Detection of EML4-ALK fusion gene in Chinese non-small cell lung cancer by using a sensitive quantitative real-time
Sha Fu1, Fang Wang, Qiong Shao
1Departments of *Molecular Diagnostics ‡Medicine Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou †Scientific and Technical Information of China (ISTIC), Beijing, China.
Abstract:
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.
Insights
Quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR) effectively identifies anaplastic lymphoma kinase (ALK) rearrangements in lung adenocarcinoma. This sensitive method aids in selecting patients for ALK inhibitor therapy.
Area of Science:
- Oncology
- Molecular Diagnostics
- Genetics
Background:
- Anaplastic lymphoma kinase (ALK) rearrangement occurs in about 5% of lung adenocarcinomas.
- ALK inhibitors show promise in treating ALK rearrangement-positive lung cancer.
- Accurate diagnostic strategies for ALK rearrangements are crucial for clinical application.
Purpose of the Study:
- To evaluate diagnostic methods for identifying anaplastic lymphoma kinase (ALK) rearrangements in lung adenocarcinoma.
- To determine the frequency of EML4-ALK fusion in Chinese lung adenocarcinoma patients.
- To assess the utility of quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR) as a screening tool.
Main Methods:
- Screening of 173 lung adenocarcinomas for ALK rearrangement using qRT-PCR, direct sequencing, fluorescence in situ hybridization (FISH), and immunohistochemistry.
- Validation of EML4-ALK fusion-positive cases identified by qRT-PCR using direct sequencing.
- Comparison of results across different diagnostic methodologies.
Main Results:
- Quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR) identified 10.4% of cases as EML4-ALK fusion-positive, all confirmed by direct sequencing.
- Fluorescence in situ hybridization (FISH) and immunohistochemistry confirmed a high proportion of these fusions.
- The detected ALK rearrangement frequency was higher in Chinese patients compared to Western populations.
Conclusions:
- Quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR) is a rapid and sensitive method for detecting EML4-ALK fusions.
- This technique can serve as an effective screening tool for identifying non-small cell lung cancer (NSCLC) patients eligible for ALK inhibitor therapy.
- Histological subtypes like cribriform adenocarcinoma were frequently associated with ALK rearrangements.
More Related Videos
08:49Exosomal miRNA Analysis in Non-small Cell Lung Cancer NSCLC Patients' Plasma Through qPCR: A Feasible Liquid Biopsy Tool
Published on: May 27, 2016
09:49Oncogenic Gene Fusion Detection Using Anchored Multiplex Polymerase Chain Reaction Followed by Next Generation Sequencing
Published on: July 5, 2019
