Author of

• 25904

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  MA15 - Colliding Approaches - EGFR and Immunotherapy (ID 916)

  • Event: WCLC 2018
  • Type: Mini Oral Abstract Session
  • Track: Targeted Therapy
  • Presentations: 1
  • Moderators:
  • Coordinates: 9/25/2018, 13:30 - 15:00, Room 107

  • 26032

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    MA15.01 - Strong PD-L1 Expression Predicts Poor Response and de Novo Resistance to EGFR TKIs Among Non-Small Cell Lung Cancer Patients with EGFR Mutation (ID 12920)

    13:30 - 13:35  |  Author(s): Jian Su
    • Abstract
    • Presentation
    • Slides

    Background
    

    This study evaluated whether tumor expression of programmed death-ligand 1 (PD-L1) predicted the response of EGFR-mutated non-small cell lung cancer (NSCLC) to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs).

    a9ded1e5ce5d75814730bb4caaf49419 Method
    

    We retrospectively evaluated patients who received EGFR-TKIs for advanced NSCLC between April 2016 and September 2017 at the Guangdong Lung Cancer Institute. None of them were enrolled in clinical studies, and their EGFR and PD-L1 statuses were simultaneously evaluated.

    4c3880bb027f159e801041b1021e88e8 Result
    

    Among the 101 eligible patients, strong PD-L1 expression significantly decreased the objective response rate (ORR) compared with those with weak or negative PD-L1 expression (35.7% vs 63.2% vs 67.3%, P=0.002) as well as shortened progression-free survival (PFS, 3.8months vs 6.0months vs 9.5months, P<0.001), regardless of EGFR mutation types (19del or L858R). Furthermore, positive PD-L1 expression was predominantly observed among patients with de novo resistance rather than acquired resistance to EGFR-TKIs (66.7% vs 30.2%, P=0.009). Notably, patients with de novo resistance had a high proportion of dual positive for PD-L1 and CD8 (46.7%, 7/15). Finally, one patient with de novo resistance to EGFR-TKIs and dual positivity for PD-L1 and CD8 experienced a favorable response to anti-PD-1 therapy.

    8eea62084ca7e541d918e823422bd82e Conclusion
    

    This study uncovered the adverse impact of PD-L1 expression on the efficacy of EGFR- TKIs, especially in those with de novo resistance NSCLC, which inclined to reshape an inflamed immune phenotype of dual positive for PD-L1 and CD8 and showed potential therapeutic sensitivity to PD-1 blockade.

    6f8b794f3246b0c1e1780bb4d4d5dc53

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• 25938

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  P2.01 - Advanced NSCLC (Not CME Accredited Session) (ID 950)

  • Event: WCLC 2018
  • Type: Poster Viewing in the Exhibit Hall
  • Track:
  • Presentations: 1
  • Moderators:
  • Coordinates: 9/25/2018, 16:45 - 18:00, Exhibit Hall

  • 26813

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    P2.01-18 - Differential Molecular Mechanisms Associated with Dramatic and Gradual Progression in NSCLC Patients with Intrathoracic Dissemination (ID 12979)

    16:45 - 18:00  |  Author(s): Jian Su
    • Abstract
    • Slides

    Background
    

    Lung cancer is a highly heterogeneous disease with diverse clinical outcomes. The pleural cavity is a frequent metastasis site of proximal lung cancer. Better understanding of its underlining molecular mechanisms associated with dramatic and gradual progression of pleural metastasis in patients with non-small cell lung cancer (NSCLC) is essential for prognosis, intervention and new therapy development.

    a9ded1e5ce5d75814730bb4caaf49419 Method
    

    We performed whole-exome sequencing (WES) of matched primary lung adenocarcinoma and pleural metastatic tumors from 26 lung cancer patients with dramatic progression (DP, n=13) or gradual progression (GP, n=13). Somatic alterations at both genome-wide level and gene level were detected. Kaplan-Meier survival analysis and multivariate Cox regression models were applied to analyze the association between different somatic alterations and clinical parameters.

    4c3880bb027f159e801041b1021e88e8 Result
    

    We first analyzed the differences in somatic alterations between AP and RP group in the primary tumors, and identified higher somatic copy number alteration (SCNA) level in DP group compared to GP group, which is significantly (p=0.016) associated with poorer progression-free survival (PFS). More specifically, patients with chromosome 18q loss in the primary tumor showed a trend (p=0.107) towards poorer PFS. PTEN (p=0.002) and GNAS (p=0.002) mutations are enriched in the primary tumors of DP group, and are associated with poorer PFS. Furthermore, pleural metastatic tumors harbor a relatively higher level of mutation burden (p=0.105) and significantly increased SCNA (p=0.035) compared to the primary tumors.

    8eea62084ca7e541d918e823422bd82e Conclusion
    

    NSCLC patients in the attenuated progression group have more stable genomes. High level of genomic instability, GNAS and PTEN mutations, as well as chromosome 18q loss are associated with rapid progression.
    

    6f8b794f3246b0c1e1780bb4d4d5dc53

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