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

Therapeutic strategies to overcome ALK-fusion and BRAF-mutation as acquired resistance mechanism in EGFR-mutated non-small cell lung cancer: two case reports

Non-small cell lung cancer (NSCLC) is one of the most common malignancies in the world. EGFR tyrosine inhibitors are the preferred first-line treatment for patients with epidermal growth factor-cell receptor mutant (EGFR mutant) advanced NSCLC. Unfortunately, drug resistance inevitably occurs leading to disease progression. Activation of the ALK and BRAF bypass signaling pathways is a rare cause of acquired drug resistance for EGFR-TKIs.We report two NSCLC-patients with EGFR- mutations, in exon 19, and exon 18, correspondingly, who were treated with EGFR-TKIs. The first case shows acquired BRAF-mutation, and the second case demonstrates acquired ALK-fusion. The overall survival of patients was significantly prolonged by drug-match therapies. As it is well-known that ALK-fusion and BRAF-mutations are described forms of acquired resistance. These two case reports contribute to the previous reports that ALK-fusion and BRAF-mutation are potential underlying mechanisms of EGFR-TKI resistance.

Concomitant EGFR Mutations and ALK Rearrangements in Lung Adenocarcinoma Treated With Osimertinib

Lung cancer is the third most common cancer in addition to being the cancer responsible for the most annual deaths in the United States, comprising 15% of all diagnosed cancers, and 28% of all cancer deaths in 2020. Major advances in survival are because of gene sequencing and the advent of targeted biological therapy. The prevalence of epidermal growth factor receptor (EGFR) mutations coexisting with anaplastic lymphoma kinase (ALK) rearrangements is quite low. However, the clinical relevance and effective treatment of these cancers require further investigation. This case series describes two patients diagnosed with stage IV adenocarcinoma with coexisting EGFR and ALK rearrangements. In Case 1, a 73-year-old male presented with worsening ataxia and headaches. In Case 2, a 64-year-old female presented with worsening dyspnea. Molecular studies revealed ALK gene fusion and the L861Q EGFR mutation in Case 1 and L858R EGFR mutation and ALK gene fusion in Case 2. Both patients received a gamma knife and an EGFR-tyrosine kinase inhibitor (TKI), osimertinib. In one of the cases, following the discovery of new brain metastases, the dose of osimertinib was increased from 80 to 160 mg. The patient passed away nine months after beginning EGFR-TKI treatment, one month after increasing the dose. The second patient experienced a significant interval reduction in the size of enhancing metastasis in both the right frontal and left parietal lobe after four months of EGFR-TKI treatment. The cases of coexisting EGFR mutations and ALK rearrangements are quite rare, and treatment can be challenging. Here, EGFR-TKI had a mixed response among our patients.

Case report: Concomitant EGFR mutation and ALK rearrangement in non-small cell lung cancer

In non-small cell lung cancer (NSCLC), two key genetic alterations, epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) rearrangements, are commonly believed to be mutually exclusive. Studies have reported that concurrent EGFR/ALK co-mutation in non-small cell lung cancer patients is rare, with a prevalence ranging from 0.1% to 1.6%. However, the clinical and pathological characteristics of these patients are not well-defined, and the optimal treatment approach for such cases remains controversial. In this report, we present a case of stage IV lung adenocarcinoma with both epidermal growth factor receptor and anaplastic lymphoma kinase mutations, along with high PD-L1 expression. The patient initially received treatment with epidermal growth factor receptor tyrosine kinase inhibitors (TKIs), but the disease progressed. However, following a switch to ALK-TKI therapy and local radiotherapy, the lesion showed regression. Our report also provides a comprehensive summary of the clinical and pathological features, as well as treatment strategies, for non-small cell lung cancer patients with concurrent epidermal growth factor receptor mutation and anaplastic lymphoma kinase rearrangement.

Coexistence of anaplastic lymphoma kinase rearrangement in lung adenocarcinoma harbouring epidermal growth factor receptor mutation: A single-center study

BACKGROUND

Accumulating evidences confirm that epidermal growth factor receptor (EGFR) mutation and anaplastic lymphoma kinase (ALK) rearrangement have coexisted in lung adenocarcinoma (LUAD). However, Its biological mechanism, clinicopathological features, and optimization of targeted drugs have not yet been completely elucidated.

AIM

To explore the clinical profile of LUAD patients with co-mutations of EGFR and ALK genes, with hopes of scientifically guiding similar patients towards selected, targeted drugs.

METHODS

Two hundred and thirty-seven LUAD patients were enrolled. EGFR mutations were detected by the amplification refractory mutation system-peptide nucleic acid technique, while the expression of ALK rearrangement was screened by the 5′/3′ imbalance strategy for reverse transcription followed by quantitative polymerase chain reaction analysis. The clinicopathological features of these patients were analysed retrospectively, and the follow-up data were collected.

RESULTS

There were six cases with co-mutations of EGFR and ALK genes, which were more common in women, non-smoking and stage IV LUAD patients with bone metastasis, hence a positive rate of 2.53% (6/237). EGFR-tyrosine kinase inhibitors (EGFR-TKIs) were their preferred drugs for targeted therapy in these patients, with progression-free survival ranging from two months to six months.

CONCLUSION

In Gannan region, the positive rate of co-mutations of EGFR and ALK genes in LUAD patients is relatively high, and the co-mutations are more common in women, non-smoking and stage IV patients with bone metastasis. These patients prefer EGFR-TKIs as their preferred targeted drugs, but the therapeutic effect is not good. EGFR/ALK dual-TKIs may be more effective targeted drugs, which needs further study.

Fifty-five months progression-free survival with crizotinib treatment in coexistence of ALK and ROS1 rearrangements in lung adenocarcinoma: an extremely rare case and review of the literature

We wanted to present a case with coexistence of anaplastic lymphoma kinase (ALK) and c-ros oncogene 1 (ROS1) rearrangements that has been in remission for a long time with crizotinib. A 62-year-old nonsmoker male patient was diagnosed with Non-small cell lung cancer. Progression developed 9 months after the treatment, and coexistence of ALK and ROS1 positivity were detected in driver mutation analysis performed with fluorescent in situ hybridization. Crizotinib 2 × 250 mg was started in November 2016. The treatment of the patient, who has been in remission for approximately 55 months since then, continues. Until recently, the use of next-generation sequencing (NGS) was not common, but the more frequent epidermal growth factor receptor, then ALK, and finally ROS1 mutation were studied in tumor tissues. Sometimes ROS1 was not studied because there was not enough tissue left. We think that this rate will increase a little more with the widespread use of NGS from now on. Showing that ALK and ROS1 are positive together, longer survivals can be obtained by choosing therapies that are responsive to both.

Response to a Combination of Full-Dose Osimertinib and Ceritinib in a Non-Small Cell Lung Cancer Patient with EML4-ALK Rearrangement and Epidermal Growth Factor Receptor Co-Mutation

Lung cancer has been the leading cause of cancer-related deaths in both developed and developing countries, with most primary lung cancers being non-small cell lung carcinomas. Treatment for this condition is sometimes individualized. With developments in modern treatment and phase III clinical trial results, epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) and ALK-TKI have proven thier superior effectivity in comparison with the standard platinum-based doublet and are commonly approved as first-line indications in previously untreated advanced non-small cell lung cancer (NSCLC) patients with EGFR or ALK mutations. In the majority of cases, the presence of the ALK rearrangement mutation does not overlap with other mutations in NSCLC. Here, we report a patient with concomitant ALK rearrangement and EGFR mutation treated with a combination of TKIs: osimertinib and ceritinib.

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.

Targeting Cysteine Located Outside the Active Site: An Effective Strategy for Covalent ALKi Design

Potent inhibitors of ALK are highly desired because of the occurrence of drug resistance. We herein firstly report the development of a rationally designed inhibitor, Con B-1, which can covalently bind to Cys1259, a cysteine located outside the ALK active site by linking a warhead with Ceritinib through a 2,2'-Oxybis(ethylamine) linker. The in vitro and in vivo assays showed ConB-1 is a potent selective ALKi with low toxicity to normal cells. In addition, the molecule showed significant improvement of anticancer activities and potential antidrug resistant activity compared with Ceritinib, demonstrating the covalent inhibitor of ALK can be a promising drug candidate for the treatment of NSCLC. This work may provide a novel perspective on the design of covalent inhibitors.

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.

Molecular Epidemiology of the Main Druggable Genetic Alterations in Non-Small Cell Lung Cancer

Lung cancer is the leading cause of death for malignancy worldwide. Its molecular profiling has enriched our understanding of cancer initiation and progression and has become fundamental to provide guidance on treatment with targeted therapies. Testing the presence of driver mutations in specific genes in lung tumors has thus radically changed the clinical management and outcomes of the disease. Numerous studies performed with traditional sequencing methods have investigated the occurrence of such mutations in lung cancer, and new insights regarding their frequency and clinical significance are continuously provided with the use of last generation sequencing technologies. In this review, we discuss the molecular epidemiology of the main druggable genetic alterations in non-small cell lung cancer, namely EGFR, KRAS, BRAF, MET, and HER2 mutations or amplification, as well as ALK and ROS1 fusions. Furthermore, we investigated the predictive impact of these alterations on the outcomes of modern targeted therapies, their global prognostic significance, and their mutual interaction in cases of co-occurrence.

Discovery of a PROTAC targeting ALK with in vivo activity

Anaplastic lymphoma kinase (ALK) was involved in the development of various cancer types. Although several ALK inhibitors have been advanced to clinical trials, the emergence of drug resistance has limited the clinical application of them. To overcome the drug resistance, proteolysis targeting chimeras (PROTACs) could be an alternative strategy. In this study, a series of ALK degraders were designed and synthesized. The degraders were developed through the conjugation of LDK378 and CRBN E3 ubiquitin ligase ligands. Among all the molecules, compound B3 showed potent selective inhibitory activity to ALK and can decrease the cellular levels of ALK fusion proteins in a concentration- and time-dependent manner in H3122 cell line. Meanwhile, B3 showed improved anticancer activity in vitro comparing with LDK378 and the antiproliferative activity to xenograft tumor model was acceptable. All the results demonstrated that ALK degrader B3 with in vitro and in vivo anti-cancer activities was valuable for further investigation.

Integration of whole-exome and anchored PCR-based next generation sequencing significantly increases detection of actionable alterations in precision oncology

BACKGROUND

Frequency of clinically relevant mutations in solid tumors by targeted and whole-exome sequencing is ∼30%. Transcriptome analysis complements detection of actionable gene fusions in advanced cancer patients. Goal of this study was to determine the added value of anchored multiplex PCR (AMP)-based next-generation sequencing (NGS) assay to identify further potential drug targets, when coupled with whole-exome sequencing (WES).

METHODS

Selected series of fifty-six samples from 55 patients enrolled in our precision medicine study were interrogated by WES and AMP-based NGS. RNA-seq was performed in 19 cases. Clinically relevant and actionable alterations detected by three methods were integrated and analyzed.

RESULTS

AMP-based NGS detected 48 fusions in 31 samples (55.4%); 31.25% (15/48) were classified as targetable based on published literature. WES revealed 29 samples (51.8%) harbored targetable alterations. TMB-high and MSI-high status were observed in 12.7% and 1.8% of cases. RNA-seq from 19 samples identified 8 targetable fusions (42.1%), also captured by AMP-based NGS. When number of actionable fusions detected by AMP-based NGS were added to WES targetable alterations, 66.1% of samples had potential drug targets. When both WES and RNA-seq were analyzed, 57.8% of samples had targetable alterations.

CONCLUSIONS

This study highlights importance of an integrative genomic approach for precision oncology, including use of different NGS platforms with complementary features. Integrating RNA data (whole transcriptome or AMP-based NGS) significantly enhances detection of potential targets in cancer patients. In absence of fresh frozen tissue, AMP-based NGS is a robust method to detect actionable fusions using low-input RNA from archival tissue.

How should molecular findings be integrated in the classification for lung cancer?

The use of molecular diagnostics in the diagnosis and management of patients with advanced lung cancer has become widespread. Although molecular classification has increasingly been incorporated in the pathologic classification of certain types of human tumors (particularly within the hematologic, glial, and bone/soft tissue malignancies), genetic findings have not been formally incorporated into the pathologic classification of lung cancer, which presently relies solely on the assessment of histologic and immunophenotypic characteristics. Whether molecular classification should be adopted in lung cancer would depend on the diagnostic, prognostic, and predictive impacts of such classification-and whether these impacts confer significant values additive to those derived from the routine histologic and immunophenotypic assessment. We provide a brief overview on the genetics of lung cancer, including adenocarcinoma, squamous cell carcinoma, and neuroendocrine tumors (small cell carcinoma, large cell neuroendocrine carcinoma, and carcinoid tumors). We consider the values of molecular information with some examples, in terms of the current diagnostic, prognostic, and predictive impacts. Finally, we discuss the conceptual and technical challenges of adopting a molecular classification for lung cancer in clinical management for patients. While there are conceptual and technical hurdles to tackle in implementing molecular classification in the pathologic classification of lung cancer, such integrated histologic-molecular diagnosis may allow one to personalize and optimize therapy for patients with advanced lung cancer.

Current Strategies for Treating NSCLC: From Biological Mechanisms to Clinical Treatment

The identification of specific epidermal growth factor receptor (EGFR)-activating mutations heralded a breakthrough in non-small-cell lung cancer (NSCLC) treatments, with the subsequent development of EGFR-tyrosine kinase inhibitor (TKIs) becoming the first-line therapy for patients harboring EGFR mutations. However, acquired resistance to EGFR-TKIs inevitably occurs in patients following initial TKI treatment, leading to disease progression. Various mechanisms are behind the acquired resistance, and mainly include (1) target gene modification, (2) alternative parallel pathway activation, (3) downstream pathway activation, and (4) histological/phenotypic transformation. Approaches to combat the acquired resistance have been investigated according to these mechanisms. Newer generations of TKIs have been developed to target the secondary/tertiary EGFR mutations in patients with acquired resistance. In addition, combination therapies have been developed as another promising strategy to overcome acquired resistance through the activation of other signaling pathways. Thus, in this review, we summarize the mechanisms for acquired resistance and focus on the potential corresponding therapeutic strategies for acquired resistance.

Concomitant EGFR mutation and ALK rearrangement in multifocal lung adenocarcinoma: a case report

Background

The prevalence of EGFR/ALK co-alterations in patients with NSCLC was low. The several previous studies focused on the simultaneous occurrence of EGFR mutations and ALK rearrangements in a unifocal lung cancer. However, the incidence of multifocal pulmonary adenocarcinomas was increasingly encountered in clinical practice, due to the increased availability and improvement of the thoracic imaging. The clinical relevance of EGFR/ALK co-alterations in multifocal adenocarcinomas required detailed investigation as well.

Case presentation

We present the case of a 57-year-old woman with solid nodule in the left upper lung and a ground glass nodule in the left lower lobe, who underwent radical operation. Pathological examination confirmed multifocal adenocarcinoma, molecular tests revealed that the left upper lung lesion was positive for ALK rearrangement but the left lower lobe displayed EGFR mutation positive separately. The patient pulmonary lesions were well controlled by adjuvant chemotherapy and radiation therapy. When brain metastases occurred, EGFR-TKI was not effective after firstly administration, while subsequent ALK inhibitors were efficient. We retrospective evaluated the oncogenic status of metastatic lymph nodes and found that the driver gene was ALK rearrangement rather than EGFR mutation.

Conclusions

The status of the oncogenic mutations in lymph node metastasis may provide some effective hints for metastasis lesion in other organ or tissue. Therefore, it is recommended to fully evaluate the driver genes in lymph node metastasis after radical resection.

Actionable Mutation Profiles of Non-Small Cell Lung Cancer patients from Vietnamese population

Comprehensive profiling of actionable mutations in non-small cell lung cancer (NSCLC) is vital to guide targeted therapy, thereby improving the survival rate of patients. Despite the high incidence and mortality rate of NSCLC in Vietnam, the actionable mutation profiles of Vietnamese patients have not been thoroughly examined. Here, we employed massively parallel sequencing to identify alterations in major driver genes (EGFR, KRAS, NRAS, BRAF, ALK and ROS1) in 350 Vietnamese NSCLC patients. We showed that the Vietnamese NSCLC patients exhibited mutations most frequently in EGFR (35.4%) and KRAS (22.6%), followed by ALK (6.6%), ROS1 (3.1%), BRAF (2.3%) and NRAS (0.6%). Interestingly, the cohort of Vietnamese patients with advanced adenocarcinoma had higher prevalence of EGFR mutations than the Caucasian MSK-IMPACT cohort. Compared to the East Asian cohort, it had lower EGFR but higher KRAS mutation prevalence. We found that KRAS mutations were more commonly detected in male patients while EGFR mutations was more frequently found in female. Moreover, younger patients (<61 years) had higher genetic rearrangements in ALK or ROS1. In conclusions, our study revealed mutation profiles of 6 driver genes in the largest cohort of NSCLC patients in Vietnam to date, highlighting significant differences in mutation prevalence to other cohorts.

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.

The expression of circulating miR-504 in plasma is associated with EGFR mutation status in non-small-cell lung carcinoma patients

MicroRNAs (miRNAs), key regulators of gene expression at the post-transcriptional level, are grossly misregulated in some human cancers, including non-small-cell lung carcinoma (NSCLC). The aberrant expression of specific miRNAs results in the abnormal regulation of key components of signalling pathways in tumour cells. MiRNA levels and the activity of the gene targets, including oncogenes and tumour suppressors, produce feedback that changes miRNA expression levels and indicates the cell's genetic activity. In this study, we measured the expression of five circulating miRNAs (miR-195, miR-504, miR-122, miR-10b and miR-21) and evaluated their association with EPIDERMAL GROWTH FACTOR RECEPTOR (EGFR) mutation status in 66 NSCLC patients. Moreover, we examined the discriminative power of circulating miRNAs for EGFR mutant-positive and -negative NSCLC patients using two different data normalisation approaches. We extracted total RNA from the plasma of 66 non-squamous NSCLC patients (31 of whom had tumours with EGFR mutations) and measured circulating miRNA levels using quantitative reverse transcription polymerase chain reaction (RT-qPCR). The miRNA expression levels were normalised using two endogenous controls: miR-191 and miR-16. We found significant associations between the expression of circulating miR-504 and EGFR-activating mutations in NSCLC patients regardless of the normalisation approach used (p = 0.0072 and 0.0236 for miR-16 and miR-191 normalisation, respectively). The greatest discriminative power of circulating miR-504 was observed in patients with EGFR exon 19 deletions versus wild-type EGFR normalised to miR-191 (area under the curve (AUC) = 0.81, p < 0.0001). Interestingly, circulating miR-504 levels were significantly reduced in the v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS)-mutated subgroup compared to EGFR-mutated patients (p < 0.0030) and those with EGFR/KRAS wild-type tumours (p < 0.0359). Our study demonstrated the feasibility and potential diagnostic value of plasma miR-504 expression analysis to distinguish between EGFR-mutated and wild-type NSCLC patients. However, quality control and normalisation strategies are very important and have a major impact on the outcomes of circulating miRNA analyses.

Chinese perspectives on clinical efficacy and safety of alectinib in patients with ALK-positive advanced non-small cell lung cancer

The incidence of lung cancer is increasing in China, in contrast to trends in Western countries, due to the increasing numbers of smokers and high levels of air pollution. Non-small-cell lung cancer (NSCLC) is the most common form of lung cancer, accounting for approximately 85% of lung cancers. Better understanding of the pathogenesis of NSCLC has led to the identification of multiple genetic mutations and chromosomal translocations such as those in the anaplastic lymphoma kinase (ALK) gene. To facilitate the identification of treatment targets, multiple guidelines (European Society for Medical Oncology, National Comprehensive Cancer Network, and American Society of Clinical Oncology) now recommend screening for genetic factors to help guide treatment decisions. In recent years, multiple ALK inhibitors have been developed to treat NSCLC, including the first-generation tyrosine kinase inhibitor (TKI) crizotinib; second-generation TKIs such as ceritinib, ensartinib, brigatinib, and alectinib; the third-generation TKI lorlatinib; and the fourth-generation TKI repotrectinib. These agents differ in structure, potency, and activity, both systemically and their effects on central nervous system (CNS) metastases. Recently, alectinib was approved in China to treat patients with locally advanced or metastatic NSCLC that were ALK+. Alectinib has demonstrated activity against NSCLC, including metastases within the CNS, with better tolerability than crizotinib. These ALK inhibitors represent significant advances in the treatment of NSCLC and yet patients will likely still exhibit disease progression. Alectinib offers greater potency with greater specificity as well as a better toxicity profile than many other TKIs that are currently available. Here, we review the role of ALK as a therapeutic target in NSCLC, the testing methods for identifying ALK-rearranged NSCLC, and the various TKIs currently being used or explored for treatment in this setting, with a focus on alectinib from a Chinese perspective.

Protein expression of close homologue of L1 (CHL1) is a marker for overall survival in non-small cell lung cancer (NSCLC)

BACKGROUND

The cell adhesion molecule close homologue of L1 (CHL1) is a potential tumour suppressor and was recently detected in non-small cell lung cancer (NSCLC) specimens. The expression pattern, prognostic, and functional role of CHL1 in NSCLCs is unknown.

METHODS

We evaluated the protein expression of CHL1 by immunohistochemistry in 2161 NSCLC patients based on a tissue microarray. The results were correlated with clinical, histopathological, and patient survival data (Chi square test, t test, and log-rank test, respectively). A multivariate analysis (Cox regression) was performed to validate its impact on patients' survival.

RESULTS

CHL1 was expressed in NSCLC patients and was significantly overexpressed in lung adenocarcinomas and squamous cell carcinomas compared to neuroendocrine and large cell carcinomas of the lung (p < 0.001). CHL1 expression was associated with the T stage in adenocarcinomas (p = 0.011) and with metastatic lymph node status and UICC stage in squamous cell carcinomas (p = 0.034 and p = 0.035, respectively). Increased CHL1 expression was associated with improved survival in univariate (p = 0.031) and multivariate analyses (odds ratio 0.797, 95% confidence interval 0.677-0.939, p = 0.007).

CONCLUSION

The prognostic significance of CHL1 makes it a potential prognostic and therapeutic target and underlines its role as a tumour suppressor. Further validation studies and functional analyses are needed to investigate its potential role in tumourigenesis and dissemination.

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.

Concurrent Driver Gene Mutations as Negative Predictive Factors in Epidermal Growth Factor Receptor-Positive Non-Small Cell Lung Cancer

BACKGROUND

Tyrosine kinase inhibitors (TKIs) are clinically effective in non-small cell lung cancer (NSCLC) patients harbouring epidermal growth factor receptor (EGFR) oncogene mutations. Genetic factors, other than EGFR sensitive mutations, that allow prognosis of TKI treatment remain undefined.

METHODS

We retrospectively screened 423 consecutive patients with advanced NSCLC and EGFR 19del or 21L858R mutations. A total of 71 patients whose progression-free survivals (PFS) were shorter than 6 months or longer than 24 months were included and stratified into separate groups. Genetic background discrepancy was analysed in the two groups using next generation sequencing (NGS).

FINDINGS

Sensitive EGFR mutations of 19del or 21L858R were detected by NGS in all patients; the 21L858R mutation was the major type. The most frequent accompanying somatic mutations were TP53, RB1, MAP2K. ALK fusion, MET amplification, and BRAF V600E were found only in the short PFS group. Concurrent pretreament T790 M mutation was found in both groups, but was proportionally higher in the short PFS group. In the short PFS group, patients had significantly more driver gene mutations than in long PFS group (P = 0·018). The numbers of concomitant somatic mutations, EGFR pathway-related mutations, and tumor mutation burden (TMB) were not significantly different between the two groups.

INTERPRETATION

Co-occuring driver gene mutations were negative predictive factors of TKI therapy in EGFR-mutated patients. This study highlights the importance of exploring co-occuring genomic alterations before initiation of EGFR-TKIs.

Co-alteration of EGFR mutation and ALK rearrangement in non-small cell lung cancer: Case series

RATIONALE

Current guidelines for advanced non-small cell lung cancer (NSCLC) recommend the use of targeted agents for specific driver genes after confirming genetic alterations. Although epidermal growth factor receptor (EGFR) mutation and anaplastic lymphoma kinase (ALK) rearrangement are usually mutually exclusive, EGFR and ALK co-alterations have been reported increasingly in cases of NSCLC. However, the optimal treatment for these cases has not been established.

PATIENT CONCERNS

This case series describes three patients diagnosed with advanced non-squamous NSCLC who harbored EGFR and ALK co-alterations. The complaints for each case are as follows: 57-year-old woman with coughing and dyspnea in case 1, 32-year-old man with diplopia in case 2 and 77-year-old woman with chest discomfort in case 3.

DIAGNOSES

Three never-smokers were diagnosed pathologically with stage IV adenocarcinoma of the lung. Subsequent molecular studies revealed the EGFR L858R mutation gene and ALK rearrangement, which were proven by real-time polymerase chain reaction and fluorescence in situ hybridization, respectively.

INTERVENTIONS

All 3 patients received first-line therapy with EGFR-tyrosine kinase inhibitors (TKIs). Cases 1 and 2 were treated with ALK-TKIs as second-line therapy and received additional EGFR-TKIs as third- and fourth-line regimens.

OUTCOMES

The patients achieved partial responses to EGFR-TKIs according to radiologic findings. However, second-line ALK-TKI therapy was ineffective in cases 1 and 2.

LESSONS

Cases of NSCLC with concomitant EGFR mutation and ALK rearrangement are rare, and the selection of an optimal targeted therapy is challenging. Here, EGFR-TKI appeared to yield better outcomes than ALK-TKI in patients with NSCLC who harbored EGFR/ALK co-alterations.

Comparison of Clinicopathological Features and Prognosis between ALK Rearrangements and EGFR Mutations in Surgically Resected Early-stage Lung Adenocarcinoma

Background: A number of mutations in key oncogenes have been identified as important for the initiation and maintenance of lung adenocarcinoma (LAC). This study elucidated the prevalence and prognostic significance of mutations in the epidermal growth factor receptor gene (EGFR) and rearrangements in the anaplastic lymphoma kinase gene (ALK) in patients with surgically resected primary LAC.

Patients and Methods: We retrospectively analyzed 675 consecutive patients who underwent radical resection at a single institution. We concurrently analyzed mutations in EGFR and the Kirsten rat sarcoma viral oncogene homolog gene (KRAS) by reverse transcription (RT)-PCR, and investigated ALK rearrangements by immunohistochemistry. LAC with or without various oncogenic mutations was studied for clinicopathological features and their association with disease-free survival (DFS) and overall survival (OS).

Result: ALK rearrangements and EGFR mutations were detected in 75 and 312 patients, respectively, with coexistence in 5 cases. ALK rearrangements and mutations in EGFR and KRAS were mutually exclusive. Compared with patients with EGFR mutations, ALK rearrangements were more common in younger patients, and those with advanced tumors, lymph node metastases, and higher rates of postoperative adjuvant therapy. Histologically, EGFR mutations were more common than ALK rearrangements in patients with the acinar predominant subtype and the lepidic predominant subtype of LAC, whereas ALK rearrangements were more frequent in the solid predominant subtype with mucin production and invasive mucinous adenocarcinomas. ALK-positive patients had a significantly worse DFS than those with EGFR mutations and wild-type (WT) patients. The mean OS after surgical procedures was significantly longer in EGFR-mutated versus WT patients. No significant differences were found in patients with ALK-positive tumors compared with EGFR-mutated and WT patients.

Conclusion: Clinicopathological features of LAC with ALK rearrangements differ from those of LAC with EGFR mutations. Patients with ALK rearrangements had a significantly worse DFS than those harboring EGFR mutations. Thus, ALK rearrangements are an adverse prognostic factor in surgically-resected LAC patients, while EGFR mutations are associated with a better prognosis.

Diagnostic and Predictive Immunohistochemistry for Non-Small Cell Lung Carcinomas

Non-small cell lung carcinoma (NSCLC) accounts for significant morbidity and mortality worldwide, with most patients diagnosed at advanced stages and managed increasingly with targeted therapies and immunotherapy. In this review, we discuss diagnostic and predictive immunohistochemical markers in NSCLC, one of the most common tumors encountered in surgical pathology. We highlight 2 emerging diagnostic markers: nuclear protein in testis (NUT) for NUT carcinoma; SMARCA4 for SMARCA4-deficient thoracic tumors. Given their highly aggressive behavior, proper recognition facilitates optimal management. For patients with advanced NSCLCs, we discuss the utility and limitations of immunohistochemistry (IHC) for the "must-test" predictive biomarkers: anaplastic lymphoma kinase, ROS1, programmed cell death protein 1, and epidermal growth factor receptor. IHC using mutant-specific BRAF V600E, RET, pan-TRK, and LKB1 antibodies can be orthogonal tools for screening or confirmation of molecular events. ERBB2 and MET alterations include both activating mutations and gene amplifications, detection of which relies on molecular methods with a minimal role for IHC in NSCLC. IHC sits at the intersection of an integrated surgical pathology and molecular diagnostic practice, serves as a powerful functional surrogate for molecular testing, and is an indispensable tool of precision medicine in the care of lung cancer patients.