453P - Utility of re-biopsy and clinical predictive factors of T790M point mutation in EGFR mutated non-small lung cancer

Date 18 December 2016
Event ESMO Asia 2016 Congress
Session Poster lunch
Topics Biomarkers
Non-Small-Cell Lung Cancer, Metastatic
Presenter Keisuke Kirita
Citation Annals of Oncology (2016) 27 (suppl_9): ix139-ix156. 10.1093/annonc/mdw594
Authors K. Kirita, H. Udagawa, S. Matsumoto, S. Umemura, K. Yoh, S. Niho, K. Goto
  • Thoracic Oncology, National Cancer Center Hospital East, 277-8577 - Kashiwa/JP

Abstract

Background

Identifying the mechanism of resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) therapy has become more essential. This requires invasive re-biopsy procedures but data on the utility and safety of re-biopsy is limited. Additionally, predictive factors of T790M point mutation, which is associated with EGFR TKI resistance, remains unknown.

Methods

Consecutive EGFR mutated non-small cell lung cancer patients demonstrating disease progression on EGFR TKI therapy underwent re-biopsy procedures. Patients with primary EGFR TKI resistance or prior treatment with 3rd generation EGFR TKIs were excluded from the analysis of T790M mutation.

Results

The overall success rate of re-biopsy was 82%(122/149) and there were no serious complications related to the biopsy procedures. Exon20 T790M point mutation was expressed in 51% of patients and one revealed small cell lung cancer transformation. Age, sex, smoking, histological subtypes and sampling lesions (lung, metastatic lymph nodes, distant metastasis or effusion cytology) were not associated with the presence of T790M. Good treatment response during prior EGFR-TKI therapy (CR+PR 63%/SD 18%, p 

Conclusions

Re-biopsy for identifying EGFR T790M mutation is feasible. Prior treatment response and duration of EGFR TKI therapy may facilitate decisions to proceed with invasive re-biopsy procedures.

Clinical trial indentification

Institutional Review Board approval was granted for this study in July 2016 (2016–072, National Cancer Center, Japan).

Legal entity responsible for the study

National Cancer Center, Japan

Funding

N/A

Disclosure

All authors have declared no conflicts of interest.