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  P1.09 - Pathology (Not CME Accredited Session) (ID 941)

  • Event: WCLC 2018
  • Type: Poster Viewing in the Exhibit Hall
  • Track:
  • Presentations: 1
  • Moderators:
  • Coordinates: 9/24/2018, 16:45 - 18:00, Exhibit Hall

  • 26513

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    P1.09-12 - Simultaneous Platform of Genotyping EGFR, ALK, and ROS1 in Patients with NSCLC Highlights Correlation of ROS1 and PD-L1 Expression (ID 12719)

    16:45 - 18:00  |  Author(s): Jongmin Lee
    • Abstract
    • Slides

    Background
    

    ROS1oncogene rearrangement is targetable oncogene of non-small-cell cancer (NSCLC) and recently approved for crizotinib. Prior to drug approval, we integrated ROS1fluorescent in situ hybridization (FISH) screening test in our routine simultaneous genotyping platform. Furthermore, the frequency of overlap of above oncogenic aberration with programmed death ligand 1 (PD-L1) in routine clinical practice is not well known in Asian cohort.

    a9ded1e5ce5d75814730bb4caaf49419 Method
    

    Reflex simultaneous genomic screening panel of EGFRby PNA clamping, ALKand ROS1by FISH was performed on all NSCLCs at the time of pathologic diagnosis in our institution. PD-L1 22C3 assay kit was then integrated in our routine biomarker test panel. We retrospectively evaluated genetic aberration, clinicopathologic characteristics and PD-L1 status.

    4c3880bb027f159e801041b1021e88e8 Result
    

    Of 407 consecutive NSCLC patients, simultaneous genotyping identified 14 (3.4%) ROS1and 19 (4.7%) ALK rearrangements,106 (26%) EGFR(26%) mutations in tumors. All three genetic aberrations shared similar clinical features including younger age, female, adenocarcinoma, and advanced stage. PD-L1 assay was performed on 130 consecutive NSCLC samples. High PD-L1 expression ( 50%) was seen in 22.3% of tumors. PD-L1 expression (≥ 1%) was significantly associated with EGFR Wild typestatus, while ROS1rearrangement was associated with High PD-L1 TPS (≥ 50%). Of 14 cases with ROS1rearrangement, 5 (35.7%) showed High PD-L1 expression.

    8eea62084ca7e541d918e823422bd82e Conclusion
    

    In our routine simultaneous biomarker screening of NSCLCs, 22C3 PD-L1 high expression was frequently overlapped with ROS1rearrangement in comparison to its negative correlation with EGFRmutation. PD-L1 expression status may not be characterized according to status of oncogenic driver mutation.

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