Circulating EGFR Mutations in Patients with Lung Adenocarcinoma by Circulating Tumor Cell Isolation Systems: A Concordance Study.

Background

We developed a hybrid platform using a negative combined with a positive selection strategy to capture circulating tumor cells (CTCs) and detect epidermal growth factor receptor (EGFR) mutations in patients with metastatic lung adenocarcinoma.

Methods

Blood samples were collected from patients with pathology-proven treatment-naïve stage IV lung adenocarcinoma. Genomic DNA was extracted from CTCs collected for EGFR mutational tests. The second set of CTC-EGFR mutational tests were performed after three months of anti-cancer therapy.

Results

A total of 80 samples collected from 28 patients enrolled between July 2016 and August 2018. Seventeen patients had EGFR mutations, including Exon 19 deletion (n = 11), L858R (n = 5), and de-novo T790 and L858R (n = 1). Concordance between tissue and CTCs before treatment was 88.2% in EGFR- mutant patients and 90.9% in non-mutant patients. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of EGFR mutation tests for CTCs were 89.3%, 88.2%, 90.9%, 93.8%, and 83.3%, respectively.

Conclusions

CTCs captured by a hybrid platform using a negative and positive selection strategy may serve as a suitable and reliable source of lung cancer tumor DNA for detecting EGFR mutations, including T790M.