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Aik-Choon Tan



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    P2.04 - Immunooncology (Not CME Accredited Session) (ID 953)

    • Event: WCLC 2018
    • Type: Poster Viewing in the Exhibit Hall
    • Track:
    • Presentations: 1
    • Moderators:
    • Coordinates: 9/25/2018, 16:45 - 18:00, Exhibit Hall
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      P2.04-15 - Heterogeneity and Correlation Between Immune Markers in Lung Cancers: Analysis of Treatment-Naïve Lesions (ID 11288)

      16:45 - 18:00  |  Author(s): Aik-Choon Tan

      • Abstract

      Background

      Immunotherapies are becoming a new standard of care for patients with lung cancers. Although a few immune-checkpoints are currently used as therapeutic targets and/or as predictive biomarkers, the complex correlation between immune-checkpoints is not well understood. Expression level of immune-checkpoint molecules is affected by numerous factors including tumor cells themselves, patients’ immunological characteristics, tumor microenvironment (metastatic sites), and previous treatments. To effectively investigate correlations of immune-checkpoints across multiple lesions, we analyzed gene expression data obtained from treatment-naïve autopsied patients.

      a9ded1e5ce5d75814730bb4caaf49419 Method

      Our cohort of 5 lung cancer patients included thirty specimens of both primary and metastatic lesions. RNA sequencing reads were mapped to the hg19 reference genome using the TopHat/Cufflinks workflow and transcripts were quantified using the FPKM method. Expression data for immune-checkpoints and total numbers of detected mutations were compared.

      4c3880bb027f159e801041b1021e88e8 Result

      We observed substantial inter-tumor heterogeneity in immune-checkpoint expression between lesions obtained from each patient. No consistent correlation was found by comparison of primary vs. metastatic lesions or between primary vs. specific metastatic sites. Evaluation of immune-checkpoints expressed by tumor cells and/or antigen presenting cells revealed a positive correlation between GAL9 and PD-L2 (R = 0.79) and GAL9 and HVEM (R = 0.69; Figure 1A). We also observed a strong correlation between these markers when lesions obtained from each patient were correlated to each other (Figure 1B and C). Comparisons between immune-checkpoints expressed by immune cells identified a positive correlation between PD-1 and LAG3 (R = 0.77). No correlation was found between immune-checkpoint expression and mutation burden.

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      8eea62084ca7e541d918e823422bd82e Conclusion

      We observed substantial inter-tumor heterogeneity in immune-checkpoints expression in each patient. We also found several positive correlations between immune-checkpoints which were consistent within the small cohort of patients. Further functional evaluation is warranted.

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