Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Feb 1;9(2):261-265.
doi: 10.1001/jamaoncol.2022.6109.

Testing for EGFR Variants in Pleural and Pericardial Effusion Cell-Free DNA in Patients With Non-Small Cell Lung Cancer

Kirsty W C Lee  1 , Molly S C Li  1   2 , Wanxia Gai  3 , Yat Ming Lau  4 , Allen K C Chan  3 , Oscar S H Chan  5 , Chee Khoon Lee  6 , Rebecca M W Yeung  5 , Sherwood Y H Fung  3 , Wai F Cheung  3 , Vivian W Chan  1 , Linda Leung  4 , Kenny N P Kam  4 , Tony S K Mok  1   2
Affiliations

Testing for EGFR Variants in Pleural and Pericardial Effusion Cell-Free DNA in Patients With Non-Small Cell Lung Cancer

Kirsty W C Lee et al. JAMA Oncol. .

Abstract

Importance: Molecular testing in non-small cell lung cancer (NSCLC) is commonly limited by inadequate tumor sample. Plasma cell-free DNA (cfDNA) genotyping as a complementary test is specific but only moderately sensitive. Genotyping of cfDNA in pleural and pericardial effusion (PE-cfDNA) can further optimize molecular diagnostic yield and reduce the need for repeated biopsies.

Objective: To prospectively validate droplet digital polymerase chain reaction (ddPCR) for detection of sensitizing EGFR variants and acquired Thr790Met variant (T790M) from PE-cfDNA in patients with NSCLC.

Design, setting, and participants: This prospective diagnostic validation study was conducted between September 6, 2016, and January 21, 2021 at 2 major Hong Kong cancer centers. Patients with advanced NSCLC with both wild-type and variant EGFR status and exudative PE who underwent thoracocentesis or pericardiocentesis were randomly enrolled. Patients were either EGFR-tyrosine kinase inhibitor (TKI) naive (cohort 1) or EGFR-TKI treated but osimertinib naive (cohort 2). Enrolled patients underwent pleural- or pericardial-fluid and blood sampling for ddPCR EGFR testing. EGFR status results with ddPCR testing of PE-cfDNA and blood were compared with EGFR status in matched tumor biopsy or PE cell block samples.

Main outcomes and measures: Specificity, sensitivity, and concordance of PE-cfDNA for detection of sensitizing EGFR variants and acquired T790M variation.

Results: Among 171 patients (54% female) enrolled, there were 104 in cohort 1 and 67 in cohort 2. In cohort 1, 37% (38/102) were EGFR-variant positive; PE-cfDNA showed 97% sensitivity (95% CI, 92%-100%), 97% specificity (95% CI, 93%-100%), and 97% concordance (ĸ = 0.94, P < .001) for the detection of sensitizing EGFR variants. It was more sensitive than plasma in detecting sensitizing EGFR variants (97% vs 74%, P < .001). In cohort 2, 38% (15 of 40) were positive for the EGFR T790M variant; PE-cfDNA showed 87% sensitivity (95% CI, 69%-100%), 60% specificity (95% CI, 41%-79%), and 70% concordance (ĸ = 0.42, P = .004) for acquired T790M. The EGFR T790M variant was detected in 51% of PE-cfDNA vs 25% of PE cell block samples.

Conclusions and relevance: In this diagnostic study, EGFR variants could be accurately detected from PE-cfDNA in patients with NSCLC. More EGFR T790M was detected in PE-cfDNA than in guideline-recommended PE cell block preparations. These results suggest that PE-cfDNA can complement plasma and tumor genotyping for detecting EGFR variants in patients with advanced NSCLC.

PubMed Disclaimer

Conflict of interest statement

Conflict of Interest Disclosures: Dr K. W. C. Lee reported being an employee and shareholder of ACT Genomics-Sanomics Group during the conduct of this study and receiving speaker fees from AstraZeneca Amgen, AstraZeneca, Boehringer Ingelheim, CStone Pharmaceuticals, GSK, Merck, Merck Sharp and Dohme, Novartis, Pfizer, and Roche; advisory fees from Janssen; and writing support from Merck and Innovent outside the submitted work. Dr Li reported receiving speaker fees from Novartis and advisory fees from Pfizer outside the submitted work. Dr Gai reported receiving personal fees from Take2 Health outside the submitted work. Dr A. K. C. Chan reported receiving personal fees from Take2 Health and equity and personal fees from Grail Consultancy outside the submitted work and holding a portfolio of patents related to molecular diagnostics, with royalties paid from Grail. Dr O. S. H. Chan reported receiving personal fees from Amgen, AstraZeneca, Bristol Myers Squibb, Janssen, Novartis, Takeda, and Merck and consulting fees from Pfizer, Merck Serono, and Takeda outside the submitted work. Dr C. K. Lee reported receiving institutional research funding from Amgen, AstraZeneca, Merck, Roche, Novartis, Pfizer, Takeda, and Yuhan; personal fees from GSK, Janssen, Novartis, Pfizer, Takeda, and Yuhan; and consulting fees from Amgen, AstraZeneca, Boehringer Ingelheim, Novartis, Takeda, and Yuhan outside the submitted work. Dr Mok reported receiving research funding from AstraZeneca, Bristol Myers Squibb, G1 Therapeutics, MSD, Merck Serono, Novartis, Pfizer, Roche, SFJ Pharmaceuticals, Takeda, XCovery; speaker and/or consulting fees from for ACEA Pharma, Adagene, Alpha Biopharma, Amgen, Amoy Diagnostics, AstraZeneca, Bayer Healthcare Pharmaceuticals, BeiGene, Boehringer Ingelheim, Bristol Myers Squibb, Cirina, Daiichi Sankyo, Da Volterra, Fishawack Facilitate, geneDecode, Janssen, Lilly, Lucence Health, Lunit USA, Merck, Merck Sharp and Dohme, MiRXES, Novartis, Omega Therapeutics, OrigiMed, Pfizer, Roche/Genentech, Roche Pharmaceuticals/Diagnostics/Foundation One, Simcere of America, Synergy Research, Takeda, Tigermed, Virtus Medical Group, Yuhan Corporation; speaker fees from Daz Group, InMed Medical Communication, MD Health Brazil, Medscape, P. Permanyer, PeerVoice, Physicians’ Education Resource, PrIME Oncology, Research to Practice, Sanofi-Aventis, Shanghai BeBirds Translation and Consulting, Liangyihui Network Technology, Taiho, Takeda Oncology, TouchIME; consulting and advisory fees from AbbVie, Berry Oncology, Blueprint Medicines, Covidien, C4 Therapeutics, CStone Pharmaceuticals, Curio Science, D3 Bio, Eisai, Elevation Oncology, Gilead Sciences, Gritstone Oncology, Guardant Health, Hengrui Therapeutics, Ignyta, Incyte Corporation, Inivata, IQVIA, Lunit, Loxo-Oncology, Mirati Therapeutics, MoreHealth, OSE Immunotherapeutics, Puma Biotechnology, Qiming Development, Sanofi-Aventis, SFJ Pharmaceutical, Vertex Pharmaceuticals, Yuhan; and advisory fees only from ACEA Pharma, Amgen, AstraZeneca, Boehringer Ingelheim, Bristol Myers Squibb, Daiichi Sankyo, Fishawack Facilitate, G1 Therapeutics, HUTCHMED, Janssen, Lilly, Merck Serono, MSD, Novartis, OrigiMed, Pfizer, Roche Genentech; being a shareholder and on the board of directors of HUTCHMED and ACT Genomics-Sanomics Group; holding stock in Aurora Tele-Oncology; and being on the board of directors or in leadership roles at AstraZeneca, Lunit, the American Society of Clinical Oncology, the Asian Thoracic Oncology Research Group, the Chinese Lung Cancer Research Foundation Limited, the Chinese Society of Clinical Oncology, the Hong Kong Cancer Fund, the Hong Kong Cancer Therapy Society, and the International Association for the Study of Lung Cancer. No other disclosures were reported.

Figures

Figure 1.
Figure 1.. Patient Flowchart
A, The preplanned sample size was 100, and 102 patients had matched PE-cfDNA and tissue for comparison. B, A separate matching analysis of the Thr790Met variant (T790M)–detection rate among 53 patients who had either negative (n = 12) or positive (n = 6) results on cytological testing of effusion but inadequate tumor DNA for molecular testing (n = 6) was performed to capture the T790M-detection rate by thoracocentesis or pericardiocentesis, which resembled actual clinical practice. cfDNA indicates cell-free DNA; EGFR-TKI, epidermal growth factor receptor–tyrosine kinase inhibitor; NSCLC, non–small cell lung cancer; PE-cfDNA, pleural and pericardial effusion cell-free DNA; and qPCR, quantitative polymerase chain reaction. aOne patient had plasma EGFR data missing; thus, 53 were included in an exploratory analysis of T790M-detection rate in the cell block, plasma cfDNA, and PE-cfDNA samples.
Figure 2.
Figure 2.. Clinical Diagnostic Utility of PE-cfDNA
CB indicates cell block, cfDNA, cell-free DNA; EGFR, epidermal growth factor receptor; PE, pleural and pericardial effusion; and T790M, Thr790Met variant.
See this image and copyright information in PMC

References

    1. Hsu W-H, Yang JC, Mok TS, Loong HH. Overview of current systemic management of EGFR-mutant NSCLC. Ann Oncol. 2018;29(suppl 1):i3-i9. doi:10.1093/annonc/mdx702 - DOI - PubMed
    1. Mok TS, Wu YL, Ahn MJ, et al. ; AURA3 Investigators . Osimertinib or platinum-pemetrexed in EGFR T790M-positive lung cancer. N Engl J Med. 2017;376(7):629-640. doi:10.1056/NEJMoa1612674 - DOI - PMC - PubMed
    1. Loong HH, Wong CKH, Chan CPK, et al. . Clinical and economic impact of upfront next-generation sequencing for metastatic NSCLC in East Asia. JTO Clin Res Rep. 2022;3(3):100290. doi:10.1016/j.jtocrr.2022.100290 - DOI - PMC - PubMed
    1. Waterhouse DM, Tseng WY, Espirito JL, Robert NJ. Understanding contemporary molecular biomarker testing rates and trends for metastatic NSCLC among community oncologists. Clin Lung Cancer. 2021;22(6):e901-e910. doi:10.1016/j.cllc.2021.05.006 - DOI - PubMed
    1. Gutierrez ME, Choi K, Lanman RB, et al. . Genomic profiling of advanced non-small cell lung cancer in community settings: gaps and opportunities. Clin Lung Cancer. 2017;18(6):651-659. doi:10.1016/j.cllc.2017.04.004 - DOI - PubMed