Revisiting the usefulness of the short acute octreotide test to predict treatment outcomes in acromegaly

• Published in: Frontiers in endocrinology (Lausanne) Vol. 14; p. 1269787
• Main Authors: Marques-Pamies, Montserrat, Gil, Joan, Valassi, Elena, Hernández, Marta, Biagetti, Betina, Giménez-Palop, Olga, Martínez, Silvia, Carrato, Cristina, Pons, Laura, Villar-Taibo, Rocío, Araujo-Castro, Marta, Blanco, Concepción, Simón, Inmaculada, Simó-Servat, Andreu, Xifra, Gemma, Vázquez, Federico, Pavón, Isabel, García-Centeno, Rogelio, Zavala, Roxana, Hanzu, Felicia Alexandra, Mora, Mireia, Aulinas, Anna, Vilarrasa, Nuria, Librizzi, Soledad, Calatayud, María, de Miguel, Paz, Alvarez-Escola, Cristina, Picó, Antonio, Sampedro, Miguel, Salinas, Isabel, Fajardo-Montañana, Carmen, Cámara, Rosa, Bernabéu, Ignacio, Jordà, Mireia, Webb, Susan M, Marazuela, Mónica, Puig-Domingo, Manel
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 2023
• Subjects: acromegaly; Acromegaly - diagnosis; Acromegaly - drug therapy; Acromegaly - metabolism; acute octreotide test; Adenoma - drug therapy; Cadherins; Humans; individualized treatment; Octreotide - therapeutic use; Pituitary Neoplasms - metabolism; precision medicine; prediction; Somatostatin - therapeutic use; somatostatin analogs; Treatment Outcome; individualized treatment; prediction; precision medicine; acromegaly; somatostatin analogs; acute octreotide test
• ISSN: 1664-2392; 1664-2392
• DOI: 10.3389/fendo.2023.1269787

We previously described that a short version of the acute octreotide test (sAOT) can predict the response to first-generation somatostatin receptor ligands (SRLs) in patients with acromegaly. We have prospectively reassessed the sAOT in patients from the ACROFAST study using current ultra-sensitive GH assays. We also studied the correlation of sAOT with tumor expression of E-cadherin and somatostatin receptor 2 (SSTR2) . A total of 47 patients treated with SRLs for 6 months were evaluated with the sAOT at diagnosis and correlated with SRLs' response. Those patients whose IGF1 decreased to <3SDS from normal value were considered and those whose IGF1 was ≥3SDS, were considered . The 2 hours GH value (GH ) after s.c. administration of 100 mcg of octreotide was used to define predictive cutoffs. E-cadherin and SSTR2 immunostaining in somatotropinoma tissue were investigated in 24/47 and 18/47 patients, respectively. In all, 30 patients were responders and 17 were non-responders. GH was 0.68 (0.25-1.98) ng/mL in responders vs 2.35 (1.59-9.37) ng/mL in non-responders (p<0.001). GH = 1.4ng/mL showed the highest ability to identify responders (accuracy of 81%, sensitivity of 73.3%, and specificity of 94.1%). GH = 4.3ng/mL was the best cutoff for non-response prediction (accuracy of 74%, sensitivity of 35.3%, and specificity of 96.7%). Patients with E-cadherin-positive tumors showed a lower GH than those with E-cadherin-negative tumors [0.9 (0.3-2.1) vs 3.3 (1.5-12.1) ng/mL; p<0.01], and patients with positive E-cadherin presented a higher score of SSTR2 (7.5 ± 4.2 vs 3.3 ± 2.1; p=0.01). The sAOT is a good predictor tool for assessing response to SRLs and correlates with tumor E-cadherin and SSTR2 expression. Thus, it can be useful in clinical practice for therapeutic decision-making in patients with acromegaly.