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Z.Y. Dong
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P2.03 - Chemotherapy/Targeted Therapy (ID 704)
- Event: WCLC 2017
- Type: Poster Session with Presenters Present
- Track: Chemotherapy/Targeted Therapy
- Presentations: 1
- Moderators:
- Coordinates: 10/17/2017, 09:30 - 16:00, Exhibit Hall (Hall B + C)
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P2.03-054 - EGFR Mutation with Acquired C-MET Positive Reveals Potential Immunotherapeutic Vulnerabilities (ID 10436)
09:30 - 09:30 | Author(s): Z.Y. Dong
- Abstract
Background:
There are few effective strategies for C-MET positive advance non-small-cell lung cancer(NSCLC) patients with epidermal growth factor receptor(EGFR) inhibitor resistance.The efficacy of PD-1 blockade immunotherapy and even the status of PD-L1 expression in such population is unclear.
Method:
Patients diagnosed as advanced NSCLC synchronously tested for EGFR status, expression of PD-L1 and C-MET at the Guangdong Lung Cancer Institute (GLCI) from 2015 to 2017 were collected.PD-L1 expression on tumor cells and immune cell was evaluated using a three-tiered grading system. C-MET positive was define as immunohistochemistry staining (2+/3+) in ≥ 50% of tumor cells. A chi-squared test was used to assess the relationships between C-MET positive and PD-L1 expression.
Result:
A total of 487 eligible cases were selected including 166 EGFR mutant and 321 wild type patients.In the general population(n=487),the difference of PD-L1 expression were observed between C-MET positive group and C-MET negative group (65.3% vs 31.7%, P=0.001),which was in accordance with the result from the Cancer Genome Atlas (TCGA) dataset (n=512,P<0.001).Furthermore,among the EGFR mutant patients (n=166), PD-L1 expression was showed in 58.1% of C-MET positive group and 28.5% of C-MET negative group,P value <0.001. Subsequently,T790M negative was identified in 55%(47/86) of EGFR TKI resistant patients (n=86).In this subgroup,a significant increase of PD-L1 expression was demonstrated in C-MET positive group compared to C-MET negative group(66.7% vs 34.6%,P=0.027).Finally, clinical efficacy of immunotherapy was further confirmed in 2 C-MET positive advanced lung adenocarcinoma patients with remarkable response to PD-1 blockade immunotherapy who had disease progression after C-MET inhibitors.Figure 1
Conclusion:
C-MET positive maybe associated with high PD-L1 expression in advanced NSCLC providing therapeutic insight into targeting the PD-1/PD-L1 pathway in EGFR inhibitor-resistant NSCLC with C-MET positive and T790M negative.
