Details

Autor(en) / Beteiligte

• Nduom, Edjah K
• Wei, Jun
• Yaghi, Nasser K
• Huang, Neal
• Kong, Ling-Yuan
• Gabrusiewicz, Konrad
• Ling, Xiaoyang
• Zhou, Shouhao
• Ivan, Cristina
• Chen, Jie Qing
• Burks, Jared K
• Fuller, Greg N
• Calin, George A
• Conrad, Charles A
• Creasy, Caitlin
• Ritthipichai, Krit
• Radvanyi, Laszlo
• Heimberger, Amy B

Titel

PD-L1 expression and prognostic impact in glioblastoma

Ist Teil von

• Neuro-oncology (Charlottesville, Va.), 2016-02, Vol.18 (2), p.195-205

Ort / Verlag

England: Oxford University Press

Erscheinungsjahr

2016

Link zum Volltext

Quelle

Oxford Journals 2020 Medicine

Beschreibungen/Notizen

• Therapeutic targeting of the immune checkpoints cytotoxic T-lymphocyte-associated molecule-4 (CTLA-4) and PD-1/PD-L1 has demonstrated tumor regression in clinical trials, and phase 2 trials are ongoing in glioblastoma (GBM). Previous reports have suggested that responses are more frequent in patients with tumors that express PD-L1; however, this has been disputed. At issue is the validation of PD-L1 biomarker assays and prognostic impact. Using immunohistochemical analysis, we measured the incidence of PD-L1 expression in 94 patients with GBM. We categorized our results according to the total number of PD-L1-expressing cells within the GBMs and then validated this finding in ex vivo GBM flow cytometry with further analysis of the T cell populations. We then evaluated the association between PD-L1 expression and median survival time using the protein expression datasets and mRNA from The Cancer Genome Atlas. The median percentage of PD-L1-expressing cells in GBM by cell surface staining is 2.77% (range: 0%-86.6%; n = 92), which is similar to the percentage found by ex vivo flow cytometry. The majority of GBM patients (61%) had tumors with at least 1% or more PD-L1-positive cells, and 38% had at least 5% or greater PD-L1 expression. PD-L1 is commonly expressed on the GBM-infiltrating T cells. Expression of both PD-L1 and PD-1 are negative prognosticators for GBM outcome. The incidence of PD-L1 expression in GBM patients is frequent but is confined to a minority subpopulation, similar to other malignancies that have been profiled for PD-L1 expression. Higher expression of PD-L1 is correlated with worse outcome.