Abstract 492P
Background
The third generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) osimertinib is a standard treatment in case of T790M mutation positive after failure to first or second generation EGFR TKI in patients with EGFR-mutant non-small cell lung cancer (NSCLC). We investigated a success rate of rebiopsy and sequential EGFR TKI treatment in real world setting in Korea.
Methods
We retrospectively reviewed medical records of patients with EGFR mutant advanced NSCLC who received first- or second- generation EGFR TKI between Jan 2012 and Jun 2018 at a single center in Korea.
Results
Among 221 patients with EGFR-mutant NSCLC, 68 patients who were lost to follow up (n = 19) or still on 1st- or 2nd- generation TKI (n = 49) at time of analysis were excluded. Forty-three out of remaining 153 patients (28%) did not have a chance of consideration for second line treatment because of deterioration of performance status (n = 21) or death (n = 22), especially in elderly over 70 years. Tests for acquired EGFR mutation were performed in 76% (84/110), among which 73 cases were tissue rebiopsy and 11 cases were plasma EGFR mutation analysis. Acquisition of tumor tissue in rebiopsy was successful in 93% (68/73). The most common reason of not doing rebiopsy was lack of sequential treatment options (n = 24). Ten patients with negative T790M or failure at initial rebiopsy underwent more than two times of repeated EGFR mutation analysis, among which four patients had eventually positive T790M at some point of disease course. Overall T790M positive rate was 54% (45/84). Among 7 patients with initially negative T790M mutation in plasma analysis, further rebiopsy from tumor tissue was performed only in one patients because of patient's refusal (n = 2), physician's decision to continue post-progression EGFR TKI (n = 2), poor performance status (n = 1), and unaccessibility to tumor tissue (n = 1).
Conclusions
About 30% of patients with EGFR mutant NSCLC did not have a chance of consideration for second line EGFR TKI treatment, especially in elderly over 70 years. Success rate of tumor tissue rebiopsy was over 90% in real world setting, and repeated rebiopsy may increase detection rate of acquired T790M mutation.
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
117P - Short-term and long-term outcomes of hepatectomy combined with intraoperative radiofrequency ablation for multiple colorectal liver metastases: A propensity score matching study
Presenter: Wenbai Huang
Session: Poster display session
Resources:
Abstract
119P - The impacts of dose-time-fractionation schedules on pathological complete response rate (pCR) and local recurrence (LR)
Presenter: Fu Jin
Session: Poster display session
Resources:
Abstract
120P - Platelet to lymphocyte ratio is associated with tumour localization and outcomes in patients with metastatic colorectal cancer
Presenter: Ahmet Bilici
Session: Poster display session
Resources:
Abstract
121P - Meta-analysis of three-dimensional versus two-dimensional laparoscopic surgery for rectal cancer
Presenter: Laiyuan Li
Session: Poster display session
Resources:
Abstract
127P - Outcomes based on albumin‐bilirubin (ALBI) grade in the phase III CELESTIAL trial of cabozantinib versus placebo in patients with advanced hepatocellular carcinoma (HCC)
Presenter: Stephen Chan
Session: Poster display session
Resources:
Abstract
128P - Tislelizumab in combination with chemotherapy for Chinese patients (Pts) with gastric/gastroesophageal junction cancer (GC/GEJC) or esophageal squamous cell carcinoma (ESCC)
Presenter: Yuxian Bai
Session: Poster display session
Resources:
Abstract
129P - Monitoring patient-specific mutation in ctDNA and CTC for tumour response evaluation after neoadjuvant chemotherapy in advanced gastric adenocarcinoma (NCT03425058)
Presenter: Tao Fu
Session: Poster display session
Resources:
Abstract
130P - Development of a liver cancer risk prediction model for the general population in china: A potential tool for screening
Presenter: Xiaoshuang Feng
Session: Poster display session
Resources:
Abstract
131P - Cabozantinib in Asian patients with hepatocellular carcinoma and other solid tumours: Population pharmacokinetics analysis
Presenter: Chih-Hung Hsu
Session: Poster display session
Resources:
Abstract
132P - Liposomal irinotecan (nal-IRI) plus 5-fluorouracil/levoleucovorin (5 FU/LV) vs 5-FU/LV in Japanese patients (pts) with gemcitabine-refractory metastatic pancreatic cancer (mPAC)
Presenter: Tatsuya Ioka
Session: Poster display session
Resources:
Abstract