Echinoderm Microtubule-associated Protein-like 4-anaplastic Lymphoma Research Articles

Utility of molecular tests in cytopathology.

With the popularity of interventional radiology, diagnostic material obtained can be limited requiring critical decisions on making the best use of it. Molecular testing using nanogram amounts of tissue can add useful diagnostic information by improving sensitivity and/or specificity of the diagnosis. This review examines the use of molecular tests in cervical cytology, “indeterminate” thyroid cytology specimens, pancreatic cyst fluid, urinary tract and pulmonary adenocarcinoma cytologic material. Molecular human papillomavirus (HPV) testing combined with cervical cytology increases sensitivity of detection of high grade lesions. In cytologically negative cases, the HPV negative predictive value endorses longer screening intervals. With the high prevalence of benign thyroid nodules, cytology plays a vital role in screening. However, 10-40% of the specimens obtained are cytologically indeterminate. Molecular analysis of these specimens can predict the malignant risk in these cases. Increased detection of pancreatic cysts has necessitated accurate pre-operative diagnosis delineating non-mucinous from mucinous cysts, which have a potential for progression to adenocarcinoma. Multimodal diagnosis of pancreatic cysts and molecular analysis help to clarify neoplastic risk; and in cases of limited fluid, may be the only available diagnostic information. Urothelial carcinoma (UC) of the bladder, a common cancer with frequent recurrences, requires lifelong surveillance. The UroVysion ™ test kit can increase the sensitivity of detection of UC especially in cases of residual/recurrent carcinoma after therapy. Subsets of lung adenocarcinomas are now commonly targeted by therapies based on molecular mutation results of epidermal growth factor receptor, KRAS or echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase re-arrangements. The move toward standardization of reporting of cytology specimens commencing with cervical smears and more recently, thyroid cytology specimens is also changing the practice of cytopathology. Combining the stringent cytology criteria with ancillary molecular testing is expected to yield more discrete and diagnostic categories for research and reporting. The profession is at an exciting point of implementing novel molecular markers to refine diagnostic criteria and create clinically relevant classification systems.

Year in review 2013: Lung cancer, respiratory infections, tuberculosis, cystic fibrosis, pleural diseases, bronchoscopic intervention and imaging

This Year in Review examines the most relevant articles published on lung cancer, respiratory infections, tuberculosis (TB), cystic fibrosis (CF), pleural diseases, and interventional pulmonology and imaging in Respirology and other respiratory medicine journals during 2013. Important findings are highlighted with comments in the following sections, each of which was contributed by an author as named in the beginning of each section.

Pulmonary Inflammatory Myofibroblastic Tumor Harboring EML4-ALK Fusion Gene

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.

Analysis of EGFR, EML4-ALK, KRAS, and c-MET mutations in Chinese lung adenocarcinoma patients

ABSTRACTIntroduction: Mutation analysis of cancer driver genes is helpful for determining an optimal treatment strategy. We evaluated mutations in four driver genes, namely epidermal growth factor receptor (EGFR), Kirsten ras oncogene (KRAS), c-MET, and echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK), in Chinese lung adenocarcinoma patients from Hunan Province. Methods: We enrolled 110 lung adenocarcinoma patients in a single institution. EGFR and KRAS mutations were examined by direct sequencing, the EML4-ALK fusion gene was analyzed by fluorescence in situ hybridization, and c-MET amplification and c-Met protein expression were detected by quantitative PCR and immunohistochemistry, respectively. Results: EGFR and KRAS mutations were observed in 52.7% (58/110) and 3.6% (4/106) of patients, respectively. c-MET amplification was detected in 5.5% (6/110) of patients. In addition, 30% (33/110) of the cases expressed c-Met protein, including all of the patients harboring c-MET amplification. Ten percent (11/110) of patients harbored the EML4-ALK fusion gene, and the frequency of ALK rearrangement was higher than that of other cohort analyses involving patients from other regions in China. Almost all of these gene mutations were exclusive except that in two female non-smoking patients, who harbored an EGFR mutation and EML4-ALK rearrangement simultaneously. In total, 70% of patients in the study harbored one of the four gene mutations. Conclusions: Most Chinese lung adenocarcinoma patients harbor driver gene mutations, among which ALK rearrangements were more common in Hunan patients than in previously reported populations. Future clinical trials should be conducted to determine the safety and efficacy of drug combination targeting different driver mutations.

CHFR aberrant methylation involves a subset of human lung adenocarcinoma associated with poor clinical outcomes

Excluding epidermal growth factor receptor (EGFR) mutation, v-Ki-ras2/Kirsten rat sarcoma viral oncogene homolog (KRAS) mutation, and echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK) fusion, the genetic alterations involved in lung adenocarcinogenesis, especially those linked to poor clinical outcomes, are still unknown. In this study, we analyzed abnormal checkpoint gene with forkhead-associated domain and ring finger (CHFR) methylation along with the above 3 mutations in 165 lung adenocarcinomas, evaluated the spectrum of each molecular abnormality, and correlated the results with clinical and pathologic variables. Reverse transcription-polymerase chain reaction assay, reverse transcription-polymerase chain reaction followed by direct DNA sequencing, and methylation-specific polymerase chain reaction were performed to detect these 3 mutations and CHFR hypermethylation. The EML4-ALK transcript or CHFR hypermethylation was found in 11 (6.7%) or 16 (10%) adenocarcinomas, respectively, whereas EGFR or KRAS mutation was detected in 48 (29%) or 13 (8%) cases, respectively. EGFR mutations occurred in patients who were negative for both CHFR hypermethylation and KRAS mutation. Among the 4 genetic or epigenetic abnormalities, only CHFR hypermethylation was significantly correlated with poor prognosis and lymphatic vessel invasion (P = .024). Histopathologically, the molecular abnormality that correlated with alveolar-destructive growth was the CHFR hypermethylation rather than the EGFR mutation (P = .03). Our results demonstrate that CHFR hypermethylation maybe one of the molecular abnormalities involved in a subset of lung adenocarcinomas with poor prognoses that might be induced by destructive growth and lymphatic vessel invasion of carcinoma cells. Thus, CHFR abnormality might be pursued as a novel therapeutic target against lung adenocarcinoma without an already-known mutation.

Histologic and Molecular Characterization of Lung Cancer With Tissue Obtained by Electromagnetic Navigation Bronchoscopy

Electromagnetic navigation bronchoscopy (ENB) is a catheter-based adjunct to standard bronchoscopic techniques for the sampling of lung lesions. We sought to evaluate the adequacy of ENB-obtained samples for histologic subtyping of lung cancer, epidermal growth factor receptor (EGFR) mutations, and echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK) translocations. We retrospectively analyzed consecutive patients who underwent ENB for the diagnosis of lung lesions between 2008 and 2011. In those proven to be a primary lung cancer by ENB, tissue adequacy for histologic subtyping was recorded. Accuracy was determined by comparison with resected specimens when available. Tissue adequacy for EGFR mutation and/or EML4-ALK analyses was also reviewed. Sixty-five ENB cases resulted in a diagnosis of lung cancer. Tissues obtained were adequate for histologic subtyping in all 65 cases. Forty-three (66.2%) were diagnosed with adenocarcinoma, 19 (29.2%) with squamous cell carcinoma, 3 (4.6%) with small cell carcinoma. In 51 cases (78.5%), subtyping was performed by morphology alone, whereas 11 (21.5%) required immunohistochemical staining. Sixteen of 65 tumors underwent surgical resection. Concordance of histologic subtyping between ENB and surgical specimens was 87.5% (14 tumors). ENB-obtained samples from 15 patients with adenocarcinoma were sent for EGFR mutation analysis, of which 14 (93.3%) were adequate. Samples from 2 patients were evaluated for EML4-ALK gene rearrangements, both of which were adequate for analysis. ENB is effective at obtaining tissue samples adequate for histologic subtyping, EGFR mutation, and EML4-ALK translocation analysis.

Histologic and Molecular Characterization of Lung Cancer With Tissue Obtained by Electromagnetic Navigation Bronchoscopy

Background: Electromagnetic navigation bronchoscopy (ENB) is a catheter-based adjunct to standard bronchoscopic techniques for the sampling of lung lesions. We sought to evaluate the adequacy of ENB-obtained samples for histologic subtyping of lung cancer, epidermal growth factor receptor (EGFR) mutations, and echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK) translocations. Methods: We retrospectively analyzed consecutive patients who underwent ENB for the diagnosis of lung lesions between 2008 and 2011. In those proven to be a primary lung cancer by ENB, tissue adequacy for histologic subtyping was recorded. Accuracy was determined by comparison with resected specimens when available. Tissue adequacy for EGFR mutation and/or EML4-ALK analyses was also reviewed. Results: Sixty-five ENB cases resulted in a diagnosis of lung cancer. Tissues obtained were adequate for histologic subtyping in all 65 cases. Forty-three (66.2%) were diagnosed with adenocarcinoma, 19 (29.2%) with squamous cell carcinoma, 3 (4.6%) with small cell carcinoma. In 51 cases (78.5%), subtyping was performed by morphology alone, whereas 11 (21.5%) required immunohistochemical staining. Sixteen of 65 tumors underwent surgical resection. Concordance of histologic subtyping between ENB and surgical specimens was 87.5% (14 tumors). ENB-obtained samples from 15 patients with adenocarcinoma were sent for EGFR mutation analysis, of which 14 (93.3%) were adequate. Samples from 2 patients were evaluated for EML4-ALK gene rearrangements, both of which were adequate for analysis. Conclusions: ENB is effective at obtaining tissue samples adequate for histologic subtyping, EGFR mutation, and EML4-ALK translocation analysis.

Advances of molecular subtype and targeted therapy of lung cancer

随着肺癌发生、发展和预后相关分子机制研究的不断深入，肺癌靶向治疗取得了较大的进展，每一种分子分型的发现都会带来相应靶向药物的研究。2004年表皮生长因子受体（epidermal growth factor receptor, EGFR）基因在非小细胞肺癌中的发现，为我们带来了EGFR突变高度敏感有效的酪氨酸激酶抑制剂（tyrosine kinase inhibitor, TKI）。2007年棘皮类微管相关样蛋白-4-间变型淋巴瘤激酶（EML4-ALK）融合基因的出现为肺癌的分子发展带来了新的有效靶点。目前多个肺癌分子靶点及其靶向药物正在研究中。本文旨在回顾并总结肺癌分子分型及其靶向治疗的研究进展。

A Screening Method for the ALK Fusion Gene in NSCLC

Lung cancer research has recently made significant progress in understanding the molecular pathogenesis of lung cancer and in developing treatments for it. Such achievements are directly utilized in clinical practice. Indeed, the echinoderm microtubule-associated protein-like 4–anaplastic lymphoma kinase (ALK) fusion gene was first described in non-small cell lung cancer in 2007, and a molecularly targeted drug against the fusion was approved in 2011. However, lung cancer with the ALK fusion constitutes only a small fraction of lung cancers; therefore, efficient patient selection is crucial for successful treatment using the ALK inhibitor. Currently, RT-PCR, fluorescent in situ hybridization (FISH), and immunohistochemistry are commonly used to detect the ALK fusion. Although FISH is currently the gold standard technique, there are no perfect methods for detecting these genetic alterations. In this article, we discuss the advantages and disadvantages of each method and the possible criteria for selecting patients who are more likely to have the ALK fusion. If we can successfully screen patients, then ALK inhibitor treatment will be the best example of personalized therapy in terms of selecting patients with an uncommon genotype from a larger group with the same tumor phenotype. In other words, the personalized therapy may offer a new challenge for current clinical oncology.

Correlation of anaplastic lymphoma kinase overexpression and the EML4-ALK fusion gene in non-small cell lung cancer by immunohistochemical study

Recently the echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK) fusion gene with transforming activity was identified in non-small cell lung cancer (NSCLC). In addition, NSCLC patients with the EML4-ALK fusion gene had a dramatic response and longer progression free survival after ALK inhibitor treatment than those without this fusion gene. However, the incidence and clinical and molecular characteristics of the EML4-ALK fusion gene in NSCLC patients of Taiwan are still unclear. Sixty-four fresh frozen tumor specimens were obtained from the tissue bank of Chang Gung Memorial Hospital for RNA extraction and EML4-ALK fusion gene detection. Paraffin sections of lung tumors from all of these patients were available and were analyzed for ALK protein expression by immunohistochemical (IHC) study. The results were correlated with clinical and molecular biomarkers. Three of the 64 tumors (4.7%) had the EML4-ALK fusion gene. Two were adenocarcinomas, and one was adenosquamous carcinoma. Twenty patients with non-squamous cell carcinomas had epidermal growth factor receptor (EGFR) mutations, so the EML4-ALK fusion gene was found in 14.3% of EGFR wild type non-squamous cell carcinomas. Two tumors were variant 3 (3a+3b with 3b predominant) and had strong staining (3+) for ALK by IHC stains. One tumor was variant 1 and had moderate staining (2+) for ALK. None of the ALK wild type tumors had strong staining for ALK. When compared with other clinical and molecular features, only the IHC stain for ALK was significantly correlated with the EML4-ALK fusion gene (p = 0.0002). ALK overexpression detected by IHC study could be a promising detection method for the EML4-ALK fusion gene and is worth further confirmation with more samples.

Personalized Therapy for Non-Small Cell Lung Cancer: Which Drug for Which Patient?

The elucidation of the molecular alterations in non-small cell lung cancer (NSCLC) and the development of molecularly targeted agents have permanently shifted NSCLC therapy to a personalized approach. In the metastatic setting, the addition of the anti-vascular endothelial growth factor monoclonal antibody, bevacizumab, to chemotherapy improves overall survival. The oral epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors, gefitinib and erlotinib, prolong progression-free survival in patients selected for the presence of an EGFR activating mutation. The monoclonal antibody to EGFR, cetuximab, improves survival in patients with metastatic NSCLC, and the inhibitor of the echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK) fusion protein, crizotinib, has resulted in an unprecedented overall survival advantage in patients harboring the EML4-ALK translocation. In the adjuvant setting, gefitinib has not been shown to improve patient survival outcomes; however, there are several ongoing clinical trials in the adjuvant setting evaluating the role of erlotinib, bevacizumab, and the MAGE-A3 and MUC1 vaccines. The realm of personalized lung cancer therapy also includes the study of chemotherapy selected on the basis of the pharmacogenetic profile of a patient's tumor. Several ongoing clinical trials in both the metastatic and adjuvant settings are studying the excision repair cross-complementing group 1 (ERCC1) protein, the ribonucleotide reductase subunit 1 (RRM1) protein, thymidylate synthase, and BRCA1 as predictors of chemotherapy response. This review will outline the current state of the art of personalized NSCLC therapy.

Bright-Field Dual-Color Chromogenic In Situ Hybridization for Diagnosing Echinoderm Microtubule-Associated Protein-Like 4-Anaplastic Lymphoma Kinase-Positive Lung Adenocarcinomas

A subset of lung cancers harbors an EML4-ALK (echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase) gene fusion, and detecting this subset may hold therapeutic implications. Many prior studies used fluorescence in situ hybridization (FISH) analysis for this detection, but FISH may have disadvantages including signal decay and dark-field examination that may obscure tissue architecture. In this study, we explored the potential of the ALK-break-apart chromogenic in situ hybridization (CISH) method to detect ALK-rearranged lung cancer. We examined 15 lung adenocarcinomas with reverse-transcriptase polymerase chain reaction-proven EML4-ALK fusion transcripts and 30 ALK-negative cases. One hundred tumor cells were evaluated by CISH and FISH for each case, and a detailed signal profile was recorded and compared. CISH preserved tissue architecture and cytomorphology considerably and facilitated the signal evaluation using a routine light microscope. Positive rearrangement signals (splits or isolated 3' signals) were identified in 13 to 78% (mean ± SD, 41% ± 19%) of tumor cells in the ALK-positive cohort and in 0 to 15% (mean ± SD, 6% ± 4%) of cells in the ALK-negative cohort. The two groups were best separated by a cutoff value of 20%, with a sensitivity of 93% and a specificity of 100%. The only false-negative tumor having only 13% CISH-positive cells displayed predominantly (76%) isolated 5' signals unaccompanied by 3' signals. FISH showed largely similar signal profiles, and the results were completely concordant with CISH. We have successfully introduced CISH for diagnosing EML4-ALK-positive lung adenocarcinoma. This method allows simultaneous visualization of genetics and tumor cytomorphology and facilitates the molecular evaluation and could be applicable in clinical practice to detect lung cancer that may be responsive to ALK inhibitors.

Crizotinib for EML4-ALK positive lung adenocarcinoma: a hope for the advanced disease?

Introduction: In lung adenocarcinoma, certain mutations such as echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (ALK) are associated with lower sensitivity to chemotherapy, when used conventionally as the first-line therapy in the advanced stage of the disease.Areas covered: This paper discusses the clinical and therapeutic importance of ALK mutations in NSCLC and the early clinical results of a Phase I study assessing crizotinib in patients with ALK mutations.Expert opinion: Abnormal ALK is evolving as an important therapeutic target in patients with more aggressive lung adenocarcinoma. Further clinical studies are needed in order to assess if crizotinib, an ALK inhibitor, is able to increase the efficacy of the conventional chemotherapy in this disease subset.

Personalized Therapy in Lung Cancer: Focused on Molecular Targeted Therapy

Lung cancer is the leading cause of cancer death worldwide, with an overall 5 year survival rate of 15%. Most patients present with advanced disease that requires systemic chemotherapy, which merely confers several months of survival benefit. Recent advances in understanding the molecular mechanisms underlying lung cancer have led to molecular targeted therapy in this field. Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are the first successful personalized therapy for non-small cell lung cancer (NSCLC), with about 30 months of median overall survival in patients with sensitive EGFR mutations. In addition, monoclonal antibodies against vascular endothelial growth factor (VEGF) or EGFR are also in current clinical use. Resistance to EGFR-TKIs has emerged as a major limitation of these agents and become challenge clinically. A number of novel targeted agents have been developed and investigated in clinical trials to overcome the limitation of agents currently available. Recently, echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase fusion gene ( EML4-ALK), as a novel molecular target of NSCLC, has been identified, and its inhibitor is under rapid clinical development. We herein review the molecular targeted therapies currently available for NSCLC and discuss the clinical data of novel agents under clinical development. (J Lung Cancer 2011;10(1):1 �� 12)

The EML4‐ALK fusion gene is involved in various histologic types of lung cancers from nonsmokers with wild‐type EGFR and KRAS

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. 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. 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. 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.