演題抄録

FACO International Workshop

開催概要
開催回
第53回・2015年・京都
 

Clinicopathological features of program death ligand-1 (PD-L1) expression and tumor-infiltrating lymphocytes (TILs) in advanced gastric cancer

演題番号 : FWS8-5

[筆頭演者]
Kawazoe Akihito:1 
[共同演者]
Kuwata Takeshi:1、Kuboki Yasutoshi:1、Nagatsuma Akiko:1、Shitara Kohei:1、Yoshino Takayuki:1、Doi Toshihiko:1、Ohtsu Atsushi:1、Ochiai Atsushi:1

1:National Cancer Center Hospital East

 

Background: Recently, anti-programmed death 1 (PD-1) antibody has shown promising results in phase I trial for patients with gastric cancer (GC). Although there have been no validated biomarkers of anti-PD-1 and its ligand (PD-L1) antibody, some reports have shown that PD-L1 expression and tumor-infiltrating lymphocytes (TILs) were associated with better clinical outcomes of PD-1/PD-L1 antibody in several malignancies. However, there is no detailed report on clinicopathological features of PD-L1 expression and TILs in a large cohort of GC including the evaluation of Epstein-Barr virus (EBV) status.
Patients and Methods: We performed a tissue microarray analysis in 487 patients with stage III and IV GC who underwent a gastrectomy without preoperative chemotherapy. Tumor membrane expression of PD-L1 and densities of TILs (CD3, CD4, CD8, and FOXP3) or EBV status were evaluated by immunohistochemistry or in situ hybridization, respectively.
Results: PD-L1 expression and EBV were detected in 22.8% and 5.1% of all cases, respectively. PD-L1 expression was more frequently observed in elderly (P = 0.002), male (P = 0.029), poorly differentiated adenocarcinoma (por1) (P < 0.001), and EBV-positive gastric cancer (P = 0.001). A strong association was observed between PD-L1 expression and high densities of CD3 (+), CD8 (+), and FOXP3 (+) TILs (P < 0.001). In multivariate analysis, high density of CD8 (+) TILs was significantly associated with better survival (hazard ratio, 0.62; 95% CI, 0.39 to 0.99; P = 0.047), while PD-L1 expression and densities of other subtypes of TILs were not independent prognostic factors.
Conclusion: PD-L1 expression in GC had some distinct clinicopathological features including EBV-positive status, which was also significantly associated with high densities of TILs. Impact of these characteristics on efficacy of anti-PD-1/PD-L1 antibody warrants further evaluation.

キーワード

臓器別:胃・十二指腸

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