Analysis of the inflammatory tumor microenvironment in meningeal neoplasms.

Abstract

BACKGROUND:

Properties of the inflammatory tumor microenvironment are associated with disease subtype, grade, and prognosis in various cancer entities. As immune-modulatory therapies are currently being explored in patients with meningeal neoplasms, we investigated their inflammatory microenvironment (meningiomas and solitary fibrous tumor/hemangiopericytoma (SFT/HPC)).

MATERIALS AND METHODS:

74 meningeal tumor specimens: (10/74 (13.5%) atypical meningioma; 8/74 (10.8%) anaplastic meningioma; 8/74 (10.8%) chordoid meningioma; 9/74 (12.2%) fibroblastic meningioma; 10/74 (13.5%) transitional meningioma; 3/74 (4.1%) rhabdoid meningioma; 7/74 (9.5%) meningothelial meningioma; SFT/HPC (19/74 (25.7%) were retrieved from the Neuro-Biobank, Medical University of Vienna, Austria.

RESULTS:

Tumor-infiltrating lymphocyte (TIL) infiltration could be observed in the majority of the investigated specimens (CD3+: 66/74 (89.2%); CD8+: 47/74 (63.5%); CD45RO+: 29/73 (39.2%); FOXP3+ 19/74 (25.7%); PD1+: 3/74 (4.1%). No difference in TIL infiltration was observed between SFT/HPC and meningioma cases. Higher density of FOXP3+ TILs was observed with increasing WHO grade in meningioma specimens (p = 0.005). Membranous programmed cell death ligand 1 (PD-L1) expression was observed in 4/74 (5.4%) specimens, with 3/74 (4.1%) presenting with 1% and 1/74 (1.4%) with 3% PD-L1 expressing tumor cells. Lymphatic vessels as identified by podoplanin immunohistochemistry were observed in 10/74 (13.5%) specimens and were significantly associated with presence of membranous PD-L1 expression on tumor cells (p = 0.003).

CONCLUSION:

Infiltration by various TIL subtypes can be observed in the majority of meningeal neoplasms, with enrichment of FOXP3-positive regulatory T-cells in higher-grade meningioma. PD-L1 expression on tumor cells was only infrequently found. A better understanding of the pathobiological role of the immune system in meningeal neoplasms may facilitate development of immunomodulatory treatment approaches in meningeal tumors.

• Authors: Anna Sophie Berghoff, Philip Kresl, Orsolya Rajky, Georg Widhalm, Gerda Ricken, Johannes A Hainfellner, Christine Marosi, Peter Birner, Matthias Preusser
• Journal: Clinical neuropathology (Clin Neuropathol) 2020 Nov/Dec Vol. 39 Issue 6 Pg. 256-262 ISSN: 0722-5091 [Print] Germany
• PMID: 32831157 (Publication Type: Journal Article)

Chemical References

• B7-H1 Antigen
• Biomarkers, Tumor
• FOXP3 protein, human
• Forkhead Transcription Factors

Topics

• Adult
• Aged
• B7-H1 Antigen (metabolism)
• Biomarkers, Tumor (analysis)
• Forkhead Transcription Factors (metabolism)
• Hemangiopericytoma (immunology, pathology)
• Humans
• Lymphocytes, Tumor-Infiltrating (immunology, metabolism, pathology)
• Male
• Meningeal Neoplasms (immunology, pathology)
• Meningioma (immunology, pathology)
• Middle Aged
• Solitary Fibrous Tumors (pathology)
• Tumor Microenvironment (immunology)