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Rui-Lian Chen
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P3.01 - Advanced NSCLC (ID 621)
- Event: WCLC 2017
- Type: Poster Session with Presenters Present
- Track: Advanced NSCLC
- Presentations: 1
- Moderators:
- Coordinates: 10/18/2017, 09:30 - 16:00, Exhibit Hall (Hall B + C)
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P3.01-063 - Concomitant EGFR Mutation and ALK Rearrangement in Non-Small-Cell Lung Cancer (ID 10058)
09:30 - 09:30 | Presenting Author(s): Rui-Lian Chen
- Abstract
Background:
The concomitance of epidermal growth factor receptor (EGFR) mutation and anaplastic lymphoma kinase (ALK) rearrangement defines a new molecular subtype of non-small-cell lung cancer (NSCLC). We investigated the factors associated with the efficacy of targeted therapy and resistance mechanisms in EGFR/ALK co-altered NSCLCs.
Method:
EGFR mutation was identified with direct sequencing or Scorpion amplification refractory mutation system (ARMS). Relatively low EGFR-mutant abundance is considered as sequencing (-)/ARMS (+), while high abundance as sequencing (+). ALK-positive is assessed with any of the 3 methods: fluorescence in situ hybridization (FISH), rapid amplification of cDNA ends -coupled polymerase chain reaction and sequencing or Ventana immunohistochemistry (IHC). Next-generation sequencing was employed to analyze genetic profiles in patients with specimens before and after targeted therapy.
Result:
From December 2011 to December 2016, sixteen patients were identified with concomitant EGFR/ALK co-alterations, accounting for 0.6% (16/2632) in NSCLC patients, 1.8% (16/867) in EGFR-mutant and 8.6% (16/185) in ALK-positive patients. Five ALK-IHC (-)/FISH (+)/EGFR (+) patients with EGFR-TKIs experienced 3 PR, 1 SD and 1 waitiing for response evaluation, with median PFS of 11 months. Three with relatively low EGFR-mutant abundance achieved PR with crizotinib, while three with relatively high EGFR-mutant abundance obtained 2 PR and 1 SD with EGFR-TKIs. Spatial and inter-tumoral heterogeneity was observed in one EGFR/ALK co-altered patient. (Figure 1B) Two patients with T790M, one with Met pathway activation and two with loss of EGFR mutation were found after resistance to EGFR-TKIs. One with KRAS mutation was found pre- and post-EGFR-TKIs. ALK_F1174C mutation was observed in one patient after progression to crizotinib and ALK_G1202R mutation after resistance to ceritinib.Figure 1
Conclusion:
ALK protein expression, EGFR mutation abundance and tumor heterogeneity were associated with efficacy of targeted treatment for EGFR/ALK co-altered patients. Most mechanisms resistance to EGFR-TKIs and crizotinib were similar to those in typical EGFR mutation and ALK rearrangement respectively.