Abstract 5440
Background
Epidermal growth factor receptor (EGFR) exon 19 deletion (19del) and L858R mutation respond differently to first generation tyrosine kinase inhibitors (TKIs), however, the clinical outcomes of different 19del variants to TKIs and the resistance patterns are not well studied.
Methods
From April 2016 to August 2017, 194 treatment-naive NSCLC patients detected as EGFR exon 19 deletions using amplification-refractory mutation system were included. DNA sequencing was used to detect the subtypes. Clinicopathological features as well as patients’ outcomes to first-line EGFR TKIs were analyzed.
Results
Twelve EGFR 19del variants were confirmed in 169 of the 194 samples. Among these, p.E746_A750del was the most frequent variant (147/169, 87.0%). p.E746_A750del was more frequently found in females (p = 0.008) and never smokers (p = 0.004) than other deletions. And deletions starting with E746 was also more frequently found in these patients than L747 (p = 0.014 and p = 0.018, respectively). Interestingly, T790M occurred more frequently in p.E746_A750del than other deletions (64.3% vs 18.2%, p = 0.017) or deletions started with E746 than L747 (63.6% vs 11.1%, p = 0.012). Patients harboringdeletions starting with L747 plus insertions had significantly shorter progression-free survival (PFS) than no insertions (8.3m vs 15.0m, p = 0.008), as well as other subtypes (8.3m vs 12.8m, p = 0.016). Multivariate analysis showed that only L747 deletion plus insertions and age were independent factors influencing PFS (p = 0.015 and 0.046, respectively).
Conclusions
p.E746_A750del was the most frequent variant of EGFR exon 19del in NSCLC patients. It was more frequently found in female and never smoking patients. T790M mutation had a higher ratio in these patients when they were resistant to first-line TKI treatment. Deletions starting with L747 plus insertions had shorter PFS than other variants.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
3157 - Efficacy and safety of anlotinib in advanced leiomyosarcoma: Subgroup analysis of a phase IIB trial (ALTER0203)
Presenter: Yihebali Chi
Session: Poster Display session 1
Resources:
Abstract
3710 - The effect of treatment line on the efficacy of Anlotinib hydrochloride in advanced alveolar soft part sarcoma patients
Presenter: Zhiwei Fang
Session: Poster Display session 1
Resources:
Abstract
3184 - Prior exposure to pazopanib (PAZ) did not minor efficacy of regorafenib (REG) in non-adipocytic soft tissue sarcoma patients (pts)
Presenter: Nicolas Penel
Session: Poster Display session 1
Resources:
Abstract
798 - Pexidartinib (Pex) for locally advanced tenosynovial giant cell tumor (TGCT): characterization of hepatic adverse reactions (ARs)
Presenter: Sebastian Bauer
Session: Poster Display session 1
Resources:
Abstract
6117 - VEGFR2 and ITGA polymorphisms as novel pan-sarcoma biomarkers for sensitivity prediction as well as toxicity prevention anti-angiogenesis therapy in pediatric and young adult
Presenter: Qiyuan Bao
Session: Poster Display session 1
Resources:
Abstract
5450 - Reversion of resistance to mTOR inhibitors with the addition of exemestane in patients with malignant PEComa.
Presenter: Roberta Sanfilippo
Session: Poster Display session 1
Resources:
Abstract
4279 - Efficacy and Safety of VEGFR2 Inhibitor Apatinib combined with chemotherapy for Sarcoma in Stage IV
Presenter: Zhiwu Ren
Session: Poster Display session 1
Resources:
Abstract
5929 - Outcomes of metastatic soft tissue sarcoma treated with Pazopanib from dedicated medical oncology sarcoma clinic: A holistic care approach from a developing country
Presenter: Akhil Kapoor
Session: Poster Display session 1
Resources:
Abstract
2469 - Inhibition of mTOR signaling enhances Trabectedin activity in Soft Tissue Sarcoma
Presenter: David Moura
Session: Poster Display session 1
Resources:
Abstract
4210 - Efficacy and safety of apatinib for advanced gastrointestinal stromal tumors after failure of imatinib and sunitinib: An open-label, multicenter, single-arm, phase II trial
Presenter: Zhaolun Cai
Session: Poster Display session 1
Resources:
Abstract