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  P2.04 - Immuno-oncology (ID 167)

  • Event: WCLC 2019
  • Type: Poster Viewing in the Exhibit Hall
  • Track: Immuno-oncology
  • Presentations: 1
  • Moderators:
  • Coordinates: 9/09/2019, 10:15 - 18:15, Exhibit Hall

  • 31978

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    P2.04-57 - Predictive and Prognostic Value of CTC Monitoring in Advanced NSCLC Patients Treated with Immune Checkpoint Inhibitors (ID 1165)

    10:15 - 18:15  |  Author(s): Jiayu Li
    • Abstract

    Background
    

    Immune checkpoint inhibitors (ICI) have recently emerged as a treatment option for selected patients with advanced non-small-cell lung cancer (NSCLC). However, there is a lack of effective biomarker to predict the treatment response and monitor disease progression. In this prospective observational study, we aimed to investigate the predictive and prognostic value of folate receptor-positive circulating tumor cell (FR+CTC), a well-established lung cancer biomarker, in advanced NSCLC patients treated with ICIs.

    Method
    

    Advanced NSCLC patients with at least one measurable lesion and expected to undergo ICIs treatment were recruited. Peripheral blood samples were collected from each participant at baseline, after each cycle of ICI treatment, and on disease progression. FR+CTCs were enumerated by using negative enrichment and ligand-targeted polymerase chain reaction methods. Treatment efficacy was analyzed according to the iRECIST criteria. The correlation of FR+CTC level and its dynamic changes with radiological responses was evaluated.

    Result
    

    Of the 35 patients, 17 received first-line treatment, 10 received second-line treatment, and 8 received third-line treatment or above. CTCs were detected (≥8.7FU/3ml) in 80.0% of patients at baseline. The baseline CTC of first-line/second-line therapy patients was significantly higher than that of third-line and above therapy patients (median values 16.68 vs 8.36, P=0.017). Meanwhile, there was no significant difference in baseline CTC values between different pathological subtypes and whether PD-L1 was expressed or not. For the radiological responses, after at least two cycles of ICI treatment, PR, SD, and PD were found in 10, 8, and 4 patients, respectively. The CTC count in the PD group at baseline was significant higher than that of the disease control (PR+SD) group (P=0.033). Similarly, the CTC value after two cycles of ICI treatment in PD group (17.84 ± 7.03) was higher than SD/PR group (12.50 ± 4.94), but not statistically significant (P=0.081). However, the changes of CTCs after one or two cycles of immunotherapy were poorly related to the treatment response (P>0.05), perhaps because of the polarization trend of CTC changes in the PR group after treatment.

    Conclusion
    

    In sum, these data confirm the predictive significance of CTCs in advanced NSCLC patients treated with immune checkpoint inhibitors. The baseline CTCs value correlated significantly with radiological response. Further studies are needed to confirm whether CTCs can be used as a prognostic factor for advanced non-small cell lung cancer.