Large-Scale EGFR Mutation Testing in Clinical Practice: Analysis of a Series of 18,920 Non-Small Cell Lung Cancer Cases

From Rarity to Reality: Osimertinib's Promising Horizon in Treating Uncommon EGFR Mutations in Non-Small Cell Lung Cancer

In the realm of advanced non-small cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EGFR) therapy with tyrosine kinase inhibitors (TKI), addressing optimal treatment for uncommon EGFR mutations like G719X in exon 18, S768I in exon 20, and L861Q in exon 21 remains a pivotal yet challenging frontier. Contrary to the well-established efficacy of EGFR-TKIs in common EGFR mutations, these uncommon alterations pose unmet medical needs due to a lack of comprehensive evidence. While afatinib, a second-generation EGFR-TKI, has received FDA approval for patients with these uncommon EGFR mutations, the approval was based on a post-hoc analysis of randomized clinical trials. Recent developments include multiple clinical trials investigating the efficacy of both second- and third-generation EGFR-TKIs in patients with uncommon EGFR mutations. A noteworthy example is a prospective phase II trial of osimertinib including the landmark UNICORN study, which has shown promising results in treating uncommon EGFR mutations. Despite various reports on the efficacy of afatinib and osimertinib in treating uncommon EGFR mutations, the appropriate use of these TKIs remains unclear. This review aims to consolidate the findings from the latest clinical trials focused on uncommon EGFR mutations, outlining variations in the therapeutic efficacy of these TKIs based on the specific genetic mutation. By synthesizing these findings, we aim to guide oncologists toward more informed decisions in employing TKIs for NSCLC with uncommon EGFR mutations other than exon 20 insertion. Additionally, we explore potential treatment strategies tailored to these patient populations to address the challenges posed by these mutations.

Activity of afatinib in patients with NSCLC harboring novel uncommon EGFR mutations with or without co-mutations: a case report

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) represent first-line standard of care in unresectable EGFR mutation-positive (EGFRm+) non-small cell lung cancer (NSCLC). However, 10-20% of patients with EGFRm+ NSCLC have uncommon EGFR variants, defined as mutations other than L858R substitutions or exon 19 deletions. NSCLC harboring uncommon EGFR mutations may demonstrate lower sensitivity to targeted agents than NSCLC with L858R or exon 19 deletion mutations. Prospective clinical trial data in patients with NSCLC uncommon EGFR mutations are lacking. Afatinib is a second-generation TKI and the only Food and Drug Administration-approved drug for some of the more prevalent uncommon EGFR mutations. We present a series of seven case reports describing clinical outcomes in afatinib-treated patients with NSCLC harboring a diverse range of extremely rare mutations with or without co-mutations affecting other genes. EGFR alterations included compound mutations, P-loop αC-helix compressing mutations, and novel substitution mutations. We also present a case with NSCLC harboring a novel EGFR::CCDC6 gene fusion. Overall, the patients responded well to afatinib, including radiologic partial responses in six patients during treatment. Responses were durable for three patients. The cases presented are in line with a growing body of clinical and preclinical evidence that indicating that NSCLC with various uncommon EGFR mutations, with or without co-mutations, may be sensitive to afatinib.

EGFR Tyrosine Kinase Inhibitors for the Treatment of Metastatic Non-Small Cell Lung Cancer Harboring Uncommon EGFR Mutations: A Podcast

Supplementary file1 (MP4 21169 KB).

Hope and Challenges: Immunotherapy in EGFR-Mutant NSCLC Patients

EGFR tyrosine kinase inhibitors (TKIs) are the preferred initial treatment for non-small cell lung cancer (NSCLC) patients harboring sensitive EGFR mutations. Sadly, remission is transient, and no approved effective treatment options are available for EGFR-TKI-advanced EGFR-mutant NSCLCs. Although immunotherapy with immune checkpoint inhibitors (ICIs) induces sustained cancer remission in a subset of NSCLCs, ICI therapy exhibits limited activity in most EGFR-mutant NSCLCs. Mechanistically, the strong oncogenic EGFR signaling in EGFR-mutant NSCLCs contributes to a non-inflamed tumor immune microenvironment (TIME), characterized by a limited number of CD8+ T cell infiltration, a high number of regulatory CD4+ T cells, and an increased number of inactivated infiltrated T cells. Additionally, EGFR-mutant NSCLC patients are generally non-smokers with low levels of PD-L1 expression and tumor mutation burden. Promisingly, a small population of EGFR-mutant NSCLCs still durably respond to ICI therapy. The hope of ICI therapy from pre-clinical studies and clinical trials is reviewed in EGFR-mutant NSCLCs. The challenges of application ICI therapy in EGFR-mutant NSCLCs are also reviewed.

Socioeconomic Inequalities in Novel NSCLC Treatments During the Era of Tumor Biomarker-Guided Therapy: A Population-Based Cohort Study in a Publicly Funded Health Care System

INTRODUCTION

Socioeconomic inequalities in the utilization of conventional NSCLC treatments are well documented. Nevertheless, it is not known whether these inequalities are also observed with novel anticancer therapies. This study evaluated associations between deprivation and utilization of novel anticancer therapies targeting tumor biology, the immune system, or both, within the English national publicly funded health care system.

METHODS

A retrospective analysis of 90,785 patients diagnosed with having a histologically confirmed stage IV NSCLC from January 1, 2012, to December 31, 2017, sourced from the English national population-based cancer registry and linked Systemic Anti-Cancer Therapy database, was undertaken. Multivariable logistic regression evaluated the likelihood of novel anticancer therapy utilization by deprivation category of area of residence at diagnosis (measured by quintiles of the income domain of the index of multiple deprivation).

RESULTS

Multivariable analyses revealed marked treatment inequalities by deprivation. Patients residing in the most deprived areas were more than half as likely to use any novel therapy (multivariable OR [mvOR] = 0.45, 95% confidence interval [CI]: 0.41-0.49) compared with patients residing in the most affluent areas. Deprivation associations with treatment utilization were slightly stronger with targeted treatments ([most versus least deprived] mvOR = 0.39, 95% CI: 0.35-0.43) than immune checkpoint inhibitors (mvOR = 0.58, 95% CI: 0.51-0.66).

CONCLUSIONS

There are marked socioeconomic inequalities in NSCLC novel treatment utilization, even in the English National Health Service where treatment is free at the point of delivery. These findings have important implications for equitable delivery of drugs, which have transformed outcomes in metastatic lung cancer. Further work exploring the underlying causes is now needed.

Overview on Therapeutic Options in Uncommon EGFR Mutant Non-Small Cell Lung Cancer (NSCLC): New Lights for an Unmet Medical Need

The majority of epidermal growth factor receptor (EGFR) mutations (85-90%) are exon 19 deletions and L858R point mutations of exon 21, characterized by high sensitivity to EGFR-tyrosine kinase inhibitors (TKIs). Less is known about uncommon mutations (10-15% of EGFR mutations). The predominant mutation types in this category include exon 18 point mutations, exon 21 L861X, exon 20 insertions, and exon 20 S768I. This group shows a heterogeneous prevalence, partly due to different testing methods and to the presence of compound mutations, which in some cases can lead to shorter overall survival and different sensitivity to different TKIs compared to simple mutations. Additionally, EGFR-TKI sensitivity may also vary depending on the specific mutation and the tertiary structure of the protein. The best strategy remains uncertain, and the data of EGFR-TKIs efficacy are based on few prospective and some retrospective series. Newer investigational agents are still under study, and there are no other approved specific treatments targeting uncommon EGFR mutations. Defining the best treatment option for this patient population remains an unmet medical need. The objective of this review is to evaluate existing data on the outcomes, epidemiology, and clinical characteristics of lung cancer patients with rare EGFR mutations, with a focus on intracranial activity and response to immunotherapy.

Landscape of EGFR mutations in lung adenocarcinoma: a single institute experience with comparison of PANAMutyper testing and targeted next-generation sequencing

Background

Activating mutations in the tyrosine kinase domain of epidermal growth factor receptor (EGFR) are predictive biomarkers for response to EGFR–tyrosine kinase inhibitor (TKI) therapy in lung adenocarcinoma (LUAD). Here, we characterized the clinicopathologic features associated with EGFR mutations via peptide nucleic acid clamping-assisted fluorescence melting curve analysis (PANAMutyper) and evaluated the feasibility of targeted deep sequencing for detecting the mutations.

Methods

We examined EGFR mutations in exons 18 through 21 for 2,088 LUADs from July 2017 to April 2020 using PANAMutyper. Of these, we performed targeted deep sequencing in 73 patients and evaluated EGFR-mutation status and TKI clinical response.

Results

EGFR mutation was identified in 55.7% of LUADs by PANAMutyper, with mutation rates higher in females (69.3%) and never smokers (67.1%) and highest in the age range of 50 to 59 years (64.9%). For the 73 patients evaluated using both methods, next-generation sequencing (NGS) identified EGFR mutation–positive results in 14 of 61 patients (23.0%) who were EGFR-negative according to PANAMutyper testing. Of the 10 patients reportedly harboring a sensitizing mutation according to NGS, seven received TKI treatment, with all showing partial response or stable disease. In the 12 PANAMutyper-positive cases, NGS identified two additional mutations in exon 18, whereas a discordant negative result was observed in two cases.

Conclusions

Although PANAMutyper identified high frequencies of EGFR mutations, targeted deep sequencing revealed additional uncommon EGFR mutations. These findings suggested that appropriate use of NGS may benefit LUAD patients with otherwise negative screening test results.

Afatinib 30 mg in the treatment of common and uncommon EGFR-mutated advanced lung adenocarcinomas: a retrospective, single-center, longitudinal study

Background

Afatinib 30 mg has been proved to be with comparable efficacy but more tolerable than the dose of 40 mg for Asian patients with non-small cell lung cancer (NSCLC). This study aimed to investigate the clinical outcomes of afatinib at 30 mg/d in the treatment of advanced lung adenocarcinomas (LAD) with common and uncommon epidermal growth factor receptor (EGFR) mutations.

Methods

EGFR-mutated advanced LAD patients receiving afatinib (30 mg/d) from January 2017 to November 2021 were retrospectively included. EGFR status was classified into three subtypes, namely common mutations including exon 19 deletions (19del) and exon 21 L858R (21L858R), uncommon mutations including G719X, L861Q, S768I, and complex mutations, and separately exon 20 insertions (20ins). Progression-free survival (PFS), objective response rate (ORR), disease control rate (DCR) and adverse events (AEs) were analyzed during regular follow-up.

Results

The overall median PFS of totally 58 included patients was 9.83 [95% confidence index (CI): 5.76–13.91] months. The number of patients with common, uncommon, and 20ins mutations was 32 (55.2%), 19 (32.8%) and 7 (12.1%), respectively. Baseline characteristics did not differ significantly among the three subtypes. The corresponding median PFS was 13.97 (12.06–15.89), 8.48 (0.32–16.64), and 3.78 (1.93–5.64) months, respectively (P=0.002). In the first-line setting, patients with common and uncommon mutations had a significantly longer PFS compared to those with 20ins [14.53 (13.53–15.53) vs. 10.39 (4.87–15.91) vs. 2.37 (0.00–5.11) months, P<0.001]. The first-line ORR showed significant differences among the three subtypes (60% vs. 80% vs. 0.0%, P=0.023). All-grade AEs occurred in 22 patients (37.9%). AEs ≥ grade 3 mainly included diarrhea (8.6%), and none of the patients discontinued treatment due to severe AEs.

Conclusions

Afatinib at 30 mg/d is associated with a favorable efficacy and tolerability in the treatment of advanced LAD with common and major uncommon EGFR mutations except 20ins. Further large-scale prospective studies are warranted to confirm our findings.

Efficacy and safety of adjuvant EGFR-TKIs for resected non-small cell lung cancer: a systematic review and meta-analysis based on randomized control trials

Background

Postoperative adjuvant cisplatin-based chemotherapy had been the standard care in patients with completely resected high-risk stage IB to IIIA non-small cell lung cancer (NSCLC) for decades. However, the survival benefits were far from satisfactory in clinical practice. Thus, this meta-analysis was performed to compare the efficacy and safety of adjuvant epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) in patients with resected NSCLC based on updated literature and research.

Methods

A systematic literature search based on random control trials (RCTs) was conducted with keywords on PubMed, Embase and the Cochrane library databases. All articles compared EGFR-TKIs to placebo or chemotherapy as adjuvant therapies for early-stage resected NSCLC. A meta-analysis was performed to generate combined hazard ratio (HR) with 95% confidence intervals (CI) for disease-free survival (DFS), overall survival (OS), and risk ratio (RR) with 95% CI for disease recurrence and adverse events (AEs). The Stata statistical software (version 14.0) was used to synthesis the data.

Results

A total of 9 RCTs comprising 3098 patients were included. Adjuvant EGFR-TKIs could significantly prolong DFS in patient with resected NSCLC harboring epidermal growth factor receptor (EGFR) mutations (HR 0.46, 95% CI 0.29–0.72), but had no impact on OS (HR 0.87, 95% CI 0.69–1.11). The subgroup analyses indicated that adjuvant EGFR-TKIs were superior in regard to DFS in most subgroups, including varied smoking status, EGFR mutations type, gender, age, Eastern Cooperative Oncology Group performance status and adenocarcinoma. Osimertinib resulted in decreased brain recurrence than first generation of EGFR-TKIs (RR 0.12, 95% CI 0.04–0.34 vs. RR 1.07, 95% CI 0.64–1.78, respectively). The AEs were generally manageable and tolerable. The incidence of high-grade (≥ 3) AEs including diarrhea (RR 5.68, 95% CI 2.94–10.98) and rash (RR 27.74, 95% CI 11.43–67.30) increased after adjuvant EGFR-TKIs treatment.

Conclusions

Adjuvant EGFR-TKIs therapy could significantly prolong DFS in patients with completely resected early-stage EGFR mutation-positive NSCLC, but had no impact on OS. Adjuvant EGFR-TKIs could be an important treatment option in patients with resected early-stage EGFR-mutant NSCLC.

Prevalence of Epidermal Growth Factor Receptor Exon 20 Insertion Mutations in Non-small-Cell Lung Cancer in Europe: A Pragmatic Literature Review and Meta-analysis

Background

Information on the epidemiology of uncommon EGFR mutations including exon 20 insertions amongst non-small-cell lung cancer (NSCLC) is lacking.

Objective

The objective of this pragmatic literature review (PLR) and meta-analysis was to generate robust prevalence and incidence estimates based on ranges of exon 20 insertion mutations reported in the literature.

Materials and methods

Searches of MEDLINE, Embase, congresses and reference lists for articles published from 2013 in key European countries of interest (Belgium, France, Germany, Italy, The Netherlands, Spain, Sweden, Switzerland, United Kingdom) were performed. Articles were reviewed against pre-specified criteria and their quality was appraised using a published checklist. Prevalence estimates were synthesised by random-effects meta-analyses.

Results

Eighty unique studies of moderate-to-high quality were included in the PLR. The meta-analysed prevalence for EGFR mutations was 12.5% (95% confidence interval [CI]: 11.0, 14.1) in any stage NSCLC and 14.8% (12.8, 17.1) in advanced/metastatic NSCLC. The prevalence of exon 20 insertions was 0.7% (0.4, 1.1) in any stage NSCLC and 6.1% (4.0, 9.4) in any stage EGFR-positive NSCLC. Mutation status was primarily measured using direct sequencing or a combination of methods. One study reporting exon 20 insertions in advanced/metastatic disease was identified, which reported a prevalence of 0.5% in overall NSCLC and 4.0% in EGFR-positive NSCLC.

Conclusions

EGFR exon 20 insertion mutations are rare in NSCLC. There is a high unmet need in patients with exon 20 insertions, including effective therapies. Prospective cohort studies are needed to better clinically characterise these patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11523-022-00868-z.

The Lifted Veil of Uncommon EGFR Mutation p.L747P in Non-Small Cell Lung Cancer: Molecular Feature and Targeting Sensitivity to Tyrosine Kinase Inhibitors

Objectives

The uncommon p.L747P mutation in epidermal growth factor receptor (EGFR) exon 19 reveals to alter the response to tyrosine kinase inhibitors (TKIs) in patients diagnosed with advanced non-small cell lung cancer (NSCLC). However, the underlying mechanism is still not clear. This study aimed to investigate the clinical outcomes, binding affinities, and modes of action of currently available EGFR TKIs towards p.L747P mutation.

Materials and Methods

Clinical data of NSCLC patients harboring p.L747P mutation who had received different generations of EGFR TKIs were collected from medical records. Computational structure of p.L747P was constructed and in vitro cellular kinase inhibition assay and mice xenograft experiment were performed to predict and confirm the binding affinities and antitumor activities of diverse EGFR TKIs.

Results

A total of five metastatic NSCLC patients with p.L747P mutation were included in the final analysis. Patients treated with second-generation (2G) TKI afatinib achieved numerically longer progression-free survival (range 2.4-8.5 months) than that with first-generation (1G, range 1.4-5.5 months) or third-generation (3G, range 1.6-7.5 months) TKIs. None of the patients administered 1G or 3G TKIs achieved tumor response, but two-thirds of them treated with afatinib achieved partial response. Dynamics simulation predicted that 2G TKIs presented the best binding affinity to p.L747P mutation. The cellular kinase inhibition assay and mice xenograft experiment confirmed that afatinib could potently inhibit p.L747P-mutant cells and significantly reduce p.L747P-mutant tumor growth (P< 0.001), together with reduced phosphorylation of EGFR and its downstream signalings.

Conclusions

The uncommon p.L747P mutation in EGFR exon 19 resulted in a poor response to first-generation EGFR TKIs. Afatinib revealed a better clinical response and binding affinity compared with osimertinib for this specific alteration.

Budget Impact di afatinib per il trattamento in prima linea del Non Small Cell Lung Cancer (NSCLC) con mutazioni non comuni EGFR

Background:

The current clinical practice for patients affected by Non-Small Cell Lung Cancer (NSCLC) with uncommon mutation is based on afatinib and osimertinib, second and third generation of Tyrosine Kinase Inhibitor (TKI) respectively. For uncommon EGFR mutations, it is still unclear which EGFR TKI is most effective, since there are few dedicated prospective studies and Next Generation Sequencing (NGS) techniques trace an increasingly large and sometimes little-known population of EGFR mutations.

Objective:

To determine the economic impact associated to afatinib and osimertinib, a Budget Impact model considering a 3-year time horizon with two scenarios was developed: a first scenario, called AS IS, based on treatment with afatinib and osimertinib according to a distribution of market shares as emerged from clinical practice; a second suitable scenario, called TO BE, based on reviewed literature data, assuming for each year a 10%, 15% and 20% increase in afatinib use, respectively.

Methods:

Budget Impact analysis was conducted using a dynamic cohort model, in which the annual number of patients with NSCLC and uncommon mutations was equally distributed over 12 months. Progression-free survival (PFS) data for afatinib and osimertinib were extrapolated up to 36 months from published Kaplan Meier curves, and then the number of patients was estimated for each treatment.

Results:

The increase of 10% in afatinib use allowed a saving of drug acquisition costs for the Italian NHS, over the 3-year time horizon, of –€ 622,432. The univariate sensitivity analysis shows the market share of osimertinib to be the parameter significantly affecting the results achieved in the base case.

Conclusions:

The potential increase in the use of afatinib in patients with NSCLC and uncommon mutations leads to lower drug acquisition costs, lower Budget Impact and a saving of money for the Italian NHS.

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.

Primary Erlotinib Resistance in a Patient with Non-Small Cell Lung Cancer Carrying Simultaneous Compound EGFR L718A, Q849H, and L858R Mutations

Nowadays, mutations in the epidermal growth factor receptor (EGFR) kinase domain are studied in targeted therapy of non-small cell lung cancer (NSCLC) with EGFR tyrosine kinase inhibitors including gefitinib and erlotinib. The present study reports a rare case of a patient harboring three simultaneous EGFR mutations (L718A, Q849H, and L858R). The development of erlotinib resistance was detected in the subsequent treatment. Using a computational approach, the current study investigated the conformational changes of wild-type and mutant EGFR's kinase domains in the interaction with erlotinib. Their binding modes with erlotinib were elucidated during molecular dynamics simulation, where higher fluctuations were detected in the mutated forms of the EGFR tyrosine kinase domain. Prediction of stability and functional effect of mutations revealed that amino acidic substitutions have decreased the protein stability as well as the binding affinity to erlotinib. These results may be useful for a recommendation of EGFR mutational analysis for patients with NSCLC carcinoma.

Uncommon EGFR mutations in non-small-cell lung cancer: A systematic literature review of prevalence and clinical outcomes

Mutations in exons 18-21 of the epidermal growth factor receptor gene (EGFR) can confer sensitivity to EGFR-tyrosine kinase inhibitors (EGFR-TKIs) in patients with non-small-cell lung cancer (NSCLC). Deletions in exon 19 or the exon 21 L858R substitution comprise approximately 85% of mutations, but comparatively few data are available on the remaining "uncommon" mutations. We conducted a systematic literature review to identify evidence on uncommon EGFR mutations in locally advanced/metastatic NSCLC (PROSPERO registration number: CRD42019126583). Electronic screening and congress searches identified studies published in 2012-2020 including patients with locally advanced/metastatic NSCLC and uncommon EGFR mutations (excluding T790M). We assessed the prevalence of uncommon mutations (in studies using direct sequencing of exons 18-21), and compared response to treatment and progression-free survival (PFS) in patients with common versus uncommon mutations and in those with exon 20 mutations versus other uncommon mutations. We identified 64 relevant studies. Uncommon mutations constituted 1.0-18.2% of all EGFR mutations, across 10 studies. The most frequently reported uncommon mutations were G719X (0.9-4.8% of all EGFR mutations), exon 20 insertions (Ex20ins; 0.8-4.2%), L861X (0.5-3.5%), and S768I (0.5-2.5%). Patients with common mutations typically experienced better treatment response and longer PFS on EGFR-TKIs than patients with uncommon mutations; Ex20ins mutations were associated with less favourable outcomes than other uncommon mutations. This review shows that uncommon mutations may comprise a clinically significant proportion of the EGFR mutations occurring in NSCLC, and highlights disparities in EGFR-TKI sensitivity between different uncommon mutations.

Lung squamous cell carcinoma with rare epidermal growth factor receptor mutation G719X: a case report and literature review

Asians who develop non-small cell lung cancer (NSCLC) have a chance of approximately 50% of harboring the epidermal growth factor receptor (EGFR) mutation. The G719X mutation in EGFR has 3 subtypes (i.e., G719A, G719C, or G719S), all of them being classified as uncommon EGFR mutations. The EGFR mutation G719X is most often associated with lung adenocarcinoma. Conversely, its occurrence in lung squamous cell carcinoma is rare. Its response to tyrosine kinase inhibitor (TKI) treatment remains unknown. A 50-year-old Asian male with no smoking history was admitted to our hospital (Affiliated Hospital of Qingdao University) with an irritating dry cough and 1 month of progressive dyspnea. The patient was diagnosed with lung squamous cell carcinoma (cT4N3M0, stage IIIC). Lung biopsy revealed the presence of EFGR G719X mutation. The patient received a tracheobronchial stent, targeted therapy, chemotherapy, seed implantation and radiotherapy, and survived for 25.4 months following diagnosis. It is crucial that gene mutation analysis is performed in non-smoking male squamous cell carcinoma patients. Compared to lung adenocarcinoma patients with rare G719X mutation, this lung squamous cell carcinoma patient with G719X-mutant tumor had a higher sensitivity to 2^nd-generation EGFR-TKI treatment, but similar progression-free survival. Importantly, the patient clearly benefited from the used comprehensive treatment plan. This article seeks to shed light on the treatment of lung squamous cell carcinoma patients with the uncommon EGFR G719X mutation.

Antitumour immunity regulated by aberrant ERBB family signalling

Aberrant signalling of ERBB family members plays an important role in tumorigenesis and in the escape from antitumour immunity in multiple malignancies. Molecular-targeted agents against these signalling pathways exhibit robust clinical efficacy, but patients inevitably experience acquired resistance to these molecular-targeted therapies. Although cancer immunotherapies, including immune checkpoint inhibitors (ICIs), have shown durable antitumour response in a subset of the treated patients in multiple cancer types, clinical efficacy is limited in cancers harbouring activating gene alterations of ERBB family members. In particular, ICI treatment of patients with non-small cell lung cancers with epidermal growth factor receptor (EGFR) alterations and breast cancers with HER2 alterations failed to show clinical benefits, suggesting that EGFR and HER2 signalling may have an essential role in inhibiting antitumour immune responses. Here, we discuss the mechanisms by which the signalling of ERBB family members affects not only autonomous cancer hallmarks, such as uncontrolled cell proliferation, but also antitumour immune responses in the tumour microenvironment and the potential application of immune-genome precision medicine into immunotherapy and molecular-targeted therapy focusing on the signalling of ERBB family members.

A Review of Monoclonal Antibody-Based Treatments in Non-small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) is one of the most common types of lung cancer worldwide. It metastasizes rapidly and has a poor prognosis. The first-line treatment for most patients is a combination of chemotherapy and radiation. In many subjects, using targeted treatments alongside chemoradiation has shown a better outcome in terms of progression and quality of life for patients. These targeted treatments include small biological inhibiting molecules and monoclonal antibodies. In this review, we have assessed studies focused upon the treatment of non-small cell lung cancer. Some therapies are approved, such as bevacizumab and atezolizumab, while some are still in clinical trials, such as ficlatuzumab and ipilimumab, and others have been rejected due to inadequate disease control, such as figitumumab.

Distinct EGFR Mutation Pattern in Patients With Non-Small Cell Lung Cancer in Xuanwei Region of China: A Systematic Review and Meta-Analysis

Background

In the Xuanwei region of China, lung cancer incidence and mortality are among the highest in China, attributed to severe air pollution generated by combustion of smoky coal. No study has yet comprehensively evaluated the prevalence of epidermal growth factor receptor (EGFR) mutation characteristics in patients with non-small cell lung cancer (NSCLC) in Xuanwei. This meta-analysis was designed to analyze the EGFR mutation pattern in NSCLC patients in Xuanwei region of Yunnan Province in China.

Methods

Electronic databases were comprehensively searched and relevant literatures were retrieved. The odds ratio (OR) for EGFR mutations between Xuanwei region and non-Xuanwei region was calculated, and the absolute incidence of EGFR mutations in Xuanwei was pooled by mutation subtype.

Results

Seven studies involving 1,355 patients with NSCLC from Yunnan Province (442 in Xuanwei and 913 in other regions) were included. The EGFR mutation rate ranged between 30.19% and 55.56%. Higher uncommon EGFR mutations (OR: 5.69, 95%CI: 2.23–14.49, P<0.001) and lower common EGFR mutations (OR: 0.18, 95%CI: 0.07–0.45, P<0.001) were found in Xuanwei region, compared with non-Xuanwei region. Specifically, the uncommon EGFR mutation rate was 59.50% and common EGFR mutation rate was 40.50% in Xuanwei. The mutation incidence of exon 18 G719X (OR: 3.21, 95%CI: 1.48–6.97, P=0.003), exon 20 S768I (OR: 6.44; 95%CI: 2.66–15.60; P<0.001), and exon 18 G719X + 20 S768I (OR: 6.55; 95%CI: 1.92–22.33; P=0.003) in Xuanwei were significantly higher, while the frequency of 19 deletion (OR: 0.28, 95%CI: 0.11–0.77, P<0.001) and 21 L858R mutation (OR: 0.51, 95%CI: 0.31–0.84, P=0.007) were lower.

Conclusions

The results highlight the distinct EGFR mutation spectrum of NSCLC patients in Xuanwei region compared with other regions, with higher uncommon mutations but lower common mutations. The distinct Xuanwei featured genetic variations provide a unique model to further study carcinogenesis of lung cancer.

Inter- and Intratumor Heterogeneity of EGFR Compound Mutations in Non-Small Cell Lung Cancers: Analysis of Five Cases

BACKGROUND

Several clinical and preclinical studies suggest that non-small cell lung cancers (NSCLCs) with EGFR compound mutations were associated with lower efficacies of first-generation EGFR inhibitors than tumors with single EGFR mutation. Some researchers hypothesize that EGFR mutation status is heterogeneous in such tumors and that second-generation EGFR inhibitors may eliminate cancer cells with uncommon EGFR mutations from tumors with EGFR compound mutations. However, this hypothesis is currently unproven; therefore, we performed the current study to determine if tumor cells with EGFR compound mutations are present in heterogeneous or homogeneous manners.

PATIENTS AND METHODS

Multiregion analysis was performed for surgically resected primary NSCLC tumors with EGFR compound mutations to examine the intratumor heterogeneity of EGFR compound mutations. In addition, we evaluated the intertumor heterogeneity of EGFR compound mutations using 2 pleural disseminations obtained from a patient with NSCLC at exploratory thoracotomy and 9 primary or metastatic lesions obtained from 2 autopsied NSCLC patients. Digital polymerase chain reaction, target sequencing, or direct sequencing were used to detect EGFR mutations.

RESULTS

This study included 5 NSCLC cases; their compound mutations were L858R+S768I, G719X+S768I, G719A+R776H, L858R+E709G, and L858R+I759M. Noncancerous pulmonary tissues from each patient did not harbor EGFR mutations, which revealed that all mutations were somatic. We did not detect any intra- or intertumor heterogeneity in these EGFR compound mutations.

CONCLUSION

No intra- or intertumor heterogeneity was observed for EGFR compound mutations. Our results indicate that both EGFR mutations were truncal and selective elimination of cancer cells with uncommon EGFR mutations is unrealistic.

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.

Role of Anti-EGFR Targeted Therapies in Stage III Locally Advanced Non-small Cell Lung Cancer: Give or Not to Give?

PURPOSE OF REVIEW

Identification of targetable mutations such as EGFR has allowed opportunity for Tyrosine Kinase Inhibitor (TKI) therapy for lung cancer treatment. EGFR-TKIs have revolutionized treatment of advanced EGFR mutant Non-Small Cell Lung Cancer (NSCLC), but there is little evidence that EGFR-TKI treatment is effective in stage III NSCLC. Here we discuss recent evidence supporting the use of EGFR-TKI therapy in combination with chemotherapy and radiation in stage III NSCLC.

RECENT FINDINGS

Recent results of small trials testing EGFR-TKI therapy in combination with chemoradiation showed promising efficacy, improved outcomes, and a tolerable toxicity profile when administered to patients with EGFR mutant stage III NSCLC. However, strong supporting evidence regarding EGFR-TKI therapy in stage III NSCLC is lacking because previous trials involved a small patient population or were terminated due to slow participant accrual. Despite the lack of large randomized clinical trials, results from early-stage trials highlight promising future directions for investigating the use of EGFR-TKI therapy in stage III NSCLC treatment.

Treatment of uncommon EGFR mutations in non-small cell lung cancer: new evidence and treatment

Sensitizing mutations in epidermal growth factor receptor (EGFR) are associated with positive responses to anti-EGFR-targeted therapy, leading to a new era of treatment for non-small cell lung cancer (NSCLC). Exon 19 deletions and exon 21 L858R substitutions are the most common mutations, accounting for approximately 90% mutations in NSCLC; these are termed classic mutations and result in high sensitivity to tyrosine kinase inhibitors (TKIs). Other EGFR mutations are termed uncommon EGFR mutations, of which G719X, S768I, L861Q, exon 20 insertions, and complex mutations are the most frequent. G719X, S768I, and L861Q are point mutations and those that exist with complex mutations are sensitive to first-generation TKIs. A prospective analysis demonstrated that afatinib, a second-generation TKI, led to a better prognosis in some patients with NSCLC compared to first-generation TKIs. Chemotherapy used to be the traditional choice for patients carrying exon 20 insertions; however, with the development of novel targeted drugs, the role of chemotherapy is changing. Tremendous progress has also been made in clinical trials on immunotherapy treatment of uncommon EGFR mutations. The treatment for patients with NSCLC harboring uncommon EGFR mutations remains a subject of debate and the sensitivity of uncommon EGFR mutations to TKIs is still unclear. Here, we summarized recent data in the literature and provide an overview of the clinical characteristics, incidence, and outcomes of patients harboring G719X, S768I, L861Q, exon 20 insertions, and complex mutations who were treated with TKIs, chemotherapy, or immunotherapy.