Shortened interval of long-acting octreotide administration is effective in patients with well-differentiated neuroendocrine carcinomas in progression on standard doses.

BACKGROUND: In patients with well-differentiated (WD) neuroendocrine tumors (NET), long-acting octreotide (LAR), conventionally administered at a dose of 30 mg every 28 days, has well-documented anti-secretive but limited antiproliferative effects. AIM: The objective of this study was to evaluate a different schedule of LAR treatment consistent with a shorter interval between administrations (21 days) in WDNET patients with progressive disease at standard-dose interval. SUBJECTS AND METHODS: Twenty-eight patients followed for diagnosis and therapy of WDNET who had tumor progression during therapy with LAR 30 mg every 28 days were enrolled. Clinical, biological, and objective tumor response was evaluated after LAR 30 mg every 21 days. Time to progression was also evaluated after LAR 30 mg every 21 days and compared to LAR 30 mg every 28 days. RESULTS: The treatment with LAR 30 mg every 21 days resulted in complete and partial control of clinical symptoms in 40% and 60% of cases, respectively. Circulating neuroendocrine markers were significantly decreased in 30% of cases. A stabilization of disease was obtained in 93% and objective response in 7%. The median time to progression was significantly longer by using the shortened interval of LAR administration as compared to the standard one (30 vs 9 months, p<0.0001). The treatment was safe and well tolerated. CONCLUSIONS: The shortened schedule of LAR administration was able to re-institute control of clinical symptoms, to decrease level of circulating neuroendocrine markers and to increase time to progression in patients previously escaping from a standard schedule treatment.

[Surgical treatment of well differentiated neuroendocrine tumours of the lung]. / Terapia chirurgica dei tumori neuroendocrini ben differenziati del polmone.

The bronchial tree represents the most frequent site of origin of carcinoids (around 25% of the total). The spectrum of differentiation of lung neuroendocrine tumors ranges from low-malignancy (carcinoids) to highly aggressive forms (small cell lung carcinoma) Diagnostic and therapeutic strategies therefore vary greatly. In well differentiated tumors (carcinoids) signs and symptoms are related to the airways obstruction in central forms, while peripheral forms are mostly discovered accidentally if asymptomatic. Clinical or subclinical paraneoplastic syndromes are associated in a minority of cases. Diagnostic work-up includes CT multislice, bronchial endoscopy and Octreoscan with chest Single Photon Emission Computed Tomography (SPECT). Further contribute may be added by the (68), Ga-DOTA-D-Phe(1)-Tyr(3)-ocreotide (DOTATOC) and 5-hydroxytryptophan (5-HTP) PET-CT, at present available only in a few centres, and by endobronchial ultrasound (EBUS), fluorescence bronchoscopy and virtual bronchoscopy. Surgery is the treatment of choice, while medical therapy is useful to treat the hypersecretion in paraneoplastic syndromes and to control tumor proliferation in metastatic or/and inoperable disease.

The biological characterization of neuroendocrine tumors: the role of neuroendocrine markers.

Neuroendocrine tumors (NET) may originate in different organs, from cells embryologically different but expressing common phenotypic characteristics, such as: the immuno-reactivity for markers of neuroendocrine differentiation (defined as "pan-neuroendocrine"), the capacity to secrete specific or aspecific peptide and hormones and the expression of some receptors, that are at the basis of the current diagnostic and therapeutical approach, peculiar to these tumors. NET have been conventionally distinguished in functioning, when associated with a recognized clinical endocrine syndrome, and non-functioning. However, this terminology may be misleading, since the great majority of NET may secrete neuroendocrine peptides, which can be employed as clinical markers for both diagnosis and follow-up. On the other hand, tissue immuno-reactivity for specific hormones does not always reflect secretory activity of the tumor cells. Finally, receptors and genetic markers are acquiring a relevant role in the characterization of NET, both improving knowledge of biology and physiopathology of NET, as well as in developing specific strategies to establish an early diagnosis and targeted therapies, to adopt prophylactic strategies in familial forms, and to identify more efficacious targets for therapy in the future.