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Haiyue Wang
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P1.07 - Immunology and Immunotherapy (ID 693)
- Event: WCLC 2017
- Type: Poster Session with Presenters Present
- Track: Immunology and Immunotherapy
- Presentations: 1
- Moderators:
- Coordinates: 10/16/2017, 09:30 - 16:00, Exhibit Hall (Hall B + C)
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P1.07-011 - PD-L1 Expression and CD8+ T Cell Infiltration Associate with the Prognosis of Pulmonary Neuroendocrine Tumor (ID 8595)
09:30 - 09:30 | Presenting Author(s): Haiyue Wang
- Abstract
Background:
For the past few years, the predictive role of programmed death-ligand 1 (PD-L1) for anti-PD1 immunotherapy in advance NSCLC has raised people’s attention. Tumor–infiltrating lymphocytes (TILs) are often observed in resected cancer tissue and anticipated in the host adaptive immune response against tumor cells as well. However, expression and the prognostic value of PD-L1 as well as CD8+ TILs in pulmonary neuroendocrine tumors (PNETs) have not been fully studied. The aim of our research is to investigate the status of PD-L1 expression and CD8+ TILs and to measure the prognostic value of PD-L1 and CD8+ TILs in different types of PNETs.
Method:
Totally 168 specimens of PNETs (36 TC, 7 AC, 100 SCLC, 25 LCNEC) were involved in this study. Immunohistochemistry (IHC) was used to detect the expression of PD-L1 on these cases. Cases demonstrating ≥ 5% tumor cell expression or any expression (>1%) of PD-L1 on TILs were considered positive. CD8+ TILs both within stroma and tumor areas of invasive carcinoma were analyzed using whole slide digital imaging. For each case, manual regional annotation and machine cell counts were taken. The number of positive cells has been evaluated by counting them in 4 peritumoral and 6 intratumoral non-overlapping fields using the fixed areas of 1.44 square milimeter.
Result:
PD-L1 was expressed on the membrane of tumor cells or immune cells of 72 cases (42.9%). Significant correlation was observed between CD8+ TILs and PD-L1 expression (P<0.001). For overall survival (OS) and progression free survival (PFS) analysis of PD-L1 as well as CD8+ TILs, there was no association between PD-L1 expression with OS and PFS, however, higher CD8+ TIL levels in stroma was demonstrated to have significant correlations with better OS (P=0.000) and PFS (P=0.020). Importantly, multivariate analysis revealed that CD8+ TILs in stroma was an independent prognostic factor for better OS (p=0.045) and PFS (p=0.006). In high grade NECs, similar analysis was performed and the result showed that positive expression of PD-L1 was associated with better OS (P=0.011) but not with PFS (P=0.383), in contrast, CD8+ TILs in stroma was proved to be an independent prognostic factor for both of OS (p=0.035) and PFS (p=0.005) as well.
Conclusion:
We found that PD-L1 was expressed in about half of PNETs and correlated with better OS in NECs. Higher CD8+ TIL levels within stroma was positively associated with PD-L1 expression and proved to be an independent prognostic factor for favorable OS and PFS in PNETs and NECs.
