ABSTRACT
Background
Microsatellite instability (MSI) analysis of tumors informs Lynch syndrome testing, therapeutic choice, and prognosis. The status of MSI is mainly detected by polymerase chain reaction coupled with capillary electrophoresis. However, there are various assays with different detection loci and the obtained results may vary. The objective of this study was to evaluate the concordance among different assays and the performance among different laboratories.
Methods
External quality assessment (EQA) for the detection of MSI was performed in 2021 and 2022. Each sample panel consisted of five samples, including microsatellite-stable and MSI tumor tissues. The sample panels were coded at random, and the returned results were compared and scored.
Results
The fully validated sample panels showed appropriate applicability with commercially available assays. There were eight false-negative results in 2021 and five false results (two false-positives and three false-negatives) in 2022. Among the participating laboratories, in 2021, 20 (74.07%) provided completely correct results; in 2022, 38 (92.68%) obtained an optimal score.
Conclusion
The molecular detection of MSI in China exhibited an improvement in a 2-year EQA study. Participation in EQA program is an efficient way of assessing the performance of laboratories and improving their ability.
Declaration of interests
The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.
Reviewer disclosures
Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.
Author contributions
All authors have accepted responsibility for the entire content of this manuscript and approved its submission. Xiaoyu Fan designed the study and wrote the manuscript; Qianming Bai performed sample preparation, histopathological diagnosis and data analysis; Chunli Shi performed the experiments; Yanqun Xiao and Xueliang Wang supervised the project, designed the study, and approved the final article.
Acknowledgments
The authors would like to thank Natural Science Foundation of Shanghai, Shanghai Municipal Health Commission, and Shanghai Center for Clinical Laboratory for financial supports of this study.
Data availability statement
The data used to support the findings of this study are available from the corresponding authors upon reasonable request.
Ethical approval
Written informed consent was obtained from all patients prior to sample collection. Research involving human subjects complied with all relevant national regulations, institutional policies and is in accordance with the tenets of the Helsinki Declaration (as revised in 2013). The study was approved by the Ethics Committee of Shanghai Center for Clinical Laboratory (NO.202301).
Supplemental data
Supplemental data for this article can be accessed online at https://doi.org/10.1080/14737159.2023.2257133.