Abstract 1942
Background
Targeted therapy is a promising treatment in oncogenic driven mutations of lung cancer. Thus exploration of molecular profile is the crucial factor to develop targeted drugs. The ethnicity might affect the molecular profile in each population. This study aims to demonstrate the unique molecular characteristic of lung adenocarcinoma in the Thai population.
Methods
We studied 56 lung cancer patients’ molecular profiles by using Next Generation Sequencing (NGS) for 45 genes lung cancer panel (Ion Torrent system) and confirmed the NGS findings by RT-PCR.
Results
We found 14.3% (8/56) of BRAF (V600E mutation), 58.9% (33/56) of EGFR mutations, 30.4% (17/56) of KRAS mutations, 5.4% (3/56) of MET exon14 splice site and 3.6% (2/56) of AKT mutation (E17K) by NGS method using the allele fraction cutoff at 2%. After we confirmed BRAF, EGFR, and KRAS mutations by using RT-PCR then the prevalence of BRAF V600E, EGFR mutations, and KRAS mutations were 10.7%, 57.1%, and 3.6%, respectively. The false positive KRAS mutation by NGS method probably due to the detection of base changing from G to A which could be similar to the artifact of formalin fixation for G12D, G12S, G13D, and G13S. We also found 5 patients (8.9%) who had more than one mutation in each person as showed in the table. Regarding EGFR mutations, we found 53.1% (17/32) of exon19 deletion, 40.6% (13/32) of L858R, 21.9% (7/32) of G719X, and 6.3% of de novo T790M. Seven out of 32 patients were EGFR dual mutations.Table: 549P
Dual different gene mutations in lung cancer patients
| Patients | EGFR | BRAF | KRAS | AKT | MET |
|---|---|---|---|---|---|
| 1 | G719S | V600E | - | - | - |
| 2 | - | - | - | E17K | exon14 splicing |
| 3 | T790M, L858R | - | - | - | exon14 splicing |
| 4 | exon 19 deletion | V600E | - | - | - |
| 5 | exon 19 deletion, G719A | V600E | - | - | - |
Conclusions
Adenocarcinoma of the lung in the Thai population has a unique molecular profile compared with other populations with high prevalence of BRAF V600E mutation and high percentage of dual different gene mutations.
Clinical trial identification
Legal entity responsible for the study
Faculty of Medicine Ramathibodi Hospital, Mahidol University
Funding
Thailand government
Disclosure
All authors have declared no conflicts of interest.