Concomitant EGFR mutation and ALK rearrangement in lung adenocarcinoma is more frequent than expected: Report of a case and review of the literature with demonstration of genes alteration into the same tumor cells

Unraveling the Impact of Intratumoral Heterogeneity on EGFR Tyrosine Kinase Inhibitor Resistance in EGFR-Mutated NSCLC

The advent of tyrosine kinase inhibitors (TKIs) for treating epidermal growth factor receptor (EGFR)-mutated non-small-cell lung cancer (NSCLC) has been a game changer in lung cancer therapy. However, patients often develop resistance to the drugs within a few years. Despite numerous studies that have explored resistance mechanisms, particularly in regards to collateral signal pathway activation, the underlying biology of resistance remains largely unknown. This review focuses on the resistance mechanisms of EGFR-mutated NSCLC from the standpoint of intratumoral heterogeneity, as the biological mechanisms behind resistance are diverse and largely unclear. There exist various subclonal tumor populations in an individual tumor. For lung cancer patients, drug-tolerant persister (DTP) cell populations may have a pivotal role in accelerating the evolution of tumor resistance to treatment through neutral selection. Cancer cells undergo various changes to adapt to the new tumor microenvironment caused by drug exposure. DTP cells may play a crucial role in this adaptation and may be fundamental in mechanisms of resistance. Intratumoral heterogeneity may also be precipitated by DNA gains and losses through chromosomal instability, and the role of extrachromosomal DNA (ecDNA) may play an important role. Significantly, ecDNA can increase oncogene copy number alterations and enhance intratumoral heterogeneity more effectively than chromosomal instability. Additionally, advances in comprehensive genomic profiling have given us insights into various mutations and concurrent genetic alterations other than EGFR mutations, inducing primary resistance in the context of tumor heterogeneity. Understanding the mechanisms of resistance is clinically crucial since these molecular interlayers in cancer-resistance mechanisms may help to devise novel and individualized anticancer therapeutic approaches.

Evolution of acquired resistance in a ROS1+ KRAS G12C+ NSCLC through the MAPK pathway

Patients with metastatic NSCLC bearing a ROS1 gene fusion usually experience prolonged disease control with ROS1-targeting tyrosine kinase inhibitors (TKI), but significant clinical heterogeneity exists in part due to the presence of co-occurring genomic alterations. Here, we report on a patient with metastatic NSCLC with a concurrent ROS1 fusion and KRAS p.G12C mutation at diagnosis who experienced a short duration of disease control on entrectinib, a ROS1 TKI. At progression, the patient continued entrectinib and started sotorasib, a small molecule inhibitor of KRAS p.G12C. A patient-derived cell line generated at progression on entrectinib demonstrated improved TKI responsiveness when treated with entrectinib and sotorasib. Cell-line growth dependence on both ROS1 and KRAS p.G12C was further reflected in the distinct downstream signaling pathways activated by each driver. Clinical benefit was not observed with combined therapy of entrectinib and sotorasib possibly related to an evolving KRAS p.G12C amplification identified on repeated molecular testing. This case supports the need for broad molecular profiling in patients with metastatic NSCLC for potential therapeutic and prognostic information.

Genomic landscape of lung adenocarcinomas in different races

Background

Lung adenocarcinoma is a molecularly heterogeneous disease. Several studies, including The Cancer Genome Atlas Research Network (TCGA) and Lung Cancer Mutation Consortium (LCMC), explored the genetic alterations among different ethnic groups. However, minority groups are often under-represented in these relevant studies and the genomic alterations among racial groups are not fully understood.

Methods

We analyze genomic characteristics among racial groups to understand the diversities and their impact on clinical outcomes.

Results

Native Americans had significantly higher rates of insertions and deletions than other races (P<0.001). Among patients with lung adenocarcinomas, EGFR and KRAS were the highest discrepancy genes in the different racial groups (P<0.001). The EGFR exon 21 L858R point mutation was three times higher in Asians than in all other races (P<0.001). Asians, Whites, and Blacks had 4.7%, 3.1%, and 1.8% ALK rearrangement, respectively (P<0.001). White patients had the highest rates of reported KRAS G12C (15.51%) than other races (P<0.001). Whites (17.2%), Blacks (15.1%), and Other (15.7%) had higher rates of STK11 mutation than Asians (3.94%) (P<0.001). RET rearrangement and ERBB2 amplification were more common in Asian patients than in Other racial groups. Apart from point mutations, structural variations, and fusion genes, we identified a significant amount of copy number alterations in each race.

Conclusions

The tumor genomic landscape is significantly distinct in different races. This data would shed light on the understanding of molecular alterations and their impacts on clinical management in different lung cancer patients.

Anaplastic Lymphoma Kinase Tyrosine Kinase Inhibitor-Associated Cardiotoxicity: A Recent Five-Year Pharmacovigilance Study

Background: Clinical trials frequently reported anaplastic lymphoma kinase tyrosine kinase inhibitors (ALK-TKIs) associated with cardiac adverse drug events (AEs) but minimal postmarketing data. We aimed to research real-world cardiac disorders associated with ALK-TKIs based on the Food and Drug Administration Adverse Event Reporting System (FAERS).

Methods: Extract reports from the FAERS from the first quarter of 2016 to the second quarter of 2021 were obtained. Data mining of cardiac disorders associated with ALK-TKIs was carried out using disproportionality analysis to determine the clinical characteristics of AEs.

Results: In total, 605 cases were screened out. These events were found to be more prevalent in patients ≥45 years (50.74%) and women (50.74%). The onset time of cardiac disorders was variable and concentrated within 2 months, with a median time of 33 days. The outcomes tended to be poor, with 20.93% fatality proportion. Cardiac arrhythmia was a common adverse event of ALK-TKIs, especially bradycardia. Crizotinib and lorlatinib showed positive signals in cardiac disorders, especially in heart failure, and brigatinib presented no signals. The study also found that myocarditis caused by ceritinib and cardiomyopathy caused by lorlatinib may be potential new adverse drug reactions.

Conclusion: ALK-TKIs were reported more frequently in cardiotoxicity than other drugs and could often manifest earlier. We also found potential new AE signals in specific drugs and need more clinical studies to confirm. Our study helps fill the safety information of ALK-TKIs in the heart and provides directions for further research.

An activatable, carrier-free, triple-combination nanomedicine for ALK/EGFR-mutant non-small cell lung cancer highly permeable targeted chemotherapy

Highly permeable targeted chemotherapy is highly desired for treating non-small cell lung cancer (NSCLC).

Effectiveness of alectinib and osimertinib in a brain metastasized lung adenocarcinoma patient with concurrent EGFR mutations and DCTN1‐ALK fusion

The echinoderm microtubule associated protein‐like 4 gene (EML4) encodes the predominant anaplastic lymphoma kinase (ALK) fusion partner in non‐small‐cell lung cancer (NSCLC); however, the dynactin subunit 1 (DCTN1)‐ALK rearrangement is extremely rare. The co‐occurrence of primary epidermal growth factor receptor (EGFR) T790M mutation with EGFR exon 19 deletion (del) in patients with NSCLC is uncommon. Here we report a female lung adenocarcinoma patient with brain metastases and possible coexistence of primary EGFR T790M mutation/EGFR exon 19 del/DCTN1‐ALK translocation. The patient received multiline treatment including chemotherapy, antivascular, and targeted therapies. To overcome developed resistance to chemotherapy or targeted therapy to prolong overall survival, the patient's circulating tumor DNA (ctDNA) was dynamically monitored. The patient responded to successive osimertinib and alectinib treatment, and alectinib achieved a nearly complete response for lung and brain lesions after she acquired osimertinib resistance. Furthermore, we summarize 22 published cases of patients with lung adenocarcinoma with concurrent EGFR mutation and ALK rearrangement, including details of clinical characteristics, natural history, and pertinent therapy of this uncommon tumor subtype. This literature review shows that EGFR inhibition was an indispensable aspect of the treatment of patients with EGFR/ALK co‐alterations in the pre‐alectinib era and that ALK inhibition with crizotinib did not show more eye‐catching therapeutic results. Considering the effectiveness achieved by alectinib, this case study provides a new perspective for the treatment of lung cancer brain metastasis patients with concurrent EGFR/ALK mutations.

Deepening the Knowledge of ROS1 Rearrangements in Non-Small Cell Lung Cancer: Diagnosis, Treatment, Resistance and Concomitant Alterations

ROS proto-oncogene 1 (ROS1) rearrangements are reported in about 1-2% of non-squamous non-small-cell lung cancer (NSCLC). After efficacy of crizotinib was demonstrated, identification of ROS1 translocations in advanced disease became fundamental to give patients the chance of specific and effective treatment. Different methods are available for detection of rearrangements, and probably the real prevalence of ROS1 rearrangements is higher than that reported in literature, as our capacity to detect gene rearrangements is improving. In particular, with next generation sequencing (NGS) techniques, we are currently able to assess multiple genes simultaneously with increasing sensitivity. This is leading to overcome the "single oncogenic driver" paradigm, and in the very near future, the co-existence of multiple drivers will probably emerge more frequently and represent a therapeutic issue. Since recently, crizotinib has been the only available therapy, but today, many other tyrosine kinase inhibitors (TKI) are emerging and seem promising both in first and subsequent lines of treatment. Indeed, novel inhibitors are also able to overcome resistance mutations to crizotinib, hypothesizing a possible sequential strategy also in ROS1-rearranged disease. In this review, we will focus on ROS1 rearrangements, dealing with diagnostic aspects, new therapeutic options, resistance issues and the coexistence of ROS1 translocations with other molecular alterations.

Genetic landscape of patients with ALK-rearranged non-small-cell lung cancer (NSCLC) and response to ceritinib in ASCEND-1 study

OBJECTIVES

To better understand genetic determinants of response to ceritinib, an exploratory analysis was conducted using tumor biopsies from anaplastic lymphoma kinase (ALK)-rearranged (ALK+) non-small-cell lung cancer (NSCLC) patients treated with ceritinib at doses of ≥ 300 mg in the ASCEND-1 study.

METHODS

ASCEND-1 was an open-label, multicentre, phase 1, dose-escalation and expansion study of ceritinib (fasted) in ALK inhibitor (ALKi)-naïve or ALKi-pretreated patients with locally advanced or metastatic ALK + NSCLC. Biopsies were assayed by next-generation sequencing (NGS) using a Foundation Medicine panel targeting 295 genes. Somatic alterations were correlated with clinical outcome (cut-off 14-Apr-2014). A total of 285 ALK + NSCLC patients were treated with ceritinib at doses ≥ 300 mg.

RESULTS

NGS data were generated for 85 pts (ALKi-pretreated [n = 54]; ALKi-naïve [n = 31]), 57 were collected from patients before exposure to any ALKi. NGS did not detect ALK rearrangement in 14 of 85 patients; several of these ALK NGS negative cases harbored alternative drivers, e.g. EGFR mutation. Of the 71 biopsies with NGS confirmed ALK rearrangement, the most frequently detected rearrangements were EML4-ALK variant 1 (V1) and EML4-ALK V3 (36.6% [26/71] and 32.4% [23/71] respectively). Eight (six crizotinib-pretreated and two pretreated with crizotinib followed by alectinib) of the 21 ALKi-pretreated patients carried a point mutation of the ALK TKD, and had the biopsy collected between 1 and 14 days before ceritinib; with the exception of one patient with a G1202R point mutation, all patients derived clinical benefit from ceritinib treatment. Of the 14 ALKi-naïve patients, ceritinib was effective in almost all patients, including a patient carrying a concomitant ERBB4 and HGF amplification.

CONCLUSIONS

This exploratory analysis highlights the potential role of NGS in improving our understanding of response and resistance to ceritinib. It also illustrates that ceritinib is active against almost all ALK resistance mutations found in ALKi-pretreated patients.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01283516. Registered January 26, 2011, https://clinicaltrials.gov/ct2/show/NCT01283516.

Co-Occurring Potentially Actionable Oncogenic Drivers in Non-Small Cell Lung Cancer

Background

Several oncogenic drivers in non-small cell lung cancer (NSCLC) are considered actionable with available or promising targeted therapies. Although targetable drivers rarely overlap with each other, there were a minority of patients harboring co-occurring actionable oncogenic targets, whose clinical characteristics and prognosis are not yet clear.

Methods

A total of 3,077 patients with NSCLC who underwent molecular analysis by NGS were included, and their demographic and clinical data were retrospectively collected.

Results

Our study found that the frequency of NSCLC patients harboring co-occurring potentially actionable alterations was approximately 1.5% (46/3077); after excluding patients with EGFR-undetermined mutations, the incidence was 1.3% (40/3077); 80% (37/46) harbored both EGFR mutations and other potentially actionable drivers such as MET amplification (21.6%; 8/37) and alterations in ERBB2 including mutations (27%; 10/37) and amplification (21.6%; 8/37); other combinations of potentially actionable drivers including alterations in ERBB2, KRAS, MET, ALK, and RET were also identified. Additionally, de novo MET/ERBB2 amplification in patients harboring EGFR-mutant NSCLC treated with first-generation EGFR tyrosine kinase inhibitors (TKIs) was associated with shorter PFS (p < 0.05). The efficacy of TKIs in NSCLC patients harboring other co-occurring potentially actionable drivers varied across different molecular subtypes.

Conclusions

Approximately 1.5% of NSCLCs harbored co-occurring potentially actionable oncogenic drivers, commonly involving EGFR mutations. Co-occurring actionable targets may impact the efficacy of TKIs; therefore, future clinical trials in these patients should be anticipated to tailor the combination or sequential treatment strategies.

Two different patterns of lung adenocarcinoma with concomitant EGFR mutation and ALK rearrangement

Epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) rearrangements are considered mutually exclusive in non-small cell lung cancer (NSCLC), especially in lung adenocarcinoma (LUAC). However, sporadic cases harboring concomitant EGFR and ALK alterations have been increasingly reported. There is no consensus opinion regarding the treatment of patients positive for both molecular alterations. NSCLC with EGFR/ALK coalterations should be separated into two subtypes: unifocal and multifocal LUAC. Here, we present an overview of the available literature regarding this rare group of patients to provide useful suggestions for therapeutic strategies.

A case of concomitant EGFR/ALK alteration against a mutated EGFR background in early-stage lung adenocarcinoma

Rare cases of lung adenocarcinoma (LUAD) with concomitant epidermal growth factor receptor (EGFR) mutation and anaplastic lymphoma kinase (ALK) translocation have been reported. However, their clonal and evolutional relationship remains unclear. We report a case of early-stage EGFR-mutated LUAD with a focal concomitant EGFR/ALK alteration. A 63-year-old male underwent lobectomy to remove a 1.9-cm-sized lung nodule, which was diagnosed with EGFR-mutated LUAD. ALK immunohistochemistry (IHC) showed focal positivity within the part of the tumor characterized by lepidic pattern, also confirmed by fluorescence in-situ hybridization (FISH). Targeted next-generation sequencing was performed separately on the ALK IHC/FISH-positive and -negative areas. EGFR L833V/L858R mutations were detected in both areas, whereas EML4 (echinoderm microtubule-associated protein-like 4)-ALK translocations was confirmed only in the ALK IHC/FISH-positive area, suggesting the divergence of an EGFR/ALK co-altered subclone from the original EGFR-mutant clone. Our study suggests that concurrent alterations of EGFR and ALK can arise via divergent tumor evolution, even in the relatively early phases of tumorigenesis.

Concomitant Pathogenic Mutations and Fusions of Driver Oncogenes in Tumors

Driver oncogene alterations have always been one of leading causes in the process of occurrence and development of tumors. And the effects of driver oncogene alterations on tumorigenesis and progression in different kinds of tumors have been studied heatedly. And the roles that the driver oncogenes alterations play have been elucidated clearly in previous studies. The phenomenon of concomitant driver oncogenes mutations and driver genes fusions has gained much concentration in the past two decades. And a growing number of studies reported this phenomenon, either coexistence or mutually exclusivity. Here we reviewed on the phenomenon of concomitant mutations in three common types of carcinomas—lung cancer, thyroid cancer, and leukemia, which have been studied relatively more detailed and more general compared with others.

Concurrent Genetic Alterations and Other Biomarkers Predict Treatment Efficacy of EGFR-TKIs in EGFR-Mutant Non-Small Cell Lung Cancer: A Review

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) greatly improve the survival and quality of life of non-small cell lung cancer (NSCLC) patients with EGFR mutations. However, many patients exhibit de novo or primary/early resistance. In addition, patients who initially respond to EGFR-TKIs exhibit marked diversity in clinical outcomes. With the development of comprehensive genomic profiling, various mutations and concurrent (i.e., coexisting) genetic alterations have been discovered. Many studies have revealed that concurrent genetic alterations play an important role in the response and resistance of EGFR-mutant NSCLC to EGFR-TKIs. To optimize clinical outcomes, a better understanding of specific concurrent gene alterations and their impact on EGFR-TKI treatment efficacy is necessary. Further exploration of other biomarkers that can predict EGFR-TKI efficacy will help clinicians identify patients who may not respond to TKIs and allow them to choose appropriate treatment strategies. Here, we review the literature on specific gene alterations that coexist with EGFR mutations, including common alterations (intra-EGFR [on target] co-mutation, TP53, PIK3CA, and PTEN) and driver gene alterations (ALK, KRAS, ROS1, and MET). We also summarize data for other biomarkers (e.g., PD-L1 expression and BIM polymorphisms) associated with EGFR-TKI efficacy.

Influence of EGFR-activating mutations on sensitivity to tyrosine kinase inhibitors in a KRAS mutant non-small cell lung cancer cell line

In non-small cell lung cancer (NSCLC), oncogenic driver mutations including those in KRAS and EGFR are typically mutually exclusive. However, recent reports indicate that multiple driver mutations are found in a certain percentage of cancers, and that the therapeutic responses of such cases with co-mutations of driver genes are largely unclear. Here, using CRISPR-Cas9-mediated genome editing, we generated isogenic cell lines harboring one or two copies of an EGFR-activating mutation from the human NSCLC cell line A549, which is known to harbor a homozygous KRAS gene mutation. In comparison with parent cells with KRAS mutation alone, cells with concomitant EGFR mutation exhibited higher sensitivity to EGFR-tyrosine kinase inhibitors (TKIs) but not to conventional anti-cancer drugs. In particular, cells with two copies of EGFR mutation were markedly more sensitive to EGFR-TKIs compared with parent cells. Thus, the presence of concomitant EGFR mutation can affect the TKI response of KRAS-mutated cells, implying that EGFR-TKI may represent an effective treatment option against NSCLC with EGFR/KRAS co-mutation.

Clinical Management of Non-Small Cell Lung Cancer with Concomitant EGFR Mutations and ALK Rearrangements: Efficacy of EGFR Tyrosine Kinase Inhibitors and Crizotinib

BACKGROUND

Patients harboring concomitant epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) arrangements constitute a small subgroup of non-small-cell lung cancer (NSCLC) patients. The efficacy of EGFR tyrosine kinase inhibitors (TKIs) and the ALK-specific TKI crizotinib in these patients has not been well-established.

OBJECTIVE

This study investigated the efficacy of targeted therapies in these patients compared with patients with EGFR or ALK alterations alone.

METHODS

Patients were screened for EGFR mutation and ALK rearrangement at the Shanghai Chest Hospital (2011-2017). Progression-free survival (PFS), objective response rate (ORR), and overall survival (OS) were retrospectively analyzed.

RESULTS

A total of 5816 patients were screened, and 26 patients were identified as having concomitant EGFR mutations and ALK rearrangements; 22 patients were eligible for survival analysis. Additionally, 95 EGFR-mutant patients and 60 ALK-rearranged patients were randomly selected for analysis. The ORR to EGFR TKIs was 63.2% (12/19) for EGFR/ALK co-altered patients and 62.1% (59/95) for EGFR-mutant patients (p = 0.93) with a median PFS of 10.3 and 11.4 months, respectively (hazard ratio [HR] 0.96; 95% confidence interval [CI] 0.59-1.57; p = 0.87). The ORR to crizotinib was 66.7% (8/12) for double-positive patients and 65.0% (39/60) for ALK-rearranged patients (p = 1.00), with a median PFS of 11.1 and 12.5 months, respectively (HR 1.39; 95% CI 0.69-2.80; p = 0.28). OS was 27.1, 36.2, and 36.8 months for EGFR-mutant, ALK-rearranged, and EGFR/ALK co-altered patients, respectively, and the EGFR/ALK co-existing subgroup tended to have a longer survival period than EGFR-mutant cohorts, though no statistical difference was found (p = 0.12). The median PFS of crizotinib as a sequential therapy after failure of EGFR TKIs was 15.0 months, which exhibited no statistically significant difference compared with the median PFS of ALK-altered patients who received crizotinib (p = 0.80).

CONCLUSIONS

Both first-generation EGFR TKIs and the ALK TKI crizotinib were effective in these patients. Sequential treatment with EGFR TKIs and crizotinib should be considered as a management option.

Anaplastic Lymphoma Kinase (ALK)-positive Tumors: Clinical, Radiographic and Molecular Profiles, and Uncommon Sites of Metastases in Patients With Lung Adenocarcinoma

INTRODUCTION

Anaplastic lymphoma kinase (ALK) gene rearrangements are observed in about 4% to 8% non-small cell lung cancer (NSCLC). ALK+ tumors have been associated with increased pleural and pericardial disease. Our primary objective was to determine the uncommon sites of metastasis of ALK+ NSCLC. Secondary objectives included study of coexisting mutations and factors impacting survival of ALK+ NSCLC.

METHODS

All patients with metastatic ALK+ NSCLC at the City of Hope Cancer Center in Duarte, California from 2010 to 2017 were selected for retrospective chart review. The demographic variables were collected. The molecular statuses of patients were evaluated through commercially available platforms for next-generation sequencing. Three-dimensional volumetric images were generated for the primary lesion and different sites of metastasis.

RESULTS

Sixty two patients with ALK+ NSCLC were identified from 2010 to 2017. The median age was 59 with 36 (58%) female individuals and only 20 (32%) smokers. Twenty four patients had uncommon sites of metastasis which were thyroid, soft tissue, chest and abdominal wall, spleen, peritoneum, omentum, kidney, and ovary. Common characteristics of the primary lesions were right upper lobe location (N=23 [37%]), oval shape (N=22 [35%]), irregular margins (N=26 [42%]), solid lesions (N=27 [44%]), presence of pleural contact or effusion (N=22 [35%]). Twenty four patients had next-generation sequencing testing which showed coexisting mutations such as TP53 (N=8), EGFR (N=5), KRAS (N=3). Patients with uncommon sites of metastasis had a decreased median survival compared with common sites (39 vs. 82 m, P=0.046).

CONCLUSION

In NSCLC, ALK rearrangements may not be mutually exclusive mutations and can present with unique radiographic patterns. Patients with uncommon sites of metastasis may have worse outcomes.

Molecular and clinical analysis of Chinese patients with anaplastic lymphoma kinase (ALK)-rearranged non-small cell lung cancer

Anaplastic lymphoma kinase (ALK) fusions have been recognized as a therapeutic target in non‐small cell lung cancer (NSCLC). However, molecular signatures and clinical characteristics of the Chinese population with ALK‐rearranged NSCLC are not well elucidated. In the present study, we carried out targeted next‐generation sequencing on tissue and plasma ctDNA samples in 1688 patients with NSCLC. Overall, ALK fusions were detected in 70 patients (4.1%), and the frequencies of ALK fusions detected in tissue and plasma samples were 5.1% and 3.3%, respectively. Additionally, the prevalence of breakpoint locations for EML4‐ALK fusions in ctDNA was significantly correlated with that in tumor tissues (R² = .91, P = .045). According to age, the incidence rates of ALK fusions among young (age <45 years), middle‐aged (between 45 and 70 years) and elderly (>70 years) patients were significantly different (P < .001). In 70 ALK‐rearranged cases, coexistence of epidermal growth factor receptor (EGFR) alterations and ALK fusions was detected in 12 cases (17.1%) and EGFR mutations tended to coexist with non‐EML4‐ALK rearrangements. Notably, novel ALK fusion partners, including TRIM66,SWAP70,WNK3,ERC1,TCF12 and FBN1 were identified in the present study. Among EML4‐ALK fusion variants, patients with variant V1 were younger than patients with variant V3 (P = .023), and TP53 mutations were more frequently concurrent with variant V3 compared with variant V1 (P = .009). In conclusion, these findings provide new insights into the molecular‐clinical profiles of patients with ALK‐rearranged NSCLC that may improve the treatment strategy of this population.

Intrinsic resistance to EGFR-Tyrosine Kinase Inhibitors in EGFR-Mutant Non-Small Cell Lung Cancer: Differences and Similarities with Acquired Resistance

Activating mutations in the epidermal growth factor receptor gene occur as early cancer-driving clonal events in a subset of patients with non-small cell lung cancer (NSCLC) and result in increased sensitivity to EGFR-tyrosine-kinase-inhibitors (EGFR-TKIs). Despite very frequent and often prolonged clinical response to EGFR-TKIs, virtually all advanced EGFR-mutated (EGFRM+) NSCLCs inevitably acquire resistance mechanisms and progress at some point during treatment. Additionally, 20-30% of patients do not respond or respond for a very short time (<3 months) because of intrinsic resistance. While several mechanisms of acquired EGFR-TKI-resistance have been determined by analyzing tumor specimens obtained at disease progression, the factors causing intrinsic TKI-resistance are less understood. However, recent comprehensive molecular-pathological profiling of advanced EGFRM+ NSCLC at baseline has illustrated the co-existence of multiple genetic, phenotypic, and functional mechanisms that may contribute to tumor progression and cause intrinsic TKI-resistance. Several of these mechanisms have been further corroborated by preclinical experiments. Intrinsic resistance can be caused by mechanisms inherent in EGFR or by EGFR-independent processes, including genetic, phenotypic or functional tumor changes. This comprehensive review describes the identified mechanisms connected with intrinsic EGFR-TKI-resistance and differences and similarities with acquired resistance and among clinically implemented EGFR-TKIs of different generations. Additionally, the review highlights the need for extensive pre-treatment molecular profiling of advanced NSCLC for identifying inherently TKI-resistant cases and designing potential combinatorial targeted strategies to treat them.

An Integrated Next-Generation Sequencing System for Analyzing DNA Mutations, Gene Fusions, and RNA Expression in Lung Cancer

We developed and characterized a next-generation sequencing (NGS) technology for streamlined analysis of DNA and RNA using low-input, low-quality cancer specimens. A single-workflow, targeted NGS panel for non-small cell lung cancer (NSCLC) was designed covering 135 RNA and 55 DNA disease-relevant targets. This multiomic panel was used to assess 219 formalin-fixed paraffin-embedded NSCLC surgical resections and core needle biopsies. Mutations and expression phenotypes were identified consistent with previous large-scale genomic studies, including mutually exclusive DNA and RNA oncogenic driver events. Evaluation of a second cohort of low cell count fine-needle aspirate smears from the BATTLE-2 trial yielded 97% agreement with an independent, validated NGS panel that was used with matched surgical specimens. Collectively, our data indicate that broad, clinically actionable insights that previously required independent assays, workflows, and analyses to assess both DNA and RNA can be conjoined in a first-tier, highly multiplexed NGS test, thereby providing faster, simpler, and more economical results.

Concomitant EGFR Mutation and EML4-ALK Rearrangement in Lung Adenocarcinoma Is More Frequent in Multifocal Lesions

BACKGROUND

The coexistence of epidermal growth factor receptor (EGFR) mutation and anaplastic lymphoma kinase (ALK) rearrangement in patients with multifocal lung adenocarcinomas (LUAC) constitutes a rare molecular subtype of lung cancer. We aimed to investigate the intertumoral heterogeneity of pathologic and genetic characteristics of multifocal LUAC with EGFR/ALK co-alterations.

PATIENTS AND METHODS

A total of 1059 LUAC patients who underwent resection were investigated to screen for EGFR or ALK alterations using amplification refractory mutation system polymerase chain reaction and immunohistochemistry/fluorescence in situ hybridization. Molecular testing was extensively performed in patients with synchronous multifocal LUAC. Clonal evolution analysis was implemented using next-generation sequencing.

RESULTS

A total of 97 multiple synchronous lesions were observed among 1059 LUAC patients. Patients with at least 1 sample harboring EGFR mutation or ALK rearrangement were 62.89% (61/97) and 14.43% (14/97), respectively. Patients with concomitant EGFR and ALK alterations were 4.71% (4/97). Comparatively, patients with unifocal LUAC harboring EGFR mutation, ALK rearrangement, and EGFR/ALK co-alterations were 58.25% (570/962), 6.44% (62/962), and 0.83% (8/962), respectively. The prevalence of EGFR/ALK co-alterations in the multifocal LUAC was significantly higher than that in the unifocal LUAC (4.71% (4/97) vs. 0.83% (8/962)). Furthermore, we present 4 cases of EGFR/ALK co-altered multifocal LUAC with different morphological and molecular patterns. In addition to radiographic, pathological, and molecular testing results, clonal evolutional analysis could also be used to distinguish intertumoral heterogeneity.

CONCLUSION

The results highlight the importance of distinguishing synchronous primary tumors from intrapulmonary metastases, and of assessing the relative abundance of EGFR mutation and ALK rearrangement in patients with multifocal adenocarcinomas with EGFR/ALK co-alterations.

Clinical features and therapeutic options in non-small cell lung cancer patients with concomitant mutations of EGFR, ALK, ROS1, KRAS or BRAF

Background

Although oncogenic driver mutations were thought to be mutually exclusive in non‐small cell lung cancer (NSCLC), certain tumors harbor co‐occurring mutations and represent a rare molecular subtype. The evaluation of the clinical features and therapeutic response associated with this NSCLC subtype will be vital for understanding the heterogeneity of treatment response and improving the management of these patients.

Methods

This retrospective study included 3774 samples from patients diagnosed with NSCLC. All samples were screened for EGFR, ALK, ROS1, KRAS, and BRAF mutation using the amplification‐refractory mutation system. The relationship between concomitant driver mutations and clinicopathologic characteristics, and patient clinical outcomes were evaluated.

Results

Sixty‐three (1.7%) samples had more than one driver gene mutation. Among these, 43 were coalterations with an EGFR mutation, 20 with an ALK rearrangement, and eight with an ROS1 rearrangement. Except for ROS1 concomitant mutations that were more frequent in male patients (87.5%, P = 0.020), the clinicopathological features of the concomitant mutation patients were not significantly different from those harboring a single EGFR, ALK, or ROS1 mutation. Furthermore, first‐line EGFR‐TKI treatment did not significantly improve the progression‐free survival (PFS) of patients harboring EGFR concomitant mutation, compared to patients harboring a single EGFR mutation. However, for EGFR concomitant mutation patients, TKI therapy was more effective than chemotherapy (median PFS of 10.8 vs 5.2 months, P = 0.023). Lastly, KRAS mutations did not influence the EGFR‐TKI therapy treatment effect.

Conclusion

In this study, concomitant mutations were found in 1.7% of the NSCLC. EGFR‐TKI therapy was more effective than chemotherapy for patients harboring EGFR concomitant mutation, and ROS1 concomitant mutations were more frequent in male patients. For patients harboring coalterations with an ALK or ROS1 rearrangement, we should be cautious when considering the therapeutic options.

[Advances in Double Mutations of EGFR and ALK Gene in Non-small Cell Lung Cancer]

Molecular target therapy is one of the most popular field of non-small cell lung cancer (NSCLC) treatmnet. Epidermal growth factor receptor (EGFR) mutation and anaplastic lymphoma kinase (ALK) rearragement are the most important two oncogenic drivers in NSCLC, early studies suggested that EGFR mutations and ALK rearrangements are mutually exclusive, but isolated cases or small sample research with concomitant EGFR and ALK alterations have been constantly reported. The co-occurrence of EGFR mutations and anaplastic lymphoma kinase (ALK) rearrangements constitutes a rare molecular, the frequency of EGFR/ALK co-alterations was about 1%, however, little has been known about clinicopathologic feature and treatment. This review summarized published case report, EGFR and ALK alterations are common in female, Asian origin, never smoker, IV stage, and denocarcinomas. First-line treatment can choose EGFR or ALK tyrosine kinase inhibitors (TKIs). However, studies about the origin and resistance mechanism in EGFR/ALK co-alterations are little, require more experimental and clinical research.
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Common cancer-driver mutations and their association with abnormally methylated genes in lung adenocarcinoma from never-smokers

OBJECTIVES

Lung adenocarcinoma in never-smokers accounts for 15-20% of all lung cancer. Although targetable mutations are more prevalent in these tumors, the biological and clinical importance of coexisting and/or mutually exclusive abnormalities is just emerging. This study evaluates the relationships between common genetic and epigenetic aberrations in these tumors.

MATERIALS AND METHODS

Next-generation sequencing was employed to screen 20 commonly mutated cancer-driver genes in 112 lung adenocarcinomas from never-smokers. The relationship of these mutations with cancer-related methylation of 59 genes, and geographical/ethnic differences in the prevalence for mutations compared to multiple East Asian never-smoker lung adenocarcinoma cohorts was studied.

RESULTS

The most common driver mutation detected in 40% (45/112) of the tumors was EGFR, followed by TP53 (18%), SETD2 (11%), and SMARCA4 (11%). Over 72% (81/112) of the cases have mutation of at least one driver gene. While 30% (34/112) of the tumors have co-mutations of two or more genes, 42% (47/112) have only one driver gene mutation. Differences in the prevalence for some of these mutations were seen between adenocarcinomas in East Asian versus US (mainly Caucasian) never-smokers including a significantly lower rate of EGFR mutation among the US patients. Interestingly, aberrant methylation of multiple cancer-related genes was significantly associated with EGFR wildtype tumors. Among 15 differentially methylated genes by EGFR mutation, 14 were more commonly methylated in EGFR wildtype compared to mutant tumors. These findings were independently validated using publicly available data.

CONCLUSION

Most lung adenocarcinomas from never-smokers harbor targetable mutation/co-mutations. In the absence of EGFR mutation that drives 40% of these tumors, EGFR wildtype tumors appear to develop by acquiring aberrant promoter methylation that silences tumor-suppressor genes.

Pulmonary Adenocarcinoma, Harboring Both an EGFR Mutation and ALK Rearrangement, Presenting a Stable Disease to Erlotinib and a Partial Response to Alectinib

A 63-year-old woman with pulmonary adenocarcinoma (stage IIIB) that was positive for an epidermal growth factor receptor (EGFR) mutation and an anaplastic lymphoma kinase (ALK) rearrangement was treated with erlotinib as the first-line treatment, resulting in a stable disease. Due to skin rashes, fatigue and anorexia, erlotinib was suspended on erlotinib day 44. Alectinib was administered as the second-line treatment, exhibiting a partial response. On alectinib day 56, drug-induced lung injury forced suspension of alectinib, which was cured with corticosteroid therapy. ALK-tyrosine kinase inhibitors may be more effective for patients positive for both EGFR mutation and ALK rearrangement than other agents.

Concomitant driver mutations in advanced EGFR-mutated non-small-cell lung cancer and their impact on erlotinib treatment

Background

Patients with EGFR-mutated non-small-cell lung cancer benefit from EGFR tyrosine kinase inhibitors (TKIs) like erlotinib. However, the efficacy may be impaired by driver mutations in other genes.

Methods

Five hundred and fourteen consecutive patients with NSCLC of all stages were tested for EGFR-mutations by cobas® EGFR Mutation Test. Fluorescent in situ hybridization (FISH) for MET-amplification, immunohistochemistry (IHC) for MET- and ALK-expression, and Next Generation Sequencing (NGS) for concomitant driver mutations were performed on EGFR-mutated tumor samples from erlotinib-treated patients.

Results

Thirty-six patients (7%) had EGFR-mutations, including 2 with intrinsic resistance mutation p.T790M together with the p.L858R sensitizing mutation and 1 harboring the p.G719C/S768I double-mutation. Twenty-three patients had either locally advanced or advanced disease and received first-line erlotinib-treatment. Concomitant driver mutations were found in 15/21 (71%) of NGS-analyzed TKI-treated NSCLCs, involving in 67% of cases TP53, in 13% CTNNB1, and in 7% KRAS, MET, SMAD4, PIK3CA, FGFR1, FGFR3, NRAS, DDR2, and ERBB4. No ALK-expression was found, whereas MET-overexpression and MET-amplification were observed in 5 and 4 patients, respectively. Objective responses occurred in 17/23 patients (74%), 4 did not respond (17%), and 2 harboring a SMAD4-mutation (p.R135^*(stop)) and a FGFR3-mutation (p.D785fs^*31), respectively, displayed mixed response with simultaneously progressing and responding tumors (8.7%). Thus, EGFR-mutated tumors harboring co-mutations were not less likely to respond.

Conclusion

Co-mutations in other cancer-driver genes (oncogenes or tumor suppressor genes) were frequent in EGFR-mutated NSCLCs and few cases harbored concomitant activating and resistance EGFR-mutations before TKI-treatment. Most co-mutations did not impact the response to first-line erlotinib-treatment, but may represent potential additional therapeutic targets.

Concurrent gene alterations with EGFR mutation and treatment efficacy of EGFR-TKIs in Chinese patients with non-small cell lung cancer

PURPOSE

We investigated the frequency of concurrent genes in EGFR-mutant non-small cell lung cancer patients and determined its value in predicting the efficacy of EGFR-TKIs treatment.

METHODS

Three hundred and twenty patients, who harbored EGFR activating mutations and received EGFR-TKIs treatment, were examined for another eight genes including KRAS, NRAS, PIK3CA, BRAF, and HER2 mutations and ALK, ROS1, and RET fusion genes based on reverse transcription PCR. Progression-free survival and overall survival with EGFR-TKIs treatment were evaluated using Kaplan-Meier methods and compared between different patients using log-rank tests.

RESULTS

Twenty-one (6.6%) of 320 EGFR mutant samples with additional gene alterations were identified. The most common concurrent gene was PIK3CA mutation (n = 9), followed by EML4-ALK rearrangement (n = 6), HER2 mutation (n = 3), RET rearrangement (n = 1), ROS1 rearrangement (n = 1) and KRAS mutation (n = 1). Patients with single EGFR mutation had a significantly longer progression-free survival than those with concurrent genes (10.9 vs. 6.0 months, P = 0.002). Among the 21 cases, patients with PIK3CA mutation had the longest median progression-free survival (7.6 months), followed by ALK rearrangement (5.0 months) and other gene types (1.2 months). No overall survival difference was found between patients with single EGFR mutation and concurrent gene alterations (21.0 vs.17.6 months, P = 0.17).

CONCLUSION

We demonstrated that concurrent gene alterations occurred in some patients with EGFR mutations. Concurrent gene alterations decreased the efficacy of EGFR-TKIs.

Clinical outcomes of advanced non-small-cell lung cancer patients with EGFR mutation, ALK rearrangement and EGFR/ALK co-alterations

The co-occurrence of epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) rearrangements constitutes a rare molecular subtype of non-small-cell lung cancer (NSCLC). Herein, we assessed the clinical outcomes and incidence of acquired resistance to tyrosine kinase inhibitors (TKIs) in this subtype. So we enrolled 118 advanced NSCLC treated with TKIs. EGFR mutations and ALK rearrangements were detected by DNA sequencing or Scorpion amplification refractory mutation system and fluorescence in situ hybridization respectively. Immunohistochemistry was used to evaluate the activation of associated proteins. We found that nine in ten patients with EGFR/ALK co-alterations had good response with first-line EGFR TKI, and the objective response rate (ORR) of EGFR TKIs was 80% (8/10) for EGFR/ALK co-altered and 65.5% (55/84) for EGFR-mutant (P = 0.57), with a median progression-free survival (PFS) of 11.2 and 13.2 months, (hazard ratio [HR]=0.95, 95% [CI], 0.49-1.84, P= 0.87). ORR of crizotinib was 40% (2/5) for EGFR/ALK co-altered and 73.9% (17/23) for ALK-rearranged (P= 0.29), with a median PFS of 1.9 and 6.9 months (hazard ratio [HR], 0.40; 95% [CI] 0.15-1.10, P = 0.08). The median overall survival (OS) was 21.3, 23.7, and 18.5 months in EGFR-mutant, ALK-rearranged, and EGFR/ALK co-altered (P= 0.06), and there existed a statistically significant difference in OS between ALK-rearranged and EGFR/ALK co-altered (P=0.03). Taken together, the first-line EGFR-TKI might be the reasonable care for advanced NSCLC harbouring EGFR/ALK co-alterations, whether or nor to use sequential crizotinib should be guided by the status of ALK rearrangement and the relative level of phospho-EGFR and phospho-ALK.

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.

ALK and ROS1 as targeted therapy paradigms and clinical implications to overcome crizotinib resistance

During the past decade, more than 10 targetable oncogenic driver genes have been validated in non-small cell lung cancer (NSCLC). Anaplastic lymphoma kinase (ALK) and ROS1 kinase are two new driver genes implicated in ALK- and ROS1-rearranged NSCLC. Inhibition of ALK and ROS1 by crizotinib has been reported to be highly effective and well tolerated in these patients. However, resistance to crizotinib emerges years after treatment, and increasing efforts have been made to overcome this issue. Here, we review the biology of ALK and ROS1 and their roles in cancer progression. We also summarize the ongoing and completed clinical trials validating ALK and ROS1 as targets for cancer treatment. In the last section of the review, we will discuss the molecular mechanisms of crizotinib resistance and focus approaches to overcome it. This review describes an exciting new area of research and may provide new insights for targeted cancer therapies.

The liquid biopsy: a tool for a combined diagnostic and theranostic approach for care of a patient with late-stage lung carcinoma presenting with bilateral ocular metastases

INTRODUCTION

Liquid biopsies (LB) are used routinely in clinical practice in two situations for late stage non-small-cell lung cancer (NSCLC) patients, (i) at the initial diagnosis when looking for activating mutations in EGFR in the absence of analyzable tissue DNA and, (ii) during tumor progression on a tyrosine kinase inhibitor treatment to look for the resistance mutation T790M in EGFR. LB is not presently recommended in daily practice for the diagnosis of NSCLC. Areas covered: We report the diagnosis of a NSCLC in a patient with bilateral ocular metastases after detection of a deletion in exon 19 of EGFR when using plasma DNA. Without histological analysis, the origin of the primary ocular metastasis was uncertain. In this context, a LB showing an activating mutation in EGFR and circulating tumor cells positive for TTF1 led to the diagnosis of NSCLC and targeted therapy. Expert commentary: When no tumor tissue sample is available a LB can be used to diagnose for metastatic NSCLC, when a mutation in EGFR is identified. While a tissue biopsy is the gold standard approach for the diagnosis of a NSCLC and for identification of activating mutations, LB can exceptionally provide both a diagnosis of the primitive tumor and indicate appropriate therapy based on a molecular analysis.

Homogeneity and High Concordance of ALK Translocation in Primary Lung Adenocarcinoma and Paired Lymph Node Metastasis

Translocation of anaplastic lymphoma kinase (ALK) gene is an important determinator for the response to ALK tyrosine kinase inhibitor (TKI) in non-small-cell lung cancer (NSCLC) patients. The existence of genetic heterogeneity will affect the results of molecular testing, especially in biopsy samples from primary or metastatic sites of patients with advanced stage NSCLC. We intended to explore the heterogeneity of ALK gene translocation in excision specimens and to examine the existence of discordance of ALK status between primary tumours and corresponding lymph node metastases. A total of 106 ALK positive lung adenocarcinoma cases were collected for assessment of intratumour heterogeneity of ALK gene translocation, which were stained by the fully automated Ventana ALK D5F3 immunohistochemistry (IHC) analysis. In addition, the ALK gene translocations were evaluated in a series of 53 primary tumours and their paired lymph node metastases using ALK D5F3 IHC staining. The concordance rate between primary tumours and paired metastatic lymph nodes was 100%. ALK status was homogeneous in lung adenocarcinoma samples and was generally stable during metastasis. Therefore, ALK gene translocation can be measured reliably in material from either primary or metastatic tumours in lung adenocarcinoma patients.

Responses to crizotinib and chemotherapy in patients with lung adenocarcinoma harboring a concomitant EGFR mutation and ALK gene rearrangement: A case report and review of the literature

Previous studies have indicated that, in lung cancers, the gene rearrangement of ALK is mutually exclusive with mutations in the epidermal growth factor receptor (EGFR) gene. However, the coexistence of EML4-ALK fusions and EGFR mutations (double positive) has been occasionally reported, with frequencies ranging from 0-8%. Currently, no consensus standard therapy exists for tumors with double positive mutations. In the present case report, the case is described of a 53-year-old woman with stage IV lung adenocarcinoma, harboring a concomitant EGFR mutation and ALK gene rearrangement, who was refractory to gefitinib administration but demonstrated a good response to crizotinib and pemetrexed chemotherapy. A review of the literature revealed a total of 65 cases, including our case, harboring double positive mutations, and of these cases, 39 (60.0%) patients had received an EGFR tyrosine kinase inhibitor (EHGR-TKI), and 15 (23%) patients had received crizotinib treatment, the majority of whom had crizotinib selected for them as a second-line or third-line therapy. The disease control rate (DCR) of EGFR-TKI was 72.2%, with the progression-free survival (PFS) being 11.9 months, whereas the DCR of crizotinib was 93.3%, with the PFS being 10 months.

Coexistence of EGFR, KRAS, BRAF, and PIK3CA Mutations and ALK Rearrangement in a Comprehensive Cohort of 326 Consecutive Spanish Nonsquamous NSCLC Patients

INTRODUCTION

Molecular screening is crucial for the care of nonsquamous non-small-cell lung cancer (NSCLC) patients. The coexistence of mutations could have important consequences regarding treatment. We described the mutational patterns and coexistence among patients and their outcomes after targeted treatment.

MATERIALS AND METHODS

Data from consecutive patients with newly diagnosed nonsquamous NSCLC were prospectively collected. Next-generation sequencing analysis of mutational hotspots in the EGFR, KRAS, PIK3CA, and BRAF genes and analysis of anaplastic lymphoma kinase (ALK) rearrangement were performed.

RESULTS

A total of 326 patients with nonsquamous NSCLC were identified. Of the 326 patients, 240 (73.6%) had EGFR, 141 (43.3%) KRAS, 137 (42.0%) BRAF, 130 (39.9%) PIK3CA mutation and 148 (45.4%) ALK rearrangement determined. Of the 240 with EGFR determination, 24.1% harbored EGFR mutations. Of these, 16.3% were activating mutations (43.6%, exon 19 deletion; 46.1%, exon 21; and 10.3%, exon 18) and 7.9% were nonsensitizing EGFR mutations. Furthermore, 39.0% had KRAS mutations, 2.9% BRAF mutations, 10.0% PIK3CA mutations, and 8.8% ALK rearrangements. Of the 154 stage IV patients with ≥ 1 mutations, analysis showed 19 coexisting cases (12.3%). Of 8 patients receiving targeted treatment, 6 had no response. Both responders to targeted treatment had coexistent PIK3CA mutations.

CONCLUSION

Driver mutations can coexist in nonsquamous NSCLC. In our cohort, 12.3% of cases with stage IV disease had multiple mutations. Targeted treatment might not be as effective in patients with coexisting mutations; however, coexistence with PIK3CA might not preclude a response.

Concomitant EML4-ALK rearrangement and EGFR mutation in non-small cell lung cancer patients: a literature review of 100 cases

The discovery of EGFR mutations and EML4-ALK gene rearrangements has radically changed the therapeutic scenario for patients with advanced non-small cell lung cancer. ALK and EGFR tyrosine-kinase inhibitors showed better activity and efficacy than standard chemotherapy in the first and second line treatment settings, leading to a clear advantage in overall survival of advanced non-small cell lung cancer patients harboring these genetic alterations.

Historically the coexistence of EGFR mutations and EML4-ALK rearrangements in the same tumor has been described as virtually impossible. Nevertheless many recent observations seem to show that it is not true in all cases.

In this review we will discuss the available literature data regarding this rare group of patients in order to give some suggestions useful for their clinical management. Furthermore we report here two cases of concomitant presence of both alterations that will help us in the development of discussion.

Concomitant Presence of EGFR and ALK Fusion Gene Mutation in Adenocarcinoma of Lung: A Case Report and Review of the Literature

Empirical evidence has long suggested that oncogenic driver mutations in non-small-cell lung cancer are mutually independent. However, recent studies reported in pertinent literature reveal that concomitant epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) rearrangement can occur in a subset of patients with NSCLC. In order to shed further light on this issue, we report a case of adenocarcinoma of lung harboring both EGFR mutation in exon 21 (L861Q) and ALK rearrangement. This allows us to speculate on likely molecular mechanisms underlying this uncommon phenomenon, while also offering some practical guidelines on the therapeutic options that could benefit patients diagnosed with this dual-positive tumor.

ALK rearrangement in specific subtypes of lung adenocarcinoma: immunophenotypic and morphological features

Lung adenocarcinomas are characterized by a variety of genetic and epigenetic changes that lead to activation of specific signaling pathways. This allowed the classification of lung adenocarcinomas according to genetic alterations and the clinical development of novel anticancer agents that affect the activity of specific oncoproteins. In such a context, chromosomal rearrangements that cause constitutive activation of ALK gene define a category of lung adenocarcinomas that is amenable to targeted therapy with ALK inhibitors. Thus, a major issue of current research is to define the morphological and immunophenotypic features of lung ALK-rearranged adenocarcinomas to improve the selection of tumors suitable for molecular genotyping. ALK status was determined, by immunohistochemistry and fluorescence in situ hybridization, in 94 surgically resected lung adenocarcinomas and correlated with histomorphological parameters. Indeed, ALK rearrangement was observed in 10/94 (11%) lung adenocarcinomas and enriched in tumors with a predominant mucinous (46%; p < 0.05) and solid (29%; p < 0.05) pattern. By contrast, it was lacking or sporadically observed in lung adenocarcinomas with predominant acinar, papillary or lepidic pattern. Moreover, the presence of signet-ring cells was predominantly observed in ALK-rearranged tumors (47%; p < 0.05). These data suggest that ALK rearrangement is associated with specific and distinct clinical-pathological characters compared to other genotypes. Thus, the knowledge of these characteristics can improve the diagnostic accuracy and lead to a better understanding of the behavior of ALK-rearranged NSCLC.

Diamond: immunohistochemistry versus sequencing in EGFR analysis of lung adenocarcinomas

AIMS

Identification of epidermal growth factor receptor (EGFR) mutations in lung adenocarcinomas is the single most important predictor of clinical response and outcome using EGFR tyrosine kinase inhibitors (TKIs). EGFR E746-A750del and L858R mutations are the most common gene alterations, also predicting the best clinical response to TKIs. We evaluated the accuracy of EGFR mutation-specific antibodies in a large cohort of lung adenocarcinomas, with different molecular settings and types of tissue samples.

METHODS

300 lung adenocarcinomas diagnosed on cytology (48 cell blocks), biopsy (157 cases) and surgical resections (95 cases) were selected. All cases were investigated for EGFR by sequencing and two mutation-specific antibodies (clone 6B6 for E746-A750del; clone 43B2 for L858R) were tested using an automated immunostainer. Discordant results were investigated by next-generation sequencing (NGS).

RESULTS

Overall sensitivity and specificity of mutant-specific antibodies were 58.6% and 98.0%, respectively, and they increased up to 84% and 100% if only tumours harbouring E746-A750del were considered. In 13 discordant cases, NGS confirmed immunohistochemistry results in eight samples.

CONCLUSIONS

The EGFR mutation-specific antibodies have a fair/good sensitivity and good/high specificity in identifying classic mutations, but they cannot replace molecular tests. The antibodies work equally well on biopsies and cell blocks, possibly permitting a rapid screening in cases with poor material.

Non-small Cell Lung Cancer with Concomitant EGFR, KRAS, and ALK Mutation: Clinicopathologic Features of 12 Cases

Background:

Although epidermal growth factor receptor (EGFR), v-Ki-ras2 Kirsten rat sarcoma viral oncogene (KRAS), and anaplastic lymphoma kinase (ALK) mutations in non-small cell lung cancer (NSCLC) were thought to be mutually exclusive, some tumors harbor concomitant mutations. Discovering a driver mutation on the basis of morphologic features and therapeutic responses with mutation analysis can be used to understand pathogenesis and predict resistance in targeted therapy.

Methods:

In 6,637 patients with NSCLC, 12 patients who had concomitant mutations were selected and clinicopathologic features were reviewed. Clinical characteristics included sex, age, smoking history, previous treatment, and targeted therapy with response and disease-free survival. Histologic features included dominant patterns, nuclear and cytoplasmic features.

Results:

All patients were diagnosed with adenocarcinoma and had an EGFR mutation. Six patients had concomitant KRAS mutations and the other six had KRAS mutations. Five of six EGFR-KRAS mutation patients showed papillary and acinar histologic patterns with hobnail cells. Three of six received EGFR tyrosine kinase inhibitor (TKI) and showed partial response for 7–29 months. All six EGFR-ALK mutation patients showed solid or cribriform patterns and three had signet ring cells. Five of six EGFR-ALK mutation patients received EGFR TKI and/or ALK inhibitor and four showed partial response or stable disease, except for one patient who had acquired an EGFR mutation.

Conclusions:

EGFR and ALK mutations play an important role as driver mutations in double mutated NSCLC, and morphologic analysis can be used to predict treatment response.

EGFR, KRAS and ROS1 variants coexist in a lung adenocarcinoma patient

The c-ros oncogene 1 (ROS1) fusion is almost mutually exclusive to epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK) or Kirsten rat sarcoma viral oncogene homolog (KRAS) mutation in non-small cell lung cancer (NSCLC), and it is not seen in the literature for patients to exhibit three mutations. The present study reported a case of a 53-year-old male diagnosed with adenocarcinoma, exhibiting combined EGFR, KRAS mutations and ROS1 rearrangement. At the first line therapy, the patient was treated with crizotinib because of the KRAS mutation that is a known resistant factor of EGFR-TKI resistance, but no responsive. At the second line therapy, EGFR-TKI Icotinib revealed a good response until now. To the best of to our knowledge, this is the first case report of a patient with concurrent EGFR, KRAS mutations and ROS1 fusion. This patient had an excellent response to Icotinib but not crizotinib, suggesting that the EGFR mutation was the oncogenic driver but ROS1 fusion and KRAS mutation not.

Nonsquamous, Non-Small-Cell Lung Cancer Patients Who Carry a Double Mutation of EGFR, EML4-ALK or KRAS: Frequency, Clinical-Pathological Characteristics, and Response to Therapy

BACKGROUND

Epidermal growth factor receptor (EGFR) and v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations, and echinoderm microtubule-associated protein-like 4 (EML4) anaplastic lymphoma kinase (ALK) translocation are generally considered to be mutually exclusive. However, concomitant mutations are found in a small number of patients and the effect of these on response to targeted therapy is still unknown.

PATIENTS AND METHODS

We considered 380 non-small-cell lung cancer (NSCLC) patients who underwent nonsequential testing for EGFR and EML4-ALK translocation. KRAS mutation analysis was also performed on 282 patients.

RESULTS

We found 1.6%, 1.1%, and 2.5% of patients who showed a double mutation comprising EGFR and EML4-ALK, EGFR and KRAS, and EML4-ALK and KRAS, respectively. Twenty-eight patients with EGFR mutation underwent first-line therapy with a tyrosine kinase receptor; a clinical benefit was observed in 81.8% of patients with EGFR mutations only and in 67% of those who also showed an EML4-ALK translocation. Twelve patients with an EML4-ALK translocation received crizotinib and 7 of these had disease progression within 3 months (2 had a concomitant KRAS mutation and 1 had a concomitant EGFR mutation). Two patients showed stable disease, 1 of whom also had a KRAS mutation. Two patients obtained a partial response and 1 had a complete response; all harbored an EML4-ALK translocation only. The median overall survival of patients who carried an EML4-ALK translocation alone or concomitant with a KRAS mutation was 57.1 (range, 10.7-not reached) and 10.7 (range, 4.6-not reached) months, respectively.

CONCLUSION

Concomitant EGFR, EML4-ALK, or KRAS mutations can occur in NSCLC. Concomitant KRAS mutation and EML4-ALK translocation represents the most common double alteration and confers a poor prognosis.

Clinical Validation of a Novel Commercial Reverse Transcription–Quantitative Polymerase Chain Reaction Screening Assay for Detection of ALK Translocations and Amplifications in Non–Small Cell Lung Carcinomas

Context.— EGFR mutations and anaplastic lymphoma kinase (ALK) translocations have significant biologic and therapeutic implications in lung cancers, particularly lung adenocarcinomas. ALK translocations are less frequent compared with EGFR mutations; interestingly, these two abnormalities are most commonly mutually exclusive. The 2013 College of American Pathologists/Association for Molecular Pathology/International Association for the Study of Lung Cancer molecular testing guideline for lung cancers recommend a testing algorithm in which detection of ALK translocations using fluorescence in situ hybridization (FISH) is to be performed following testing for EGFR mutations. Such an algorithm is cost-effective but potentially slows down turnaround time; and as a secondary test, ALK FISH assay may not be completed because it requires the use of additional tissue, and the small biopsies or cytology specimens may have been exhausted in the extraction of nucleic acid for EGFR mutation screening.

Objective.—To provide efficient testing of both EGFR and ALK genetic alterations in small biopsies and cytology specimens.

Design.—We validated a highly sensitive ALK reverse transcription–quantitative polymerase chain reaction (RT-qPCR) assay as a screening tool for ALK translocations and amplifications.

Results.—We performed a retrospective review of cases previously tested by FISH and found that all FISH ALK translocation–positive specimens were RT-qPCR positive, and all FISH ALK translocation–negative cases were RT-qPCR negative (the sensitivity and specificity of the ALK RT-qPCR assay were 100%).

Conclusion.—This assay allows rapid identification of ALK alterations, can be performed in conjunction with EGFR testing, and does not require use of valuable additional tumor tissue.