Efficacy analysis of tyrosine kinase inhibitors on rare non-small cell lung cancer patients harboring complex EGFR mutations

Near-Complete Response to Osimertinib for Advanced Non-Small-Cell Lung Cancer in a Pretreated Patient Bearing Rare Compound Exon 20 Mutation (S768I + V774M): A Case Report

Third-generation tyrosine kinase inhibitors are the first-line gold standard in treating advanced non-small-cell lung cancer bearing common EGFR mutations, but data documenting clinical efficacy in uncommon mutations are currently limited. In this paper, we describe the case of a patient bearing uncommon compound EGFR mutations in exon 20, who experienced a near-complete response to third-line Osimertinib, with metabolic complete response of pulmonary, nodal and ostheolytic lesions. This radiological assessment corresponded to an ECOG PS improvement (from three to one) and a substantial clinical benefit for the patients. Out of two mutations, S768I was associated with poor response to third-generation TKI and V774M had unknown clinical significance, highlighting the complexity of the correct management of these kinds of mutations. We reviewed the literature to document the up-to-date preclinical and clinical data concerning third-generation tyrosine kinase inhibitors for the treatment of patients bearing uncommon EGFR mutations.

Epidermal growth factor receptor compound and concomitant mutations: advances in precision treatment strategies

ABSTRACT

Epidermal growth factor receptor ( EGFR ) mutations are common oncogenic driver mutations in patients with non-small cell lung cancer (NSCLC). The application of EGFR-tyrosine kinase inhibitors (TKIs) is beneficial for patients with advanced and early-stage NSCLC. With the development of next-generation sequencing technology, numerous patients have been found to have more than one genetic mutation in addition to a single EGFR mutation; however, the efficacy of conventional EGFR-TKIs and the optimal treatments for such patients remain largely unknown. Thus, we review the incidence, prognosis, and current treatment regimens of EGFR compound mutations and EGFR concomitant mutations to provide treatment recommendations and guidance for patients with these mutations.

In-silico design, pharmacophore-based screening, and molecular docking studies reveal that benzimidazole-1,2,3-triazole hybrids as novel EGFR inhibitors targeting lung cancer

Lung cancer is a complex and heterogeneous disease, which has been associated with various molecular alterations, including the overexpression and mutations of the epidermal growth factor receptor (EGFR). In this study, designed a library of 1843 benzimidazole-1,2,3-triazole hybrids and carried out pharmacophore-based screening to identify potential EGFR inhibitors. The 164 compounds were further evaluated using molecular docking and molecular dynamics simulations to understand the binding interactions between the compounds and the receptor. In-si-lico ADME and toxicity studies were also conducted to assess the drug-likeness and safety of the identified compounds. The results of this study indicate that benzimidazole-1,2,3-triazole hybrids BENZI-0660, BENZI-0125, BENZI-0279, BENZI-0415, BENZI-0437, and BENZI-1110 exhibit dock scores of -9.7, -9.6, -9.6, -9.6, -9.6, -9.6 while referencing molecule -7.9 kcal/mol for EGFR (PDB ID: 4HJO), respectively. The molecular docking and molecular dynamics simulations revealed that the identified compounds formed stable interactions with the active site of EGFR, indicating their potential as inhibitors. The in-silico ADME and toxicity studies showed that the compounds had favorable drug-likeness properties and low toxicity, further supporting their potential as therapeutic agents. Finally, performed DFT studies on the best-selected ligands to gain further insights into their electronic properties. The findings of this study provide important insights into the potential of benzimidazole-1,2,3-triazole hybrids as promising EGFR inhibitors for the treatment of lung cancer. This research opens up a new avenue for the discovery and development of potent and selective EGFR inhibitors for the treatment of lung cancer.Communicated by Ramaswamy H. Sarma.

Efficacy and safety of original EGFR-TKI combined with bevacizumab in advanced lung adenocarcinoma patients harboring EGFR-mutation experiencing gradual progression after EGFR-TKI treatment: a single-arm study

Background

Keeping on original epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) treatment is the standard treatment for gradual progression EGFR-positive metastatic non-small cell lung cancer (NSCLC). Angiogenic pathway can lead to EGFR-TKI resistance, but the effectiveness of combination strategies in this group is still controversial. This study aimed to assess the efficacy and safety of the original EGFR-TKI combined with bevacizumab in advanced and metastatic lung adenocarcinoma patients harboring EGFR-mutation who experience gradual progression in a real-world setting.

Methods

From June 2019 to December 2021, a total of 35 metastatic EGFR positive NSCLC patients experienced gradual progression after EGFR-TKI treatments and received original TKI combined with bevacizumab were identified at Chongqing University Cancer Hospital, China. All patients were confirmed EGFR positive by rebiopsy before treatment. Patients were treated with EGFR-TKI and bevacizumab (15 mg/kg Q3W) after gradual progression until rapid progression or intolerable toxicity. The overall survival (OS), progression-free survival 1 (PFS1, period from the beginning of EGFR-TKI treatment to the rapid progression of the disease), PFS2 (period from the beginning of EGFR-TKI combined with bevacizumab treatment to the rapid progression of the disease), disease control rate (DCR), and adverse events of the combined treatment were collected and analyzed.

Results

A total of 33 patients could participate the efficacy evaluation. Median PFS1 and PFS2 were 20.5 and 8 months, respectively; DCR was 93.94%; median OS was immature. Multivariate Cox proportional hazards model showed that smoking status [hazard ratio (HR) =3.692, 95% confidence interval (CI): 1.450-9.404, P=0.006], combined EGFR T790M mutation or rare mutation (HR =2.480, 95% CI: 1.073-5.729, P=0.034), and malignant pleural effusion (HR =3.707, 95% CI: 1.460-9.414, P=0.006) were independent risk factors for PFS2. The most common treatment-related adverse events greater than grade 3 included hypertension (23.7%), proteinuria (8.3%), and increased alanine aminotransferase (ALT; 4.1%) and aspartate aminotransferase (AST; 2.9%).

Conclusions

Continuous original TKI combined with bevacizumab showed partly favorable efficacy and safety and may represent a therapeutic option for metastatic EGFR-mutation NSCLC patients experiencing gradual progression after EGFR-TKI treatment.

Uncovering the Molecular Basis for the Better Gefitinib Sensitivity of EGFR with Complex Mutations over Single Rare Mutation: Insights from Molecular Simulations

Epidermal growth factor receptor (EGFR) is an intensively focused target for anti-tumor compounds used in non-small cell lung cancer (NSCLC) therapy. Compared to the classical activating mutations, there are still many uncommon EGFR mutations associated with poorer responses to EGFR inhibitors. A detailed understanding of the molecular basis for multiple EGFR mutants exhibiting diverse responses to inhibitors is of critical importance for related drug development. Herein, we explored the molecular determinants contributing to the distinct responses of EGFR with a single rare mutation (G719S) or combined mutations (G719S/L858R and G719S/l861Q) to Gefitinib (IRE). Our results indicated that interactions, formed within the tetrad of residues S768 (in the αC-helix), D770 (in the αC-β4 loop), Y827 (in the αE-helix), and R831 (in the catalytic loop), play an important role in the stability of αC-helix and the maintenance of K745–E762 salt bridge in the absence of IRE, which are weakened in the EGFR^G719S system and enhanced in the EGFR^G719S/L858R system upon IRE binding. Besides, the introduced hydrogen bonds by the co-occurring mutation partner also contribute to the stability of αC-helix. The work done for inhibitor dissociation suggests that IRE exhibits a stronger binding affinity to EGFR^G719S/L858R mutant. Together, these findings provide a deeper understanding of minor mutations, which is essential for drug development targeting EGFR with less common mutations.

Treatment Strategies for Non-Small Cell Lung Cancer Harboring Common and Uncommon EGFR Mutations: Drug Sensitivity Based on Exon Classification, and Structure-Function Analysis

The identification of epidermal growth factor receptor (EGFR) mutations and development of EGFR tyrosine kinase inhibitors (EGFR-TKIs) have dramatically improved the prognosis of advanced EGFR-mutated non-small cell lung cancer (NSCLC), setting a landmark in precision oncology. Exon 19 deletions and exon 21 L858R substitutions, which comprise the majority of common EGFR mutations, are predictors of good sensitivity to EGFR-TKIs. However, not all cancers harboring EGFR mutations are sensitive to EGFR-TKIs. Most patients harboring uncommon EGFR mutations demonstrate a poorer clinical response than those harboring common EGFR mutations. For example, cancers harboring exon 20 insertions, which represent approximately 4-12% of EGFR mutations, are generally insensitive to first- and second-generation EGFR-TKIs. Although understanding the biology of uncommon EGFR mutations is essential for developing treatment strategies, there is little clinical data because of their rarity. Moreover, clarifying the acquired resistance of EGFR-mutated NSCLC may lead to more precise treatments. Sequencing and structure-based analyses of EGFRmutated NSCLC have revealed resistance mechanisms and drug sensitivity. In this review, we discuss the strategies in development for treating NSCLC harboring common and uncommon EGFR mutations. We will also focus on EGFR-TKI sensitivity in patients harboring EGFR mutations based on the structural features.

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.

Uncommon EGFR Compound Mutations in Non-Small Cell Lung Cancer (NSCLC): A Systematic Review of Available Evidence

Compound epidermal growth factor receptor (EGFR) mutations represent a heterogeneous subgroup of non-small cell lung cancer (NSCLC) patients with uncommon EGFR mutations. We conducted a systematic review to investigate the available data on this patients' subgroup. Overall, we found a high heterogeneity in the incidence of compound mutations (4-26% of total EGFR mutant cases), which is dependent on the different testing methods adopted and the specific mutations considered. In addition, the relative incidence of distinct compound subclasses identified is reported with extreme variability in different studies. Preclinical and clinical data, excluding de novoEGFR exon 20 p.T790M compound mutations, show good responses with EGFR tyrosine kinase inhibitors (TKIs) (combined common mutations: response rate (RR) ≥ 75% with either first- or second-generation TKIs; combined common plus uncommon: RR 40-80% and 100% with first-generation TKIs and afatinib, respectively; combined uncommon: RR 20-70%, ~80% and ~75% with first-generation TKIs, afatinib and osimertinib, respectively). Overall, data are consistent in supporting the use of EGFR TKIs in treating compound EGFR mutations, taking into account different sensitivity profile of accompanying EGFR mutations for selecting the most adequate EGFR TKI for individual patients.

Uncommon single and compound EGFR mutations: clinical outcomes of a heterogeneous subgroup of NSCLC

Molecular characterization of non-small-cell lung cancer (NSCLC) is essential to define the correct therapeutic algorithm in metastatic disease. Approximately 90% of epidermal growth factor receptor (EGFR) mutations are usually associated with sensitivity to EGFR tyrosine kinase inhibitors (TKIs). The remaining 10% defines a small, extremely heterogeneous subgroup of mutations, with a varied profile of sensitivity and response to target therapies.This retrospective observational study includes 47 patients affected by metastatic NSCLC harboring uncommon EGFR mutations (single or compound mutation). Patients were treated with EGFR-targeting TKIs or platinum-based chemotherapy as first-line treatment.Median OS resulted longer in the compound mutation group when compared to single rare mutations (33.6 vs 12 months; P = 0.473); a similar result was observed for PFS (16 vs 7.6 months; P = 0.281), although statistical significance was not reached. ORR, PFS and OS resulted similar for patients treated with first-line EGFR TKIs or chemotherapy. No difference in terms of PFS and OS was found according to the TKI administered.Compound mutations seem to be a good prognostic indicator for OS; they are also predictive of response to 1st and 2nd generation EGFR TKIs, as well as exon 19 insertions and mutations in codon 719 of exon 18. For mutations in exon 18 (not in codon 719) and exon 20 insertions, chemotherapy seems the most effective available option. The addition of immunotherapy to chemotherapy could change this approach in the next future.

Recent Advances on the Role of EGFR Tyrosine Kinase Inhibitors in the Management of NSCLC With Uncommon, Non Exon 20 Insertions, EGFR Mutations

The first-line treatment of choice for patients with EGFR mutation-positive NSCLC is an EGFR tyrosine kinase inhibitor (TKI), of which five as follows are predominantly available in practice: gefitinib, erlotinib, afatinib, dacomitinib, and osimertinib. Most prospective clinical trial data with these agents are limited to patients with the common activating and sensitizing EGFR mutations as follows: exon 19 deletions and exon 21 L858R point mutations. However, 10% to 20% of patients with NSCLC harbor uncommon EGFR mutations that have variable sensitivity to different EGFR TKIs. Owing to their molecular structures, afatinib, dacomitinib, and osimertinib have broader inhibitory profiles than the first-generation agents, gefitinib and erlotinib. Nevertheless, the paucity of prospective clinical data, the wide heterogeneity of uncommon mutations, and the existence of compound mutations in up to 25% of the cases complicate treatment decisions in this patient subgroup. Here, we collate the latest preclinical and clinical data regarding the activity of different TKIs against major uncommon EGFR mutations including compound mutations, but excluding exon 20 insertions which are generally insensitive to TKIs. On the basis of these data, we offer suggestions regarding treatment strategies for uncommon EGFR mutations. Moving forward, it will be important to include uncommon EGFR mutations in the first-line molecular analysis of all patients with adenocarcinoma of the lung, as this will help optimize patient outcomes according to their precise genotype.

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.

The significance of epidermal growth factor receptor uncommon mutations in non-small cell lung cancer: A systematic review and critical appraisal

Uncommon epidermal growth factor receptor (EGFR) mutations collectively account for 10% of EGFR mutations, harboring heterogeneous molecular alterations within exons 18-21 with clinically variable responses to EGFR tyrosine kinase inhibitors (TKIs) in advanced Non-Small Cell Lung Cancer (NSCLC) patients. In addition, with the introduction of different NGS gene approach an improvement of EGFR mutations detection was reported. Today, no specific studies have prospectively evaluated uncommon sensitizing mutations in detail and no firm standard of care has been established in the first-line setting. The aim of this comprehensive review is to critically consider the clinical role of uncommon EGFR mutations highlighting the results of several in vitro and in vivo studies, which singly evaluated the sensitivity of uncommon mutations to currently European of Medicines Agency (EMA)-approved EGFR TKIs in cell lines, xenograft models and humans, in order to obtain a practical guide for refining the clinical decision-making process.

Real-world efficacy and potential mechanism of resistance of icotinib in Asian advanced non-small cell lung cancer with EGFR uncommon mutations: A multi-center study

The response to icotinib in advanced non‐small cell lung cancers (NSCLC) with EGFR uncommon mutation (EGFRum) is unclear. Here we reported the efficacy and potential resistance mechanism of icotinib in Chinese EGFRum NSCLC patients. Between July 2013 and November 2016, 3117 NSCLC patients were screened for EGFRum in a multi‐center study in China. Circulating tumor DNA (ctDNA) was detected and analyzed using next‐generation sequencing (NGS) after progression from icotinib. The efficacy, safety and the potential resistance mechanism of icotinib were explored. After a median follow‐up of 6.2 months, 69 patients (70.41%) developed disease progression, the objective rate (ORR) and disease control rate (DCR) were 13.27% and 29.59% respectively, and the median progression‐free survival (PFS) was 5.5 months (95% CI: 1.2‐13.0 months). Both complex‐pattern with EGFR classical mutations (EGFRcm) and single‐pattern have better PFS than complex‐pattern without EGFRcm (median PFS was 7.2 (95% CI: 4.65‐9.75), 5.2 (95% CI: 3.24‐7.16) and 3.2 (95% CI: 2.97‐3.44) months, respectively, P < .05); patients harboring S768I mutation had the worst PFS than others (2.0 months, P < .05). Diarrhea was the most frequent side effect (42.9%). Forty‐eight (69.6%) patients developed drug resistance after 3.0 months and 81.2% of them acquired T790M mutation. Better response was observed in complex‐pattern with the EGFRcm group. S768I mutation carriers may not benefit from icotinib. Acquired T790M mutation was common in icotinib‐resistant EGFRum NSCLC patients.

[A Review of EGFR-TKIs Therapy of Non-small Cell Lung Cancer with Uncommon EGFR Mutations]

肺癌是目前最常见的癌症，也是导致癌症死亡的首要原因。非小细胞肺癌（non-small cell lung cancer, NSCLC）占85%以上，且高达50%的亚洲NSCLC患者携带表皮生长因子受体（epidermal growth factor receptor, EGFR）基因突变。研究证明，伴有EGFR突变的NSCLC患者接受表皮生长因子受体-酪氨酸激酶抑制剂（epidermal growth factor receptor-tyrosine kinase inhibitors, EGFR-TKIs）治疗能获得更好的生存结果。然而，因为EGFR罕见突变相对治疗效果较差，会对研究结果带来负面影响，所以大部分研究EGFR-TKIs疗效的临床试验都不包含罕见突变患者，另外EGFR罕见突变本身就少见，就导致临床试验中这部分患者数量较少。由于EGFR罕见突变样本量少且具有高度异质性，EGFR-TKIs对EGFR罕见突变患者的疗效仍然不清楚。本文就EGFR罕见突变与EGFR-TKIs的疗效关系进行综述，为携带EGFR罕见突变的NSCLC患者合理选择治疗方式提供指导和建议。

Clinical Impact of Rare and Compound Mutations of Epidermal Growth Factor Receptor in Patients With Non-Small-Cell Lung Cancer

BACKGROUND

Standard therapy of advanced non-small-cell lung cancer harboring an activating mutation in the epidermal growth factor receptor (EGFR) gene is treatment with tyrosine kinase inhibitors (TKI). However, for rare and compound mutations of the EGFR gene, the clinical evidence of TKI therapy is still unclear.

PATIENTS AND METHODS

A total of 2906 lung cancer samples were analyzed for EGFR mutations during routine analysis between 2010 and 2017. The samples have been investigated by Sanger sequencing and since 2014 by next-generation sequencing.

RESULTS

We detected EGFR mutations in 408 specimens (14%). Among these, we found 41 samples with rare and 22 with compound mutations. In these 63 samples, 56 different rare EGFR mutations occurred. Information about the clinical outcome was available for 37. Among those with rare mutations, only one patient harboring the mutation p.G874D had disease that responded to first-generation TKI therapy. In contrast, the disease of all patients with compound mutations responded to first- or second-generation TKI therapy. Furthermore, we collected data on clinical relevance regarding TKI therapy from different databases and from an additional literature search, and only found data for 36 of the 56 detected rare mutations.

CONCLUSION

Information about the clinical outcome of patients with rare and compound EGFR mutations remains limited. At present, second- and third-generation TKIs are available, which may represent new treatment strategies for these patients. Therefore, it is becoming increasingly important to maintain databases concerning rare EGFR mutations.

Heterogeneous Responses to Epidermal Growth Factor Receptor (EGFR) Tyrosine Kinase Inhibitors (TKIs) in Patients with Uncommon EGFR Mutations: New Insights and Future Perspectives in this Complex Clinical Scenario

Uncommon Epidermal Growth Factor Receptor (EGFR) mutations represent a distinct and highly heterogeneous subgroup of Non-Small Cell Lung Cancers (NSCLCs), that accounts for approximately 10% of all EGFR-mutated patients. The incidence of uncommon EGFR mutations is growing, due to the wider adoption of next-generation sequencing (NGS) for diagnostic purposes, which enables the identification of rare variants, usually missed with available commercial kits that only detect a limited number of EGFR mutations. However, the sensitivity of uncommon mutations to first- and second-generation EGFR Tyrosine Kinase Inhibitors (TKIs) is widely heterogeneous and less well known, compared with classic mutations (i.e., exon 19 deletions and exon 21 L858R point mutation), since most of the pivotal studies with EGFR TKIs in the first line, with few exceptions, excluded patients with rare and/or complex variants. Recently, the third generation EGFR TKI osimertinib further revolutionized the therapeutic algorithm of EGFR-mutated NSCLC, but its role in patients harboring EGFR mutations besides exon 19 deletions and/or L858R is largely unknown. Therefore, a better knowledge of the sensitivity of uncommon mutations to currently available EGFR TKIs is critical to guiding treatment decisions in clinical practice. The aim of this paper is to provide a comprehensive overview of the treatment of NSCLC patients harboring uncommon EGFR mutations with currently approved therapies and to discuss the emerging therapeutic opportunities in this peculiar subgroup of patients, including chemo-immunotherapy combinations, next-generation EGFR TKIs, and novel targeted agents.

SOX30 specially prevents Wnt-signaling to suppress metastasis and improve prognosis of lung adenocarcinoma patients

BACKGROUND

Different histological subtypes of non-small cell lung cancer (NSCLC) show different molecular characteristics and responses to therapeutic strategy. Identification of specific gene, clarification of its special roles and molecular mechanisms are crucial for developing new therapeutic approach for particular subtype patients.

METHODS

Surgical specimens of 540 NSCLC patients were recruited. Immunohistochemistry was used to detect SOX30 expression, and correlations with clinical parameters were analyzed. Functional experiments and gene ontology analysis were performed to investigate roles of SOX30. Network analysis, TOP/FOP-Flash assays, luciferase reporter assays and ChIP-PCR assays were performed to determine the mechanism. Survival analyses were calculated by Kaplan-Meier and Cox regression. Recovery experiment was investigated the importance of the target of SOX30.

RESULTS

SOX30 expression is closely associated with histological types of NSCLC, and metastasis of adenocarcinoma (ADC) patients but not of squamous cell carcinoma (SCC) patients. SOX30 strongly inhibits cancer cell migration and invasion in ADC cell lines, whrereas not affects cell migration and invasion in SCC cell lines. The genes associated with SOX30 preferentially enrich in metastasis process and Wnt-signaling in only ADC patients. Consistently, SOX30 is negatively associated with the expression of Wnt-signaling and metastasis-related gene CTNNB1 (β-catenin) in ADC, but not in SCC. At the molecular level, SOX30 represses Wnt-signaling by directly transcriptional inhibition of CTNNB1 in ADC, and also not in SCC. In the clinical, SOX30 is a favorable and independent prognostic factor in ADC patients, whereas is an unfavorable and independent prognostic factor in SCC patients. Moreover, SOX30 expression is a double face early-stage prognostic biomarker in ADC and SCC patients. In addition, forcible restoration of CTNNB1 indeed can inhibit the anti-metastatic role of SOX30 in ADC patients.

CONCLUSIONS

In early-stage ADC patients, elevated SOX30 expression inhibits tumor-metastasis by directly binding to CTNNB1 promoter resulting in a favorable prognosis of these patients. However, in early-stage SCC patients, SOX30 has no inhibitory role on tumor-metastasis due to not binding to CTNNB1 promoter leading to an unfavorable prognosis of the patients. This study highlights a special role and prognostic value of SOX30 in ADC, providing a novel therapeutic target for particular subtype NSCLC patients.

First-generation EGFR tyrosine kinase inhibitor therapy in 106 patients with compound EGFR-mutated lung cancer: a single institution's clinical practice experience

Background

The antitumour efficacy of tyrosine kinase inhibitors (TKIs) in lung cancer patients with compound epidermal growth factor receptor (EGFR) mutations has not been resolved. Our study summarizes a single institutional experience of first-generation TKI therapy for lung cancers with compound EGFR mutations.

Methods

A total of 106 consecutive patients with tumours bearing compound EGFR mutations were identified between January 2012 and May 2016; all patients received first-generation TKI therapy. Deletions in exon 19 and the L858R point mutation in exon 21 were considered common mutations; T790M was considered separately because of its association with TKIs resistances. Any other mutation was defined as a rare mutation. Patients were divided as follows: double common mutations (group A); common plus T790M mutations (group B); common plus rare mutations (group C); double rare mutations (group D); and rare plus T790M mutations (group E). A separate group of 115 consecutive patients with a single common mutation was created for comparative analysis (group F).

Results

The frequency of patients with compound EGFR was 2.9% (114/3925) and their response rate to first-generation TKIs was 50.9%, which was not significantly different from group F (67.0%, P = 0.088). The progression-free survival (PFS) of the 106 patients receiving TKI therapy was worse than that of group F (median, 9.1 vs. 13.0 months, respectively; P < 0.001). The PFS of the compound mutation group was shorter than that of the single common mutation group (median, 10.1 months in group A, P = 0.240; 9.1 months in group B, P < 0.001; 9.6 months in group C, P = 0.010; 6.5 months in group D, P = 0.048; 5.4 months in group E, P = 0.017). Patients with a co-occurring mutation in exon 20 (excluding T790M) exhibited significantly worse PFS than the patients with other compound mutations or with a single common mutation (median, 6.5 vs. 9.1 vs. 13.0 months, respectively, P = 0.002).

Conclusions

There was significant heterogeneity among the compound EGFR mutations and their response to first-generation TKIs. Individualized treatment in clinical practice should be considered for each case.

Clinical features and treatment outcome of non-small cell lung cancer (NSCLC) patients with uncommon or complex epidermal growth factor receptor (EGFR) mutations

Introduction

Tyrosine-kinase inhibitors (TKIs) represent the best treatment for advanced non-small cell lung cancer (NSCLC) with common exon 19 deletion or exon 21 epidermal growth factor receptor mutation (EGFRm). This is an observational study investigating epidemiology, clinical features and treatment outcome of NSCLC cases harbouring rare/complex EGFRm.

Results

Among 764 non-squamous NSCLC cases with known EGFRm status, 26(3.4%) harboured rare/complex EGFRm. Patients receiving first-line TKIs (N = 17) achieved median Progression Free Survival (PFS) and Overall Survival (OS) of 53 (IC 95%, 2–105) and 84 (CI 95%, 27–141) weeks respectively, without significant covariate impact. Response Rate and Disease Control Rate (DCR) were 47% and 65%, respectively. Uncommon exon 19 mutations achieved longer OS and PFS and higher DCR compared with exon 18 and 20 mutations. No additional gene mutation was discovered by MassARRAY analysis. TKIs were globally well tolerated.

Materials and methods

A retrospective review of advanced non-squamous NSCLC harbouring rare/complex EGFRm referred to our Center between 2010 and 2015 was performed. Additional molecular pathways disregulation was explored in selected cases, through MassARRAY analysis.

Conclusions

Peculiar clinical features and lower TKIs sensitivity of uncommon/complex compared with common EGFRm were shown. Exon 19 EGFRm achieved the best TKIs treatment outcome, while the optimal treatment of exon 18 and 20 mutations should be further clarified.

Complex epidermal growth factor receptor mutations and their responses to tyrosine kinase inhibitors in previously untreated advanced lung adenocarcinomas

BACKGROUND

Two or more different epidermal growth factor receptor (EGFR) mutations can be detected within a single tumor sample, which represents complex mutations. However, the frequency and efficacy of tyrosine kinase inhibitor (TKI) treatments for patients harboring these mutations are unknown.

METHODS

From January 2011 to January 2017, patients diagnosed with EGFR mutations were screened. The effectiveness of TKIs in patients with complex mutations was retrospectively analyzed.

RESULTS

A total of 16,840 subjects were screened, and there were 5898 positive patients. One hundred eighty-seven patients (3.2% of all patients with EGFR mutations) had complex EGFR mutations, and 51 of the patients with advanced adenocarcinoma were treated with TKIs as a first-line treatment. The objective response rates for patients who had Del-19+21L858R mutations (n = 15), Del-19/21L858R+atypical mutations (n = 16), double atypical mutations (n = 8), and complex mutations with a primary drug-resistant pattern (n = 12) were 75.0%, 60.0%, 71.0%, and 8.3%, respectively. The median progression-free survival times for the 4 groups were 18.2 months (95% confidence interval [CI], 10.6-25.9 months), 9.7 months (95% CI, 3.3-15.8 months), 9.6 months (95% CI, 3.3-19.0 months), and 1.4 months (95% CI, 0.4-2.3 months), respectively.

CONCLUSIONS

These results from the largest sample size suggest that EGFR-TKI therapy is effective in patients with Del-19+21L858R mutations, Del-19/21L858R+atypical mutations, and double atypical mutations but is less effective in patients with a primary drug-resistant pattern. Patients with the Del-19+21L858R mutations may, therefore, benefit more from treatment with first-generation TKIs. Cancer 2018;124:2399-406. © 2018 American Cancer Society.

Down-regulation of FN1 inhibits colorectal carcinogenesis by suppressing proliferation, migration, and invasion

Fibronectin 1 (FN1) is involved in cell adhesion and migration processes including embryogenesis, wound healing, blood coagulation, host defense, metastasis, and implicated in various biochemical processes. However, its effects on the development and progression of human cancer, especially colorectal cancer (CRC), are unclear. To evaluate the relationship between the expression of FN1 and the histopathologic parameters of patients with CRC or the proliferation, migration, and invasion of colorectal cancer cell lines, we screened FN1 as a new candidate gene which promotes development of CRC, in an independent dataset (The Human Protein Atlas website). Here, we reported that FN1 was elevated in CRC tissues compared with normal colon tissues. Further, FN1 expression level was correlated with age, lymph vascular invasion, and survival rate. Knockdown of FN1 in two CRC cell lines, LOVO, and SW1116, significantly inhibited cell proliferation, migration and invasion, and induced cell apoptosis. Western blot analysis showed that down-regulation of FN1 significantly decreased the expression of Bcl-2, MMP-9, Twist, and increased the expression of Bax, Caspase-3, and E-cadherin in LOVO and SW1116 cells. Then, we found that the protein ITGA5 was identified as a binding partner of FN1 and ITGA5 overexpression reversed FN1-induced tumorigenesis of CRC in vitro. Taken together, FN1 suppressed apoptosis and promoted viability, invasion, and migration in CRC through interacting with ITGA5. FN1 may be a prognostic factor and potential target for CRC treatment.

Clinical Characteristics and Survival Outcomes for Non-Small-Cell Lung Cancer Patients with Epidermal Growth Factor Receptor Double Mutations

Multiple randomized clinical trials have demonstrated that epidermal growth factor receptor (EGFR) exon 19 deletion (19Del) and exon 21 L858R mutation (L858R) are highly correlated with sensitivity to epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) treatment in non-small-cell lung cancer (NSCLC). A mutation in exon 20 (T790M) is reportedly associated with resistance to EGFR-TKIs. However, few studies have focused on patients harboring double mutations in these 3 mutation sites. In this retrospective study, forty-five patients (45/2546, 1.7%) harbored double mutations of 19Del, L858R, and T790M. Twenty-four patients with EGFR double mutations received EGFR-TKI therapy. Clinical characteristics of these patients, including the response to EGFR-TKIs and progression-free survival outcome for EGFR-TKI treatment (PFS-TKI), were analyzed. Patients with EGFR double mutations were more likely to be nonsmokers, have an Eastern Cooperative Oncology Group Performance Status (ECOG PS) of 0-1, have adenocarcinoma, and be at stage III-IV. The ORR, DCR, and median PFS-TKI in patients harboring EGFR double mutations were lower than in patients with a single EGFR-activating mutation. The differences in ORR and DCR were statistically insignificant between the 3 groups. Patients with double mutations of 19Del and T790M had longer PFS-TKIs than patients in the other 2 groups.

Detection of EGFR and BRAF mutations by competitive allele-specific TaqMan polymerase chain reaction in lung adenocarcinoma

Epithelial growth factor receptor (EGFR)-tyrosine kinase inhibitors are the standard first-line treatment for patients with metastatic non-small cell lung cancer (NSCLC) expressing sensitive EGFR-mutants. Other drugs target different driver mutants, including the serine/threonine-protein kinase B-raf (BRAF) inhibitor dabrafenib, which has exhibited promising efficacy for treating patients with metastatic BRAF-mutated NSCLC. Therefore, identifying patients carrying mutations that may be treated using targeted therapies is important. However, the methods of molecular detection presently applied in clinical practice, particularly detection of BRAF in NSCLC patients, require further investigation. Therefore, more sensitive and economic methods are required. The present study applied the competitive allele-specific TaqMan polymerase chain reaction (CastPCR) technology to the molecular detection of EGFR (del2235-2249, del2236-2250, T790M, L858R) and BRAF (V600E, G469A, D594G) mutations in 144 treatment-naive patients with lung adenocarcinoma, and analyzed the association between the mutation rates and patients' clinicopathological features. 51.4% (74/144) cases were identified harboring EGFR mutations. A total of 40.3% (58/144) patients carried sensitizing mutations (exon 19 deletion or L858R) and 14.6% (21/144) carried T790M mutations. 6.9% (10/144) mutation-positive patients were double-mutated. Total EGFR mutation rate was significantly increased in female compared with that of males (60.9 vs. 43.8%, P<0.05), in non-smokers compared with that of smokers (62.8 vs. 34.5%, P<0.05). In total, 8.3% (12/144) patients were identified with BRAF mutations. 16.7% were V600E (2/12) and 83.3% (10/12) were non-V600E mutants. Among the 10 non-V600E mutations, D594G accounted for 90.0% (9/10) and G469A accounted for 10.0% (1/10). Statistical analysis demonstrated that the BRAF mutation rate was not associated with any of the following clinicopathological features: Sex, age, smoking history, clinical stages, distant metastasis, differentiation degree, tumor size and regional lymph node metastasis (P≥0.05). CastPCR technology is a robust method with high sensitivity for the molecular detection of EGFR and BRAF mutations in clinical formalin-fixed paraffin-embedded samples.

Comparative safety and efficacy of tyrosine kinase inhibitors (TKIs) in the treatment setting of different types of leukemia, and different types of adenocarcinoma

Tyrosine kinase inhibitors (TKIs) are blockers of tyrosine kinase proteins which are known for the activation of signaling pathways especially in neoplastic cells. TKIs are among targeted anticancer medications that are available in the market. Imatinib was introduced in the late 1990s as the first TKI medicine in oncology, followed by gefitinib, erlotinib, sorafenib, sunitinib, dasatanib and the list of TKIs is being updated nearly every month. To review the safety, efficacy, and current clinical stage of TKIs in different malignancies, particularly leukemia, advanced gastrointestinal and breast cancer, whole literature over the last decade (2006 to 2017) were searched to find all related studies. Criticizing current data indicates that TKIs have shown better clinical outcome in terms of both safety and efficacy compared to conventional therapies. Meanwhile, regarding the results of available clinical trials, the best approach into maximizing the benefits of this novel targeting therapy and also minimizing the undesirable adverse effects, is to evaluate the pharmacogenetic data of patients before allocating these agents in their treatment setting.

Outcome of patients with lung adenocarcinoma with transformation to small-cell lung cancer following tyrosine kinase inhibitors treatment: A systematic review and pooled analysis

BACKGROUND

Lung adenocarcinoma can transform to small-cell lung cancer (SCLC) when resistance to tyrosine kinase inhibitors (TKIs) develops. This phenomenon has repeatedly been described in several case reports and small patient series. The characteristics and treatment outcomes of this population, however, have not been comprehensively reported.

METHODS

We performed a systematic review of the published literature to obtain explorative information on the clinical and pathological features and prognosis of the reported cases.

RESULTS

Twenty-five eligible publications were identified, contributing to 39 patients. The median time from initial diagnosis of lung adenocarcinoma to the transformation to SCLC (ttSCLC) was 19months (range 1-61months). The median survival after SCLC diagnosis was 6months. Female gender was significantly associated with longer ttSCLC at the multivariable analysis. Smoking status seemed to be associated with worse prognosis after the diagnosis of SCLC.

CONCLUSION

In this series of published cases, the transformation to a SCLC phenotype after an initial diagnosis of lung adenocarcinoma following TKI therapy appeared to be a late phenomenon. The prognosis after SCLC diagnosis is poor and current treatment strategies derived from primary SCLC seem to be largely inefficacious. New therapies are needed in the management of transformed SCLC.

Double Trouble: A Case Series on Concomitant Genetic Aberrations in NSCLC

Several oncogenic drivers have been identified in non-small cell lung cancer. Targeted therapies for these aberrations have already been successfully developed and implemented in clinical practice. Owing to improved sensitivity in genetic testing, more and more tumors with multiple driver mutations are identified, resulting in dilemmas for treating physicians whether and which targeted therapy to use. In this case series, we provide an overview of patients with intrinsic double mutations in oncogenic drivers and their reported response to targeted therapies, with a focus on epidermal growth factor receptor, anaplastic lymphoma kinase, cMET, and Kirsten rat sarcoma viral oncogene. We also include an unpublished case report on a patient with an epidermal growth factor receptor L858R and cMET exon 14 skipping.

Uncommon EGFR mutations in advanced non-small cell lung cancer

Molecular profiling in advanced non-small cell lung cancer (NSCLC) has allowed for the detection of actionable mutations, which has revolutionized the treatment paradigm in this highly fatal disease. Mutations involving the epidermal growth factor receptor (EGFR) gene are most common and the 'classical mutations', exon 19 deletions and the point mutation L858R at exon 21, predict response to EGFR tyrosine kinase inhibitors (TKIs). The 'uncommon' EGFR mutations account for 10-18% of all EGFR mutations and primarily consist of exon 20 insertions, exon 18 point mutations and complex mutations. Improved detection techniques have broadened the spectrum of reported aberrations within the 'uncommon group' but response to TKIs is variable and not fully elucidated. This review provides an overview of the biology and incidence of uncommon EGFR mutations and summarizes reported outcomes when treated with EGFR-TKIs.

Clinical characteristics and response to tyrosine kinase inhibitors of patients with non-small cell lung cancer harboring uncommon epidermal growth factor receptor mutations

Objective

To investigate the clinical features of patients with non-small cell lung cancer (NSCLC) harboring uncommon epidermal growth factor receptor (EGFR) mutations, and the treatment outcomes of EGFR tyrosine kinase inhibitors (TKIs) in these patients.

Methods

We retrospectively analyzed the data of 128 NSCLC patients pathologically diagnosed with uncommon EGFR mutation in the Department of Pathology, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College and Beijing Hospital from January 2010 to December 2015, including 40 advanced patients who received EGFR-TKI.

Results

Among the total 128 patients, 11 patients were non-adenocarcinoma, including squamous carcinoma (3.9%), adenosquamous carcinoma (2.3%), large cell carcinoma (0.8%), and composite neuroendocrine carcinoma (1.6%). Single mutations accounted for 75.0% (96/128), including G719X (29.7%), S768I (18.0%), 20 exon insertion (13.3%), L861Q (12.5%),De novo T790M (0.8%), and T725 (0.8%). Thirty-two patients harbored complex mutations. Forty advanced patients received EGFR-TKI, the objective response rate (ORR) was 20.0%, the disease control rate (DCR) was 85.0%, and the progression-free survival (PFS) was 6.4 [95% confidence interval (95% CI), 4.8–7.9] months. The exploratory analysis of tumor response and PFS in 33 patients with G719X/S768I/L861Q subtypes showed that ORR was 21.2% (7/33), the DCR was 93.9% (31/33), and PFS was 7.6 (95% CI, 5.8–9.4) months. Patients with exon 20 insertion mutation andDe novo T790M experienced rapid disease progression with PFS no more than 2.7 months.

Conclusions

Uncommon EGFR-mutant NSCLCs are heterogeneous, EGFR-TKIs can have different efficacy in this specific subtype, and thus further individual assessment is required for each case.

From Type I to Type II: Design, Synthesis, and Characterization of Potent Pyrazin-2-ones as DFG-Out Inhibitors of PDGFRβ

Reversible protein kinase inhibitors that bind in the ATP cleft can be classified as type I or type II binders. Of these, type I inhibitors address the active form, whereas type II inhibitors typically lock the kinase in an inactive form. At the molecular level, the conformation of the flexible activation loop holding the key DFG motif controls access to the ATP site, thereby determining an active or inactive kinase state. Accordingly, type I and type II kinase inhibitors bind to so-called DFG-in or DFG-out conformations, respectively. Based on our former study on highly selective platelet-derived growth factor receptor β (PDGFRβ) pyrazin-2-one type I inhibitors, we expanded this scaffold toward the deep pocket, yielding the highly potent and effective type II inhibitor 5 (4-[(4-methylpiperazin-1-yl)methyl]-N-[3-[[6-oxo-5-(3,4,5-trimethoxyphenyl)-1H-pyrazin-3-yl]methyl]phenyl]benzamide). In vitro characterization, including selectivity panel data from activity-based assays (300 kinases) and affinity-based assays (97 kinases) of these PDGFRβ type I (1; 5-(4-hydroxy-3-methoxy-phenyl)-3-(3,4,5-trimethoxyphenyl)-1H-pyrazin-2-one) and II (5) inhibitors showing the same pyrazin-2-one chemotype are compared. Implications are discussed regarding the data for selectivity and efficacy of type I and type II ligands.

ROR1 is a novel prognostic biomarker in patients with lung adenocarcinoma

Currently, there is no reliable biomarker to clinically predict the prognosis of lung adenocarcinoma (ADC). The receptor-tyrosine-kinase like orphan receptor 1 (ROR1) is reported to be overexpressed and associated with poor prognosis in several tumors. This study aimed to examine the expression of ROR1 and evaluate its prognostic significance in human lung ADC patients. In this present study, Western blot analysis and immunohistochemistry were performed to characterize expression of ROR1 protein in lung ADC patients. The results revealed that ROR1 protein expression was significantly higher in lung ADC tissues than that in their adjacent non-tumor tissues. Patients at advanced stages and those with positive lymph node metastasis expressed higher level of ROR1 (P < 0.001). Moreover, Chi-square test showed that ROR1 expression was correlated to gender (P = 0.028), the 7^th edition of the American Joint Committee on Cancer tumor-node-metastasis (AJCC TNM) staging system and lymph node metastasis (P < 0.001). Kaplan-Meier survival analysis indicated an association of high ROR1 expression with worse overall survival (OS) in lung ADC patients (P < 0.001). Multivariate COX regression analysis further confirmed that ROR1 is an independent prognostic predictor (P < 0.001, HR = 4.114, 95% CI: 2.513–6.375) for OS. Therefore, ROR1 expression significantly correlates with malignant attributes of lung ADC and it may serve as a novel prognostic marker in lung ADC patients.

Massive parallel sequencing and digital gene expression analysis reveals potential mechanisms to overcome therapy resistance in pulmonary neuroendocrine tumors

Background: Lung cancer is the leading cause of cancer-related deaths worldwide. 25% show neuroendocrine differentiation (typical/atypical carcinoids, large-/small-cell neuroendocrine carcinomas). Carcinoids present with long survival rates, but metastatic carcinoids correlate with decreased survival and are commonly insensitive to standard chemotherapy or radiation. Therefore, novel therapeutic strategies are urgently needed.

Material and methods: 70 representative tumor specimens were used for next-generation sequencing analysis of 14 genes related to therapy response. Additionally, mRNA-expression profiles of 60 matching samples were determined for 13 selected drug targets by using the NanoString nCounter technology.

Results: A number of features known to sensitize tumors for different targeted therapies could be identified, which hopefully improve the clinical management of this subgroup of lung neoplasias. In particular, EGFR expression was observed in the investigated tumors in a noteworthy manner. Additionally, MDM2 was strongly expressed in the majority of all samples whereas the expression of its physiological inhibitor, CDKN2A, was nearly absent in all low-grade tumors. TP53 showed a high frequency of variants in high-grade tumors but mutations were rare in carcinoids.

Conclusion: Based on our results, therapeutic approaches with MDM2-inhibitors and monoclonal anti-EGFR antibodies may be promising in pulmonary carcinoid tumors.

EGFR mutations in non-small cell lung cancer: an audit from West China Hospital

OBJECTIVES

To discover the incidence and characteristics of EGFR mutations in non-small cell lung cancer (NSCLC) in a single, large cohort as a part of routine diagnostic investigations.

METHODS

We reviewed EGFR mutations investigated by Amplification Refractory Mutation System (ARMS) PCR (covering 29 known mutations) using DNA samples from FFPE tissue or cell clot specimens in a total of 3894 cases of NSCLC analysed between 2012-2014.

RESULTS

EGFR mutations are preferentially associated with adenocarcinomaand adenosquamous histology, particularly those well to moderately differentiated, and were significantly more common in female than male patients irrespective of histological subtypes. Exon 19 deletion (45.7%) and exon 21 L858R (45.6%) accounted for the vast majority of the EGFR mutations detected, with the remaining mutations being infrequent (<2%). Compound mutations were seen in 51 (3%) of the mutant cases, the combination of these compound mutations could be classified into three subgroups according to the potential impact of individual mutations on EGFR TKI therapy. Accordingly, 7 cases had both sensitive mutations, 4 cases harboured one sensitive and one less responsive /uncertain mutation, 19 cases contained one sensitive and one resistant change, and a further 21 cases had two less responsive /uncertain mutations.

CONCLUSION

Our data represents the largest EGFR mutation survey based on routine clinical diagnostic laboratory data from a single institution, it confirms the incidence and characteristics of EGFR mutations in NSCLC seen in Asian patients, and also unravels the combinatorial nature of rare compound EGFR mutations.

[Effectiveness of Tyrosine Kinase Inhibitors on Uncommon Epidermal Growth Factor Receptor Mutations in Non-small Cell Lung Cancer]

背景与目的

表皮生长因子受体（epidermal growth factor receptor, EGFR）敏感性突变是EGFR酪氨酸激酶抑制剂（tyrosine kinase inhibitors, TKIs）的有效预测因子。85%-90%敏感性突变发生于19缺失突变及21外显子L858R突变。常见EGFR敏感性突变患者EGFR-TKIs治疗的客观缓解率（objective response rate, ORR）和无病进展生存时间（progression-free survival, PFS）显著延长，可分别达70%-80%和9个月-14个月。但EGFR-TKIs对于EGFR少见突变（uncommon mutations）的疗效尚不明确。本研究旨在探讨EGFR少见突变的临床病理特征及EGFR-TKIs治疗的远近期疗效。

方法

收集2010年4月-2015年4月北京大学肿瘤医院胸部肿瘤内科24例少见EGFR突变患者的临床资料，分析少见EGFR突变的临床病理特征及与TKIs疗效及PFS之间的关系。

结果

24例携带少见突变的患者中，单突变者15例，双突变者9例。15例单突变中，S768I、L861Q、20外显子插入突变、G719X分别为4例、4例、3例、2例。双突变中以S768I合并G719X最为常见（3/9）。在接受EGFR-TKIs治疗的13例患者中，ORR为46.1%（6/13），疾病控制率（disease control rate, DCR）为76.9%（10/13），中位PFS为7.4个月。

结论

作为特殊类型的EGFR突变，EGFR少见突变对于一代EGFR-TKIs的敏感性介于EGFR敏感性突变和EGFR野生型之间。相对于一代EGFR-TKIs而言，二代EGFR-TKIs可能更适用于EGFR少见突变的治疗。。

S768I Mutation in EGFR in Patients with Lung Cancer

INTRODUCTION

Epidermal growth factor receptor gene (EGFR) mutations are relatively common oncogenic drivers in non-small cell lung cancer (NSCLC). The outcomes of patients who present with less common EGFR mutations or more than one EGFR mutation are uncertain. We reviewed our experience with the S768I mutation of exon 20 of EGFR to provide insight into the clinical significance of this mutation.

METHODS

We used a natural language search program to search our electronic medical record system and every EGFR mutation analysis of patients with NSCLC treated at Mayo Clinic that was performed in our Department of Molecular Genetics to identify patients with EGFR S768I mutation. Relevant clinical and laboratory data were abstracted for selected cases, including evaluation of response after treatment with tyrosine kinase inhibitors.

RESULTS

A total of 1527 patients with NSCLC who underwent EGFR testing were reviewed. The S768I mutation was present in nine patients (0.59%), four of whom were female. Only three had an isolated S768I mutation, four had a concurrent G719 mutation, and two had a concurrent L858R mutation. Among patients with stage IV disease treated with erlotinib (n = 4), one had an isolated S768I mutation and three had additional mutations (two patients with G719 and one patient with L858R). The tumor response to erlotinib of patients with stage IV disease was highly variable (progression-free survival ranged from 3 to 30 months and overall survival ranged from 5 to more than 51 months).

CONCLUSIONS

S768I mutations in exon 20 of the EGFR gene are rare and are typically seen in conjunction with sensitizing EGFR mutations. Because of this mutation's rarity and the variability of responses of treated cases, its exact prognostic and predictive role is not fully understood. In our experience, S768I mutations in isolation do not necessarily confer sensitivity to erlotinib, but in conjunction with sensitizing EGFR mutations, S768I mutations do not restrict efficacy.

EGFR-tyrosine kinase inhibitor treatment in a patient with advanced non-small cell lung cancer and concurrent exon 19 and 21 EGFR mutations: A case report and review of the literature

Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are considered to be effective treatments for advanced non-small cell lung cancer (NSCLC) patients with sensitizing EGFR mutations, including exon 19 deletion and exon 21 L858R mutations. However, with the development of EGFR mutation detection assays, patients with complex EGFR mutations are emerging, and their response to EGFR-TKIs remains unclear. The present study reports a case of a 62-year-old, non-smoking female patient with advanced NSCLC, presenting with concurrent EGFR 19+21 sensitizing mutations, who had a poor response to the first-line EGFR-TKI erlotinib and succumbed 5 months subsequent to diagnosis. Furthermore, the present study performed a literature review, and 18 patients with complex EGFR 19+21 mutations that had received EGFR-TKIs were identified. The majority of these patients responded well to EGFR-TKIs. To the best of our knowledge, the present case is the first to report a patient with lung adenocarcinoma with complex EGFR 19+21 sensitizing mutations that had a poor clinical response to a first-line EGFR-TKI. Despite the 70% response rate of sensitizing EGFR-mutant NSCLCs to EGFR-TKIs, there is still a proportion of patients that experience de novo resistance, and heterogeneity is likely to be important in this resistance mechanism. Therefore, comprehensive genomic detection assays and multi-targeted therapies for patients with NSCLC with complex EGFR mutations require additional investigation.

Compound EGFR mutation is frequently detected with co-mutations of actionable genes and associated with poor clinical outcome in lung adenocarcinoma

Compound EGFR mutations, defined as double or multiple mutations in the EGFR tyrosine kinase domain, are frequently detected with advances in sequencing technology but its clinical significance is unclear. This study analyzed 61 cases of EGFR mutation positive lung adenocarcinoma using next-generation sequencing (NGS) based repeated deep sequencing panel of 16 genes that contain actionable mutations and investigated clinical implication of compound EGFR mutations. Compound EGFR mutation was detected in 15 (24.6%) of 61 cases of EGFR mutation-positive lung adenocarcinoma. The majority (12/15) of compound mutations are combination of the atypical mutation and typical mutations such as exon19 deletion, L858R or G719X substitutions, or exon 20 insertion whereas 3 were combinations of rare atypical mutations. The patients with compound mutation showed shorter overall survival than those with simple mutations (83.7 vs. 72.8 mo; P = 0.020, Breslow test). Among the 115 missense mutations discovered in the tested genes, a few number of actionable mutations were detected irrelevant to the subtype of EGFR mutations, including ALK rearrangement, BCL2L11 intron 2 deletion, KRAS c.35G>A, PIK3CA c.1633G>A which are possible target of crizotinib, BH3 mimetics, MEK inhibitors, and PI3K-tyrosine kinase inhibitors, respectively. 31 missense mutations were detected in the cases with simple mutations whereas 84 in those with compound mutation, showing that the cases with compound missense mutation have higher burden of missense mutations (P = 0.001, independent sample t-test). Compound EGFR mutations are detected at a high frequency using NGS-based repeated deep sequencing. Because patients with compound EGFR mutations showed poor clinical outcomes, they should be closely monitored during follow-up.

Mutational analysis of pulmonary tumours with neuroendocrine features using targeted massive parallel sequencing: a comparison of a neglected tumour group

Background:

Lung cancer is the leading cause of cancer-related deaths worldwide. The typical and atypical carcinoid (TC and AC), the large-cell neuroendocrine carcinoma (LCNEC) and the small-cell lung cancers (SCLC) are subgroups of pulmonary tumours that show neuroendocrine differentiations. With the rising impact of molecular pathology in routine diagnostics the interest for reliable biomarkers, which can help to differentiate these subgroups and may enable a more personalised treatment of patients, grows.

Methods:

A collective of 70 formalin-fixed, paraffin-embedded (FFPE) pulmonary neuroendocrine tumours (17 TCs, 17 ACs, 19 LCNECs and 17 SCLCs) was used to identify biomarkers by high-throughput sequencing. Using the Illumina TruSeq Amplicon-Cancer Panel on the MiSeq instrument, the samples were screened for alterations in 221 mutation hot spots of 48 tumour-relevant genes.

Results:

After filtering >26 000 detected variants by applying strict algorithms, a total of 130 mutations were found in 29 genes and 49 patients. Mutations in JAK3, NRAS, RB1 and VHL1 were exclusively found in SCLCs, whereas the FGFR2 mutation was detected in LCNEC only. KIT, PTEN, HNF1A and SMO were altered in ACs. The SMAD4 mutation corresponded to the TC subtype. We prove that the frequency of mutations increased with the malignancy of tumour type. Interestingly, four out of five ATM-mutated patients showed an additional alteration in TP53, which was by far the most frequently altered gene (28 out of 130; 22%). We found correlations between tumour type and IASLC grade for ATM- (P=0.022; P=0.008) and TP53-mutated patients (P<0.001). Both mutated genes were also associated with lymph node invasion and distant metastasis (P⩽0.005). Furthermore, PIK3CA-mutated patients with high-grade tumours showed a reduced overall survival (P=0.040) and the mutation frequency of APC and ATM in high-grade neuroendocrine lung cancer patients was associated with progression-free survival (PFS) (P=0.020).

Conclusions:

The implementation of high-throughput sequencing for the analysis of the neuroendocrine lung tumours has revealed that, even if these tumours encompass several subtypes with varying clinical aggressiveness, they share a number of molecular features. An improved understanding of the biology of neuroendocrine tumours will offer the opportunity for novel approaches in clinical management, resulting in a better prognosis and prediction of therapeutic response.

EGFR Exon 18 Mutations in East Asian Patients with Lung Adenocarcinomas: A Comprehensive Investigation of Prevalence, Clinicopathologic Characteristics and Prognosis

Our aim was to investigate the clinical and pathologic characteristics of the epidermal growth factor receptor (EGFR) exon 18 mutations in East Asian lung adenocarcinomas patients. A total of 1,201 lung adenocarcinomas were analyzed for mutation in EGFR. Clinical and pathologic characteristics of patients with EGFR exon 18 mutations were compared with those who harbored classic activating mutations (exon 19 deletions and the L858R point mutation). The mutations in EGFR exon 18 were observed in 2.8% of 1,201 lung adenocarcinomas and 4.6% of patients with EGFR mutations. Patients with a single EGFR exon of 18 mutations had a worse overall survival than those harboring the complex EGFR exon of 18 mutations (p = 0.002) or those with classic activating mutations (p = 0.014). Four of five patients with EGFR exon 18 mutations showed objective response to the EGFR-TKI therapies after disease recurrence. Our results demonstrated that single EGFR exon 18 mutations may be an indicator of poor prognosis compared with complex EGFR exon 18 mutations or classic mutations. Furthermore, the results of the current study will be helpful for decision-making in the treatment of patients with EGFR exon 18 mutations.

High expression of SOX30 is associated with favorable survival in human lung adenocarcinoma

In our previous study, we had identified SOX30 as a novel tumor suppressor that acts through direct regulation of p53 transcription in human lung cancer. Here, we sought to determine the clinical relevance of SOX30 expression in a series of surgically-resected non-small cell lung cancer (NSCLC) patients. Analysis of SOX30 expression and clinico-pathologic features reveal a significant correlation of SOX30 expression with histological type (n = 220, P = 0.008) and clinical stage (n = 220, P = 0.024). Kaplan-Meier analysis indicates an association of high SOX30 expression with better prognosis in NSCLC patients (n = 220, P = 0.007). Via multivariate Cox-regression analysis, SOX30 expression is revealed to be an independent prognostic factor for overall survival (OS) of NSCLC patients (n = 220, P = 0.014, hazard ratio (HR) = 0.816). In particular, SOX30 is a favorable and independent prognostic factor in one main subtype of NSCLC, lung adenocarcinoma (ADC) patients (n = 150, P = 0.000, HR = 0.405), but not in another main subtype of NSCLC, squamous cell carcinoma patients. Furthermore, high expression of SOX30 represents a favorable and independent factor for the prognosis of ADC patients at clinical stage II (P = 0.013), with positive lymph node (P = 0.003), at histological grade 2 (P = 0.000) or grade 3 (P = 0.025). In summary, SOX30 expression represents an important prognostic factor for survival time in ADC patients.

[Research Progress of Mechanisms on Intracranial Metastasis of Non-small Cell Lung Cancer after Clinical Benefit from EGFR-TKI]

表皮生长因子受体酪氨酸激酶抑制剂（epidermal growth factor receptor tyrosine kinase inhibitor, EGFR-TKI）广泛用于治疗EGFR突变阳性的非小细胞肺癌（non-small cell lung cancer, NSCLC）。然而，部分患者在接受EGFR-TKI治疗后、原发病灶稳定甚至缩小的同时，却出现了新发颅内转移灶或者原有颅内病灶进展，其机制未明。近年来多项研究表明，这种现象可能与EGFR-TKI的药物代谢动力学、NSCLC原发灶与转移灶的异质性、EGFR突变本身特质及患者生存期的延长有关。因此，本文就NSCLC患者在EGFR-TKI治疗临床获益后发生颅内转移的相关机制研究进展作一综述。

Next-generation sequencing for molecular diagnosis of lung adenocarcinoma specimens obtained by fine needle aspiration cytology

Identification of multi-gene variations has led to the development of new targeted therapies in lung adenocarcinoma patients, and identification of an appropriate patient population with a reliable screening method is the key to the overall success of tumor targeted therapies. In this study, we used the Ion Torrent next-generation sequencing (NGS) technique to screen for mutations in 89 cases of lung adenocarcinoma metastatic lymph node specimens obtained by fine-needle aspiration cytology (FNAC). Of the 89 specimens, 30 (34%) were found to harbor epidermal growth factor receptor (EGFR) kinase domain mutations. Seven (8%) samples harbored KRAS mutations, and three (3%) samples had BRAF mutations involving exon 11 (G469A) and exon 15 (V600E). Eight (9%) samples harbored PIK3CA mutations. One (1%) sample had a HRAS G12C mutation. Thirty-two (36%) samples (36%) harbored TP53 mutations. Other genes including APC, ATM, MET, PTPN11, GNAS, HRAS, RB1, SMAD4 and STK11 were found each in one case. Our study has demonstrated that NGS using the Ion Torrent technology is a useful tool for gene mutation screening in lung adenocarcinoma metastatic lymph node specimens obtained by FNAC, and may promote the development of new targeted therapies in lung adenocarcinoma patients.