Pulmonary neuroendocrine tumours and somatostatin receptor status: an assessment of unlicensed use of somatostatin analogues in the clinical practice

• Published in: ESMO open Vol. 7; no. 3; p. 100478
• Main Authors: Kiesewetter, B., Mazal, P., Kretschmer-Chott, E., Mayerhoefer, M.E., Raderer, M.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.06.2022; Elsevier
• Subjects: carcinoid; Original Research; pulmonary neuroendocrine tumours; somatostatin analogues; carcinoid; somatostatin analogues; pulmonary neuroendocrine tumours
• ISSN: 2059-7029; 2059-7029
• DOI: 10.1016/j.esmoop.2022.100478

The use of somatostatin analogues (SSAs) has not been formally approved in pulmonary neuroendocrine tumours (NETs) in the absence of positive controlled trials, even though it is recommended as a potential therapeutic option in recent guidelines. We have assessed the use of SSA in the general practice in Austria by retrospectively analysing patients with pulmonary NETs referred to our European Neuroendocrine Tumor Society centre in Vienna for second opinion or further therapy. In addition, we have analysed the somatostatin receptor (SSTR) expression of those patients by immunohistochemistry (IHC) and SSTR imaging, e.g. 68Ga-DOTANOC-positron emission tomography/computed tomography, and whether such analyses had been carried out before referral at our centre. Out of 34 patients (19 atypical and 15 typical carcinoids) with metastatic or advanced disease, 10/34 (29%) had been prescribed SSA before referral. No IHC for SSTR had been carried out, and only 9/34 (27%) had undergone SSTR imaging by nuclear medicine. Sufficient material for IHC was available in 29/34 (85%) patients and SSTR-IHC was rated negative in 13/29 (45%), weakly positive in 4/29 (14%), moderately positive in 5/29 (17%) and strongly positive in 7/29 (24%) patients. On SSTR imaging, 8/34 patients (24%) were positive, 13/34 (38%) negative and 13/34 patients (38%) showed a mix of positive and negative NET lesions. In 11/29 (38%) patients with both IHC and imaging available, discordance of SSTR expression on imaging and histological assessment was detected. These data show that uncritical use of SSA should be discouraged, and assessment of SSTR, preferably by imaging, is mandatory before prescription of SSA in pulmonary NETs. •SSAs are not formally approved in pulmonary NETs.•SSAs are recommended as a potential therapeutic option for advanced lung NETs in guidelines.•We assessed the use of SSAs for lung NET in the general practice in Austria.•Only 27% had undergone SSTR imaging before referral and receptor status was highly heterogeneous.•Our data emphasize that uncritical use of SSAs should be discouraged; assessment of SSTRs is recommended.