REFERENCES
1. Dong H, Strome SE, Salomao DR, Tamura J, Hirano F, Flie DB, Roche PC, Lu J, Zhu G, Tamada K, Lennon VA, Celis E, Chen L. Tumor-associated B7-H1 promotes T-cell apoptosis: a potential mechanism of immune evasion. Nat Med 2002;8:793-800.
2. Pardoll DM. The blockade of immune checkpoints in cancer immunotherapy. Nat Rev Cancer 2012;12:252-64.
3. Lu P, Youngblood BA, Austin JW, Mohammed AU, Butler R, Ahmed R, Boss JM. Blimp-1 represses CD8 T cell expression of PD-1 using a feed-forward transcriptional circuit during acute viral infection. J Exp Med 2014;211:515-27.
4. Qing Y, Li Q, Ren T, Xia W, Peng Y, Liu GL, Luo H, Yang YX, Dai XY, Zhou SF, Wang D. Upregulation of PD-L1 and APE1 is associated with tumorigenesis and poor prognosis of gastric cancer. Drug Des Devel Ther 2015;9:901-9.
5. Anagnostou VK, Brahmer JR. Cancer immunotherapy: a future paradigm shift in the treatment of non-small cell lung cancer. Clin Cancer Res 2015;21:976-84.
6. Xu F, Xu L, Wang Q, An G, Feng G, Liu F. Clinicopathological and prognostic value of programmed death ligand-1 (PD-L1) in renal cell carcinoma: a meta-analysis. Int J Clin Exp Med 2015;8:14595-603.
7. Hsu MC, Hsiao JR, Chang KC, Wu YH, Su IJ, Jin YT. Increase of programmed death-1-expressing intratumoral CD8 T cells predicts a poor prognosis for nasopharyngeal carcinoma. Mod Pathol 2010;23:1393-403.
8. Baptista MZ, Sarian LO, Derchain SF, Pinto GA, Vassallo J. Prognostic significance of PD-L1 and PD-L2 in breast cancer. Hum Pathol 2016;47:78-84.
9. Liu Y, Carlsson R, Ambjorn M, Hasan M, Badn W, Darabi A, Siesjo P. PD-L1 expression by neurons nearby tumors indicates better prognosis in glioblastoma patients. J Neurosci 2013;33:14231-45.
10. Thierauf J, Veit JA, Affolter A, Bergmann C, Grunow J, Laban S, Lennerz JK, Grunmuller L, Mauch C, Plinkert PK, Hess J, Hoffmann TK. Identifcation and clinical relevance of PD-L1 expression in primary mucosal malignant melanoma of the head and neck. Melanoma Res 2015;25:503-9.
11. Darb-Esfahani S, Kunze CA, Kulbe H, Sehouli J, Wienert S, Lindner J, Budczies J, Bockmayr M, Dietel M, Denkert C, Braicu I, Jöhrens K. Prognostic impact of programmed celldeath-1 (PD-1) and PD-ligand 1 (PD-L1) expression in cancer cells and tumor-infltrating lymphocytes in ovarian high grade serous carcinoma. Oncotarget 2016;7:1486-99.
12. Badoual C, Hans S, Merillon N, Ravel P, Benhamouda N, Levionnoks E, Besnier N, Gev A, Pere H, Tran T, Guerin CL, Chauvat A, Dransart E, Alanio C, Albert S, Bruneval P, Gridman WH, Lenoine FM, Oudard S, Johannes L, Olive D, Brasnu D, Tartour E. PD-1-expressing tumor-infiltrating T cells are a favorable prognostic biomarker in HPV-associated head and neck cancer. Cancer Res 2013;73:128-38.
13. Feng Z, Xiang LL, Hai TW, Zuo PW, Bao LH, Hai FZ, Xiao LW, Li L. Programmed cell death 1 expression in esophageal squamous cell carcinoma and association with clinical characteristics. Indian J Cancer 2015;52:176-8.
14. Wu P, Wu D, Li LJ, Chai Y, Huang J. PD-L1 and survival in solid tumors: a meta analysis. PLoS One 2016;10:e0131403.
15. Stang A. Critical evaluation of the Newcastle-Ottawa scale for the assessment of the quality of nonrandomized studies in meta-analyses. Eur J Epidemiol 2010;25:603-5.
16. Tierney JF, Stewart LA, Ghersi D, Burdett S, Sydes MR. Practical methods for incorporating summary time-to-event data into meta-analysis. Trials 2007;7:16-24.
17. Higgins JP, Thompson SG, Deeks JJ, Altaman DG. Measuring inconsistency in meta-analyses. BMJ 2003;327:557-60.
19. Mantel N, Haenszel W. Statistical aspects of the analysis of data from retrospective studies of disease. J Natl Cancer Inst 1959;22:719-48.
20. Begg CB, Mazumdar M. Operating characteristics of a rank correlation test for publication bias. Biometrics 1994;50:1088-101.
21. Egger M, Davey SG, Schneider M. Bias in meta-analysis detected by a simple, graphical test. BMJ 1997;315:629-34.
22. Zheng H, Liu X, Zhang JH, Shawn JR, Matthias W, Kong YX, Zhu LL, Zhu JJ, Monika J, Chandra PB. Expression of PD-1 on CD4+ T cells in peripheral blood associates with poor clinical outcome in non-small cell lung cancer. Oncotarget 2016;7:56233-40.
23. Shen T, Zhou L, Shen H, Shi C, Jia S, Ding G, Cao L. Prognostic value of programmed cell death protein 1 expression on CD8+ T lymphocytes in pancreatic cancer. Sci Rep 2017;7:7848-58.
24. Harter PN, Bernatz S, Scholz A, Zeiner PS, Zinke J, Kiyose M, Blasel S, Beschorner R, Senft C, Bender B, Ronellenfitsch MW, Wikman H, Glatzel M, Meinhardt M, Juratli TA, Steinbach JP, Plate KH, Wischhusen J, Weide B, Mittelbronn M. Distribution and prognostic relevance of tumor-infltrating lymphocytes (TILs) and PD-1/PD-L1 immune checkpoints in human brain metastases. Oncotarget 2015;6:40836-49.
25. Webb JR, Milne K, Nelson BH. PD-1 and CD103 are widely coexpressed on prognostically favorable intraepithelial CD8 T cells in human ovarian cancer. Cancer Immunol Res 2015;3:926-35.
26. Mittal D, Gubin MM, Schreiber RD, Smyth MJ. New insights into cancer immunoediting and its three component phases-elimination, equilibrium and escape. Curr Opin Immunol 2014;27:16-25.
27. Duchnowska R, Peksa R, Radecka B, Trojanwski T, Jarosz B, Olszewski WP, Och W, Kozłowski W, Kowalczyk A, Loi S, Biernat W, Jassem J; Polish Brain Metastasis Consortium. Immune response in breast cancer brain metastases and their microenvironment: the role of the PD-1/PD-L axis. Breast Cancer Res 2016;18:43-51.
28. Chen KY, Cheng GP, Zhang FR, Zhang N, Li D, Jin JY, Wu JZ, Ying LS, Mao WM, Su D. Prognostic significance of programmed death-1 and programmed death-ligand 1 expression in patients with esophageal squamous cell carcinoma. Oncotarget 2016;7:30772-80.
29. Muenst S, Soysal SD, Gao F, Obermann EC, Oertli D, Gillanders WE. The presence of programmed death 1 (PD-1)-positive tumor-infiltrating lymphocytes is associated with poor prognosis in human breast cancer. Breast Cancer Res Treat 2013;139:667-76.
30. Sun L, Liu AL, Ku JW, Wei Y, Liu S, Zhang DY. Programmed death 1 expression on tumor tissues correlates with prognosis in esophageal squamous cell carcinoma patients. Clin J Exp Surg 2015;32:1817-9.
31. Xu H, Lin G, Huang C, Zhu W, Miao Q, Fan X, Wu B, Zheng X, Lin X, Jiang K, Hu D, Li C. Assessment of concordance between 22C3 and SP142 immunohistochemistry assays regarding PD-L1 expression in non-small cell lung cancer. Sci Rep 2017;7:16956-7034.
32. Herbst RS, Soria JC, Kowanetz M, Fine GD, Hamid O, Gordon MS, Sosman JA, McDermott DF, Powderly JD, Gettinger SN. Predictive correlates of response to the anti-PD-L1 antibody MPDL3280A in cancer patients. Nature 2014;515:563-7.
33. He Y, Rozeboom L, Rivard CJ, Ellison K, Dziadziuszko R, Yu H, Zhou C, Hirsch FR. PD-1, PD-L1 protein expression in non-small cell lung cancer and their relationship with tumor-infiltrating lymphocyte. Med Sci Monit 2017;23:1208-16.
34. Hamanishi J, Mandai M, Iwasaki M, Okazaki T, Tanaka Y, Yamaguchi K, Higuchi T, Yagi H, Takakura K, Honjo T, Fujii S. Programmed cell death 1 ligand1 and tumor-infiltrating CD8+ T lymphocytes are prognostic factors of human ovarian cancer. Proc Natl Acad Sci U S A 2007;104:3360-5.
35. Nakano O, Sato M, Naito Y, Orikasa S, Aizawa M, Suzuki Y, Shintaku I, Nagura H, Ohtani H. Proliferative activity of intratumoral CD8(+)T-lymphocytes as a prognostic factor in human renal cell carcinoma: clinicopathologic demonstration of antitumor immunity. Cancer Res 2001;61:5132-6.
36. D'Angelo SP, Shoushtari AN, Agaram NP, Kuk D, Qin LX, Carvajal RD, Dickson MA, Gounder M, Keohan ML, Schwartz GK. Prevalence of tumor-infiltrating lymphocytes and PD-L1 expression in the soft tissue sarcoma microenvironment. Hum Pathol 2015;46:357-65.
37. Dai C, Lin F, Geng R, Ge X, Tang W, Chang J, Wu Z, Liu X, Lin Y, Zhang Z, Li J. Implication of combined PD-L1/PD-1 blockade with cytokine-induced killer cells as a synergistic immunotherapy for gastrointestinal cancer. Oncotarget 2016;7:10332-44.
38. Abdel RO. PD-L1 expression and outcome of advanced melanoma patients treated with anti-PD-1/PD-L1 agents: a meta-analysis. Immunotherapy 2016;8:1081-9.