Quantitative detection of the T790M EGFR mutation in plasma and pleural effusion DNA derived from lung adenocarcinomas
( 血中及び胸水中DNAを用いた肺腺癌におけるゲフィチニブ耐性変異T790Mの定量的検出 )
||【ポスター発表】P2086 （Sep.20, 16:30-17:20）
|●抄 録 ：
○Taniguchi Kazuya1、Kukita Yoji2、Uchida Junji3、Nishino Kazumi3、Kumagai Toru3、
Okuyama Takako3、Okami Jiro3、Higashiyama Masahiko3、Maoba Ryo1、
Imamura Fumio3、Kato Kikuya2
- DNA chip research Inc.
- Res. Inst., Osaka Medical Center for Cancer and Cardiovascular Diseases
- Osaka Medical Center for Cancer and Cardiovascular Diseases
EGFR-TKIs are effective therapeutic agents, but most patients develop resistance. A secondary EGFR T790M mutation is reported to correlate with acquired resistance and accounts for about half of the resistance cases.
As for monitoring of the T790M, cell-free DNA in plasma and pleural effusion are promising targets for non invasive and minimally invasive cancer diagnostics, although detection of rare mutation alleles is technically demanding. BEAMing is currently the most sensitive technique which can quantitative the abundance of the mutated allele.
With the technique, activating mutations were identified from plasma DNA in 73% (33/44). The T790M mutation was identified in 44% (10/23) of patients with progressive disease during EGFR-TKIs. Furthermore, we reported the EGFR status of plasma and malignant pleural effusion DNA in patients who were treated with TKIs. In our patients, pleural effusion DNA had higher mutation allele fraction than plasma DNA.
The BEAMing enables the detection of increases and decreases in the number of T790M mutations in cancer cells, regardless of normal cell DNA contamination, which may be useful for monitoring disease progression.