Aim: The present pilot study assessed the usefulness of nanofluidic digital polymerase chain reaction (PCR) arrays in epidermal growth factor receptor (EGFR)-mutant lung adenocarcinoma after tyrosine kinase inhibitor (TKI) resistance.
Patients and methods: We enrolled 12 patients with primary lung adenocarcinoma with sensitive EGFR mutation-confirmed T790M status by re-biopsy after TKI resistance. Nanofluidic digital PCR arrays were used to quantify T790M in genomic DNA from the pre-treatment primary site and in serum cell-free DNA (cfDNA).
Results: On digital PCR, quantified T790M at the pre-treatment primary site was higher in re-biopsy-positive T790M patients (n=4) than in re-biopsy-negative patients (n=8) (0.78%±0.36% vs. 0.07%±0.09%, p<0.01). T790M at the pre-treatment primary site correlated with progression-free survival (PFS) after gefitinib therapy (r=0.67, p=0.016).
Conclusion: Use of digital PCR to quantify T790M at the primary site of EGFR-mutant lung adenocarcinoma predicted T790M emergence in re-biopsies after TKI resistance and PFS after gefitinib therapy.
Keywords: Digital PCR; T790M; epidermal growth factor receptor tyrosine kinase inhibitor; non-small-cell lung cancer.
Copyright© 2015, International Institute of Anticancer Research (Dr. John G. Delinasios), All rights reserved.