Somatostatin Receptors in Human Meningiomas—Clinicopathological Aspects

Abstract

Meningiomas have high recurrence rates despite frequently benign histopathological appearances. Somatostatin receptors (SSTRs) may be reliable biomarkers that could identify patients with increased risk of recurrence. Even though SSTRs are previously detected in meningiomas, their associations to clinicopathological features remain unclear. The aim of this study was to investigate the diagnostic and prognostic value of SSTRs in a large series of human meningiomas with long follow-up data. Immunohistochemistry was used to measure the expression of SSTR1-SSTR5 in tissue samples from 162 patients diagnosed with intracranial meningiomas of World Health Organization (WHO) grade 1 or 2. Digital scoring and a manual staining index were applied to assess immunoreactivity. All SSTRs, except SSTR4, were upregulated in our series of meningiomas. SSTR1 (p = 0.036), SSTR2 (p = 0.036) and SSTR5 (p = 0.029) were associated with a higher malignancy grade. SSTR2 presented as the most reliable marker. Only SSTR2 was associated with time to recurrence (TTR) in univariate Cox regression analyses. Manual staining index was strongly correlated with digital scoring for all SSTRs (r > 0.65, p < 0.001). SSTRs, and especially SSTR2, are useful in the diagnostics of meningiomas, even though their prognostic value appears limited. Digital scoring is valuable to ensure reproducibility.

Correlation of the apparent diffusion coefficient with the standardized uptake value in meningioma of the skull plane using [68]Ga-DOTATOC PET/MRI

“…Most importantly, a different radiotracer has to be utilized: Meningiomas are proven to express large quantities of somatostatin receptors (SSTR). In particular the receptors of the subtype two (SSTR 2 ) are expressed to a high degree in meningioma cells [24,25]. Thus, radiotracers based on octreotide analogues such as DOTATOC can be utilized to reliably quantify these receptors [26].…”

Meningiomas and Somatostatin Analogs: A Systematic Scoping Review on Current Insights and Future Perspectives

“…Lanreotide binds to SSTR5, but mainly to SSTR2 [46]. Even though SSTR2 is established as present in most meningiomas, the distribution of the other SSTRs differs between publications [20,21,47,48]. Hence, identification of different SSTRs within the tumor biology could help decide on the most efficient somatostatin analog and influence the treatment response.…”

“…Hence, the discovery of SSTRs in meningiomas led to prospering hope of targeted drug therapy [19][20][21]. Due to the potent effect and short half time of somatostatin, synthetic somatostatin analogs were developed for drug trials [22,23]; with octreotide, pasireotide and lanreotide as the most prominent.…”