these two drugs demonstrates strong efficacy, but with an intense array of side effects. Another targetable driver mutation is the human epidermal growth factor receptor 2 (HER2) exon20ins, representing approximately 2-3% of NSCLC patients. This mutation has been heavily studied in vitro as well as clinically, and trastuzumab deruxtecan was just recently granted accelerated FDA approval based on the high efficacy demonstrated in the Destiny-Lung01 study. However, similar to their EGFR counterparts, HER2 inhibitors also have evidence of toxicity in clinical studies. In this paper, we discuss the limited response of EGFR and HER2 exon20ins to a wide range of standard treatment regimens, such as platinum-based chemotherapy and classic EGFR tyrosine kinase inhibitors, as well as immunotherapy. We also review recently approved and upcoming targeted therapeutic options, considering what research is presently being done regarding efficacy and the reduction of side effects, as well as the agents' risks and benefits for incorporation into an approved treatment regimen.

CD73 (NT5E) Promotes the Proliferation and Metastasis of Lung Adenocarcinoma through the EGFR/AKT/mTOR Pathway

Introduction

Lung cancer is the most common malignant tumor and the main cause of tumor-related death globally. As the 5-year survival rate of lung adenocarcinoma (LUAD) remains low, it is necessary to investigate novel molecular markers and therapeutic targets for LUAD.

Materials and Methods

The protein expression of CD73 (NT5E) in LUAD specimens was analyzed using immunohistochemistry. Reverse transcription-quantitative PCR and western blot analysis were used to analyze the mRNA and protein expression levels of several genes in LUAD cells. The proliferation of LUAD cells was evaluated using proliferation and colony formation assays and apoptosis analysis. Wound healing and Transwell invasion assays were used to analyze the migration and invasion of the A549 cells, respectively. In addition, overexpression plasmids and small interfering RNAs were used to overexpress or knockdown the expression levels of CD73 in the A549 cell line, respectively. Finally, the interaction between CD73 and EGFR in the A549 cell line was analyzed using immunoprecipitation.

Results

Our research emphasized the importance of CD73 in the prognosis of LUAD and highlighted it as a potential therapeutic target. We also found that the mRNA and protein expression levels of CD73 are increased in LUAD specimens and cell lines and were associated with a poor prognosis in patients with LUAD. Furthermore, it was revealed that CD73 may promote the proliferation, migration, and invasion of the A549 cell line. Finally, we demonstrated that CD73 could bind epidermal growth factor receptor (EGFR) to further regulate the activation of the AKT/mTOR signaling pathway.

Conclusions

CD73 promotes LUAD proliferation and metastasis through EGFR/AKT/mTOR axis.

Diagnostic-Therapeutic Pathway and Outcomes of Early Stage NSCLC: a Focus on EGFR Testing in the Real-World

Background

Osimertinib is considered the standard-of-care for previously-untreated EGFR mutant advanced non-small cell lung cancer (NSCLC). Oncogene driver screening in early NSCLC is not standard practice. A real-world study has been designed in order to investigate the optimal testing frequency and timing for EGFR mutations in early NSCLC in clinical practice.

Patients and Methods

The present observational, retrospective study evaluated the real-world diagnostic-therapeutic pathway and clinical outcomes of 225 patients with stage I-III NSCLC, with particular reference to the EGFR-mutant subgroup.

Results

Prior to surgery, 101 patients had undergone a diagnostic biopsy; EGFR mutational analysis was available in 56 (55%) patients and 12 patients (21%) had a cancer harboring an EGFR mutation. Among surgical specimens, reflex EGFR test was performed in 181 (80%) of 225 and 35 cases (19%) were EGFR mutant. The majority of patients had not received adjuvant chemotherapy (N=174, 77%) or adjuvant radiotherapy (N=201, 89%). Of 49 (22%) patients experiencing disease relapse, 26 (53%) received first-line systemic treatment. All EGFR-mutant relapsed patients (N=6, 12.2%) received an EGFR-TKI. Median overall survival (OS) and relapse-free survival for the entire population were not reached. Multivariate analysis for OS confirmed a significant correlation with age, female gender, EGFR status, necrosis score, perineural invasion, and relapsed disease. EGFR test costs represented 1.6-2.4% of the total costs of management per patient (€34,340).

Conclusions

Our results suggest that the frequency of EGFR mutations in early stage (I-III) NSCLC is similar to that of advanced stages. Reflex EGFR testing in all early-stage NSCLC at diagnosis or after surgery appears to be a valid tool to give patients the chance to benefit from targeted adjuvant treatment.

Dealing with NSCLC EGFR mutation testing and treatment: A comprehensive review with an Italian real-world perspective

Since their discovery, relevant efforts have been made to optimize the detection approaches to EGFR mutations as well as the clinical management of EGFR-mutated NSCLC. The recent shift from single gene testing to novel comprehensive detection platforms along with the development of new generation tyrosine kinase inhibitors, targeting both common and uncommon EGFR-mutations, is leading to a progressive increase in the number of patients who may benefit from targeted approaches, with subsequent impact on their long-term survival and quality of life. However, a prompt and adequate implementation of the most recent diagnostic and treatment advances in the routine practice often remains critical to be specifically addressed. In this review we provide a complete and updated overview of the different detection platforms and therapeutic options currently available for the clinical management of advanced EGFR-positive NSCLC, summarizing scientific evidence and describing molecular testing as well as treatment practice in the real-word scenario.

Targeted Assessment of the EGFR Status as Reflex Testing in Treatment-Naive Non-Squamous Cell Lung Carcinoma Patients: A Single Laboratory Experience (LPCE, Nice, France)

Background: Assessment of actionable EGFR mutations is mandatory for treatment-naïve advanced or metastatic non-squamous lung carcinoma (NSLC), but the results need to be obtained in less than 10 working days. For rapid EGFR testing, an EGFR-specific polymerase chain reaction (PCR) assay is an alternative and simple approach compared to next generation sequencing (NGS). Here, we describe how a rapid EGFR-specific PCR assay can be implemented in a single laboratory center (LPCE, Nice, France) as reflex testing in treatment-naïve NSLC. Methods: A total of 901 biopsies from NSLC with more than 10% of tumor cells were prospectively and consecutively evaluated for EGFR mutation status between November 2017 and December 2019 using the Idylla system (Biocartis NV, Mechelen, Belgium). NGS was performed for nonsmokers with NSLC wild type for EGFR, ALK, ROS1, and BRAF and with less than 50% PD-L1 positive cells using the Hotspot panel (Thermo Fisher Scientific, Waltham, MA, USA). Results: Results were obtained from 889/901 (97%) biopsies with detection of EGFR mutations in 114/889 (13%) cases using the Idylla system. Among the 562 EGFR wild type tumors identified with Idylla, NGS detected one actionable and one nonactionable EGFR mutation. Conclusions: Rapid and targeted assessment of EGFR mutations in treatment-naïve NSLC can be implemented in routine clinical practice. However, it is mandatory to integrate this approach into a molecular algorithm that allows evaluation of potentially actionable genomic alterations other than EGFR mutations.

Current applications of molecular testing on body cavity fluids

INTRODUCTION

Effusion cytology has a high sensitivity for the diagnosis of malignancy and provides abundant material for molecular testing. Effusion draining is a minimally invasive procedure with few complications.

MATERIALS AND METHODS

We performed a review of publications regarding the use of molecular testing in serous effusions.

RESULTS

In diagnostics, BAP-1 IHC and CDKN2A FISH are powerful tools for the diagnosis of malignant mesothelioma. FISH, PCR, and EBER-ISH work well in lymphomas. RT-PCR may enhance the diagnosis of secondary epithelial malignancies. In theranostics, molecular testing on serous effusions is widely reported for the detection of alterations in genes related to lung carcinomas, such as EGFR, ALK, ROS1, and BRAF. PD-L1 expression testing by immunohistochemistry (IHC) also seems to be viable in this type of sample. HER2 FISH and IHC provide actionable results in the context of breast malignancies. Results in serous effusions seem to be equivalent to tissue biopsies for most applications and across different molecular techniques. The most interesting technology is next-generation sequencing (NGS), given its ability to sequence multiple genes on a single sample and the decreasing costs that have closely followed increasing throughputs. Cell-free DNA from effusion supernatants might be the most promising area for future research, showing superiority to serum and even to cell-block samples in limited studies.

CONCLUSIONS

Molecular tests are viable in serous effusion specimens when sufficient material is available. Given the rising importance of molecular testing we expect this to be an active field of research in the near future.

A profile on cobas® EGFR Mutation Test v2 as companion diagnostic for first-line treatment of patients with non-small cell lung cancer

INTRODUCTION

Among non-small cell lung cancer (NSCLC) patients, there is one molecularly defined subgroup harboring activating mutations in the epidermal growth factor receptor gene (EGFR), which results in constitutive activation of its intrinsic kinase activity. Consistent data have demonstrated that these patients have a better outcome when treated with specific tyrosine-kinase inhibitors (EGFR-TKIs). Therefore, analysis of EGFR mutational status for treatment guidance is mandatory in this context.

AREAS COVERED

Herein we review the clinical development and technical features of cobas® EGFR Mutation Test v2 as a companion diagnostic test (CDx) for therapy with EGFR-TKIs, such as gefitinib, in advanced NSCLC. We also discuss the pros and cons of the current version of the CDx and its performance in both tissue and plasma samples.

EXPERT OPINION

The RT-PCR based cobas® EGFR Mutation Test v2 is a reliable and rapid solution for EGFR mutational status assessment at the time of diagnosis in advanced NSCLC that allows eligibility of patients for EGFR-TKI treatment. This test determines EGFR mutations with acceptable sensitivity in tissue or plasma samples. Pre-analytical considerations like tumor cell content, tumor burden or location of metastasis should be considered to better interpret results in the clinical contexture.

[Histology, cytology and molecular diagnostics of lung cancer]

Traditionally, tissue-based histopathological approaches play an outstanding role in the diagnostics of lung cancer. The importance of these methods has become even more important with the introduction of individualized treatment options. Lung cancer is basically classified following the World Health Organization (WHO) guidelines using conventional histology and immunohistochemistry. For individual entities in certain clinical stages, the evaluation of the tumor biological profile serves as the basis for the so-called individualized treatment or precision medicine where changes in the intracellular signal transduction mechanisms are the target of therapeutic efforts or the therapy tries to re-initiate immunogenic reactions of the autologous immune system against the tumor cells. The histopathologic overexpression of receptors as well as various genetic and epigenetic changes (e.g. inversion, translocation and methylation) are the key players for predictive approaches to uncover the individual tumor biology and to make treatment decisions.

Proceedings of the American Society of Cytopathology companion session at the 2019 United States and Canadian Academy of Pathology Annual meeting, part 2: effusion cytology with focus on theranostics and diagnosis of malignant mesothelioma

We live in the "era" of minimally invasive procedures, molecular testing, and personalized care. Effusions have a high sensitivity and will often yield diagnostic cytological material. The companion session presented by the American Society of Cytopathology at the 2019 United States and Canadian Academy of Pathology meeting outlined our current and future projected practices in characterizing, managing, and diagnosing serous cavity fluids. In this second part, the role of theranostics and the diagnosis of malignant mesothelioma, as was discussed at the meeting, have been highlighted. In theranostics, a vast amount of data has been reported regarding the epidermal growth factor receptor and related molecules. Some studies have also reported on HER2 immunohistochemistry and fluorescence in situ hybridization. This follows the most active areas of research in targeted therapy. Furthermore, during this session, malignant mesothelioma was extensively discussed. The cytologic diagnosis of malignant mesothelioma in effusion specimens has been controversial; however, a definitive diagnosis will be possible in many cases. Radiologic information should be sought, because the radiologist can often provide a definite or very likely diagnosis of malignancy. Microscopically, high cellularity and/or numerous balls of cells or papillary groups will favor the diagnosis of mesothelioma. It is important to exclude metastatic carcinoma with a broad-spectrum carcinoma marker, of which claudin-4 has been the best, because it will not cross react with mesothelioma. BAP1 and MTAP immunohistochemistry and CDKN2A fluorescence in situ hybridization are very useful adjunctive techniques for separating benign from malignant mesothelial proliferations. The use of 2 of these approaches together will produce a sensitivity of 80% to 90% for epithelial mesotheliomas in the pleura, although the sensitivity has been lower in the peritoneal cavity.

Selecting short length nucleic acids localized in exosomes improves plasma EGFR mutation detection in NSCLC patients

Background

Exosomal nucleic acid (exoNA) is a feasible target to improve the sensitivity of EGFR mutation testing in non-small cell lung cancer patients with limited cell-free DNA (cfDNA) mutant copies. However, the type and size of target exoNA related to the sensitivity of EGFR mutation testing has not been explored extensively.

Methods

The type and size of target exoNA related to the sensitivity of EGFR mutation testing was evaluated using ddPCR. A total of 47 plasma samples was tested using short-length exoTNA (exosomal DNA and RNA) and cfDNA.

Results

The sensitivity of short-length exoTNA (76.5%) was higher than that of cfDNA (64.7%) for detecting EGFR mutations in NSCLC patients. In EGFR-mutant NSCLC patients with intrathoracic disease (M0/M1a) or cases with low-copy T790M, the positive rate was 63.6% (N = 7/11) and 45.5% (N = 5/11) for short-length exoTNA and cfDNA, respectively. On average, the number absolute mutant copies of short-length exoTNA were 1.5 times higher than that of cfDNA. The mutant allele copies (Ex19del and T790M) in short-length exoTNA were relatively well preserved at 4 weeks after storage. The difference (%) in absolute mutant allele copies (Ex19del) between 0 days and 4 weeks after storage was − 61.0% for cfDNA.

Conclusion

Target nucleic acids and their size distribution may be critical considerations for selecting an extraction method and a detection assay. A short-length exoTNA (200 bp) contained more detectable tumor-derived nucleic acids than exoDNA (~ 200 bp length or a full-length) or cfDNA. Therefore, a short-length exoTNA as a sensitive biomarker might be useful to detect EGFR mutants for NSCLC patients with low copy number of the mutation target.

Comparison of Epidermal Growth Factor Receptor Gene Mutations Identified Using Pleural Effusion and Primary Tumor Tissue Samples in Non-Small Cell Lung Cancer

BACKGROUND

Although the use of pleural effusion samples for epidermal growth factor receptor (EGFR) testing in lung cancer is increasing, the accuracy rate and effectiveness of identifying EGFR mutations using these samples, rather than primary tumor tissue samples, is not established.

MATERIALS AND METHODS

One hundred ninety-two advanced, non-small cell lung cancer patients were enrolled into this study. All patients had primary tumor tissue and corresponding pleural effusion samples, and we employed the Amplification Refractory Mutation System to detect EGFR gene mutations in these samples.

RESULT

The number of EGFR mutations detected in primary tumor tissue and pleural effusion samples was 119 (61.98%) and 113 (58.85%), respectively. The EGFR-mutation rate was significantly higher in female than in male patients, and in adenocarcinoma than in nonadenocarcinoma patients (P=0.000). Single mutations in exons 19 and 21 were the predominant observed mutation type, and the overall concordance rate of EGFR-mutation status between the 192 matched pleural effusion and primary tumor tissue samples was 86.98%.

CONCLUSIONS

We observed a high concordance rate between EGFR mutations identified using primary tumor tissue and corresponding pleural effusion samples by Amplification Refractory Mutation System. Thus, it is likely that pleural effusion sampling from advanced non-small cell lung cancer patients, especially those with adenocarcinoma, may be effective in EGFR-mutation screening.

Lycorine inhibited the cell growth of non-small cell lung cancer by modulating the miR-186/CDK1 axis

AIMS

Lycorine is a kind of natural alkaloid with anti-cancer potential. It has been demonstrated that lycorine processes high activity and specificity against the progression of cancers. However, the underlying molecular mechanisms by which lycorine regulates the formation and development of non-small cell lung cancer (NSCLC) remain largely unknown.

MAIN METHODS

The effects of lycorine on the growth of NSCLC cells were determined by the cell counting kit-8 (CCK-8) assay, colony formation and flow cytometry analysis. RT-qPCR was performed to detect the expression of microRNA with lycorine treatment. The binding of miRNA and target genes was confirmed by luciferase reporter assay.

KEY FINDINGS

Lycorine significantly inhibited the proliferation and induced apoptosis of NSCLC cells. Mechanistically, lycorine up-regulated the expression of microRNA-186 in NSCLC cells. Depletion of miR-186 significantly reversed the suppressive effect of lycorine on the proliferation of NSCLC cells. Furthermore, the cyclin dependent kinase 1 (CDK1) was identified as one of the binding candidates of miR-186. Experimental analysis showed that miR-186 bound the 3'-untranslated region (3'-UTR) of CDK1 and suppressed the level of CDK1 in NSCLC cells. Consistently, exposure of lycorine significantly decreased the expression of CDK1. Restoration of CDK1 remarkably attenuated the inhibition of lycorine on the proliferation of NSCLC cells.

SIGNIFICANCE

Our results uncovered the novel molecular mechanism of lycorine in suppressing the progression of NSCLC partially via regulating the miR-186/CDK1 axis.

Impact of KEAP1/NFE2L2/CUL3 mutations on duration of response to EGFR tyrosine kinase inhibitors in EGFR mutated non-small cell lung cancer

OBJECTIVES

For patients with Epidermal Growth Factor Receptor (EGFR)-mutated non-small cell lung cancer (NSCLC), frontline EGFR-tyrosine kinase inhibitor (TKI) therapy compared to chemotherapy improves outcomes. However, resistance to these agents uniformly develops. Recently, mutations in the KEAP1-NFE2L2 pathway have been implicated as a potential mechanism of acquired EGFR TKI resistance.

MATERIALS AND METHODS

We examined all patients with metastatic NSCLC with mutations in both EGFR and KEAP1/NFE2L2/CUL3 identified on next generation sequencing from 2015 - 2018. These patients were compared to a NSCLC control cohort with mutations in EGFR and wild type in KEAP1/NFE2L2/CUL3 matched on the basis of sex, smoking status, age and race. Time to treatment failure on EGFR TKI therapy and overall survival were examined.

RESULTS

Among 228 EGFR mutant NSCLCs, 17 (7%) also carried mutations in KEAP1, NFE2L2, or CUL3. The most common co-mutation in both the KEAP1/NFE2L2/CUL3 mutant and wild-type cohort was TP53. Patients with KEAP1/NFE2L2/CUL3 mutations had a shorter median time to treatment failure on EGFR TKI (4.7 months) compared with the wild-type matched cohort (13.0 months), p= 0.0014. There was no difference in overall survival.

CONCLUSION

For NSCLC patients with mutations in EGFR, co-mutations in KEAP1/NFE2L2/CUL3 are associated with significantly decreased time to treatment failure. Our results suggest that these mutations represent a mechanism of intrinsic resistance to TKI treatment.

Biomarkers in Non-Small Cell Lung Cancers: Indian Consensus Guidelines for Molecular Testing

Novel molecular targets and promising targeted therapies have reshaped diagnostics in patients with advanced non-small cell lung cancer (NSCLC). Despite this progress, the implementation of molecular screening to identify predictive biomarkers in Indian clinical and pathology settings has been challenging due to operational and logistical constraints. This consensus guideline brings together medical oncologists, molecular pathologists and pathologists from India to provide a quick and competent reference for biomarker testing in NSCLC. The guideline summarizes the importance of targetable mutations in NSCLC such as epidermal growth factor receptor (EGFR), rearrangements in anaplastic lymphoma kinase and receptor tyrosine kinase encoded by ROS-1 gene, overexpression of programmed cell death ligand-1 and resistant EGFR mutations. It reaffirms recommendations from international working groups, discusses vulnerable pre-analytical procedures and provides a balanced review on the pros and cons of different diagnostic tests (immunohistochemistry, fluorescence in situ hybridization, polymerase chain reaction-based testing and next-generation sequencing). The document also provides an algorithm to aid diagnostic decision-making and a checklist to assess the quality of testing laboratories that will help the medical oncologists make an informed choice. Overall, these recommendations are based on evidence and clinical experience and will aid policymakers, oncologists, health care practitioners and pathologists who strive to implement molecular strategies and make informed decisions for improved care in NSCLC in India.Funding: AstraZeneca Pharma India Limited.

Acquired Resistance to Tyrosine Kinase Inhibitors in Non-Small Cell Lung Cancers: The Role of Next-Generation Sequencing on Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration Samples

CONTEXT

- Molecular testing is essential for the diagnostic workup of patients with advanced non-small cell lung cancers. Cytology specimens from minimally invasive procedures, such as endobronchial ultrasound-guided transbronchial needle aspiration, are often the only available samples for these patients. The implementation of molecular diagnostic testing, and in particular next-generation sequencing-based testing, on these cytologic specimens is currently an evolving field for lung cytopathology. The application of these molecular analyses on tyrosine kinase inhibitor-resistant non-small cell lung cancers raises unique technical, biologic, and clinical challenges.

OBJECTIVE

- To provide an overview of the implementation of next-generation sequencing analysis on endobronchial ultrasound-guided transbronchial needle aspiration samples to detect the molecular aberrations underneath the phenomenon of acquired resistance in patients with non-small cell lung cancers progressing while on the EGFR/ALK tyrosine kinase inhibitor treatment.

DATA SOURCES

- Peer-reviewed original articles, review articles, and published guidelines and expert opinion reports were reviewed, together with our single-center experience.

CONCLUSIONS

- Next-generation sequencing analyses and the endobronchial ultrasound-guided transbronchial needle aspiration procedure may represent a valuable strategy to address the unique requirements of molecular testing on tyrosine kinase inhibitor-resistant non-small cell lung cancers.

The Dynamic Use of EGFR Mutation Analysis in Cell-Free DNA as a Follow-Up Biomarker during Different Treatment Lines in Non-Small-Cell Lung Cancer Patients

Epidermal growth factor receptor (EGFR) mutational testing in advanced non-small-cell lung cancer (NSCLC) is usually performed in tumor tissue, although cfDNA (cell-free DNA) could be an alternative. We evaluated EGFR mutations in cfDNA as a complementary tool in patients, who had already known EGFR mutations in tumor tissue and were treated with either EGFR-tyrosine kinase inhibitors (TKIs) or chemotherapy. We obtained plasma samples from 21 advanced NSCLC patients with known EGFR tumor mutations, before and during therapy with EGFR-TKIs and/or chemotherapy. cfDNA was isolated and EGFR mutations were analyzed with the multiple targeted cobas EGFR Mutation Test v2. EGFR mutations were detected at baseline in cfDNA from 57% of patients. The semiquantitative index (SQI) significantly decreased from the baseline (median = 11, IQR = 9.5-13) to the best response (median = 0, IQR = 0-0, p < 0.01), followed by a significant increase at progression (median = 11, IQR = 11-15, p < 0.01) in patients treated with either EGFR-TKIs or chemotherapy. The SQI obtained with the cobas EGFR Mutation Test v2 did not correlate with the concentration in copies/mL determined by droplet digital PCR. Resistance mutation p.T790M was observed at progression in patients with either type of treatment. In conclusion, cfDNA multiple targeted EGFR mutation analysis is useful for treatment monitoring in tissue of EGFR-positive NSCLC patients independently of the drug received.

Epidermal Growth Factor Receptor Gene Mutation Status in Primary Lung Adenocarcinoma and Corresponding Bone Metastases

BACKGROUND

The aim of this study was to compare epidermal growth factor receptor (EGFR) mutations between primary tumors and corresponding bone metastases (BMs) in lung adenocarcinoma.

MATERIALS AND METHODS

In total, 115 paired primary lung adenocarcinoma and corresponding BM tumors were analyzed for EGFR mutations by Amplification Refractory Mutation System.

RESULTS

EGFR mutations were detected in 61 primary lung adenocarcinomas (53.04%) and in 67 corresponding metastases (58.26%), respectively. The EGFR mutation rate was significantly higher in female and in never-smoker patients. The consistency of EGFR mutations between the 115 matched BMs and primary tumor tissue samples reached to 80.87%, and the disparity was 19.13%. Mutations in exons 19 (19-del) and 21 (point mutation L858R) were the predominant mutation type.

CONCLUSIONS

The concordance rate demonstrated the feasibility of EGFR mutations in corresponding metastases using Amplification Refractory Mutation System when the primary tumor tissue is unavailable in the lung adenocarcinoma patients, and the inconsistency indicates that corresponding metastasis being screened simultaneously with the primary tumor samples may present some supplementary information for the patients.

De Novo MET Amplification in Chinese Patients With Non-Small-Cell Lung Cancer and Treatment Efficacy With Crizotinib: A Multicenter Retrospective Study

BACKGROUND

De novo mesenchymal-epithelial transition (MET) amplification represents an uncommon oncogenic event in patients with non-small-cell lung cancer, and little is known about the clinicopathologic characteristics, treatment, and prognosis of these patients.

PATIENTS AND METHODS

Patient data were retrospectively collected in 5 hospitals in China from 2014 to 2016. All MET amplification was identified with fluorescence in-situ hybridization. A MET/centromere ratio (MET/CEN) of ≥ 1.8 was defined as positive for MET amplification.

RESULTS

Amplification of the de novo MET gene was identified in 47 patients with lung cancer. Thirty-two patients had a MET/CEN > 5, while 12 patients had intermediate-level amplification and only 3 had low-level amplification. Nine of 40 patients with advanced stage disease had brain metastases, and 15 had a solid predominant subtype of adenocarcinoma. Fifteen patients were treated with crizotinib. Of these, 11 patients (73.3%) had a partial response, 3 (20%) stable disease, and 1 (6.7%) progressive disease. The median progression-free survival of the 15 patients treated with crizotinib was 6.5 months (95% confidence interval, 2.7-10.3). Notably, treatment efficacy was more pronounced in patients with high-level MET amplification than in those with intermediate-level amplification (8.6 vs. 4.4 months, P = .008). The overall survival of patients with and without crizotinib treatment was 31.0 and 13.7 months, respectively (P = .001).

CONCLUSION

We observed a trend toward a high prevalence of the solid predominant subtype of adenocarcinoma and of brain metastases in this group of patients. Patients with de novo MET amplification benefit from crizotinib treatment, especially those with high-level amplification.

EGFR-TKI-sensitive mutations in lung carcinomas: are they related to clinical features and CT findings?

Background

Epidermal growth factor receptor (EGFR) mutation testing is restricted to several limitations. In this study, we examined the relationship between EGFR mutation status and clinicoradiological characteristics in a Chinese cohort of patients.

Materials and methods

The data of patients who were diagnosed with lung carcinoma and underwent both EGFR testing and chest computed tomography (CT) at our hospital between January 1, 2011, and November 31, 2015, were retrospectively analyzed. The age, sex, and smoking index of the patients, the size, margin, and density of the tumor, and the presence of specific signs visible on the CT images were assessed.

Results

The results showed a higher rate of EGFR-tyrosine kinase inhibitor (TKI)-sensitive group than nonsensitive group in female patients and patients with a low smoking index (P<0.001, both). In logistic regression analyses, tumor size (P<0.001), smooth margins (P=0.015), and angular margins (P<0.001) were independent negative predictors of EGFR-TKI-sensitive group. Pleural indentation (P<0.001) and air bronchogram (P=0.025) were independent positive predictors of EGFR-TKI-sensitive group. Patients with squamous cell carcinoma had fewer sensitive mutations than those with either adenocarcinoma (P<0.001) or adenosquamous carcinoma (P<0.001).

Conclusion

Clinical and CT characteristics differed significantly between EGFR-TKI-sensitive and nonsensitive groups. Our findings may be useful in deciding therapeutic strategies for patients in whom EGFR testing is not possible.

A Clamp-Based One-Step Droplet Digital Reverse Transcription PCR (ddRT-PCR) for Precise Quantitation of Messenger RNA Mutation in Single Cells

Precise detection of the low copy numbers of messenger RNA (mRNA) mutation in single cells is of great significance but still remains challenging. Herein, by integrating the outstanding features of a rationally designed peptide nucleic acid (PNA) clamp for highly selective discrimination of single-nucleotide variation, and droplet digital PCR for ultrasensitive and precise quantification, we have developed a robust one-step droplet digital reverse transcription PCR (ddRT-PCR) method which enables precise mRNA mutation detection in single cells with ultrahigh specificity to clearly discern as low as 0.01% mutated mRNA in a high background of wild-type mRNA. Because of its outstanding single-molecule level sensitivity and ultrahigh specificity, this ddRT-PCR method holds great promise for studying cellular heterogeneity at the single cell level, as well as for the precise quantification of mutant mRNAs in complex plasma or serum for liquid biopsy.

A method of high-throughput functional evaluation of EGFR gene variants of unknown significance in cancer

Numerous variants of unknown significance (VUS) have been identified through large-scale cancer genome projects, although their functional relevance remains uninvestigated. We developed a mixed-all-nominated-mutants-in-one (MANO) method to evaluate the transforming potential and drug sensitivity of oncogene VUS in a high-throughput manner and applied this method to 101 nonsynonymous epidermal growth factor receptor (EGFR) mutants. We discovered a number of mutations conferring resistance to EGFR tyrosine kinase inhibitors (TKIs), including gefitinib- and erlotinib-insensitive missense mutations within exon 19 and other gefitinib-resistant mutations, such as L833V, A839T, V851I, A871T, and G873E. L858R-positive tumors (12.8%) harbored compound mutations primarily in the cis allele, which decreased the gefitinib sensitivity of these tumors. The MANO method further revealed that some EGFR mutants that are highly resistant to all types of TKIs are sensitive to cetuximab. Thus, these data support the importance of examining the clinical relevance of uncommon mutations within EGFR and of evaluating the functions of such mutations in combination. This method may become a foundation for the in vitro and in vivo assessment of variants of cancer-related genes and help customize cancer therapy for individual patients.

Tissue and Blood Biomarkers in Lung Cancer: A Review

Lung cancer is the most common cause of cancer-related death, worldwide. Historically, lung cancer has been divided into two main histological types: small cell and nonsmall cell (NSC) type with the latter being subdivided into adenocarcinoma, squamous cell type, and large cell type. The treatment of the NSC lung cancer (NSCLC), especially the adenocarcinoma subtype, has been transformed in the last decade by the availability of predictive biomarkers for molecularly targeted therapies. Currently, for patients with advanced adenocarcinomas, testing for sensitizing mutations in epidermal growth factor receptor (EGFR) is mandatory prior to the administration of anti-EGFR inhibitors such as erlotinib, gefitinib, afatinib, or osimertinib. For patients unable to provide tumor tissue, EGFR mutational analysis may be performed on plasma. For predicting response to crizotinib, testing for ALK and ROS1 gene rearrangement is necessary. The presence of ALK rearrangements is also a prerequisite for treatment with ceritinib, alectinib, or brigatinib. For predicting response to single agent pembrolizumab in the first-line treatment of patients with advanced adenocarcinoma or squamous cell NSCLCs, PD-L1 should be measured by an approved assay (e.g., PD-L1 IHC 22C3 pharmDx method). Although not widely used, serum biomarkers such as neuron-specific enolase, progastrin-releasing peptide, carcinoembryonic antigen, CYFRA 21-1, and squamous cell carcinoma antigen may help in the differential diagnosis of lung cancer when a tissue diagnosis is not possible. Serum biomarkers may also be of use in determining prognosis and monitoring response to systemic therapies. With the increasing use of biomarkers, personalized treatment especially for patients with adenocarcinoma-type NSCLC is finally on the horizon.

Gambogenic acid inhibits fibroblast growth factor receptor signaling pathway in erlotinib-resistant non-small-cell lung cancer and suppresses patient-derived xenograft growth

Erlotinib resistance causes a high degree of lethality in non-small-cell lung cancer (NSCLC) patients. The high expression and activation of several receptor tyrosine kinases, such as JAK/STAT3, c-Met, and EGFR, play important roles in drug resistance. The development of tyrosine kinase inhibitors is urgently required in the clinic. Our previous study found that Gambogenic acid (GNA), a small molecule derived from the traditional Chinese medicine herb gamboge, induced cell death in several NSCLC cell lines through JAK/STAT3 inhibition. In this study, we investigated the mechanism of action of GNA in erlotinib-resistant NSCLC and patient-derived cells. The inhibition of GNA on FGFR signaling pathway was examined using biochemical kinase assays. NSCLC cell lines (HCC827, HCC827-Erlotinib-resistant, and H1650) and primary cells from patients with NSCLC with clinical resistance to erlotinib were treated with GNA, erlotinib, or their combination. Both kinase assays and cell- based assays showed that GNA inhibits the phosphorylation of multiple kinases in FGFR signaling pathway in NSCLC. The combination of GNA and erlotinib significantly attenuates the tumor growth of HCC827 and erlotinib-resistant HCC827 xenografts with low toxicity. Importantly, GNA significantly suppresses tumor growth in a lung patient-derived xenograft (PDX) model with FGFR fusion and low EGFR expression. Our findings provide preclinical evidence for using GNA as an FGFR signaling pathway inhibitor to overcome erlotinib resistance in NSCLC treatment or to enhance erlotinib efficacy when used as a combined administration.

Non-invasive quantification of cell-free DNA mutations in plasma during lung tumor progression in mice

Testing carcinogenicity caused by chemicals requires a noninvasive tool that can be used before autopsy because autopsy takes a long time. We investigated whether non-small cell lung cancer related gene mutations could be detected in cell-free DNA in plasma by Insight OncoTM next-generation sequencing, which is a fast and sensitive method. Adenoma formation was confirmed in urethane-injected 17-week-old mice. Seven single nucleotide polymorphisms, such as Cdkn2a and Vegfa, were selected. Mutant-enriched Insight OncoTM NGS and normal NGS were performed on genomic DNA. The results demonstrate that Insight OncoTM NGS detected Cdkn2a and Vegfa SNPs at 0.05%. The sensitivity of Insight OncoTM NGS was twice higher than that of normal NGS. In this analysis, the Cdkn2a gene mutation was detected not only in two genomic DNA samples of lung tissue from the 11th week of urethane injection but also in two cell-free DNA samples. In addition, the Vegfa gene mutation was detected not only in three genomic DNA samples of lung tissue of injection but also in one cell-free DNA sample, showing 33% concordance. Our results confirm that Insight OncoTM NGS is a rapid and sensitive detection method that enables lung cancer-associated gene mutations to be detected in cell-free DNA before the end of the carcinogenicity test.

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.

Australian recommendations for EGFR T790M testing in advanced non-small cell lung cancer

First-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are used as first-line therapy in patients with non-small cell lung cancer (NSCLC) harboring a sensitizing mutation in the EGFR gene. Unfortunately, resistance to these therapies often occurs within 10 months of commencing treatment and is mostly commonly due to the development of the EGFR T790M mutation. Treatment with the third-generation EGFR TKI, osimertinib can prolong progression free survival in patients with the T790M mutation, so it is important to determine the resistance mechanism in order to plan ongoing therapeutic strategies. Here we review the evidence and make recommendations for the timing of T790M mutation testing, the most appropriate specimens to test and the available testing methods in patients progressing during treatment with first line EGFR TKIs for NSCLC.

Conventional real-time PCR-based detection of T790M using tumor tissue or blood in patients with EGFR TKI-resistant NSCLC

Blood biopsy has many advantages over tissue biopsy for diagnosing acquired T790M mutation in patients with non-small-cell lung cancer, such as being less risky and painful. New techniques with high sensitivity (eg, droplet digital PCR) show promising results during blood biopsy, but the positive rates of identification are still quite unclear. Whether there are other factors, except technology, affecting the results of blood biopsy is unclear. In this study, we used conventional amplification refractory mutation system to detect tumor tissue or blood for T790M mutation in patients clinically resistant to tyrosine kinase inhibitors. A total of 45 patients treated at West China Hospital between 2014 and 2016 were analyzed. The positive rate of T790M mutation was 70.8% based on tissue biopsy and 37.5% based on blood biopsy. Of the 24 patients whose epidermal growth factor receptor gene was genotyped through tissue and blood biopsy, 10 (41.7%) were concordant for T790M mutation status (κ=0.006). Of the 17 patients positive for T790M by tissue biopsy, 7 (41.2%) were positive for T790M by blood biopsy, and 3 of these 7 were only weakly positive. Of the 7 patients negative for T790M by tissue biopsy, 2 (28.6%) were positive by blood biopsy. Our T790M detection rate is higher than that reported by other studies using digital droplet PCR. These results suggest that other factors (eg, clinical features), intrinsically connected with circulating tumor DNA level, also affect the results of blood biopsy, and thus cannot be controlled through technological optimization.

Quantitative proteomics in lung cancer

Lung cancer is the most common cause of cancer-related death worldwide, less than 7% of patients survive 10 years following diagnosis across all stages of lung cancer. Late stage of diagnosis and lack of effective and personalized medicine reflect the need for a better understanding of the mechanisms that underlie lung cancer progression. Quantitative proteomics provides the relative different protein abundance in normal and cancer patients which offers the information for molecular interactions, signaling pathways, and biomarker identification. Here we introduce both theoretical and practical applications in the use of quantitative proteomics approaches, with principles of current technologies and methodologies including gel-based, label free, stable isotope labeling as well as targeted proteomics. Predictive markers of drug resistance, candidate biomarkers for diagnosis, and prognostic markers in lung cancer have also been discovered and analyzed by quantitative proteomic analysis. Moreover, construction of protein networks enables to provide an opportunity to interpret disease pathway and improve our understanding in cancer therapeutic strategies, allowing the discovery of molecular markers and new therapeutic targets for lung cancer.

Correlation between Classic Driver Oncogene Mutations in EGFR, ALK, or ROS1 and 22C3-PD-L1 ≥50% Expression in Lung Adenocarcinoma

INTRODUCTION

Targeted somatic genomic analysis (EGFR, anaplastic lymphoma receptor tyrosine kinase gene [ALK], and ROS1) and programmed death ligand 1 (PD-L1) tumor proportion score (TPS) determined by immunohistochemistry (IHC) are used for selection of first-line therapies in advanced lung cancer; however, the frequency of overlap of these biomarkers in routine clinical practice is poorly reported.

METHODS

We retrospectively probed the first 71 pairs of patients with lung adenocarcinoma from our institution. They were analyzed for PD-L1 by IHC using the clone 22C3 pharmDx kit (Agilent Technologies, Santa Clara, CA) and evaluated for co-occurrence of genomic aberrations and clinicopathologic characteristics.

RESULTS

Surgical resection specimens, small biopsy (transbronchial or core needle) samples, and cytologic cell blocks (needle aspirates or pleural fluid) were tested. A PD-L1 TPS of at least ≥50% was seen in 29.6% of tumors. Of 19 tumors with EGFR mutations, ALK fluorescence in situ hybridization positivity, or ROS1 fluorescence in situ hybridization positivity, 18 had a PD-L1 TPS less than 50% versus only one tumor with a PD-L1 TPS of at least 50% (p = 0.0073). Tumors with a PD-L1 TPS of at least 50% were significantly associated with smoking status compared with tumors with a PD-L1 TPS less than 50% but were not associated with patient sex, ethnicity, tumor stage, biopsy site, or biopsy type/preparation.

CONCLUSIONS

PD-L1 IHC can be performed on routine clinical lung cancer specimens. A TPS of at least 50% seldom overlaps with presence of driver oncogenes with approved targeted therapies. Three biomarker-specified groups of advanced lung adenocarcinomas can now be defined, each paired with a specific palliative first-line systemic therapy of proven clinical benefit: (1) EGFR/ALK/ROS1-affected adenocarcinoma paired with a matched tyrosine kinase inhibitor (∼20% of cases), (2) PD-L1-enriched adenocarcinoma (TPS ≥50%) paired with anti-PD-1 pembrolizumab (∼30% of cases), and (3) biomarker-negative (i.e., EGFR/ALK/ROS1/PD-L1-negative) adenocarcinoma paired with platinum doublet chemotherapy with or without bevacizumab (∼50% of cases).