Detection of EGFR mutations in plasma DNA from lung cancer patients by mass spectrometry genotyping is predictive of tumor EGFR status and response to EGFR inhibitors
Introduction
The detection of EGFR mutations in lung adenocarcinomas has become a routine molecular test with important implications for patient prognosis and selection of therapy. The presence of an activating mutation predicts response to the EGFR tyrosine kinase inhibitors (TKI) erlotinib or gefitinib, and is prognostically favorable regardless of therapy [1]. Unfortunately, in some cases, tumor tissue is either inadequate for molecular testing because of its small quantity or very low tumor content or is not readily available. Therefore, there is a need to develop new techniques for detecting clinically significant EGFR mutations in patients with little or no available tumor DNA.
Plasma samples from patients with lung cancer contain much higher levels of DNA than plasma from cancer-free patients. Most of this excess circulating DNA is believed to be released from the dying lung cancer cells at primary or metastatic sites [2]. As such, plasma DNA may therefore provide a noninvasive source of genotypic information which could be used as a substitute for tumor tissue for detecting cancer-specific molecular markers that could be used to predict response and prognosis. Several groups have detected EGFR mutations in DNA isolated from plasma [3], [4], [5], [6], [7] or serum samples [8], [9] and show some correlation between mutation status in plasma and tumor tissue [3], [4], [6], [8], [9], [10]. Furthermore, EGFR mutation detected in plasma or serum may, by itself, be predictive of response to EGFR TKI [3], [5], [6], [7], [9].
In this study, we report the detection of EGFR L858R mutations and EGFR Exon 19 deletions in plasma samples from patients with NSCLC using a novel, mass spectrometry assay. The detection of these mutations in plasma samples is correlated with better survival when patients are treated with TKIs.
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Patients characteristics
We studied 31 patients with a biopsy-proven diagnosis of stage III or IV NSCLC and available plasma and tumor tissue. All patients gave informed consent, and the collection and analysis of their health information was approved by the Memorial Sloan-Kettering Cancer Center (MSKCC) Institutional Review Board. The patients were followed for tumor responses and survival outcomes.
EGFR Exon 19 deletion assay
Detection of the small in-frame deletions in exon 19 of EGFR was performed by fragment analysis of fluorescently labeled
Patients and tumor characteristics
Patient characteristics are summarized in Table 2. There were 16 women and 15 men, 30 with lung adenocarcinoma and one patient with poorly differentiated squamous cell carcinoma. Seventeen patients were former or current-smokers and 14 were never smokers. At time of blood collection, all patients were stage IV except one with stage III disease. By the mutation-specific PCR assays used in routine practice at MSKCC to establish EGFR mutation status in tumor tissue [10], 14 tumors had EGFR Exon 19
Discussion
The detection of EGFR mutations in tumor tissue has important prognostic and predictive value, and can be used to select therapy for the treatment of lung adenocarcinoma. Many patients with stage IV adenocarcinoma are diagnosed with small biopsies, or by fine needle aspiration of tumors which often yields insufficient DNA for molecular testing. Detection of EGFR mutations in plasma samples would be of value for patients in whom sufficient tumor tissue is not available.
In the present study, we
Conflict of interest statement
None declared.
Acknowledgments
This work was supported by NIH P01 grant CA129243 (M.L.), the Gretchen and Samuel Feldman Fellowship (M.B.) and La Fondation de France (M.B.).
References (21)
- et al.
EGFR mutations detected in plasma are associated with patient outcomes in erlotinib plus docetaxel-treated non-small cell lung cancer
J Thorac Oncol
(2009) - et al.
EGFR mutation of tumor and serum in gefitinib-treated patients with chemotherapy-naive non-small cell lung cancer
J Thorac Oncol
(2006) - et al.
Rapid PCR-based detection of epidermal growth factor receptor gene mutations in lung adenocarcinomas
J Mol Diagn
(2005) - et al.
Whole genome amplification of plasma-circulating DNA enables expanded screening for allelic imbalance in plasma
J Mol Diagn
(2006) - et al.
DNA degradation test predicts success in whole-genome amplification from diverse clinical samples
J Mol Diagn
(2007) - et al.
A fast and convenient new technique to detect the therapeutic target, K-ras mutant, from peripheral blood in non-small cell lung cancer patients
Lung Cancer
(2010) - et al.
Assessment of EGFR mutation status in lung adenocarcinoma by immunohistochemistry using antibodies specific to the two major forms of mutant EGFR
J Mol Diagn
(2010) - et al.
Gefitinib or carboplatin-paclitaxel in pulmonary adenocarcinoma
N Engl J Med
(2009) - et al.
Quantification of free circulating DNA as a diagnostic marker in lung cancer
J Clin Oncol
(2003) - et al.
Epidermal growth factor receptor mutations in plasma DNA samples predict tumor response in Chinese patients with stages IIIB to IV non-small-cell lung cancer
J Clin Oncol
(2009)
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