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MO10 - Molecular Pathology II (ID 127)
- Event: WCLC 2013
- Type: Mini Oral Abstract Session
- Track: Pathology
- Presentations: 1
MO10.01 - Integrative and comparative genomic analysis of East-Asian lung squamous cell carcinomas (ID 2667)
16:15 - 17:45 | Author(s): Y. Choi
Lung squamous cell carcinoma (SqCC) is the second most prevalent type of lung cancer. Currently, no targeted-therapeutics are approved for treatment of this cancer, largely due to a lack of systematic understanding of the molecular pathogenesis of the disease. To identify therapeutic targets and perform comparative analyses of lung SqCC, we probed somatic genome alterations of lung SqCC cases from Korean patients.
We performed whole-exome sequencing of DNA from 104 lung SqCC samples from Korean patients and matched normal DNA. In addition, copy number analysis and transcriptome analysis were conducted for a subset of these samples. Clinical association with cancer-specific somatic alterations was investigated.
This cancer cohort is characterized by a very high mutational burden with an average of 261 somatic exonic mutations per tumor and a mutational spectrum showing a signature of cigarette-smoke exposure. Seven genes demonstrated statistical enrichment for mutation (TP53, RB1, PTEN, NFE2L2, KEAP1, MLL2 and PIK3CA). Comparative analysis between Korean and North American lung SqCC demonstrated similar spectrum of alterations in these two populations, in contrast to the differences seen in lung adenocarcinoma. We also uncovered recurrent occurrence of therapeutically actionable FGFR3-TACC3 fusion in lung SqCC.
These findings provide new steps towards the identification of genomic target candidates for precision medicine in lung SqCC, a disease with a significant unmet medical need.
P3.06 - Poster Session 3 - Prognostic and Predictive Biomarkers (ID 178)
- Event: WCLC 2013
- Type: Poster Session
- Track: Biology
- Presentations: 1
- Coordinates: 10/30/2013, 09:30 - 16:30, Exhibit Hall, Ground Level
P3.06-004 - T790M Mutation in Patients with Acquired Resistance to EGFR Tyrosine Kinase Inhibitors: Is It Associated with Clinically Distinct Features? (ID 352)
09:30 - 16:30 | Author(s): Y. Choi
The T790M mutation is considered to be the major mechanism of acquired resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs). However, its clinical implication in patients with non-small cell lung cancer (NSCLC) is yet determined.
NSCLC patients with acquired resistance to initial EGFR TKIs such as gefitinib or erlotinib were identified, and post-progression tumor specimens were prospectively collected for T790M mutation analysis. Clinical features including the pattern of disease progression (intrathoracic only versus extrathoracic), treatment outcomes for initial or subsequent TKIs, post-progression survival, and overall survival were compared between patients with and without T790M.
Out of 70 cases, 36 (51%) were identified to have the T790M mutation in the rebiopsy specimen. There was no difference in the pattern of disease progression, progression-free survival for initial TKIs (12.8 and 11.3 months), post-progression survival (14.7 and 14.1 months), or overall survival (43.5 and 36.8 months) in patients with and without T790M. In total, 34 patients received afatinib after post-progression biopsy as a subsequent treatment. Among them, six (18%) achieved objective response. The median progression-free survival for afatinib was 3.7 months for the entire group, and 3.2 and 4.6 months for the groups with (n = 21) and without (n = 13) T790M, respectively (p = 0.33). Figure 1Figure 2
Although T790M had no prognostic or predictive role in the present study, further research is necessary to identify patients with T790M-mutant tumors who might benefit from new treatment strategies.