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Gene alteration in anaplastic lymphoma kinase (ALK) is rare, and the efficacy of ALK inhibitors in the treatment of carcinoma of unknown primary (CUP) with ALK alteration remains unclear. The patient was a 56-year-old woman who presented with cervical lymph node swelling. Computed tomography revealed paraaortic, perigastric, and cervical lymph node swelling; ascites; a liver lesion; and a left adrenal mass. A cervical lymph node biopsy was performed, and pathological diagnosis of an undifferentiated malignant tumor was conducted. Finally, the patient was diagnosed with CUP and treated with chemotherapy. To evaluate actionable mutations, we performed a multigene analysis, using a next-generation sequencer (FoundationOne® CDx). It revealed that the tumor harbored an echinoderm microtubule-associated protein-like 4 (EML4) and ALK fusion gene. Additionally, immunohistochemistry confirmed ALK protein expression. Alectinib, a potent ALK inhibitor, was recommended for the patient at a molecular oncology conference at our institution. Accordingly, alectinib (600 mg/day) was administered, and the multiple lesions and symptoms rapidly diminished without apparent toxicity. The administration of alectinib continued for a period of 10 months without disease progression. Thus, ALK-tyrosine kinase inhibitors should be considered in patients with CUP harboring the EML4-ALK fusion gene.

Anti-epithelial growth factor receptor or anti-vascular endothelial growth factor agents combined with chemotherapy were the standard of treatment for metastatic colorectal cancer (CRC). However, increasing evidence of molecularly stratified treatment makes the complexity of treatment. Anaplastic lymphoma kinase (ALK) gene alternation is one of potential target for biomarker-guided therapy for CRC. We present a case of a 56-year-old man who suffered from advanced ascending colon cancer, harboring echinoderm microtubule associated protein-like 4 (EML4)-ALK fusion gene E21; A20 variant, a rare variant in EML4-ALK fusion gene in lung cancer. We also detected this fusion gene from different tissue types including circulating tumor DNA (ctDNA) and ascites fluid. The patient was offered alectinib, an ALK inhibitor, with partial response in lung, liver, and peritoneal metastasis for 8 months. Tumor heterogeneity, especially in gastrointestinal tract cancer, raise our interest in comprehensive genetic profiling in clinical practice. Convenience and reliability of next-generation sequencing, including using ctDNA, help physicians deal with clinical dilemma. ALK-positive CRC is rare. However, advanced CRC with ALK gene alteration responds to ALK inhibitor. It is reasonable to check ALK gene alteration in clinical practice for CRC.

Detection of the fusion gene composed of echinoderm microtubule-associated protein-like 4 (EML4) and anaplastic lymphoma kinase (ALK) is important for diagnosis of lung adenocarcinoma. We developed a simple PCR-based fluorometric method for detecting the EML4-ALK fusion using a fluorescent probe DNA and graphene oxide (GO). The fluorophore-labeled probe DNA complementary to the EML4-ALK fusion junction was hydrolyzed during PCR by the 5′ to 3′ exonuclease activity of the Taq DNA polymerase. The fluorophore released from the probe DNA retained fluorescence without adsorption onto GO. Our GO-based fluorometric system was able to detect a single cancer cell harboring the EML4-ALK fusion in 106 wild-type cells.

Lung cancer patients harbouring driver oncogene alterations are markedly responsive to molecular target agents, such as epidermal growth factor receptor (EGFR), tyrosine kinase inhibitor (TKI), and echinoderm microtubule-associated protein like 4 – anaplastic lymphoma kinase (EML4-ALK)-TKI. We encountered an exceptionally rare case, harbouring both EGFR mutation and EML4-ALK fusion gene, and suffering from severe disseminated intravascular coagulation. In this case report, we present two notable points. First, our patient was successfully treated with a third-generation EGFR-TKI, osimertinib. Second, osimertinib could manage severe conditions, such as disseminated intravascular coagulation. Third-generation EGFR-TKIs may be a viable option for patients harbouring both EGFR mutations and EML4-ALK fusion genes, even in severe conditions.

Background. Under the National Comprehensive Cancer Network (NCCN) guidelines for non-small-cell lung carcinoma (NSCLC), anaplastic lymphoma kinase (ALK) gene rearrangement is required to be assessed. However, data showing the prevalence of the ALK rearrangement is still deficient and is not yet available in Indonesia. This study used direct smear preparation from transthoracic needle specimens that are minimally invasive. The main objective of the study is to identify the prevalence of the ALK fusion rearrangement gene in cytological specimens. Materials and Methods. A total of 35 direct smear preparations diagnosed as lung adenocarcinoma and EGFR mutation negative were involved in this study. The samples were taken between 2017 and 2019. These samples were examined for EML4-ALK fusion rearrangement gene using qRT-PCR. The EML4-ALK rearrangement status was determined by qRT-PCR with high-resolution melting (HRM) analysis. Results. A total of 28 (80%) samples were from males, and 7 samples were from females. Seven (20% 95% CI: 8.4%-36.9%) samples were EML4-ALK rearrangement positive. The average age of the patients was 63.5 years old. The most common sites of metastasis in this study were pleural cavity, bone, liver, and CNS. Conclusions. qRT-PCR successfully identified EML4-ALK fusion rearrangement in direct smear preparations of lung adenocarcinoma. Direct smear samples can be used for EML4-ALK rearrangement detection using qRT-PCR. The EML4-ALK rearrangement gene has high prevalence in selected lung adenocarcinoma and EGFR mutation-negative populations. ALK inhibitors in lung cancer can be openly considered for use in Indonesian patients to improve the outcome of this subset of patients.

Objective: Oncogenic echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK) (EML4-ALK) fusion proteins found in non-small cell lung cancers (NSCLC) are constitutively phosphorylated and activated by dimerization via the coiled-coil domain (cc) within EML4. Here, we investigated whether disruption of ALK fusion protein oligomerization via competitive cc mimetic compounds could be a therapeutic strategy for EML4-ALK NSCLC. Methods: A Ba/F3 cell model was created that expressed an ALK intracellular domain in which the dimer/monomer state is ligand-regulated. This novel cell model was used to investigate the effect of disrupting ALK fusion protein oligomerization on tumor cell growth in vitro and in vivo using nude mice. Subsequently, the antiproliferative effects of endogenous cc domain co-expression and mimetic cc peptides were assayed in EML4-ALK cancer cell lines. Results: Cells induced to express monomeric ALK in vitro did not survive. When transplanted into mice, induction of monomers abrogated tumor formation. Using a fluorescent protein system to quantify protein-protein interactions of EML4-ALK and EML4cc, we demonstrated that co-expression of EML4cc suppressed EML4-ALK assembly concomitant with decreasing the rate of tumor growth in vitro and in vivo. In EML4-ALK cancer cell lines, administration of synthetic EML4cc peptide elicited a decrease of phosphorylation of ALK leading to reduction in tumor cell growth. Conclusions: Our findings support the monomerization of ALK fusion proteins using EML4cc peptides for competitive inhibition of dimerization as a promising therapeutic strategy for EML4-ALK NSCLC. Further studies are warranted to explore the use of specific cc peptide as a therapeutic option for other lung cancers harboring driver fusion genes containing a cc or oligomerization domain within the fusion partner.

Ovarian cancer is prone to recurrence and chemotherapy resistance. Ovarian tumours of some patients have been positive for anaplastic lymphoma kinase fusion gene expression (ALK+). Preclinical studies indicate that anaplastic lymphoma kinase inhibitor can suppress the growth of ovarian cancer cells and transplantation tumours. Here, we present a patient with metastatic ALK+ high-grade serous ovarian cancer that testing positive for EML4-ALK (microtubule-associated protein-like 4 gene, fused to the anaplastic lymphoma kinase gene), experienced dramatic benefit after administration of the anaplastic lymphoma kinase inhibitor alectinib. This is the first clinical evidence that treatment with alectinib may provide a personalized maximum benefit for patients with high-grade serous ovarian cancer who are positive for EML4-ALK.

BACKGROUND: Brigatinib, a next-generation anaplastic lymphoma kinase (ALK) inhibitor, has robust efficacy in patients with ALK-positive non-small-cell lung cancer (NSCLC) that is refractory to crizotinib. The efficacy of brigatinib, as compared with crizotinib, in patients with advanced ALK-positive NSCLC who have not previously received an ALK inhibitor is unclear. METHODS: In an open-label, phase 3 trial, we randomly assigned, in a 1:1 ratio, patients with advanced ALK-positive NSCLC who had not previously received ALK inhibitors to receive brigatinib at a dose of 180 mg once daily (with a 7-day lead-in period at 90 mg) or crizotinib at a dose of 250 mg twice daily. The primary end point was progression-free survival as assessed by blinded independent central review. Secondary end points included the objective response rate and intracranial response. The first interim analysis was planned when approximately 50% of 198 expected events of disease progression or death had occurred. RESULTS: A total of 275 patients underwent randomization; 137 were assigned to brigatinib and 138 to crizotinib. At the first interim analysis (99 events), the median follow-up was 11.0 months in the brigatinib group and 9.3 months in the crizotinib group. The rate of progression-free survival was higher with brigatinib than with crizotinib (estimated 12-month progression-free survival, 67% [95% confidence interval {CI}, 56 to 75] vs. 43% [95% CI, 32 to 53]; hazard ratio for disease progression or death, 0.49 [95% CI, 0.33 to 0.74]; P

Oncogenic fusion gene Echinoderm Microtubule-associated protein-Like 4-Anaplastic Lymphoma Kinase (EML4-ALK) contributes to tumorigenesis of a subset of non-small cell lung cancer (NSCLC). Recently, we demonstrated that F-circEA-4a, a tumor-promoting circular RNA (circRNA) generated from the back-splicing of EML4-ALK variant 3b (v3b), is a novel liquid biopsy biomarker for NSCLC. However, circRNAs produced from EML4-ALK gene and their roles in NSCLC are not well-characterized. Here, we identify another EML4-ALK-v3b-derived circRNA, F-circEA-2a, harboring “AA” (rather than “AAAA” in F-circEA-4a) motif at the junction site. F-circEA-2a mainly locates in the cytoplasm and promotes cell migration and invasion, but has little effect on cell proliferation. Moreover, F-circEA-2a exists in tumor, but not in the plasma of NSCLC patients with EML4-ALK fusion gene, further supporting the significant diagnostic value of F-circEA-4a for EML4-ALK-positive NSCLC. This work finds a novel oncogenic circRNA generated from EML4-ALK fusion gene, highlighting the pivotal role of circRNA in EML4-ALK-positive NSCLC development.

BACKGROUND The EML4-ALK fusion gene has recently been identified as a driver mutation in a subset of non-small cell lung cancers. In subsequent studies, EML4-ALK has been detected in a low percentage of patients, and was associated with a lack of EGFR or KRAS mutations, younger age, and adenocarcinoma with acinar histology. Cases with the EML4-ALK fusion gene were examined to clarify the clinicopathological characteristics of young adenocarcinoma patients. METHODS Between December 1998 and May 2009, 85 patients aged ≤ 50 with lung adenocarcinoma were treated at our hospital. We examined 49 samples from adenocarcinoma patients who underwent surgical resection, chemotherapy, and/or radiotherapy for the EML4-ALK gene. None of the patients received ALK inhibitors because these drugs had not been approved in Japan before 2012. EML4-ALK fusion genes were screened using multiplex reverse-transcription PCR assay, and were confirmed by direct sequencing. RESULTS The EML4-ALK fusion gene was detected in five tumors (10.2%). One patient had stage IB disease, one had stage IIIA, and three had stage IV. Histologically, there was one solid adenocarcinoma, two acinar adenocarcinomas, and two papillary adenocarcinomas. EML4-ALK fusion genes were mutually exclusive to EGFR and KRAS mutations. The five-year survival rate was 59.4% in patients without EML4-ALK fusion and was not reached in patients with EML4-ALK fusion. CONCLUSION The EML4-ALK fusion gene may be a strong oncogene in younger patients with lung adenocarcinoma.

Aims: The anaplastic lymphoma kinase (ALK) Break Apart FISH Probe Kit and Ventana anti-ALK (D5F3) CDx immunohistochemistry (IHC) assay are the Food and Drug Administration-approved companion diagnostic for targeted therapy with the ALK inhibitor crizotinib in lung cancers. The aim of this study was to assess the efficacy and safety of twice daily crizotinib tablet (250 mg) in IHC-proven echinoderm microtubule-associated protein-like 4 (EML4)-ALK fusion gene among Indian patients with adenocarcinoma lung in the routine clinical practice. Subjects and Methods: Patients with nonsmall cell lung cancer (NSCLC), adenocarcinoma histology, whose tumors were found to be positive for EML4-ALK fusion gene using IHC, were considered for this study. IHC analysis was performed using a Ventana automated immunostainer (Benchmark XT). Detection was performed using Optiview DAB detection and amplification kit. Results: A total of 25 NSCLC adenocarcinoma patients were included in the study. There were 14 (56%) women and 10 (44%) men with a median age of 53 years. All patients had Stage IV disease at the time of initiation of crizotinib therapy. One patient achieved complete response and 20 achieved response rate (PR) for an overall PR of 84%. The median progression-free survival (PFS) was 11.8 months and median overall survival (OS) was 20.6 months. Two (8%) patients experienced severe hepatotoxicity requiring permanent discontinuation of crizotinib therapy. Conclusions: A very high PR, PFS, and OS achieved in our study population indicates that IHC can accurately identify EML4 ALK fusion gene mutations in lung adenocarcinoma patients who are responsive to ALK inhibitors such as crizotinib. IHC should be considered as a cost-effective alternative to FISH, especially in low-resource countries.

Since the identification of anaplastic lymphoma kinase (ALK) gene rearrangements in non-small cell lung cancer (NSCLC) in 2005, the treatment of ALK-rearranged NSCLC (ALK+ NSCLC) has evolved at a rapid pace. This molecularly distinct subset of NSCLC has uniquely important biology, clinicopathologic features and mechanisms of drug resistance which impact on the choice of treatment for a patient with this disease. There are multiple ALK tyrosine kinase inhibitors now available in clinical practice with efficacy data continuing to emerge and guide the optimal treatment algorithm. A detailed search of medical databases and clinical trial registries was conducted to capture all relevant articles on this topic enabling an updated detailed overview of the landscape of management of ALK-rearranged NSCLC.

Inflammatory myofibroblastic tumors (IMT) in the head and neck region are rare neoplasms that generally mimic benign/low-grade neoplasms. Overexpression of anaplastic lymphoma kinase (ALK) has been reported in 50% of IMT cases, secondary to ALK activation by structural rearrangements in the ALK gene, which results in a fusion protein with echinoderm microtubule associated protein like 4 (EML4) in ~20% of cases. The present study describes a case of a 74-year-old woman with a malignant IMT in the right posterior hypopharynx harboring a previously unreported chromosomal rearrangement resulting in EML4 and ALK gene fusion. Strong ALK immunoreactivity was observed in neoplastic cells, while fluorescent in situ hybridization combined with fluorescent fragment analysis and direct sequencing identified the first case of the 3a/b variants of the EML4-ALK fusion gene in IMT. The results of the current study highlight the uncommon occurrence of ALK-positive IMT in the head/neck region and demonstrate the importance of integrating different molecular methodologies to identify unequivocal gene fusion characterization.

In the eighth edition of the TNM classification of lung cancer, the M1b and M1c descriptors are newly defined by the number of extrathoracic metastases. To verify the prognostic value of these descriptors in Japan, we reclassified our cases and re-evaluated prognosis in M1b and M1c patients. All non-small cell lung cancer (NSCLC) patients with extrathoracic metastases who visited Saitama Medical Center from 2010 to 2016 were evaluated, divided according to the eighth edition of the TNM classification criteria into two groups (M1b, patients with single extrathoracic metastasis, and M1c, patients with multiple extrathoracic metastases), and followed up until December 31, 2017. Survival time analysis was performed using the Kaplan–Meier method, and between-group differences in overall survival time (OS) were evaluated by the log-rank test. A total of 231 NSCLC patients were divided into 57 patients with M1b and 174 with M1c. Median OS was 15.2 months (95% confidence interval [CI]: 9.3–19.9) and 7.3 months (95% CI 5.7–10.7) for M1b and M1c, respectively, with no significant between-group difference (P = 0.239). However, after excluding patients with epidermal growth factor receptor (EGFR) mutation or echinoderm microtubule-associated protein-like 4 and anaplastic lymphoma kinase (EML4–ALK) fusion gene, median OS was 12.9 months (95% CI 7.2–19.9) for M1b and 5.4 months (95% CI 3.8–6.3) for M1c, respectively, showing a significant difference (P = 0.029). The effect of therapy directed toward EGFR mutation or EML4–ALK fusion gene might obscure the significant prognostic difference between M1b and M1c.

Anaplastic lymphoma kinase (ALK) is a transmembrane receptor tyrosine kinase, which is a member of the insulin receptor superfamily. Fusions in ALK result in constitutively activated signaling which is susceptible to inhibition by ALK tyrosine kinase inhibitors (TKIs). In this chapter we are describing management of patients with ALK-fused lung cancer. We will discuss molecular basis of ALK fusion including different fusion partners and variants, testing for ALK, targeting ALK with TKI, and managing resistance. Targeting ALK oncogenic driver has been an example of rapid drug development with the first ALK inhibitor approved in 2011 just 4 years after the first publication of ALK discovery by Soda et al. In the following years, we have discovered second- and third-generation ALK inhibitors which are able to circumvent ALK resistance and distinguished by better CNS penetration.

Crizotinib is an effective drug for patients with anaplastic lymphoma kinase (ALK)-positive non-small-cell lung cancer (NSCLC), but upon treatment, the tumors inevitably become crizotinib resistant in time. The resistance mechanisms are only partly understood. In this study, we aim to identify gene mutations associated with resistance in ALK positive advanced non-squamous NSCLC treated with crizotinib. Four ALK positive patients with progressive disease following crizotinib treatment were identified with paired pre- and post-crizotinib tumor tissue from our previously published cohort. Somatic variants in these samples were detected by whole exome sequencing. In one of the four patients, an ALK-resistance associated mutation was identified. In the other three patients, no ALK-resistance associated mutations were present. In these patients we identified 89 relevant somatic mutations in 74 genes that were specific to the resistant tumors. These genes were enriched in 15 pathways. Four pathways, were related to epithelial-mesenchymal transition (EMT): proteoglycans in cancer, HIF-1 signaling, FoxO signaling pathway, and ECM-receptor interaction. Analysis of other EMT-related pathways revealed three additional genes with mutations specific to the crizotinib-resistant tumor samples. The enrichment of mutations in genes associated with EMT-related pathways indicates that loss of epithelial differentiation may represent a relevant resistance mechanism for crizotinib.

Introduction: Improvement in the clinical outcome of lung cancer is likely to be achieved by identification of the molecular events that underlie its pathogenesis. The frequency of epidermal growth factor receptor (EGFR) mutations is ethnicity-dependent, with a higher proportion in Asian populations than in whites, while the incidence of EML4-ALK (echinoderm microtubule-associated-protein like 4-anaplastic lymphoma kinase) fusion gene ranged from 1.6% to 16.4% in patients with NSCLC and these individuals were distinct from those harbouring mutations in the epidermal growth factor receptor gene. This study was conducted to determine the frequency of EGFR mutation and EML4-ALK fusion gene in our population and to determine the effect of different clinicopathological features on the expression of those mutations in patients with lung adenocarcinoma. Results: EGFR mutations were detected in approximately 33% of our patients in this series; the most frequently detected mutation was exon 19 deletion. EML4-ALK fusion gene was detected in 7.3% of patients. Conclusion: Our population exhibited the incidence of EGFR mutation approximately similar to that reported in East Asia and Japanese patients, higher than that recorded in USA, and Australia. However, more studies with larger patients’ numbers are needed to verify this finding.

We carried out an experiment on a 58-year-old man with multiple left lung tumors and swelling of multiple lymph nodes. For clinical staging and therapeutic purposes, bronchoalveolar lavage (BAL) cytology and lung biopsy were performed. The biopsy specimen revealed the left lower lung mass to be immunohistochemically ALK (anaplastic lymphoma kinase)-positive adenocarcinoma. Using the BAL specimen from the left lower lung, EML4 (echinoderm microtubule-associated protein-like 4)-ALK variant 1 fusion gene was detected by reverse transcription-polymerase chain reaction (RT-PCR). His past history showed that he had undergone an operation for lung adenocarcinoma of the right lower lobe 15 years before, and the pathological specimen at that time revealed that the lung adenocarcinoma with pleural invasion and single metastasis of mediastinal lymph node showed a mucinous cribriform pattern and/or signet-ring cell pattern. The typical histology led us to examine the ALK rearrangement in the primary lung cancer and mediastinal metastatic tumor. Immunohistochemistry (IHC) for ALK was positive, and ALK break apart fluorescence in situ hybridization (FISH) showed a positive result. Moreover, RT-PCR using formalin-fixed, paraffin-embedded tissue from the right lung cancer also demonstrated EML4-ALK variant 1 fusion gene. Although there is a possibility that the left lung cancer is de novo one with multiple metastases, detection of the same fusion gene of the very rare EML4-ALK variant 1 in both tumors suggests that the left cancer is a recurrence of the right lung cancer after an interval of 15 years.

The discovery of EML4-ALK fusion gene in a subgroup of patients with lung adenocarcinoma led to the development of a new class of agents, the ALK inhibitors, and dramatically improved the clinical outcome of these patients. The striking results from clinical trials with crizotinib, the first ALK inhibitor evaluated, allowed the accelerated approval of crizotinib from the USA Food and Drug Administration (FDA). Despite the high initial results, patients acquire resistance to crizotinib, and different next generation ALK kinase inhibitors have been developed. In the current review, we will analyze the biology of EML4-ALK gene, the acquired resistance mechanisms to crizotinib, the therapeutic strategies, currently under evaluation, designed to overcome crizotinib resistance, and the open issues that need to be addressed in order to improve outcome in ALK+ Non Small Cell Lung Cancer (NSCLC) patients.

Background: Chromosomal inversions involving Anaplastic lymphoma kinase (ALK) and Echinoderm Microtubule Associated Protein Like 4 (EML4) generate a fusion protein EML4-ALK with the constitutive ALK kinase activity in non-small cell lung carcinoma (NSCLC). The basic understanding of EML4-ALK remains insufficient due to the lack of functional studies using normal human cells. Material and Method: We investigate the activities of EML4-ALK in mortal and immortalized normal human cells. Results: The expression of EML4-ALK in normal, mortal human fibroblasts caused, through its ALK kinase activity, the early induction of cellular senescence with senescence-associated β-galactosidase activity, upregulation of p16INK4A and p21WAF1, telomere shortening and fusions, and accumulated DNA damage. In contrast, when EML4-ALK was expressed in telomerase reverse transcriptase (hTERT)-immortalized normal human fibroblasts, the cells showed accelerated proliferation and anchorage-independent growth, revealing its transformation activity. No chromosome aberration, no mutation or loss of p53, nor impairment of the p16INK4A response was associated with this transformation, likely reflecting clinical features of EML4-ALK-positive NSCLC. In both mortal and immortalized cells, EML4-ALK induced the phosphorylation of STAT3, which is involved in both cellular senescence and transformation. EML4-ALK was also able to transform hTERT-immortalized human bronchial epithelial cells, a cell type relevant to NSCLC. Conclusions: Our data not only validate that EML4-ALK functions as an oncogene in human cells, but also suggest that telomerase-mediated immortalization manifests the oncogenic activity of EML4-ALK, switching from its senescence-inducing activity. This study also provides the isogenic pairs of human cell lines with and without EML4-ALK as an in vitro model for screening and testing candidate drugs. Citation Format: Akihiko Miyanaga, Izumi Horikawa, Masaru Matsumoto, Takahiro Oike, Jessica Beck, Hiromi Tanaka, Ana I. Robles, Masahiro Seike, Akihiko Gemma, Curtis C. Harris. Cellular senescence and transformation induced by an oncogenic EML4-ALK fusion gene in normal and immortalized human cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4648.

Inflammatory myofibroblastic tumor is a rare tumor deriving from mesenchymal tissue. Approximately 50% of inflammatory myofibroblastic tumors harbor an anaplastic lymphoma kinase fusion gene. Pulmonary inflammatory myofibroblastic tumors harboring tropomyosin3-anaplastic lymphoma kinase or protein tyrosine phosphatase receptor-type F polypeptide-interacting protein-binding protein 1-anaplastic lymphoma kinase have been reported previously. However, it has not been reported that inflammatory myofibroblastic tumors harbor echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase fusion gene which is considered to be very specific to lung cancers. A few tumors harboring echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase fusion gene other than lung cancers have been reported and the tumors were all carcinomas. A 67-year-old man had been followed up for a benign tumor for approximately 3 years before the tumor demonstrated malignant transformation. Lobectomy and autopsy revealed that an inflammatory myofibroblastic tumor harboring echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase fusion gene had transformed into an undifferentiated sarcoma. This case suggests that echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase fusion is an oncogenic event in not only carcinomas but also sarcomas originating from stromal cells.

Objectives Patients with non-small cell lung cancer (NSCLC) positive for anaplastic lymphoma kinase (ALK) gene rearrangements may be treated successfully with the ALK inhibitor crizotinib. ALK copy-number abnormalities have also been described. In this study, we evaluated the suitability of fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) to determine ALK status in endobronchial ultrasound (EBUS)-derived cytology samples. Methods Samples were obtained from 55 consecutive patients with NSCLC who had undergone EBUS-transbronchial needle aspiration (TBNA) according to our standard clinical protocols. All tumours had been screened previously for epithelial growth factor receptor (EGFR) and v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations. FISH, using commercially available ALK rearrangement-specific probes, was employed to assess ALK status. IHC using the ALK-1 monoclonal antibody (DAKO) was also performed. Results FISH analysis was successful in 52 of 55 samples (94.5%); ALK rearrangement was demonstrated in 3 of 52 samples from patients with NSCLC (5.7%). ALK amplification was observed in 3 of 52 patient samples (5.7%) and an increase in ALK copy number was found in 28 of 52 patient samples (53.8%). IHC on cell blocks demonstrated ALK expression in one of three samples with ALK rearrangement. One patient sample had concomitant ALK rearrangement and KRAS mutation. Conclusions We found FISH to be superior to IHC using the ALK-1 monoclonal antibody for the detection of ALK rearrangement in EBUS-TBNA cytology specimens in NSCLC, and also that ALK rearrangement can co-exist with KRAS mutation in the same tumour.

The advent of targeted molecular therapy against the EML4-ALK fusion gene is the latest therapeutic intervention for a subset of patients with non-small cell lung cancer (NSCLC). Crizotinib (Xalkori) is an orally available small molecule tyrosine kinase inhibitor proven in clinical trials to significantly impact progression free survival and overall response rate. We present a case of a 56-year-old male with NSCLC whose lack of a positive treatment response to this therapy led to the clinical suspicion and identification of the underdiagnosed entity known as synchronous multiple primary lung cancer (SMPLC).

Background: In the last decade, the search for gene mutations in lung cancer has been constantly growing. EGFR, KRAS mutations and, recently, the EML4-ALK fusion can guide the selection of treatment for patients who carry a specific mutation. Methods: During 2010-2011, EML4-ALK fusion test has been performed in Israel, mostly for wild type EGFR non-squamous NSCLC patients based on fluorescent in-situ hybridization (FISH) technique to detect EML4-ALK rearrangements. Results: Between January 2010 and December 2011, 3341 patients were diagnosed with lung cancer in Israel. Of the 2997 patients with NSCLC 687 had squamous cell carcinoma and 2310 had non-squamous NSCLC. This study focused on available 125 non-squamous NSCLC cases in which analysis for EML4-ALK rearrangement was available. All were negative for EGFR mutation. Nineteen (15.2%) were found positive for the fusion, a figure 2 - 10 times higher compared with previously reported findings. The EML4-ALK fusion was significantly more prevalent in younger male patients (52.1 vs. 61.3 years, p = 0.049), in whom every additional year reduced the chance to find the fusion by 7% [CI = 0.93 (0.88 - 0.99), p = 0.03]. Conclusions: A stepwise approach based on histology and prior EGFR analysis to detect EML4-ALK fusion is highly efficient with a related increased yield of detection. We recommend testing patients with non-squamous cell lung carcinoma after ruling out an EGFR mutation. The chance to find the ALK fusion is significantly greater in younger men.

A pulmonary lymphoepithelioma‐like carcinoma (PLELC) is similar to a lymphoepithelioma, a subtype of nasopharyngeal carcinoma and commonly associated with Epstein–Barr virus infection which is a rare tumour and classified in the group of “other and unclassified carcinoma” in the latest 2015 World Health Organization (WHO) classification. Some reports of lymphoepithelioma‐like carcinoma (LELC) have noted an epidermal growth factor receptor (EGFR) mutation, whereas none have noted a mutation of the echinoderm microtubule‐associated protein‐like 4‐anaplastic lymphoma kinase (EML4‐ALK) fusion gene. This is the first reported case of PLELC with ALK rearrangement. A 76‐year‐old woman underwent a right lower lobectomy and complicated partial resection of the upper lobe with lymph node dissection under complete thoracoscopic approach. A histopathological diagnosis of PLELC was made and the stage was classified as T1aN1(#12l) M0, pl0, G2, Ly1, V1. The results of both ALK immunohistochemistry and EML4‐ALK fusion gene on fluorescence in situ hybridization (FISH) examinations were positive; however, EGFR mutational analysis results showed wild‐type mutation.

Based on our preclinical study results, which showed that the activation of the hepatocyte growth factor/MET pathway is a potential mechanism of acquired resistance to alectinib, we launched the ALRIGHT (OLCSG1405 [alectinib-refractory non-small-cell lung cancer patients harboring the EML4-ALK fusion gene]), a phase II trial of the anaplastic lymphoma kinase (ALK)/MET inhibitor crizotinib in patients with non-small-cell lung cancer refractory to alectinib and harboring the echinoderm microtubule-associated protein-like 4 (EML4)-ALK fusion gene. Patients with ALK-rearranged tumors who have developed disease progression during alectinib treatment will receive crizotinib monotherapy until disease progression or the occurrence of unacceptable toxicity. The primary endpoint is set as the objective response rate, assuming that a response in 50% of eligible patients will indicate potential usefulness and that 15% would be the lower limit of interest (1-sided α of 0.05, β of 0.20). The estimated accrual number of patients is 9. The secondary endpoints include progression-free survival, overall survival, adverse events, and patient-reported outcomes. We will also take tissue samples before crizotinib monotherapy to conduct an exploratory analysis of ALK and hepatocyte growth factor/MET expression levels and gene alterations (eg, mutations, amplifications, and translocations). We will obtain information regarding whether crizotinib, which targets not only ALK, but also MET, can truly produce efficacy with acceptable safety profiles in ALK+ non-small-cell lung cancer even in the alectinib-refractory setting.

Anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors (TKI), including crizotinib, are effective treatments in preclinical models and in cancer patients with ALK-translocated cancers. However, their efficacy will ultimately be limited by the development of acquired drug resistance. Here we report two mechanisms of ALK TKI resistance identified from a crizotinib-treated non–small cell lung cancer (NSCLC) patient and in a cell line generated from the resistant tumor (DFCI076) as well as from studying a resistant version of the ALK TKI (TAE684)–sensitive H3122 cell line. The crizotinib-resistant DFCI076 cell line harbored a unique L1152R ALK secondary mutation and was also resistant to the structurally unrelated ALK TKI TAE684. Although the DFCI076 cell line was still partially dependent on ALK for survival, it also contained concurrent coactivation of epidermal growth factor receptor (EGFR) signaling. In contrast, the TAE684-resistant (TR3) H3122 cell line did not contain an ALK secondary mutation but instead harbored coactivation of EGFR signaling. Dual inhibition of both ALK and EGFR was the most effective therapeutic strategy for the DFCI076 and H3122 TR3 cell lines. We further identified a subset (3/50; 6%) of treatment naive NSCLC patients with ALK rearrangements that also had concurrent EGFR activating mutations. Our studies identify resistance mechanisms to ALK TKIs mediated by both ALK and by a bypass signaling pathway mediated by EGFR. These mechanisms can occur independently, or in the same cancer, suggesting that the combination of both ALK and EGFR inhibitors may represent an effective therapy for these subsets of NSCLC patients. Cancer Res; 71(18); 6051–60. ©2011 AACR.

The echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK) fusion oncogene represents a molecular target in a small subset of non-small cell lung cancers (NSCLCs). This fusion leads to constitutive ALK activation with potent transforming activity. In a pivotal phase 1 clinical trial, the ALK tyrosine kinase inhibitor (TKI) crizotinib (PF-02341066) demonstrated impressive antitumor activity in the majority of patients with NSCLC harboring ALK fusions. However, despite these remarkable initial responses, cancers eventually develop resistance to crizotinib, usually within 1 y, thereby limiting the potential clinical benefit. To determine how cancers acquire resistance to ALK inhibitors, we established a model of acquired resistance to crizotinib by exposing a highly sensitive EML4-ALK–positive NSCLC cell line to increasing doses of crizotinib until resistance emerged. We found that cells resistant to intermediate doses of crizotinib developed amplification of the EML4-ALK gene. Cells resistant to higher doses (1 μM) also developed a gatekeeper mutation, L1196M, within the kinase domain, rendering EML4-ALK insensitive to crizotinib. This gatekeeper mutation was readily detected using a unique and highly sensitive allele-specific PCR assay. Although crizotinib was ineffectual against EML4-ALK harboring the gatekeeper mutation, we observed that two structurally different ALK inhibitors, NVP-TAE684 and AP26113, were highly active against the resistant cancer cells in vitro and in vivo. Furthermore, these resistant cells remained highly sensitive to the Hsp90 inhibitor 17-AAG. Thus, we have developed a model of acquired resistance to ALK inhibitors and have shown that second-generation ALK TKIs or Hsp90 inhibitors are effective in treating crizotinib-resistant tumors harboring secondary gatekeeper mutations.

The EML4 (echinoderm microtubule-associated protein-like 4)-ALK (anaplastic lymphoma kinase) fusion-type tyrosine kinase is an oncoprotein found in 4 to 5% of non-small-cell lung cancers, and clinical trials of specific inhibitors of ALK for the treatment of such tumors are currently under way. Here, we report the discovery of two secondary mutations within the kinase domain of EML4-ALK in tumor cells isolated from a patient during the relapse phase of treatment with an ALK inhibitor. Each mutation developed independently in subclones of the tumor and conferred marked resistance to two different ALK inhibitors. (Funded by the Ministry of Health, Labor, and Welfare of Japan, and others.).

Purpose: Approximately 5% of lung adenocarcinomas harbor an EML4-ALK gene fusion and define a unique tumor group that may be responsive to targeted therapy. However ALK-rearranged lung adenocarcinomas are difficult to detect by either standard fluorescence in situ hybridization or immunohistochemistry (IHC) assays. In the present study, we used novel antibodies to compare ALK protein expression in genetically defined lung cancers and anaplastic large cell lymphomas. Experimental Design: We analyzed 174 tumors with one standard and two novel monoclonal antibodies recognizing the ALK protein. Immunostained tissue sections were assessed for the level of tumor-specific ALK expression by objective quantitative image analysis and independently by three pathologists. Results: ALK protein is invariably and exclusively expressed in ALK-rearranged lung adenocarcinomas but at much lower levels than in the prototypic ALK-rearranged tumor, anaplastic large cell lymphoma, and as a result, is often not detected by conventional IHC. We further validate a novel IHC that shows excellent sensitivity and specificity (100% and 99%, respectively) for the detection of ALK-rearranged lung adenocarcinomas in biopsy specimens, with excellent interobserver agreement between pathologists (κ statistic, 0.94). Conclusions: Low levels of ALK protein expression is a characteristic feature of ALK-rearranged lung adenocarcinomas. However, a novel, highly sensitive IHC assay reliably detects lung adenocarcinomas with ALK rearrangements and obviates the need for fluorescence in situ hybridization analysis for the majority of cases, and therefore could be routinely applicable in clinical practice to detect lung cancers that may be responsive to ALK inhibitors. Clin Cancer Res; 16(5); 1561–71

Purpose: EML4-ALK is a transforming fusion tyrosine kinase, several isoforms of which have been identified in lung cancer. Immunohistochemical detection of EML4-ALK has proved difficult, however, likely as a result of low transcriptional activity conferred by the promoter-enhancer region of EML4. The sensitivity of EML4-ALK detection by immunohistochemistry should be increased adequately. Experimental Design: We developed an intercalated antibody-enhanced polymer (iAEP) method that incorporates an intercalating antibody between the primary antibody to ALK and the dextran polymer-based detection reagents. Results: Our iAEP method discriminated between tumors positive or negative for EML4-ALK in a test set of specimens. Four tumors were also found to be positive for ALK in an archive of lung adenocarcinoma (n = 130) and another 4 among fresh cases analyzed in a diagnostic laboratory. These 8 tumors were found to include 1 with EML4-ALK variant 1, 1 with variant 2, 3 with variant 3, and 2 with previously unidentified variants (designated variants 6 and 7). Inverse reverse transcription-PCR analysis revealed that the remaining tumor harbored a novel fusion in which intron 24 of KIF5B was ligated to intron 19 of ALK. Multiplex reverse transcription-PCR analysis of additional archival tumor specimens identified another case of lung adenocarcinoma positive for KIF5B-ALK. Conclusions: The iAEP method should prove suitable for immunohistochemical screening of tumors positive for ALK or ALK fusion proteins among pathologic archives. Coupling of PCR-based detection to the iAEP method should further facilitate the rapid identification of novel ALK fusion genes such as KIF5B-ALK.

BACKGROUND: The echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK) fusion gene resulting from the chromosome inversion inv(2)(p21;p23) recently was identified in nonsmall cell lung cancer (NSCLC). The authors of this study investigated the frequency, genetic and clinicopathologic profiles of EML4-ALK in Chinese patients with NSCLC. METHODS: EML4-ALK was investigated in 266 resected primary NSCLC, including adenocarcinomas (AD), lymphoepithelioma-like carcinomas, squamous cell carcinomas, mucoepidermoid carcinomas, and adenosquamous carcinomas, by reverse transcriptase-polymerase chain reaction and was verified by sequencing. EML4-ALK protein expression was studied by immunohistochemistry. RESULTS: Thirteen tumors (4.9%) had EML4-ALK comprising 4 fusion transcript variants with fusion of the variable segments from 5′ EML4 to 3′ ALK and with preservation of the ALK kinase domain. The most common variant consisted of 8 tumors with variant 3 that involved EML4 exon 6. The others included 2 tumors with variant 1 (exon 13), 2 tumors with variant 2 (exon 20), and 1 tumor with the novel variant 5 (exon 18). There were 11 ADs and 2 unusual carcinomas with mixed squamous and glandular components. Immunohistochemistry demonstrated diffuse ALK fusion proteins in the tumor cell cytoplasm. EML4-ALK was associated with nonsmokers (P = .009). Tumors with the fusion gene had the wild-type epidermal growth factor receptor (EGFR) (P = .001) and v-Ki-ras2/Kirsten rat sarcoma viral oncogene homolog (KRAS) genes. Patients who had EML4-ALK-positive AD had a younger median age (P = .018) compared with patients who did not have the fusion gene. CONCLUSIONS: The EML4-ALK fusion gene was present in various histologic types of NSCLC. It occurred in mutual exclusion to EGFR and KRAS mutations and was associated with nonsmokers. The authors concluded that EML4-ALK may be useful for predicting the potential response to ALK inhibitors as a therapeutic option for patients with lung cancer. Cancer 2009. © 2009 American Cancer Society.

A subset of lung cancers harbors a small inversion within chromosome 2p, giving rise to a transforming fusion gene, EML4-ALK (echinoderm microtubule-associated protein-like 4 gene and the anaplastic lymphoma kinase gene), which encodes an activated tyrosine kinase. We have earlier examined the presence of EML4-ALK by multiplex reverse transcription-polymerase chain reaction in 363 specimens of lung cancer, identifying 11 adenocarcinoma cases featuring the fusion gene. In this study, we clinicopathologically examined the characteristics of the EML4-ALK-positive cases, including the mutation status of EGFR, KRAS, and TP53, and whether they were of thyroid transcription factor-1 (TTF-1) cell lineage or not. Of 11 patients, 4 (36%) with EML4-ALK-positive lung adenocarcinomas who were below 50 years of age were affected by these diseases, as compared with 12 of 242 patients (5.0%) with EML4-ALK-negative lung adenocarcinomas (P=0.00038). EML4-ALK-positive lung adenocarcinomas were characterized by less-differentiated grade (P=0.0082) and acinar-predominant structure (P

A fusion gene, echinoderm microtubule associated protein like 4 – anaplastic lymphoma kinase (EML4-ALK), with transforming activity has recently been identified in a subset of non-small cell lung cancer (NSCLC), but its pathogenetic, diagnostic, and therapeutic roles remain unclear. Both frequency and type of EML4-ALK transcripts were investigated by reverse transcription PCR in 120 frozen NSCLC specimens from Italy and Spain; non-neoplastic lung tissues taken far from the tumor were used as controls. In cases carrying the fusion transcript, we determined EML4-ALK gene and protein levels using fluorescence in situ hybridization, Western blotting, and immunoprecipitation. We also analyzed ALK protein levels in paraffin samples from 662 NSCLC specimens, including the 120 cases investigated in the molecular studies. EML4-ALK transcripts (variants 1 and 3) were detected in 9 of 120 NSCLC samples but were not specific for NSCLC since they were also found in non-cancerous lung tissues taken far from the tumor. Notably, no transcripts were detected in matching tumor samples from these patients. Fluorescence in situ hybridization analysis of cases expressing EML4-ALK transcripts showed that only a minority of cells harbored the EML4-ALK gene. None of these cases was found to express the EML4-ALK protein as examined by immunohistochemistry, Western blotting, and immunoprecipitation. The EML4-ALK transcript cannot be regarded as a specific diagnostic tool for NSCLC. Our results show therefore that the causal role and value of EML4-ALK as a therapeutic target remain to be defined.

Purpose: EML4-ALK is a fusion-type protein tyrosine kinase that is generated by inv(2)(p21p23) in the genome of non–small cell lung cancer (NSCLC). To allow sensitive detection of EML4-ALK fusion transcripts, we have now developed a multiplex reverse transcription-PCR (RT-PCR) system that captures all in-frame fusions between the two genes. Experimental Design: Primers were designed to detect all possible in-frame fusions of EML4 to exon 20 of ALK, and a single-tube multiplex RT-PCR assay was done with total RNA from 656 solid tumors of the lung (n = 364) and 10 other organs. Results: From consecutive lung adenocarcinoma cases (n = 253), we identified 11 specimens (4.35%) positive for fusion transcripts, 9 of which were positive for the previously identified variants 1, 2, and 3. The remaining two specimens harbored novel transcript isoforms in which exon 14 (variant 4) or exon 2 (variant 5) of EML4 was connected to exon 20 of ALK. No fusion transcripts were detected for other types of lung cancer (n = 111) or for tumors from 10 other organs (n = 292). Genomic rearrangements responsible for the fusion events in NSCLC cells were confirmed by genomic PCR analysis and fluorescence in situ hybridization. The novel isoforms of EML4-ALK manifested marked oncogenic activity, and they yielded a pattern of cytoplasmic staining with fine granular foci in immunohistochemical analysis of NSCLC specimens. Conclusions: These data reinforce the importance of accurate diagnosis of EML4-ALK–positive tumors for the optimization of treatment strategies.

EML4-ALK gene fusions have recently been discovered in a subset of human lung carcinomas, and fusions of the ALK tyrosine kinase gene with the NPM, TPM3, CLTC, ATIC, and TFG genes have been found in hematological malignancies. To elucidate the role of fusions between ALK and other genes in pulmonary carcinogenesis, we examined 77 non-small cell lung carcinomas (NSCLCs) for EML4-, NPM-, TPM3-, CLTC-, ATIC-, and TFG-ALK fusion transcripts by RT-PCR and subsequent sequencing analysis. Although no expression of NPM-, TPM3-, CLTC-, ATIC-, or TFG-ALK fusion transcripts were detected in any of the cases, expression of EML4-ALK fusion transcripts was detected in two (2.6%) of the 77 NSCLCs. In one of the two NSCLCs there was fusion between exon 13 of EML4 and exon 20 of ALK, i.e., variant 1, and in the other there was fusion between exon 20 of EML4 and exon 20 of ALK, i.e., variant 2. Both patients had a history of smoking, and histologically the carcinomas were adenocarcinoma. No somatic mutations were detected in the mutation cluster regions of the EGFR, K-RAS, and PIK3CA genes in these two carcinomas, however, a Pro177Ser mutation of the p53 gene was detected in the carcinoma that contained the variant 1 EML4-ALK fusion transcripts. In situ PCR of a paraffin block section showed that the carcinoma with expression of the variant 1 actually contained an EML4-ALK fusion gene. These results suggested that the EML4-ALK fusion gene product is involved in the carcinogenesis of a subset of NSCLCs.

The genome of a subset of non–small-cell lung cancers (NSCLC) harbors a small inversion within chromosome 2 that gives rise to a transforming fusion gene, EML4-ALK, which encodes an activated protein tyrosine kinase. Although breakpoints within EML4 have been identified in introns 13 and 20, giving rise to variants 1 and 2, respectively, of EML4-ALK, it has remained unclear whether other isoforms of the fusion gene are present in NSCLC cells. We have now screened NSCLC specimens for other in-frame fusion cDNAs that contain both EML4 and ALK sequences. Two slightly different fusion cDNAs in which exon 6 of EML4 was joined to exon 20 of ALK were each identified in two individuals of the cohort. Whereas one cDNA contained only exons 1 to 6 of EML4 (variant 3a), the other also contained an additional 33-bp sequence derived from intron 6 of EML4 (variant 3b). The protein encoded by the latter cDNA thus contained an insertion of 11 amino acids between the EML4 and ALK sequences of that encoded by the former. Both variants 3a and 3b of EML4-ALK exhibited marked transforming activity in vitro as well as oncogenic activity in vivo. A lung cancer cell line expressing endogenous variant 3 of EML4-ALK underwent cell death on exposure to a specific inhibitor of ALK catalytic activity. These data increase the frequency of EML4-ALK–positive NSCLC tumors and bolster the clinical relevance of this oncogenic kinase. [Cancer Res 2008;68(13):4971–6]

Introduction Very recently, we have found a novel fusion product between the echinoderm microtubule-associated protein-like4 (EML4) and the anaplastic lymphoma kinase (ALK) in non-small cell lung cancers (NSCLCs). Tumors featuring EML4-ALK fusion constitute one subtype of NSCLC that might be highly sensitive to ALK inhibitors. Herein, we present results of a first large scale study of EML4-ALK fusion in lung cancers. Methods Using reverse transcription-polymerase chain reaction for EML4-ALK fusion mRNA, we investigated 149 lung adenocarcinomas, 48 squamous cell carcinomas, 3 large-cell neuroendocrine carcinomas, and 21 small-cell carcinomas. For EML4-ALK-positive cancers, we further investigated the presence of ALK fusion proteins by immunohistochemistry. Results Five of 149 adenocarcinomas (3.4%) showed EML4-ALK fusion mRNA, this being totally lacking in carcinomas of other types (0/72). In all the fusion-positive cases, ALK fusion protein could be detected in the cytoplasm immunohistochemically. The five fusion cases featured two EML4-ALK variant 1 fusions and three variant 2 fusions. Histologically, both variant 1 cases were mixed type adenocarcinomas, showing papillary with bronchioloalveolar components. Interestingly, all three variant 2 cases were acinar adenocarcinomas, the link being statistically significant (p = 0.00018). None of the five fusion-positive cases demonstrated any mutations of EGFR or KRAS, pointing to a mutually exclusive relationship (p = 0.014). There was no association with smoking habits. Conclusions In the present first investigation of EML4-ALK fusion in a large study of lung cancers (5/221), we found an interesting histotype-genotype relationship. Furthermore, we could detect the fusion protein by immunohistochemistry, pointing to possible clinical applications.

Tyrosine kinases are involved in the pathogenesis of most cancers. However, few tyrosine kinases have been shown to have a well-defined pathogenetic role in lymphomas. The anaplastic lymphoma kinase (ALK) is the oncogene of most anaplastic large cell lymphomas (ALCL), driving transformation through many molecular mechanisms. In this Review, we will analyse how translocations or deregulated expression of ALK contribute to oncogenesis and how recent genetic or pharmacological tools, aimed at neutralizing its activity, can represent the basis for the design of powerful combination therapies.

Improvement in the clinical outcome of lung cancer is likely to be achieved by identification of the molecular events that underlie its pathogenesis. Here we show that a small inversion within chromosome 2p results in the formation of a fusion gene comprising portions of the echinoderm microtubule-associated protein-like 4 (EML4) gene and the anaplastic lymphoma kinase (ALK) gene in non-small-cell lung cancer (NSCLC) cells. Mouse 3T3 fibroblasts forced to express this human fusion tyrosine kinase generated transformed foci in culture and subcutaneous tumours in nude mice. The EML4-ALK fusion transcript was detected in 6.7% (5 out of 75) of NSCLC patients examined; these individuals were distinct from those harbouring mutations in the epidermal growth factor receptor gene. Our data demonstrate that a subset of NSCLC patients may express a transforming fusion kinase that is a promising candidate for a therapeutic target as well as for a diagnostic molecular marker in NSCLC.

Anaplastic lymphoma kinase (ALK) gene rearrangements in lung adenocarcinoma result in kinase activity targetable by crizotinib. Although fluorescence in situ hybridisation (FISH) is the reference diagnostic technique, immunohistochemistry (IHC) could be useful for pre-screening.Diagnostic yields of ALK IHC, FISH and quantitative reverse transcriptase PCR performed in 14 French pathology/molecular genetics platforms were compared. 547 lung adenocarcinoma specimens were analysed using 5A4 and D5F3 antibodies, two break-apart FISH probes and TaqMan kits. Clinicopathological data were recorded.140 tumours were ALK rearranged (FISH with ≥15% of rearranged cells) and 400 were ALK FISH negative (ALK patients were young (p=0.003), mostly females (p=0.007) and light/nonsmokers (p20%. Variants were undetected in 36% of ALK tumours.Discordances predominated with FISH ranging from 10% to 20% of rearranged cells and were centre dependent. IHC remains a reliable pre-screening method for ALK rearrangement detection.

Anaplastic lymphoma kinase (ALK) rearrangement is present in approximately 5% of lung adenocarcinoma. Clinical trials on ALK inhibitor phase I to III have shown an interesting disease control rate and acceptable tolerability in ALK rearrangement patients. In clinical application, the precise diagnostic strategy for identifying ALK rearrangements remains to be determined. In this study, ALK rearrangement was screened by using quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR), direct sequencing, 2 fluorescence in situ hybridization (FISH) assays, and immunohistochemistry in 173 lung adenocarcinomas. We identified 18 cases (10.4%) with EML4-ALK fusion-positive by qRT-PCR, and all were positive for EML4-ALK fusion gene validated by direct sequencing. The result was consistent with that of other methods. Furthermore, of the 18 EML4-ALK fusion-positive cases, 16 (9.2%) were positive by using EML4-ALK fusion probe FISH, and 15 (8.7%) were positive by using ALK break-apart probe FISH and immunohistochemistry staining. Of the 18 ALK fusion-positive lung adenocarcinomas, 8 cases (44.4%) were histologically diagnosed as subtypes of cribriform adenocarcinoma, 7 cases (38.9%) as cribriform adenocarcinoma mixed with papillary and/or mucinous pattern, 2 cases (11.1%) as papillary adenocarcinoma, and 1 case (5.6%) as mucinous adenocarcinoma. In the present study, the ALK rearrangement frequency detected by qRT-PCR in Chinese NSCLC patients was higher than that in the western populations. QRT-PCR is a rapid, sensitive technology that could be used as a screening tool for identifying EML4-ALK fusion-positive NSCLC patients who would be sensitive for receiving ALK inhibitor therapy.