The detectability of the pretreatment EGFR T790M mutations in lung adenocarcinoma using CAST-PCR and digital PCR

Tatematsu, Tsutomu; Okuda, Kunio; Suzuki, Ayumi; Oda, Risa; Sakane, Tadashi; Kawano, Osamu; Haneda, Hiroshi; Moriyama, Satoru; Sasaki, Hidefumi; Nakanishi, Ryoichi

doi:10.21037/jtd.2017.07.02

Cited by 12 publications

(8 citation statements)

References 28 publications

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“…Using ddPCR, Watanabe and colleagues detected the EGFR T790M mutation in 79.9% of cases (298 of 373) in a concordant population and the same ddPCR approach (21). Two other ddPCR-based studies have reported an EGFR T790M mutation frequency of 40% and 100% for pretreated samples assessed (34,35); the large range of frequency might be explained by the limited size of the tested populations, with 20 and 13 cases, respectively. In this study, we observed a clear advantage of ddPCR compared with conventional techniques (HRM and direct sequencing), as the former was capable of detecting the EGFR T790M mutation when present at very low frequency, even as low as 0.0009% of total DNA.…”

Section: Discussionmentioning

confidence: 99%

Ultra-sensitive EGFRT790M Detection as an Independent Prognostic Marker for Lung Cancer Patients Harboring EGFRdel19 Mutations and Treated with First-generation TKIs

Vendrell

Mazières

Senal

et al. 2019

Clinical Cancer Research

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Purpose: The detection of preexisting EGFR T790M subclones and the assessment of their clinical significance in the pretreatment of patients with EGFR T790M non-small cell lung cancer (NSCLC) remain unclear.Experimental Design: A total of 179 tumor samples from patients treated or not with a first-generation tyrosine kinase inhibitor (TKI) was analyzed. The presence of ultra-low levels of preexisting EGFR T790M mutation was evaluated using ultrasensitive droplet digital PCR (ddPCR) and the clinical implication of these mutations on first-generation TKI efficiency assessed.Results: With a ddPCR linear performance of 0.999 and an analytical sensitivity of approximately 0.001%, we observed a 66% (99/150) overall incidence of ultra-low EGFR T790M mutation. Among 82 patients harboring EGFR activating mutations, the presence of a preexisting EGFR T790M mutation prior to any treatment was significantly associated with a longer progression-free survival (PFS; P ¼ 0.009; log-rank test). Interestingly, longer PFS was linked to concomitant EGFR del19 and ultra-low EGFR T790M mutations. Moreover, the presence of both EGFR del19 and ultra-low EGFR T790M mutations was identified as the best fit for predicting the clinical outcome of patients treated with TKI compared with an ultra-low EGFR T790M mutation status or an activating mutation alone (P ¼ 0.042 and P ¼ 0.0071, respectively).Conclusions: We demonstrate that the detection of the ultra-low EGFR T790M mutation in TKI-na€ ve patients is not a rare event. We suggest that ddPCR should be used in clinical practice to distinguish patients who may respond to firstor third-generation TKIs.

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Section: Discussionmentioning

confidence: 99%

Ultra-sensitive EGFRT790M Detection as an Independent Prognostic Marker for Lung Cancer Patients Harboring EGFRdel19 Mutations and Treated with First-generation TKIs

Vendrell

Mazières

Senal

et al. 2019

Clinical Cancer Research

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“…Therefore, when tumor samples were classified into two groups based on the abundance of T790M-MAF, multivariate analysis demonstrated that high-preT790M was the independent factor related to a poor prognosis (RFS), irrespective of patient background, including pathological stage, age, and sex. A previous retrospective study by Tatematsu et al, which analyzed the incidence of minor-frequency preT790M using competitive allele-specific PCR in 153 surgically resected EGFR -mutated lung adenocarcinoma tissues, the incidence of preT790M was 29.4%, and T790M-MAF ranged from 0.13 to 2.65% (median MAF 0.20%) [ 36 ]. However, in their study, no significant impact of preT790M on RFS was shown.…”

Section: Discussionmentioning

confidence: 99%

Prognostic impact of pretreatment T790M mutation on outcomes for patients with resected, EGFR-mutated, non-small cell lung cancer

et al. 2022

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Background Many previous studies have demonstrated that minor-frequency pretreatment T790M mutation (preT790M) could be detected by ultrasensitive methods in a considerable number of treatment-naïve, epidermal growth factor receptor (EGFR)-mutated, non-small cell lung cancer (NSCLC) cases. However, the impact of preT790M in resected cases on prognosis remains unclear. Methods We previously reported that preT790M could be detected in 298 (79.9%) of 373 surgically resected, EGFR-mutated NSCLC patients. Therefore, we investigated the impact of preT790M on recurrence-free survival (RFS) and overall survival (OS) in this cohort by multivariate analysis. All patients were enrolled from July 2012 to December 2013, with follow-up until November 30, 2017. Results The median follow-up time was 48.6 months. Using a cutoff value of the median preT790M allele frequency, the high-preT790M group (n = 151) had significantly shorter RFS (hazard ratio [HR] = 1.51, 95% confidence interval [CI]: 1.01–2.25, P = 0.045) and a tendency for a shorter OS (HR = 1.87, 95% CI: 0.99–3.55, P = 0.055) than the low-preT790M group (n = 222). On multivariate analysis, higher preT790M was independently associated with shorter RFS (high vs low, HR = 1.56, 95% CI: 1.03–2.36, P = 0.035), irrespective of advanced stage, older age, and male sex, and was also associated with shorter OS (high vs low, HR = 2.16, 95% CI: 1.11–4.20, P = 0.024) irrespective of advanced stage, older age, EGFR mutation subtype, and history of adjuvant chemotherapy. Conclusions Minor-frequency, especially high-abundance of, preT790M was an independent factor associated with a poor prognosis in patients with surgically resected, EGFR-mutated NSCLC.

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“…The reason we did not nd co-existing de novo T790M and 19 Del in our study perhaps because of the small sample size and rare de novo T790M cases. However, it was reported that acquired T790M mutation always coexist with 19Del [20][21][22]. Tian's study [22] reported that the ratio of allele frequency (Relative allele frequency, RAF) of the T790M mutation to the EGFR sensitizing mutation was different between the de novo and acquired T790M mutations (86.1% vs. 22.3%, P< 0.0001).…”

Section: Discussionmentioning

confidence: 99%

Highly sensitive droplet digital PCR method for detection of de novo EGFR T790M mutation in patients with Non-small cell lung cancer

Wang

Xiao

Guo

et al. 2020

Preprint

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Background This study was aimed to investigate the allelic relation between de novo T790M and concomitant sensitizing EGFR mutations in EGFR-TKIs naïve NSCLCs and to explore whether the formalin-fixed and paraffin-embedded (FFPE) materials affect the detection of de novo T790M mutation. Methods 300 consecutive EGFR-TKI naïve NSCLCs who received surgical resection between January 2016 and June 2018 was retrospectively investigated. All the snap-frozen tumor tissues from 300 NSCLCs were screened by droplet digital PCR (ddPCR) for the detection of de novo T790M mutation. The allelic relation between de novo T790M mutation and concomitant sensitizing EGFR mutations was also investigated. Furthermore, we assessed de novo T790M mutation in paired FFPE specimens of 50 patients which included tumor tissues and paired normal lung tissues of the pretreatment NSCLCs to investigate whether FFPE materials affect the detection of de novo T790M mutation. Results The de novo T790M mutation was observed in four patients which included one patient of single de novo T790M mutation and three patients of de novo T790M mutation coexisting with L858R mutation. The incidence of de novo T790M in pretreatment NSCLCs who harboring EGFR mutations was 2.9% (4/139). All the de novo T790M mutations were detected in cis with the concomitant L858R mutations for the three NSCLCs. Our ddPCR method demonstrated that the frequency of de novo T790M mutation were ranging from 0.1% to 0.5% among 90% (45/50) of the FFPE tumor samples and 92% (46/50) of the paired FFPE adjacent normal lung samples. The frequency of de novo T790M mutation in the paired snap-frozen samples were all below 0.1%. Conclusion Our study demonstrated that most de novo T790M mutation were detected in cis with concomitant sensitizing mutations for pretreatment NSCLCs. Analytical cut-off of ddPCR assay for FFPE specimens should be validated carefully considering the possibility of FFPE-derived artificial gene mutations.

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The detectability of the pretreatment EGFR T790M mutations in lung adenocarcinoma using CAST-PCR and digital PCR

Cited by 12 publications

References 28 publications

Ultra-sensitive EGFRT790M Detection as an Independent Prognostic Marker for Lung Cancer Patients Harboring EGFRdel19 Mutations and Treated with First-generation TKIs

Ultra-sensitive EGFRT790M Detection as an Independent Prognostic Marker for Lung Cancer Patients Harboring EGFRdel19 Mutations and Treated with First-generation TKIs

Prognostic impact of pretreatment T790M mutation on outcomes for patients with resected, EGFR-mutated, non-small cell lung cancer

Highly sensitive droplet digital PCR method for detection of de novo EGFR T790M mutation in patients with Non-small cell lung cancer

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