Clinical outcomes of EGFR kinase domain duplication to targeted therapies in NSCLC

EGFR kinase domain duplication in lung adenocarcinoma with systemic and intracranial response to a double-dose of furmonertinib: a case report and literature review

Background

EGFR kinase domain duplication (EGFR-KDD) is an infrequent oncogenic driver mutation in lung adenocarcinoma. It may be a potential target benefit from EGFR-tyrosine kinase inhibitors (TKIs) treatment.

Case presentation

A 66-year-old Chinese male was diagnosed with lung adenocarcinoma in stage IVb with brain metastases. Next-generation sequencing revealed EGFR-KDD mutation. The patient received furmonertinib 160mg daily for anti-cancer treatment and obtained therapeutic efficacy with partial response (PR). Progression-free survival (PFS) duration from monotherapy was 16 months. With slow progressions, combined radiotherapy and anti-vascular targeted therapy also brought a continuous decrease in the tumors. The patient has an overall survival (OS) duration of more than 22 months and still benefits from double-dose furmonertinib.

Conclusions

This report provided direct evidence for the treatment of EGFR-KDD to use furmonertinib. A Large-scale study is needed to confirm this preliminary finding.

Colorectal cancer harboring EGFR kinase domain duplication response to EGFR tyrosine kinase inhibitors

Epidermal growth factor receptor kinase domain duplication (EGFR-KDD) is a rare, recurrent oncogenic variant that constitutively activates EGFR in non-small-cell lung cancer. Herein, we report the case of a 70-year-old man with resectable colorectal adenocarcinoma who underwent surgery followed by adjuvant therapy. He relapsed with multiple liver metastases and received standard chemotherapy until his disease became refractory. Comprehensive genomic profiling of his postoperative colorectal cancer tissue revealed EGFR-KDD. He was treated with an EGFR tyrosine kinase inhibitor (TKI), afatinib and achieved a partial response (- 55%) after 8 weeks; however, he developed massive malignant ascites after 13 weeks. Osimertinib, another EGFR-TKI, controlled his tumors for 9 months. Patient-derived cancer organoids from his malignant ascites confirmed sensitivity to EGFR-TKIs. The findings suggest that EGFR-TKIs can be a potential treatment option for this molecular subgroup.

Expanding the Clinical Utility of Targeted RNA Sequencing Panels beyond Gene Fusions to Complex, Intragenic Structural Rearrangements

Gene fusions are a form of structural rearrangement well established as driver events in pediatric and adult cancers. The identification of such events holds clinical significance in the refinement, prognostication, and provision of treatment in cancer. Structural rearrangements also extend beyond fusions to include intragenic rearrangements, such as internal tandem duplications (ITDs) or exon-level deletions. These intragenic events have been increasingly implicated as cancer-promoting events. However, the detection of intragenic rearrangements may be challenging to resolve bioinformatically with short-read sequencing technologies and therefore may not be routinely assessed in panel-based testing. Within an academic clinical laboratory, over three years, a total of 608 disease-involved samples (522 hematologic malignancy, 86 solid tumors) underwent clinical testing using Anchored Multiplex PCR (AMP)-based RNA sequencing. Hematologic malignancies were evaluated using a custom Pan-Heme 154 gene panel, while solid tumors were assessed using a custom Pan-Solid 115 gene panel. Gene fusions, ITDs, and intragenic deletions were assessed for diagnostic, prognostic, or therapeutic significance. When considering gene fusions alone, we report an overall diagnostic yield of 36% (37% hematologic malignancy, 41% solid tumors). When including intragenic structural rearrangements, the overall diagnostic yield increased to 48% (48% hematologic malignancy, 45% solid tumor). We demonstrate the clinical utility of reporting structural rearrangements, including gene fusions and intragenic structural rearrangements, using an AMP-based RNA sequencing panel.

Clinical and molecular characteristics of kinase domain duplications across diverse cancer types in the Chinese population

BACKGROUND

Kinase domain duplications (KDDs) have recently been recognized as oncogenic mutations and possible association with drug resistance in cancers.

METHOD

Here, targeted sequencing was performed with the tumor tissue and/or plasma from 65 cancer patients with KDDs.

RESULT

Intact KDDs were identified in approximately 0.1% of the total population across multiple cancer types. EGFR KDD was first identified in colorectal cancer and breast cancer, whereas FGFR2 KDD was first identified in gastric cancer. Tumors with EGFR KDD displayed lower concurrent TP53 gene alterations (p = 0.03) and slightly higher chromosome instability (p = 0.27) compared to tumors with non-EGFR-KDDs. Immune pathway analysis further revealed the enrichment of the cytokine receptors pathway (93%) in the KDD carriers. Hyperprogression-related gene mutations were identified in four cases.

CONCLUSION

Collectively, our data revealed the genomic features of KDD alterations in a multi-cancer cohort, providing more information for the potential treatment application in the KDD carriers.

Structure-Guided Strategies of Targeted Therapies for Patients with EGFR-Mutant Non-Small Cell Lung Cancer

Oncogenic mutations within the EGFR kinase domain are well-established driver mutations in non-small cell lung cancer (NSCLC). Small-molecule tyrosine kinase inhibitors (TKIs) specifically targeting these mutations have improved treatment outcomes for patients with this subtype of NSCLC. The selectivity of these targeted agents is based on the location of the mutations within the exons of the EGFR gene, and grouping mutations based on structural similarities has proved a useful tool for conceptualizing the heterogeneity of TKI response. Structure-based analysis of EGFR mutations has influenced TKI development, and improved structural understanding will inform continued therapeutic development and further improve patient outcomes. In this review, we summarize recent progress on targeted therapy strategies for patients with EGFR-mutant NSCLC based on structure and function analysis.

EGFR internal tandem duplications in fusion-negative congenital and neonatal spindle cell tumors

Next-generation sequencing (NGS) assays can sensitively detect somatic variation, and increasingly can enable the identification of complex structural rearrangements. A subset of infantile spindle cell sarcomas, particularly congenital mesoblastic nephromas with classic or mixed histology, have structural rearrangement in the form of internal tandem duplications (ITD) involving EGFR. We performed prospective analysis to identify EGFR ITD through clinical or research studies, as well as retrospective analysis to quantify the frequency of EGFR ITD in pediatric sarcomas. Within our institution, three tumors with EGFR ITD were prospectively identified, all occurring in patients less than 1 year of age at diagnosis, including two renal tumors and one mediastinal soft tissue tumor. These three cases exhibited both cellular and mixed cellular and classic histology. All patients had no evidence of disease progression off therapy, despite incomplete resection. To extend our analysis and quantify the frequency of EGFR ITD in pediatric sarcomas, we retrospectively analyzed a cohort of tumors (n = 90) that were previously negative for clinical RT-PCR-based fusion testing. We identified EGFR ITD in three analyzed cases, all in patients less than 1 year of age (n = 18; 3/18, 17%). Here we expand the spectrum of tumors with EGFR ITD to congenital soft tissue tumors and report an unusual example of an EGFR ITD in a tumor with cellular congenital mesoblastic nephroma histology. We also highlight the importance of appropriate test selection and bioinformatic analysis for identification of this genomic alteration that is unexpectedly common in congenital and infantile spindle cell tumors.

Tobacco Smoking-Related Mutational Signatures in Classifying Smoking-Associated and Nonsmoking-Associated NSCLC

INTRODUCTION

Patient-reported smoking history is frequently used as a stratification factor in NSCLC-directed clinical research. Nevertheless, this classification does not fully reflect the mutational processes in a tumor. Next-generation sequencing can identify mutational signatures associated with tobacco smoking, such as single-base signature 4 and indel-based signature 3. This provides an opportunity to redefine the classification of smoking- and nonsmoking-associated NSCLC on the basis of individual genomic tumor characteristics and could contribute to reducing the lung cancer stigma.

METHODS

Whole genome sequencing data and clinical records were obtained from three prospective cohorts of metastatic NSCLC (N = 316). Relative contributions and absolute counts of single-base signature 4 and indel-based signature 3 were combined with relative contributions of age-related signatures to divide the cohort into smoking-associated ("smoking high") and nonsmoking-associated ("smoking low") clusters.

RESULTS

The smoking high (n = 169) and smoking low (n = 147) clusters differed considerably in tumor mutational burden, signature contribution, and mutational landscape. This signature-based classification overlapped considerably with smoking history. Yet, 26% of patients with an active smoking history were included in the smoking low cluster, of which 52% harbored an EGFR/ALK/RET/ROS1 alteration, and 4% of patients without smoking history were included in the smoking high cluster. These discordant samples had similar genomic contexts to the rest of their respective cluster.

CONCLUSIONS

A substantial subset of metastatic NSCLC is differently classified into smoking- and nonsmoking-associated tumors on the basis of smoking-related mutational signatures than on the basis of smoking history. This signature-based classification more accurately classifies patients on the basis of genome-wide context and should therefore be considered as a stratification factor in clinical research.

Hyperprogression under treatment with immune-checkpoint inhibitors in patients with gastrointestinal cancer: A natural process of advanced tumor progression?

Immunotherapy has shown great promise in treating various types of malignant tumors. However, some patients with gastrointestinal cancer have been known to experience rapid disease progression after treatment, a situation referred to as hyperprogressive disease (HPD). This minireview focuses on the definitions and potential mechanisms of HPD, natural disease progression in gastrointestinal malignancies, and tumor immunological microenvironment.

EGFR signaling pathway as therapeutic target in human cancers

Epidermal Growth Factor Receptor (EGFR) enacts major roles in the maintenance of epithelial tissues. However, when EGFR signaling is altered, it becomes the grand orchestrator of epithelial transformation, and hence one of the most world-wide studied tyrosine kinase receptors involved in neoplasia, in several tissues. In the last decades, EGFR-targeted therapies shaped the new era of precision-oncology. Despite major advances, the dream of converting solid tumors into a chronic disease is still unfulfilled, and long-term remission eludes us. Studies investigating the function of this protein in solid malignancies have revealed numerous ways how tumor cells dysregulate EGFR function. Starting from preclinical models (cell lines, organoids, murine models) and validating in clinical specimens, EGFR-related oncogenic pathways, mechanisms of resistance, and novel avenues to inhibit tumor growth and metastatic spread enriching the therapeutic portfolios, were identified. Focusing on non-small cell lung cancer (NSCLC), where EGFR mutations are major players in the adenocarcinoma subtype, we will go over the most relevant discoveries that led us to understand EGFR and beyond, and highlight how they revolutionized cancer treatment by expanding the therapeutic arsenal at our disposal.

Role of the EGFR-KDD mutation as a possible mechanism of acquired resistance of non-small cell lung cancer to EGFR tyrosine kinase inhibitors: A case report

Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are currently considered as the standard therapy for patients with advanced non-small cell lung cancer (NSCLC) who have EGFR-activating mutations. However, despite an initially profound response to these drugs, these patients ultimately develop drug resistance. The most common resistance mechanism is the development of a secondary mutation in EGFR (T790M), although activation of the MNNG/HOS transforming gene (MET), amplification of the Erb-B2 receptor tyrosine kinase 2 gene and histological transformation to small cell lung cancer may also lead to resistance. In addition, there may be additional, rare mechanisms leading to resistance that remain unidentified. Mutations in the EGFR kinase domain duplication (EGFR-KDD) are rare, although they act as oncogenic drivers in NSCLC. To the best of our knowledge, all studies to date have reported EGFR-KDD as the primary mutation in NSCLC. The aim of the present study was to report the case of an EGFR-KDD mutation in a patient with NSCLC who developed acquired resistance to gefitinib, but responded well to afatinib. Therefore, EGFR-KDD mutation is an additional potential mechanism underlying the development of acquired resistance to EGFR-TKIs.

Osimertinib is an effective epidermal growth factor receptor-tyrosine kinase inhibitor choice for lung cancer with epidermal growth factor receptor exon 18-25 kinase domain duplication: report of two cases

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are an effective treatment for common EGFR mutations in non-small-cell lung cancer (NSCLC). Rarer EGFR mutations such as kinase domain duplications (KDDs) have been identified, but the optimal therapy following treatment resistance remains unknown. We report two patients who were diagnosed with NSCLC including KDD. For case 1, afatinib (40 mg once daily) was at first effective but then became ineffective. Consequently, osimertinib therapy (80 mg once daily) was administered. As of 26 May 2021, the osimertinib therapy achieved a stable disease state according to the chest computed tomography scan. As for case 2, the patient received second-line chemotherapy and anlotinib (12 mg once daily) for 6 months and died in May 2020. Here, we describe osimertinib as an effective therapy for EGFR-KDD positive lung adenocarcinoma and thereby provide a new alternative for further treatment following resistance to first- and second-generation EGFR-TKIs.

Acquired Resistance Mechanism of EGFR Kinase Domain Duplication to EGFR TKIs in Non-Small Cell Lung Cancer

PURPOSE

Epidermal growth factor receptor kinase domain duplication (EGFR-KDD) is a rare and poorly understood oncogenic mutation in non-small cell lung cancer (NSCLC). We aimed to investigate the acquired resistance mechanism of EGFR-KDD against EGFR-TKIs.

MATERIALS AND METHODS

We identified EGFR-KDD in tumor tissue obtained from a patient with stage IV lung adenocarcinoma and established the patient-derived cell line SNU-4784. We also established several EGFR-KDD Ba/F3 cell lines: EGFR-KDD wild type (EGFR-KDDWT), EGFR-KDD domain 1 T790M (EGFR-KDDD1T), EGFR-KDD domain 2 T790M (EGFR-KDDD2T), and EGFR-KDD both domain T790M (EGFR-KDDBDT). We treated the cells with EGFR tyrosine kinase inhibitors (TKIs) and performed cell viability assays, immunoblot assays, and ENU (N-ethyl-N-nitrosourea) mutagenesis screening.

RESULTS

In cell viability assays, SNU-4784 cells and EGFR-KDDWT Ba/F3 cells were sensitive to 2nd generation and 3rd generation EGFR TKIs. In contrast, the T790M-positive EGFR-KDD Ba/F3 cell lines (EGFR-KDDT790M) were only sensitive to 3rd generation EGFR TKIs. In ENU mutagenesis screening, we identified the C797S mutation in kinase domain 2 of EGFR-KDDBDT Ba/F3 cells. Based on this finding, we established an EGFR-KDD domain 1 T790M/domain 2 cis-T790M+C797S (EGFR-KDDT/T+C) Ba/F3 model, which was resistant to EGFR TKIs and anti-EGFR monoclonal antibody combined with EGFR TKIs.

CONCLUSION

Our study reveals that the T790M mutation in EGFR-KDD confers resistance to 1st and 2nd generation EGFR TKIs, but is sensitive to 3rd generation EGFR TKIs. In addition, we identified that the C797S mutation in kinase domain 2 of EGFR-KDDT790M mediates a resistance mechanism against 3rd generation EGFR TKIs.

Receptor Tyrosine Kinases and Their Signaling Pathways as Therapeutic Targets of Curcumin in Cancer

Receptor tyrosine kinases (RTKs) are transmembrane cell-surface proteins that act as signal transducers. They regulate essential cellular processes like proliferation, apoptosis, differentiation and metabolism. RTK alteration occurs in a broad spectrum of cancers, emphasising its crucial role in cancer progression and as a suitable therapeutic target. The use of small molecule RTK inhibitors however, has been crippled by the emergence of resistance, highlighting the need for a pleiotropic anti-cancer agent that can replace or be used in combination with existing pharmacological agents to enhance treatment efficacy. Curcumin is an attractive therapeutic agent mainly due to its potent anti-cancer effects, extensive range of targets and minimal toxicity. Out of the numerous documented targets of curcumin, RTKs appear to be one of the main nodes of curcumin-mediated inhibition. Many studies have found that curcumin influences RTK activation and their downstream signaling pathways resulting in increased apoptosis, decreased proliferation and decreased migration in cancer both in vitro and in vivo. This review focused on how curcumin exhibits anti-cancer effects through inhibition of RTKs and downstream signaling pathways like the MAPK, PI3K/Akt, JAK/STAT, and NF-κB pathways. Combination studies of curcumin and RTK inhibitors were also analysed with emphasis on their common molecular targets.

Therapeutic advances in non-small cell lung cancer: Focus on clinical development of targeted therapy and immunotherapy

Lung cancer still contributes to nearly one-quarter cancer-related deaths in the past decades, despite the rapid development of targeted therapy and immunotherapy in non-small cell lung cancer (NSCLC). The development and availability of comprehensive genomic profiling make the classification of NSCLC more precise and personalized. Most treatment decisions of advanced-stage NSCLC have been made based on the genetic features and PD-L1 expression of patients. For the past 2 years, more than 10 therapeutic strategies have been approved as first-line treatment for certain subgroups of NSCLC. However, some major challenges remain, including drug resistance and low rate of overall survival. Therefore, we discuss and review the therapeutic strategies of NSCLC, and focus on the development of targeted therapy and immunotherapy in advanced-stage NSCLC. Based on the latest guidelines, we provide an updated summary on the standard treatment for NSCLC. At last, we discussed several potential therapies for NSCLC. The development of new drugs and combination therapies both provide promising therapeutic effects on NSCLC.

The Genomics of Young Lung Cancer: Comprehensive Tissue Genomic Analysis in Patients Under 40 With Lung Cancer

Introduction

Lung adenocarcinomas in young patients (<40 y) are more likely to harbor targetable genomic alterations. This study aimed to determine whether the prevalence of targetable alterations is greater in young adults with lung carcinoma than in the overall lung cancer population. To reach this rare patient population, a web-based platform was used to recruit and enroll patients remotely.

Methods

In this prospective study, patients less than 40 years old at the time of primary lung cancer diagnosis with confirmed lung carcinoma were recruited from four global sites and remotely by means of a website. Genotyping data were collected, if available, or obtained by means of next-generation sequencing using the FoundationOne platform. The prevalence of targetable alterations was quantified across patients with advanced adenocarcinoma.

Results

Overall, 133 patients across five continents were included, 41% of whom enrolled online. The mean (SD) age at diagnosis was 34 (5.2) years; 79% had stage IV disease at diagnosis. Among patients with adenocarcinoma (n = 115), 112 entered the study with previous genomic testing results and 86 (77%) had targetable alterations in EGFR, ALK, ROS1, MET, ERBB2, or RET. Among those without targetable alterations, 14 received further testing and a targetable alteration was identified in eight (57%).

Conclusions

This study revealed the feasibility of using a web-based platform to recruit young patients with lung cancer and revealed that 94 of 112 (84%) with adenocarcinoma at any stage had targetable genomic alterations. Among patients with stage IV adenocarcinoma, 85% had a targetable alteration, which is higher than historical expectations for the general population.

Durable response to EGFR tyrosine kinase inhibitors in a patient with non-small cell lung cancer harboring an EGFR kinase domain duplication

Epidermal growth factor receptor (EGFR) kinase domain duplication (KDD) has been identified as an oncogenic driver in 0.05% to 0.14% of non-small cell lung cancer (NSCLC) patients. However, little is known of the efficacy of EGFR tyrosine kinase inhibitors (TKIs) for such patients. Here, we report the case of a 45-year-old Japanese woman with NSCLC positive for EGFR-KDD (duplication of exons 18-25) who developed carcinomatous meningitis and showed a marked response to the EGFR-TKIs erlotinib and osimertinib. As far as we are aware, this is the first report of EGFR-TKI efficacy for carcinomatous meningitis in a NSCLC patient harboring EGFR-KDD.

Lung Adenocarcinoma Patient Harboring EGFR-KDD Achieve Durable Response to Afatinib: A Case Report and Literature Review

The rapid development of epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) has revolutionized the treatment of patients with advanced or metastatic non-small cell lung cancer (NSCLC) harboring EGFR mutations including but not limited to exon 19 deletions (19 del) and point mutation L858R in exon 21. However, the efficacy of EGFR-TKIs in patients with rare mutations, such as EGFR-kinase domain duplication (KDD), remains elusive. EGFR-KDD often results from in-frame tandem duplication of EGFR exons 18-25, causing subsequent constitutive activation of EGFR signaling. Several case reports have revealed the efficacies of EGFR-TKIs in advanced lung adenocarcinoma (LUAD) with EGFR-KDD but yielded variable antitumor responses. In the present study, we report a 61-year-old male patient diagnosed with T1N3M0 (stage IIIB) LUAD harboring EGFR-KDD involving exons 18-25. He was treated with afatinib and achieved partial response (PR) with progression-free survival (PFS) of 12 months and counting. Our work, confirming EGFR-KDD as an oncogenic driver and therapeutic target, provides clinical evidence to administer EGFR-TKIs in patients with advanced LUAD harboring EGFR-KDD.

Structure-function analysis of oncogenic EGFR Kinase Domain Duplication reveals insights into activation and a potential approach for therapeutic targeting

Mechanistic understanding of oncogenic variants facilitates the development and optimization of treatment strategies. We recently identified in-frame, tandem duplication of EGFR exons 18 - 25, which causes EGFR Kinase Domain Duplication (EGFR-KDD). Here, we characterize the prevalence of ERBB family KDDs across multiple human cancers and evaluate the functional biochemistry of EGFR-KDD as it relates to pathogenesis and potential therapeutic intervention. We provide computational and experimental evidence that EGFR-KDD functions by forming asymmetric EGF-independent intra-molecular and EGF-dependent inter-molecular dimers. Time-resolved fluorescence microscopy and co-immunoprecipitation reveals EGFR-KDD can form ligand-dependent inter-molecular homo- and hetero-dimers/multimers. Furthermore, we show that inhibition of EGFR-KDD activity is maximally achieved by blocking both intra- and inter-molecular dimerization. Collectively, our findings define a previously unrecognized model of EGFR dimerization, providing important insights for the understanding of EGFR activation mechanisms and informing personalized treatment of patients with tumors harboring EGFR-KDD. Finally, we establish ERBB KDDs as recurrent oncogenic events in multiple cancers.

An EGFR mutant with kinase domain duplication (EGFR-KDD) was previously identified in an index patient, but the functional and therapeutic implications remain unclear. Here, the authors show that KDD occurs in other ErbB receptors in multiple cancers, and characterize the mechanism and inhibition of EGFR-KDD.

Predictive molecular pathology of lung cancer in Germany with focus on gene fusion testing: Methods and quality assurance

Predictive molecular testing has become an important part of the diagnosis of any patient with lung cancer. Using reliable methods to ensure timely and accurate results is inevitable for guiding treatment decisions. In the past few years, parallel sequencing has been established for mutation testing, and its use is currently broadened for the detection of other genetic alterations, such as gene fusion and copy number variations. In addition, conventional methods such as immunohistochemistry and in situ hybridization are still being used, either for formalin-fixed, paraffin-embedded tissue or for cytological specimens. For the development and broad implementation of such complex technologies, interdisciplinary and regional networks are needed. The Network Genomic Medicine (NGM) has served as a model of centralized testing and decentralized treatment of patients and incorporates all German comprehensive cancer centers. Internal quality control, laboratory accreditation, and participation in external quality assessment is mandatory for the delivery of reliable results. Here, we provide a summary of current technologies used to identify patients who have lung cancer with gene fusions, briefly describe the structures of NGM and the national NGM (nNGM), and provide recommendations for quality assurance.

Lung Adenocarcinoma Harboring EGFR Kinase Domain Duplication (EGFR-KDD) Confers Sensitivity to Osimertinib and Nivolumab: A Case Report

Background

Kinase domain duplication of EGFR (EGFR-KDD) is a rare oncogenic driver alteration and serves as a potential therapeutic target. Its effect on EGFR-tyrosine kinase inhibitors (TKIs), especially the third-generation drug Osimertinib, and immune checkpoint inhibitors (ICIs) remains inconclusive.

Case Presentation

A 45-year old male with lung adenocarcinoma progressed with liver metastasis after receiving pemetrexed and cisplatin as adjuvant chemotherapy. Targeted next-generation sequencing (NGS) identified an EGFR-KDD in the resected left upper lung. Icotinib was used in the following treatment and the liver metastasis was found to shrink but the progression-free survival (PFS) only lasted for 4 months with the appearance of right hepatic metastasis. Meantime, the same EGFR-KDD was identified in the left hepatic re-biopsy. Afterward, the patient benefited from the third-line therapy of Osimertinib with a PFS as long as 21 months. Then he progressed with enlarged mediastinal lymph nodes, and targeted NGS consistently identified EGFR-KDD, as well as a new RELN p.G1774E mutation. Given the continually increasing tumor mutation burden (TMB, 3.4 mutation/Mb) and PD-L1 expression-based tumor proportion score (TPS, 1%), Nivolumab was used as the fourth-line salvage therapy, which lead to considerable efficacy, with decreased blood carcinoembryonic antigen (CEA), regressed mediastinal lymph nodes, and reduced liver metastases.

Conclusions

Our case provided direct evidence to support the role of Osimertinib in the treatment of EGFR-KDD, as well as added valuable insights into application of immune-based therapeutics in the specific subgroups bearing EGFR alteration(s).

The landscape of kinase domain duplication in Chinese lung cancer patients

Background

Kinase domain duplication (KDD) is a special type of large genomic rearrangement (LGR), occurring in the kinase domain of protein kinase genes. KDD of some lung cancer driver genes, such as

EGFR

KDD, has been identified and implicated to be oncogenic in non-small cell lung cancer (NSCLC). The present study aims to interrogate the spectrum of KDD occurring on classic driver genes in Chinese lung cancer patients without the presence of classic lung cancer driver mutations.

Methods

We retrospectively enrolled 10,525 Chinese lung cancer patients who met the following inclusion criteria; (I) do not carry classic lung cancer driver mutations in any of the 8 driver genes and (II) tyrosine kinase inhibitor (TKI)-naïve. Capture-based targeted sequencing was performed on tissue or plasma samples. LGR and KDD were identified by using in-house analysis scripts. The prevalence and distribution of LGR and KDD in our cohort were analyzed.

Results

The median age of the cohort was 64 years with 68.7% being male. Among all patients, 23.2% and 51.8% were diagnosed with stage III and IV disease respectively. We identified 43 cases (0.41%) harboring LGR in one of the driver genes (EGFR/ERBB2/ALK/RET/ROS1/MET/BRAF), with 24 (0.23%) patients harboring KDD. Of the patients harboring KDD, a majority (n=19) harbored canonical EGFR-KDD involving exons 18–25, whilst one patient harbored duplications of EGFR exons 18–26. There were three MET-KDD patients; in two, the alteration occurred in exons 15–21 and in one, the alteration occurred in exons 3–21. One patient harbored RET-KDD involving exons 12–18. KDD showed a comparable prevalence in lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) (0.33% vs. 0.11%, P=0.118). Nineteen non-KDD LGRs, spanning six genes including EGFR (n=6), MET (n=3), ALK (n=4), ROS1 (n=2), ERBB2 (n=2) and BRAF (n=2), were found, each occurring in one patient. The prevalence of LGR in LUADs and LUSCs was comparable (0.55% vs. 0.38%, P=0.452).

Conclusions

We observed a prevalence of 0.41% and 0.23% for LGR and KDD, respectively. Twenty-four different LGR alterations, including 5 KDDs and 19 non-KDD LGRs, were observed. KDDs mainly occurred in EGFR involving exons 18–25 and non-KDD LGRs were distributed more randomly. The prevalence of LGR/KDD in LUSCs and LUADs was comparable.

Molecular diagnosis and clinical outcome of a lung cancer patient with TP53-E285K mutated Li-Fraumeni syndrome harboring a somatic EGFR-KDD mutation

OBJECTIVES

Li-Fraumeni syndrome (LFS) is an autosomal dominant cancer predisposition, mostly caused by germline TP53 mutations. Lung adenocarcinoma (ADC) has been identified as the most frequent LFS-related cancer outside the common LFS core spectrum. EGFR-kinase domain duplication (KDD) is rare in lung cancer and the effective therapy for LFS patients with EGFR-KDD mutated ADC is unclear. This study reports the first case of a TP53-mutated LFS patient with confirmed family history, developing advanced lung ADC harboring EGFR-KDD.

MATERIALS AND METHODS

The patient's lung tumor, lymph nodes, liquid biopsies and germline control sample at various disease stages were subjected to next-generation sequencing (NGS). The TP53 germline mutation was confirmed using the peripheral blood of the patient's relatives by Sanger sequencing.

RESULTS

A rare EGFR-KDD somatic mutation that was missed in the routine EGFR hotspots test, and a TP53-E285K temperature-sensitive germline mutation were identified by NGS. The patient was diagnosed with breast cancer in 2006 and her family cancer history review revealed that seven out of 13 relatives were diagnosed or died from LFS-spectrum cancers before the age of 45 years. Three of the six relatives were positive for the TP53-E285K germline mutation. This patient received multi-line chemotherapy followed by anlotinib, a multi-target tyrosine kinase inhibitor, upon the identification of EGFR-KDD, and achieved an overall survival of 18 months.

CONCLUSIONS

Our study highlights the importance of NGS in discovering rare genetic alterations to guide treatment decision-making, and provides meaningful insight into the potential treatment options for LFS patients with EGFR-KDD mutations.

Hyperprogression: A novel response pattern under immunotherapy

Checkpoint blockade therapy has shown significant therapeutic benefits and resulted in durable responses in patients with various tumors. However, accumulating evidence has demonstrated that 4-29% of all patients with cancers with various histologies may suffer from tumor flare following such therapy. This novel tumor response pattern, termed hyperprogression, is a potentially deleterious side effect of checkpoint blockade therapy that accelerates disease progression in a subset of patients. In this review, we describe possible immune checkpoint blockade biomarkers and the epidemiology, different definitions, and predictors of hyperprogression based on the research findings and further present the available evidence supporting pathophysiological hypotheses that might explain hyperprogression during checkpoint blockade therapy. We also compare hyperprogression and pseudoprogression. Finally, we discuss areas requiring further study.

Hyperprogression to camrelizumab in a patient with esophageal squamous cell carcinoma harboring EGFR kinase domain duplication

Background

Previous studies have reported that the amplification of some genes, such as Murine Double Minute 2 or 4 and Epidermal Growth Factor Receptor (EGFR), may be related to hyperprogressive disease (HPD). Exploring somatic gene alterations might be an effective method to predict HPD. Herein we characterize the somatic alterations in a patient with esophageal squamous cell carcinoma (ESCC) who developed HPD to investigate the potential origins of HPD.

Case presentation

A man in his mid-40s was diagnosed with ESCC. After the failure of first-line treatment with cisplatin and docetaxel, the patient participated in a phase III randomized, open, multicenter clinical trial (CTR20170307) and subsequently received camrelizumab. After 4 weeks of immunotherapy, the tumor size increased by 79% compared with baseline imaging; the progressive pace was 2.5-fold higher than preimmunotherapy, and a new liver metastasis appeared. A rare EGFR exon 2–28 duplication was discovered in both preimmunotherapy and postimmunotherapy tumor tissues.

Conclusion

This is the first report on a patient with ESCC harboring rare EGFR kinase domain duplication in exons 2–28 and developing HPD in the process of camrelizumab treatment. This case suggested that EGFR kinase domain duplication might be associated with HPD. Administration of immune checkpoint inhibitor monotherapy in this subgroup of patients harboring EGFR kinase domain duplication should be performed with caution. These results need to be further confirmed in a larger cohort of patients.

Rare epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer

Epidermal growth factor receptor (EGFR) mutations are the second most common oncogenic driver event in non-small cell lung cancer (NSCLC). Classical activating mutations (exon 19 deletions and the L858R point mutation) comprise the vast majority of EGFR mutations and are well defined as strong predictors for good clinical response to EGFR tyrosine kinase inhibitors (EGFRi). However, low frequency mutations including point mutations, deletions, insertions and duplications occur within exons 18-25 of the EGFR gene in NSCLC and are associated with poorer responses to EGFRi. Despite an increased uptake of more sensitive detection methods to identify rare EGFR mutations in patients, our understanding of the biology of these rare EGFR mutations is poor compared to classical mutations. In particular, clinical data focused on these mutations is lacking due to their rarity and challenges in trial recruitment, resulting in an absence of effective treatment strategies for many low frequency EGFR mutations. In this review, we describe the structural and mechanistic features of rare EGFR mutations in NSCLC and discuss the preclinical and clinical evidence for EGFRi response for individual rare EGFR mutations. We also discuss EGFRi sensitivity for complex EGFR mutations, and conclude by offering a perspective on the outstanding questions and future steps required to make advances in the treatment of NSCLC patients that harbour rare EGFR mutations.

Novel conjugates of endoperoxide and 4-anilinoquinazoline induce myeloma cell apoptosis by inhibiting the IGF1-R/AKT/mTOR signaling pathway

4-anilinoquinazoline-containing inhibitors of the epidermal growth factor receptor (EGFR) are widely used in non-small cell lung cancer patients with mutated EGFR, but they are less effective in multiple myeloma (MM), a fatal malignancy derived from plasma cells. The present study designed a series of novel compounds by conjugating a peroxide bridge to the 4-anilinoquinazoline pharmacophore. Further studies showed that these agents such as 4061 and 4065B displayed potent activity to induce MM cell apoptosis by upregulating pro-apoptotic p53 and Bax while downregulating pro-survival Bcl-2. The mechanistic analysis revealed that both 4061 and 4065B inhibited IGF1-R, AKT and mTOR activation in a concentration dependent manner but had no effects on the expression of their total proteins, suggesting the conjugates of endoperoxide and 4-anilinoquinazoline may exert its anti-myeloma activity by targeting the IGF1-R/AKT/mTOR pathway.

Combing the Cancer Genome for Novel Kinase Drivers and New Therapeutic Targets

Protein kinases are critical regulators of signaling cascades that control cellular proliferation, growth, survival, metabolism, migration, and invasion. Deregulation of kinase activity can lead to aberrant regulation of biological processes and to the onset of diseases, including cancer. In this review, we focus on oncogenic kinases and the signaling pathways they regulate that underpin tumor development. We highlight genomic biomarker-based precision medicine intervention strategies that match kinase inhibitors alone or in combination to mutationally activated kinase drivers, as well as progress towards implementation of these treatment strategies in the clinic. We also discuss the challenges for identification of novel protein kinase cancer drivers in the genomic era.

GATA6-upregulating autophagy promotes TKI resistance in nonsmall cell lung cancer

Autophagy plays a complicated role in tumorigenesis, and the effects of autophagy in drug resistance have not been fully known. The aim of this study was to evaluate autophagy activity in lung cancer cells derived from different origins and explore the mechanism regulating autophagy in tyrosine kinase inhibitor (TKI) resistance. We found basal level of autophagy had no significant increase in resistant H1650 and H1975 cells compared with sensitive HCC827 and PC9 cells. After erlotinib treatment, the autophagy activity enhanced threefold in H1650 cells but a little in H1975 cells. Inhibiting autophagy with 3-MA increased apoptosis in H1650 rather than H1975 cells. Combined with transmission microscope, results showed PC9 cells tended to be apoptotic and more autophagosomes formed in H1650 cells, which may be correlated with cell viability. GATA6 expression was found markedly elevated in H1650 cells after erlotinib and knocking down GATA6 led to significantly reduced autophagy activity and cell viability. Furthermore, a significant increase of GATA6 and LC3-II expression was observed in insensitive tissues compared with sensitive ones by immunostaining in nonsmall cell lung cancer (NSCLC) patients. With chi-square test, we found GATA6 was positively correlated with LC3-II. The Kaplan-Meier curve analyses further showed patients with high GATA6 had lower overall survival and progression-free survival rates than those with low GATA6 after EGFR-TKI treatment. Our results suggest that GATA6 could enhance autophagy activity contributing to TKI resistance. Targeting GATA6 and autophagy together with TKI may be promising to overcome drug resistance in NSCLC.