Abstract
Diffuse gliomas are classified according to the 2016 WHO Classification of Tumors of the Central Nervous System, which now defines entities by both histology and molecular features. Somatostatin receptor subtype 2A (SSTR2A) expression has been reported in various solid tumors as associated with favorable outcomes. Its expression has been reported in gliomas with uncertain results regarding its prognostic value. The objective of this study was to assess the prognostic impact of SSTR2A protein expression in a large cohort of grade III and IV gliomas classified according to the updated 2016 WHO classification. We further validated our result with an independent cohort of low grade glioma using dataset generated by The Cancer Genome Atlas (TCGA) Research Network.We analyzed clinical and molecular data from 575 patients. SSTR2A protein expression was evaluated using immunohistochemistry on tissue microarrays. High expression of SSTR2A protein associated with the anaplastic oligodendroglioma IDH-mutant and 1p/19q-codeleted subgroup (p < 0.001). Among these tumors, SSTR2A protein expression was significantly associated with a lower proliferative index, the absence of microvascular proliferation and the absence of necrosis (p < 0.001). Furthermore SSTR2A protein expression associated with better overall survival (p = 0.007) and progression-free survival (p = 0.01) in both univariate and multivariate analysis when adjusted by the age, the presence of necrosis and the mitotic index. Similar results were obtained regarding SSTR2 mRNA expression in the TCGA low grade glioma, subtype IDH-mutant and 1p/19q-codeleted, dataset.SSTR2A might represent an attractive biomarker and therapeutic target in anaplastic oligodendroglioma IDH-mutant and 1p/19q-codeleted specific subgroup. Understanding the implicated molecular pathways may represent a step forward to improve therapeutic approaches.
Highlights
Diffuse gliomas are the most common primary brain cancers. They are classified according to the 2016 WHO (World Health Organization) Classification of Tumors of the Central Nervous System (CNS), which combines for the first time histological and molecular
Scoring of Somatostatin receptor subtype 2A (SSTR2A) immunohistochemistry and its association with tumor entity Expression of SSTR2A was detected in 59% (337/575) of gliomas
Because of the inclusion criteria defined by the POLA network it is worth noticing that the percentage of each category in our study does not reflect the normal distribution of gliomas
Summary
Diffuse gliomas are the most common primary brain cancers. They are classified according to the 2016 WHO (World Health Organization) Classification of Tumors of the Central Nervous System (CNS), which combines for the first time histological and molecularAppay et al Acta Neuropathologica Communications (2018) 6:89 subgroups among gliomas belonging to the same histo-molecular category is crucial to open perspectives of therapeutic development.Somatostatin (SST), known as growth hormoneinhibiting hormone (GHIH), was first described in 1968 as a hormone secretion [18]. Diffuse gliomas are the most common primary brain cancers. They are classified according to the 2016 WHO (World Health Organization) Classification of Tumors of the Central Nervous System (CNS), which combines for the first time histological and molecular. SSTRs are commonly expressed on neuroendocrine tumors (NETs). In NETs, the expression of SSTR2A by tumor cells is of interest for both diagnostic and therapeutic strategy. Recent studies demonstrated that SST analogs can inhibit growth of SSTRs-dependent tumors by regulating intracellular signaling pathways, including dephosphorylation of actors implicated in the mitogen-activated protein kinase (MAPK) signaling and induction of apoptosis [13, 26, 32]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
