The presence of T790M mutation in EGFR accounts for nearly 50% of the acquired resistance to EGFR-TKIs. Earlier studies performed in small cohorts suggest that T790M was also detected in TKI-naïve NSCLC. Here, we use an ultra-sensitive ddPCR to address the incidence and clinical significance of T790M in a larger cohort of TKI-naïve NSCLC.
We analyzed 343 EGFR mutated patients of IFCT Biomarkers France program with available tumor DNA that were finally treated by EGFR-TKI. ddPCRTM was performed with QX200 system (BIO-RAD®, Hercules, USA). All samples were tested in duplicate. Colon cancers DNA were used negative controls.
ddPCR identified a T790M mutation in 23/256 specimens (9%). T790M Fractional Abundance (FA) was ≥10%; ≥1%
Ultrasensitive detection of T790M is related in 9% of EGFR mutated TKI naïve NSCLC patients and has a negative prognostic value for T790M FA over 10%.
Clinical trial identification
Legal entity responsible for the study
French Cooperative Thoracic Intergroup (IFCT)
Institut National du Cancer (INCa), AstraZeneca, IFCT (Alain Depierre Award 2015)
P-P. Bringuier: Research funding from Institut National du Cancer (INCa) and honoraria from AstraZeneca, Roche. F. Barlesi: Honorarium from Bristol-Myers Squibb. D. Moro-Sibilot: Personal fees from Roche, Eli Lilly, Pfizer, Novartis, AstraZeneca, Bristol-Myers Squibb, MSD, Boehringer Ingelheim. J. Cadranel: Personnal fees from AstraZeneca, Bristol-Myers Squibb and Roche for participating to board of experts. All other authors have declared no conflicts of interest.