Background: This study evaluated the distribution of epidermal growth factor receptor (EGFR) T790M mutations in treatment-naïve tumor and normal samples obtained from cancer patients. Methods: We utilized allele-specific PCR (AS-PCR), digital droplet PCR (ddPCR) and next generation sequencing (NGS) to detect EGFR T790M allele in several collections of tumor and normal human tissues. Results: AS-PCR analysis of treatment-naïve tumor samples revealed somatic T790M mutation in 3/394 (1%) non-small cell lung carcinomas (NSCLC) carrying the tyrosine kinase inhibitor (TKI)-sensitizing EGFR mutation, but in none of 334 NSCLC lacking EGFR exon 19 deletions (ex19del) or L858R substitutions and in none of 235 non-lung tumors. Use of highly sensitive and quantitative assays, such as ddPCR and NGS, produced a high number of T790M-specific signals even in presumably T790M-negative DNA specimens. This background noise was evidently higher in degraded DNA isolated from formalin-fixed paraffin-embedded tissues as compared to high molecular weight DNA. A combination of AS-PCR, ddPCR and NGS revealed mosaic EGFR T790M allele in 2/68 (3%) NSCLC treated with the first-generation TKI. Both these tumors produced evident and durable response to gefitinib. Conclusion: Detection of mosaic EGFR T790M mutation in treatment-naïve samples may be compromised by yet unresolved technical issues and may have limited clinical value.

1.
Russo A, Franchina T, Ricciardi GR, et al.: A decade of EGFR inhibition in EGFR-mutated non-small cell lung cancer (NSCLC): Old successes and future perspectives. Oncotarget 2015;6:26814-26825.
[PubMed]
2.
Piotrowska Z, Sequist LV: Epidermal growth factor receptor-mutant lung cancer: New drugs, new resistance mechanisms, and future treatment options. Cancer J 2015;21:371-377.
[PubMed]
3.
Pao W, Miller VA, Politi KA, et al.: Acquired resistance of lung adenocarcinomas to gefitinib or erlotinib is associated with a second mutation in the EGFR kinase domain. PLoS Med 2005;2:e73.
[PubMed]
4.
Yun CH, Mengwasser KE, Toms AV, et al.: The T790M mutation in EGFR kinase causes drug resistance by increasing the affinity for ATP. Proc Natl Acad Sci USA 2008;105:2070-2075.
[PubMed]
5.
Chen HJ, Mok TS, Chen ZH, et al.: Clinicopathologic and molecular features of epidermal growth factor receptor T790M mutation and c-MET amplification in tyrosine kinase inhibitor-resistant Chinese non-small cell lung cancer. Pathol Oncol Res 2009;15:651-658.
[PubMed]
6.
Yu HA, Arcila ME, Rekhtman N, et al.: Analysis of tumor specimens at the time of acquired resistance to EGFR-TKI therapy in 155 patients with EGFR-mutant lung cancers. Clin Cancer Res 2013;19:2240-2247.
[PubMed]
7.
Denis MG, Vallée A, Théoleyre S: EGFR T790M resistance mutation in non small-cell lung carcinoma. Clin Chim Acta 2015;444:81-85.
[PubMed]
8.
Kobayashi S, Boggon TJ, Dayaram T, et al.: EGFR mutation and resistance of non-small-cell lung cancer to gefitinib. N Engl J Med 2005;352:786-792.
[PubMed]
9.
Jänne PA, Yang JC, Kim DW, et al.: AZD9291 in EGFR inhibitor-resistant non-small-cell lung cancer. N Engl J Med 2015;372:1689-1699.
[PubMed]
10.
Sequist LV, Soria JC, Goldman JW, et al.: Rociletinib in EGFR-mutated non-small-cell lung cancer. N Engl J Med 2015;372:1700-1709.
[PubMed]
11.
Bell DW, Gore I, Okimoto RA, et al.: Inherited susceptibility to lung cancer may be associated with the T790M drug resistance mutation in EGFR. Nat Genet 2005;37:1315-1316.
[PubMed]
12.
Gazdar A, Robinson L, Oliver D, et al.: Hereditary lung cancer syndrome targets never smokers with germline EGFR gene T790M mutations. J Thorac Oncol 2014;9:456-463.
[PubMed]
13.
Inukai M, Toyooka S, Ito S, et al.: Presence of epidermal growth factor receptor gene T790M mutation as a minor clone in non-small cell lung cancer. Cancer Res 2006;66:7854-7858.
[PubMed]
14.
Sequist LV, Martins RG, Spigel D, et al.: First-line gefitinib in patients with advanced non-small-cell lung cancer harboring somatic EGFR mutations. J Clin Oncol 2008;26:2442-2449.
[PubMed]
15.
Kim HR, Cho BC, Shim HS, et al.: Prediction for response duration to epidermal growth factor receptor-tyrosine kinase inhibitors in EGFR mutated never smoker lung adenocarcinoma. Lung Cancer 2014;83:374-382.
[PubMed]
16.
Li H, Hu H, Wang R, et al.: Primary concomitant EGFR T790M mutation predicted worse prognosis in non-small cell lung cancer patients. Onco Targets Ther 2014;7:513-524.
[PubMed]
17.
Li S, Li L, Zhu Y, et al.: Coexistence of EGFR with KRAS, or BRAF, or PIK3CA somatic mutations in lung cancer: A comprehensive mutation profiling from 5125 Chinese cohorts. Br J Cancer 2014;110:2812-2820.
[PubMed]
18.
Yu HA, Arcila ME, Hellmann MD, et al.: Poor response to erlotinib in patients with tumors containing baseline EGFR T790M mutations found by routine clinical molecular testing. Ann Oncol 2014;25:423-428.
[PubMed]
19.
Godin-Heymann N, Bryant I, Rivera MN, et al.: Oncogenic activity of epidermal growth factor receptor kinase mutant alleles is enhanced by the T790M drug resistance mutation. Cancer Res 2007;67:7319-7326.
[PubMed]
20.
Mulloy R, Ferrand A, Kim Y, et al.: Epidermal growth factor receptor mutants from human lung cancers exhibit enhanced catalytic activity and increased sensitivity to gefitinib. Cancer Res 2007;67:2325-2330.
[PubMed]
21.
Chmielecki J, Foo J, Oxnard GR, et al.: Optimization of dosing for EGFR-mutant non-small cell lung cancer with evolutionary cancer modeling. Sci Transl Med 2011;3:90ra59.
[PubMed]
22.
Oxnard GR, Arcila ME, Sima CS, et al.: Acquired resistance to EGFR tyrosine kinase inhibitors in EGFR-mutant lung cancer: Distinct natural history of patients with tumors harboring the T790M mutation. Clin Cancer Res 2011;17:1616-1622.
[PubMed]
23.
Hata A, Katakami N, Kaji R, et al.: Does T790M disappear? Successful gefitinib rechallenge after T790M disappearance in a patient with EGFR-mutant non-small-cell lung cancer. J Thorac Oncol 2013;8:e27-29.
[PubMed]
24.
Sutto L, Gervasio FL: Effects of oncogenic mutations on the conformational free-energy landscape of EGFR kinase. Proc Natl Acad Sci USA 2013;110:10616-10621.
[PubMed]
25.
Leone A: Highly sensitive detection of EGFR T790M mutation in pre-TKI specimens of EGFR-mutated NSCLC: In cis, in trans, or a different clone? J Thorac Oncol 2013;8:e26-27.
[PubMed]
26.
Fujita Y, Suda K, Kimura H, et al.: Highly sensitive detection of EGFR T790M mutation using colony hybridization predicts favorable prognosis of patients with lung cancer harboring activating EGFR mutation. J Thorac Oncol 2012;7:1640-1644.
[PubMed]
27.
Watanabe M, Kawaguchi T, Isa S, et al.: Ultra-sensitive detection of the pretreatment EGFR T790M mutation in non-small cell lung cancer patients with an EGFR-activating mutation using droplet digital PCR. Clin Cancer Res 2015;21:3552-3560.
[PubMed]
28.
Xu Q, Zhu Y, Bai Y, et al.: Detection of epidermal growth factor receptor mutation in lung cancer by droplet digital polymerase chain reaction. Onco Targets Ther 2015;8:1533-1541.
[PubMed]
29.
Chen LY, Molina-Vila MA, Ruan SY, et al.: Coexistence of EGFR T790M mutation and common activating mutations in pretreatment non-small cell lung cancer: A systematic review and meta-analysis. Lung Cancer 2016;94:46-53.
[PubMed]
30.
Rosell R, Molina MA, Costa C, et al.: Pretreatment EGFR T790M mutation and BRCA1 mRNA expression in erlotinib-treated advanced non-small-cell lung cancer patients with EGFR mutations. Clin Cancer Res 2011;17:1160-1168.
[PubMed]
31.
Su KY, Chen HY, Li KC, et al.: Pretreatment epidermal growth factor receptor (EGFR) T790M mutation predicts shorter EGFR tyrosine kinase inhibitor response duration in patients with non-small-cell lung cancer. J Clin Oncol 2012;30:433-440.
[PubMed]
32.
Costa C, Molina MA, Drozdowskyj A, et al.: The impact of EGFR T790M mutations and BIM mRNA expression on outcome in patients with EGFR-mutant NSCLC treated with erlotinib or chemotherapy in the randomized phase III EURTAC trial. Clin Cancer Res 2014;20:2001-2010.
[PubMed]
33.
Ding D, Yu Y, Li Z, et al.: The predictive role of pretreatment epidermal growth factor receptor T790M mutation on the progression-free survival of tyrosine-kinase inhibitor-treated non-small cell lung cancer patients: a meta-analysis. Onco Targets Ther 2014;7:387-393.
[PubMed]
34.
Lee Y, Lee GK, Lee YS, et al.: Clinical outcome according to the level of preexisting epidermal growth factor receptor T790M mutation in patients with lung cancer harboring sensitive epidermal growth factor receptor mutations. Cancer 2014;120:2090-2098.
[PubMed]
35.
Ye X, Zhu ZZ, Zhong L, et al.: High T790M detection rate in TKI-naive NSCLC with EGFR sensitive mutation: Truth or artifact? J Thorac Oncol 2013;8:1118-1120.
[PubMed]
36.
Moiseyenko VM, Procenko SA, Levchenko EV, et al.: High efficacy of first-line gefitinib in non-Asian patients with EGFR-mutated lung adenocarcinomas. Onkologie 2010;33:231-238.
[PubMed]
37.
Mitiushkina NV, Iyevleva AG, Poltoratskiy AN, et al.: Detection of EGFR mutations and EML4-ALK rearrangements in lung adenocarcinomas using archived cytological slides. Cancer Cytopathol 2013;121:370-376.
[PubMed]
38.
Ulybina YM, Kuligina ESh, Mitiushkina NV, et al.: Coding polymorphisms in Casp5, Casp8 and DR4 genes may play a role in predisposition to lung cancer. Cancer Lett 2009;278:183-191.
[PubMed]
39.
Milbury CA, Zhong Q, Lin J, et al.: Determining lower limits of detection of digital PCR assays for cancer-related gene mutations. Biomol Detect Quantif 2014;1:8-22.
[PubMed]
40.
Li J, Jänne PA, Makrigiorgos G: Biotinylated probe isolation of targeted gene region improves detection of T790M epidermal growth factor receptor mutation via peptide nucleic acid-enriched real-time PCR. Clin Chem 2011;57:770-773.
[PubMed]
41.
Hidaka N, Iwama E, Kubo N, et al.: Most T790M mutations are present on the same EGFR allele as activating mutations in patients with non-small cell lung cancer. Lung Cancer 2017;108:75-82.
[PubMed]
42.
Kobayashi Y, Mitsudomi T: Not all epidermal growth factor receptor mutations in lung cancer are created equal: Perspectives for individualized treatment strategy. Cancer Sci 2016;107:1179-1186.
[PubMed]
43.
Do H, Molania R, Mitchell PL, et al.: Reducing artifactual EGFR T790M mutations in DNA from formalin-fixed paraffin-embedded tissue by use of thymine-DNA glycosylase. Clin Chem 2017;63:1506-1514.
[PubMed]
44.
Maheswaran S, Sequist LV, Nagrath S, et al.: Detection of mutations in EGFR in circulating lung-cancer cells. N Engl J Med 2008;359:366-377.
[PubMed]
45.
Zhao J, Feng HH, Zhao JY, et al.: A sensitive and practical method to detect the T790M mutation in the epidermal growth factor receptor. Oncol Lett 2016;11:2573-2579.
[PubMed]
46.
Rosell R, Dafni U, Felip E, et al.: Erlotinib and bevacizumab in patients with advanced non-small-cell lung cancer and activating EGFR mutations (BELIEF): An international, multicentre, single-arm, phase 2 trial. Lancet Respir Med 2017;5:435-444.
[PubMed]
47.
Liu Y, Sun L, Xiong ZC, et al.: Meta-analysis of the impact of de novo and acquired EGFR T790M mutations on the prognosis of patients with non-small cell lung cancer receiving EGFR-TKIs. Onco Targets Ther 2017;10:2267-2279.
[PubMed]
48.
Ma G, Zhang J, Yin L, et al.: The prognostic role of pretreatment epidermal growth factor receptor T790M mutation in advanced non-small cell lung cancer patients treated with EGFR tyrosine kinase inhibitors. Oncotarget 2017;8:50941-50948
[PubMed]
49.
Shields PG: Publication bias is a scientific problem with adverse ethical outcomes: The case for a section for null results. Cancer Epidemiol Biomarkers Prev 2000;9:771-772.
[PubMed]
50.
Ioannidis JP, Trikalinos TA, Ntzani EE, Contopoulos-Ioannidis DG: Genetic associations in large versus small studies: An empirical assessment. Lancet 2003;361:567-571.
[PubMed]
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