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Y. Nishii
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P1.03 - Poster Session with Presenters Present (ID 455)
- Event: WCLC 2016
- Type: Poster Presenters Present
- Track: Radiology/Staging/Screening
- Presentations: 1
- Moderators:
- Coordinates: 12/05/2016, 14:30 - 15:45, Hall B (Poster Area)
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P1.03-001 - The Utility of Liquid-Biopsy for Detecting EGFR Mutation in Clinical Practice: 169 Cases in a Single Institution Research Study (ID 6321)
14:30 - 14:30 | Author(s): Y. Nishii
- Abstract
Background:
EGFR-TKIs have promising anti-tumor activities for EGFR-mutant NSCLC, however, almost all patients invariably experience progression on EGFR-TKI therapy. The T790M mutation is known as a major mechanism of resistance to EGFR-TKIs, and re-biopsy is essential for detecting the T790M mutation in EGFR-TKI failure patients. We conducted both tissue-biopsy and liquid-biopsy for all patients who were diagnosed with NSCLC in our institution, and we retrospectively evaluated the utility of liquid-biopsy in clinical practice.
Methods:
We reviewed all patients who were diagnosed with or suspected of having NSCLC and received a liquid-biopsy between April 2015 and June 2016 in Matsusaka Municipal Hospital. The aim of this study was to evaluate the clinical benefit of liquid-biopsy by comparing of the results of the liquid-biopsies against the results of the tissue-biopsies. The proportions were compared using Chi-square statistics, or the Fisher’s exact test where appropriate.
Results:
A total of 169 patients who received liquid-biopsy for the purpose of detecting an EGFR mutation were enrolled in this assessment. The median patient age was 74 (range 37-95); 104 patients were male, 66 patients were never-smokers, 102 patients(58.3%) had been pathologically diagnosed with adenocarcinoma; 14 patients(8.3%) were both liquid-positive and tissue-positive for an EGFR mutation, 32 patients(18.9%) displayed a discrepancy, having a liquid-negative and a tissue-positive result, although no patients were liquid-positive and tissue-negative.(sensitivity, 33.3%; specificity, 100%) There were 20 patients who had an EGFR mutation detected by liquid-biopsy, and all patients with a liquid-positive result were either clinical stage 3B, 4, or in recurrence. There was a significant difference in the proportion of stage 3B, 4, and recurrent patients between liquid-positive and liquid-negative patients among EGFR mutated patients. (p<0.0001) Of all patients, 19 patients with a liquid-positive result, and 4 patients with a tissue-positive result alone, experienced EGFR-TKI therapy. There was no significant difference in the response rate to EGFR-TKIs between the liquid-positive and liquid-negative patients among EGFR mutated patients. (61.1% vs. 66.6%, p=0.684)
Conclusion:
This study demonstrated that liquid-biopsy indicates high specificity, and is available for detecting EGFR mutation in clinical practice. In addition, our institutional experience indicated that liquid-biopsy could be beneficial especially for patients who are unable to receive a tissue biopsy procedure for any reason. Although some patients had a discrepancy between the results of the liquid biopsy and the tissue-biopsy, advanced EGFR mutated NSCLC was highly detectable by liquid-biopsy. Further investigation is warranted to confirm the clinical benefit of liquid-biopsy.