Virtual Library

Start Your Search

R. Rodriguez



Author of

  • +

    P1.03 - Poster Session with Presenters Present (ID 455)

    • Event: WCLC 2016
    • Type: Poster Presenters Present
    • Track: Radiology/Staging/Screening
    • Presentations: 1
    • +

      P1.03-006 - Quantification of PD-L1 Expression on Tumor Cells in Non-Small Cell Lung Cancer Using Non-Enzymatic Tissue Dissociation and Flow Cytometry (ID 5095)

      14:30 - 15:45  |  Author(s): R. Rodriguez

      • Abstract
      • Slides

      Background:
      Tumors use many mechanisms to evade the immune system, often manipulating pathways to evade cell death. The PD-L1/PD-1 pathway in particular, has become a promising target for immuno-oncology drug development. PD-L1/PD-1 therapy has been shown to be effective in patients with NSCLC, regardless of their PD-L1 expression profile by immunohistochemistry. This creates a challenge in determining potential responders from non-responders prior to treatment. The objective of this study was to develop a trulyquantitative technology for PD-L1 expression in NSCLC. In addition, we also present a non-enzymatic technology that creates a tumor cell suspension from fresh tumor tissue so that either FNA or fresh tissue can be used.

      Methods:
      4 mm punches were taken from each tumor. Non-enzymatic tissue homogenization (IncellPREP; IncellDx, CA) was performed. Cells were labeled with antibodies directed against CD45 and PD-L1, fixed and permeabilized then stained with DAPI to identify intact, single cells, and to analyze cell cycle.

      Results:
      We compared PD-L1 expression by flow cytometry using a 1% cut-off for positivity in the tumor cell population and a 1% cut-off of cells with at least 1+ intensity in immunohistochemically stained tissue sections as positive (Table 1). As demonstrated in the table, 10 of 12 lung tumor samples were concordant while 2 were discordant, one positive by flow and negative by IHC and one negative by flow and positive by IHC. PD-L1 expression by flow cytometry varied widely (1.2% to 89.4%) even in the positive concordant cases. In addition, PD-L1 expression in the aneuploid tumor population did not necessarily agree with the expression in the diploid tumor population. Figure 1



      Conclusion:
      Fine, unequivocal, quantification of PD-L1 on tumor and immune cells in NSCLC may allow for better prediction of response to therapies. The present study also offers a technology that can create a universal sample type from either FNA or fresh tissue.

      Only Active Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login or select "Add to Cart" and proceed to checkout.