Neuroendocrine neoplasms of the small intestine and the appendix — update of the diagnostic and therapeutic guidelines (recommended by the Polish Network of Neuroendocrine Tumours) [Nowotwory neuroendokrynne jelita cienkiego i wyrostka robaczkowego — uaktualnione zasady diagnostyki i leczenia (rekomendowane przez Polską Sieć Guzów Neuroendokrynnych)]

Abstract

Updated Polish recommendations for the management of patients with neuroendocrine neoplasms (NENs) of the small intestine (SINENs) and of the appendix (ANENs) are presented herein. The small intestine, and especially the ileum, is one of the most common locations for these neoplasms. Most of them are well-differentiated and slow-growing tumours; uncommonly -neuroendocrine carcinomas. Their symptoms may be untypical, and their diagnosis may be delayed or accidental. Most often, the first manifestation of ANEN is their acute inflammation. Typical symptoms of carcinoid syndrome occur in approximately 20-30% of SINENs patients with distant metastases. In laboratory diagnostics, it is most useful to determine the concentration of chromogranin A (CgA) and assessment of urinary or plasma the 5-hydroxyindoleacetic acid concentration is helpful in the diagnosis of carcinoid syndrome. The most commonly used imaging methods are ultrasound (US) examination, computed tomography (CT), magnetic resonance imaging (MRI), colonoscopy, and somatostatin receptor imaging (SRI). Histopathological examination is crucial for the proper diagnosis and treatment of patients with SINENs and ANENs. The treatment of choice is a surgical procedure, either radical or palliative. Long-acting somatostatin analogues (SSAs) are essential in the medical treatment of functional and non-functional SINENs. In patients with SINENs, at the stage of dissemination with progression during SSAs treatment, with high expression of somatostatin receptors on functional imaging, radioligand therapy should be considered first followed by targeted therapies -everolimus. Recommendations for patient monitoring are also presented.

Circulating Neuroendocrine Tumor Biomarkers: Past, Present and Future

“…In small intestine and pancreatic NEN, measuring CgA has a utility before introducing treatment and for monitoring. Additionally, in patients diagnosed with small intestine NEN, bronchopulmonary NEN or when suspecting carcinoid syndrome, it is recommended to measure 5-HIAA in urine (at least two samples, collected over 24 h period each) [ 8 , 161 , 162 ]. Though not a NET biomarker sensu stricto, the N-terminal prohormone of brain natriuretic peptide (NT-proBNP) should be measured for the diagnosis and monitoring of carcinoid heart disease in carcinoid syndrome patients [ 163 ].…”

The Risk of Venous Thromboembolism in Neuroendocrine Neoplasms

“…Hormonally active serotonin-producing NENs most often in the small intestine with metastases to the liver are associated with the development of carcinoid syndrome [9,52]. Elevated serotonin concentration leads to endothelial fibrosis, which may represent one of the thrombosis causative factors, however, this requires further study [15].…”

Association between Biomarkers (VEGF-R2, VEGF-R3, VCAM-1) and Treatment Duration in Patients with Neuroendocrine Tumors Receiving Therapy with First-Generation Somatostatin Analogues

“…For this reason, first-line therapy is systemic treatment with prolonged-acting somatostatin analogs (SSAs). SSA is the treatment for patients with functional (antisecretory effect) and non-functional NETs (NF-NETs) (antiproliferative effect as well as an anti-angiogenic action) [ 1 , 2 , 3 , 4 ]. SSAs reduce symptoms such as diarrhea; flush, by decreasing the secretion of biologically active substances and hormones and are used in NET patients with stable (SD) or progressive disease (PD) and a low proliferation index (Ki-67 ≤ 10%).…”