Start Your Search
OA 10 - Liquid Biopsy for Genomic Alterations (ID 678)
- Event: WCLC 2017
- Type: Oral
- Track: Advanced NSCLC
- Presentations: 1
- Moderators:Adrian G. Sacher, Pasi A Jänne
- Coordinates: 10/18/2017, 11:00 - 12:30, F201 + F202 (Annex Hall)
OA 10.02 - Unique Genetic Profiles from Circulating Cell-Free DNA of Cerebrospinal Fluid in Leptomeningeal Metastases of EGFR Mutant NSCLC (ID 8258)
11:00 - 12:30 | Author(s): Y. Li
Leptomeningeal metastases (LM) are more frequent in non-small cell lung cancer (NSCLC) with EGFR mutations. Resistance mechanisms of LM remained unclear due to limited access to leptomeningeal lesions.
Primary tumor, cerebrospinal ﬂuid (CSF) and plasma in patients with suspected LM of NSCLC were tested by Next-Generation Sequencing with 168 genes panel. Thirty patients diagnosed as LM and harboring EGFR mutation were enrolled in this cohort, and CSF cfDNA and plasma of two patients and CSF precipitates of another two patients were not available
Driver genes were detected in 100% (28/28) , 85.7% (24/28) and 75% (21/28) patients of CSF cfDNA, CSF precipitates and plasma, respectively; and 92.9% (26/28) patients had much higher allele fractions in CSF cfDNA than the other two media. Unique genetic profiles were captured in CSF cfDNA when compared with those in plasma and primary tissue. Multiple copy number variations (CNVs) were privately detected in CSF cfDNA, and CNVs in patients after TKI failure were more complicated when compared to those TKI naïve before LM. MET copy number gain identified in 44.0% (11/25) patients was the most frequent one, other CNVs included ERBB2, KRAS, ALK, MYC and FGFR1. Moreover, loss of heterozygosity (LOH) of TP53 was identified in 67.9% (19/28) CSF cfDNA, which was much higher than that in plasma (2/28, 7.1%; p<0.001), and there was a trend towards higher rate of concomitant resistance mutations in patients with TP53 LOH than those without one (70.6% vs. 25%; p=0.036 ). EGFR T790M was identified in 28% (7/25) patients with progression to TKIs in CSF cfDNA.
CSF cfDNA could reveal the unique genetic profiles of LM, and it should be the most representative medium of liquid biopsy for LM in NSCLC harboring EGFR mutations.
Only Active Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login or select "Add to Cart" and proceed to checkout.