Development And Application Of Quality Control For Laboratory Quality Evaluation Of Individualized Medical Laboratory

As one of human ERBB family, HER2 gene amplification occur frequently in most breast cancer patients. Accurate and reliable detection of HER2 gene amplification by fluorescence in situ hybridization (FISH) is the premise behind targeted therapy utilizing trastuzumab. In order to understand the performance of this assay in China, national center for clinical laboratories (NCCL) used formalin-fixed paraffin-embedded (FFPE) samples made of breast cancer cell lines to organize an external quality assurance (EQA) in China in 2014. In our study, we chose three cell lines which have different HER2 gene amplification status. After validation of results and characteristic, we established a panel of five samples including highly positive, weekly positive and negative samples. The panels were sent to laboratories in China and we assessed the results from the participants. We evaluated the performance of these participants and the factors which might affect the performance. In this study,67 laboratories returned the results.94.03% laboratories had eligible EQA scores and 56.72% could detect completely correctly. We found the reagent was an important factor and other factors include operation, environment and staff. Except for reagents, participants should take notice of their operations. Our EQA process is necessary to help participants understand their performances and problems during routine work. Except for HER2 gene amplification in breast cancer, EML4-ALK rearrangement in non-small cell lung cancer (NSCLC) was significant in molecular targeted therapy by ALK kinase inhibitors. Currently, several approaches have been used to detect this fusion gene, including FISH, immunohistochemistry (IHC) and real-time fluorescent quatitative reverse transcription polymerase chain reaction (RT-qPCR). Moreover, next-generation sequencing (NGS) can also be applied for detection of EML4-ALK rearrangement. However, the performance of laboratories in China was unknown. In this study, NCCL organized an EQA to evaluate the performance of different laboratories. In this EQA, we prepared FFPE samples derived from the xenograft tumor tissue of two NSCLC cell lines with different EML4-ALK rearrangement variants and one NSCLC cell line without EML4-ALK rearrangement. Once validation, we established a panel of five samples, including three samples with two different variants and two samples without EML4-ALK rearrangement, which was subsequently sent to laboraotires throughout China. We evaluated the performance and the factors influencing the detection by results returned by these laboratories. In our study, we received results from 94 laboratories.75.53% participants correctly identified all of the panel. According to the methodology applied,82.86%,76.67%,77.78%, and 66.67% of laboratories using RT-qPCR, FISH, NGS, and IHC, respectively could analyze all the samples correctly. In this study, our EQA with xenograft tumor samples as quality controls revealed different factors which might affect the performance of laboratories and helped laboratories to assure reliable detection of EML4-ALK rearrangement detection.