In:
Journal of the Endocrine Society, The Endocrine Society, Vol. 4, No. Supplement_1 ( 2020-05-08)
Kurzfassung:
Context. Somatostatin receptor type 5 (SST5), a target of pasireotide, is inconsistently expressed by corticotroph tumors. Somatic driver mutations in the ubiquitin-specific protease 8 (USP8) gene have been describes in 35% to 60% of corticotropinomas. SST5 expression has been found to be higher in USP8mut corticotropinomas. Objective. To study the correlation between clinical and biochemical characteristics of a large cohort of functioning and silent corticotroph tumor and SST5 expression or USP8 mutation status. To describe SST5 expression and the response to pasireotide in 5 patients. Design. Retrospective cohort study. Setting. University hospitals of Lyon. Patients. 62 patients operated for a corticotroph tumors between 2013 and 2017. Intervention. None. Main Outcome Measure. Clinical, biological, radiological and pathological data were evaluated depending on SST5 expression measured by immunohistochemistry (rabbit monoclonal antibody, clone UMB-4, Abcam). Membrane immune-positivity with an IRS & gt;1 was considered positive. USP8 analysis was performed by Sanger sequencing in 50 tumors. Results. SST5 expression was positive in 26 (41.9%) pituitary tumors. A moderate or strong IRS was found in 24.2% of the cohort and in 32.5% of the functioning pituitary tumors. Compared to SST5-negative pituitary tumors, those expressing SST5 were more frequent in women (92.3% vs 55.6%; p=0.002), fewer were silent (7.7% vs 58.3%; p & lt;0.001), smaller (7 vs 19mm; p=0.001) and less invasive (15.4% vs 44.4%; p=0.03). USP8 mutations were identified in 26% of the cohort and more frequent in functioning (n=11/30, 36.7%) compared to silent corticotroph tumors (n=2/20, 10%; p=0.05). SST5 expression was more frequent in USP8mut vs USP8neg tumors (58.8% vs 7.7%; p & lt;0.001). Among treated patients, normal urinary free cortisol (UFC) levels were obtained in 3 patients (IRS 0, 2, and 6) and a 4-fold decrease of UFC in one patient (IRS 4). Conclusion. SST5 expression seems to be associated with functioning, well-differentiated pituitary tumors and USP8 mutation. However, a correlation between SST5 expression or USP8mut and response to pasireotide treatment remains to be confirmed.
Materialart:
Online-Ressource
ISSN:
2472-1972
DOI:
10.1210/jendso/bvaa046.1669
Sprache:
Englisch
Verlag:
The Endocrine Society
Publikationsdatum:
2020
ZDB Id:
2881023-5
