@article {SAITO107, author = {HIROAKI SAITO and YUSUKE KONO and YUKI MURAKAMI and YUJI SHISHIDO and HIROHIKO KURODA and TOMOYUKI MATSUNAGA and YOJI FUKUMOTO and TOMOHIRO OSAKI and KEIGO ASHIDA and YOSHIYUKI FUJIWARA}, title = {Highly Activated PD-1/PD-L1 Pathway in Gastric Cancer with PD-L1 Expression}, volume = {38}, number = {1}, pages = {107--112}, year = {2018}, publisher = {International Institute of Anticancer Research}, abstract = {Background: A recent study demonstrated that immune-checkpoint molecules are associated with tumoral immune evasion. Materials and Methods: Programmed cell death protein 1 (PD-1) expression on CD4+ and CD8+ T-cells obtained from gastric cancer tissue was evaluated by multicolor flow cytometry. Immunohistochemical staining was also performed to evaluate programmed cell death ligand-1 (PD-L1) expression on gastric cancer cells. Results: There were statistically significant correlations between PD-L1 expression and age, histology, tumor size, depth of invasion, lymph node metastasis, lymphatic vessel invasion, venous invasion, and disease stage. The 5-year survival rates of patients with and without PD-L1{\textendash}positive tumors were 48.9\% and 80.7\%, respectively, and the difference was statistically significant. Multivariate analysis indicated that PD-L1 expression was an independent prognostic indicator. The frequency of PD-1-positive CD4+ and CD8+ T-cells from gastric cancer tissue with PD-L1 expression was significantly more than that from gastric cancer tissue without PD-L1 expression. Conclusion: PD-L1 expression was related to a poor prognosis in patients with gastric cancer. Furthermore, PD-1 expression on T-cells was up-regulated in patients with tumors with PD-L1 expression.}, issn = {0250-7005}, URL = {https://ar.iiarjournals.org/content/38/1/107}, eprint = {https://ar.iiarjournals.org/content/38/1/107.full.pdf}, journal = {Anticancer Research} }