Predictive and prognostic factors for treatment and survival in 305 patients with advanced gastrointestinal neuroendocrine carcinoma (WHO G3): the NORDIC NEC study.

BACKGROUND: As studies on gastrointestinal neuroendocrine carcinoma (WHO G3) (GI-NEC) are limited, we reviewed clinical data to identify predictive and prognostic markers for advanced GI-NEC patients. PATIENTS AND METHODS: Data from advanced GI-NEC patients diagnosed 2000-2009 were retrospectively registered at 12 Nordic hospitals. RESULTS: The median survival was 11 months in 252 patients given palliative chemotherapy and 1 month in 53 patients receiving best supportive care (BSC) only. The response rate to first-line chemotherapy was 31% and 33% had stable disease. Ki-67<55% was by receiver operating characteristic analysis the best cut-off value concerning correlation to the response rate. Patients with Ki-67<55% had a lower response rate (15% versus 42%, P<0.001), but better survival than patients with Ki-67≥55% (14 versus 10 months, P<0.001). Platinum schedule did not affect the response rate or survival. The most important negative prognostic factors for survival were poor performance status (PS), primary colorectal tumors and elevated platelets or lactate dehydrogenase (LDH) levels. CONCLUSIONS: Advanced GI-NEC patients should be considered for chemotherapy treatment without delay.PS, colorectal primary and elevated platelets and LDH levels were prognostic factors for survival. Patients with Ki-67<55% were less responsive to platinum-based chemotherapy, but had a longer survival. Our data indicate that it may not be correct to consider all GI-NEC as one single disease entity.

Characteristics of 252 patients with bronchopulmonary neuroendocrine tumours treated at the Copenhagen NET Centre of Excellence.

BACKGROUND: Bronchopulmonary neuroendocrine tumours are divided into typical carcinoid (TC), atypical carcinoid (AC), large cell neuroendocrine carcinoma (LCNEC), and small cell lung cancer (SCLC). AIM: To thoroughly describe a cohort of 252 patients with TC, AC and LCNEC (SCLC excluded). MATERIAL AND METHODS: Collection of data from 252 patients referred to and treated at Rigshospitalet 2008-2016. Data was collected from electronic patient files and our prospective NET database. Statistics were performed in SPSS. RESULTS: 162 (64%) had TC, 29 (12%) had AC and 61 (24%) had LCNEC. Median age at diagnosis was 69 years (range: 19-89) with no difference between genders. Thoraco-abdominal CT was performed in all patients at diagnosis. FDG-PET/CT was performed in 207 (82%) at diagnosis and was positive in 95% of the entire cohort, with no difference between tumour types. Synaptophysin was positive in 98%, chromogranin A in 92% and CD56 in 97%. Mean Ki67 index was 5% in TC, 16% in AC and 69% in LCNEC (p < 0.001). Metastatic disease was found in 4% of TC, 27% of AC and 58% of LCNEC at time of initial diagnosis (p < 0.001). In total 179 patients (71%) underwent surgical resection; TC: 87%, AC: 72% and LCNEC: 28% (p < 0.001). Of the resected patients, 11 (6%) had recurrence. Five-year survival rate was 88% for TC, 63% for AC and 20% for LCNEC. CONCLUSION: In this comprehensive study of a cohort of 252 patients, one of the largest until date, with TC, AC and LCNEC, the gender distribution showed female predominance with 68%. FDG-PET/CT was positive in 95% of the patients independent of tumour type, which confirms that FDG-PET/CT should be a part of the preoperative work-up for TC, AC and LCNEC. Tumour type was the single most potent independent prognostic factor.

Interventional treatment of neuroendocrine liver metastases.

Neuroendocrine gastroenteropancreatic tumours are rare with an incidence of 2-4/100.000 per year. More than 75% of the patients develop hepatic metastases, which reduce the five year survival from 70-80% to 30-40%. In addition to chemo- and biotherapy, interventional therapy of liver metastases should be considered in order to prolong survival and reduce endocrine and local symptoms. Surgical resection is the only curative treatment, but possible in less than 10% of the patients. Curative and palliative resection, which is possible in less than 20-25% of the patients, relieve endocrine and local symptoms in 90% of the patients for more than two years, and the five year survival is prolonged to 40-85%, although metastases recur or progress in almost all patients. Tumour ablation by radiofrequency therapy has a palliative effect on endocrine symptoms in 70-90% of the patients for up to two years, but should not be a substitute for surgical treatment. When metastases are not eligible for surgical treatment or ablation, embolization or chemoembolization are alternative options with a reduction in tumour burden in about 50% and a five year survival of around 60% ofthe patients. The symptomatic response rate is 90% with a mean duration of two years. Liver transplantation should be restricted to very few and highly selected patients without extrahepatic disease. Recurrence is inevitable in nearly all patients.

Results after surgical treatment of liver metastases in patients with high-grade gastroenteropancreatic neuroendocrine carcinomas.

BACKGROUND: Gastroenteropancreatic neuroendocrine carcinomas (GEP-NEC) are generally characterized by synchronous metastases, high aggressiveness and a dismal prognosis. Current international guidelines do not recommend surgical treatment of liver metastases, however the existing data are scarce. The aim of this study was to evaluate the results of curatively intended resection/radiofrequency ablation (RFA) of liver metastases in patients with metastatic GEP-NEC. METHODS: 32 patients with a diagnosis of high-grade gastroenteropancreatic neuroendocrine neoplasm (Ki-67 > 20%) and with intended curative resection/RFA of liver metastases, were identified among 840 patients from two Nordic GEP-NEC registries. Tumor morphology (well vs poor differentiation) was reassessed. Overall survival (OS) and progression-free survival (PFS) was assessed by Kaplan-Meier analyses for the entire cohort and for subgroups. RESULTS: Median OS after resection/RFA of liver metastases was 35.9 months (95%-CI: 20.6-51.3) with a five-year OS of 43%. The median PFS was 8.4 months (95%-CI: 3.9-13). Four patients (13%) were disease-free after 5 years. Two patients had well-differentiated morphology (NET G3) and 20 patients (63%) had Ki-67 ≥ 55%. A Ki-67 < 55% and receiving adjuvant chemotherapy were statistically significant factors of improved OS after liver resection/RFA. CONCLUSION: This study shows a long median and long term survival after liver surgery/RFA for these selected metastatic GEP-NEC patients, particularly for the group with a Ki-67 in the relatively lower G3 range. Our findings indicate a possible role for surgical treatment of liver metastases in the management of this patient population.

Gastrin-releasing peptide stimulation of corticotropin secretion in male rats.

Gastrin-releasing peptide (GRP; mammalian bombesin) may be involved in the neuroendocrine regulation of pituitary hormone secretion. We investigated the effect of GRP on ACTH secretion in conscious male rats. GRP (7-700 pmol) stimulated ACTH secretion dose-dependently after intracerebroventricular (icv) administration but had no effect after iv administration. GRP infused icv in a dose of 7 pmol, which alone increased ACTH 1.5-fold, potentiated the ACTH-releasing effect of arginine vasopressin (AVP; 80 pmol iv) and corticotropin-releasing hormone (CRH; 100 pmol iv). A higher dose of GRP (70 pmol icv), which stimulated ACTH secretion 2-fold, potentiated the effect of 80 and 400 pmol AVP iv, but had only additive effect on the ACTH response to 800 pmol AVP iv or 100 pmol CRH iv. GRP infused iv in a dose of 210 pmol, which in itself had no effect on ACTH secretion, potentiated the ACTH-stimulating effect of AVP and CRH approximately 2.5-fold. The effect of GRP (icv or iv) on AVP or CRH-stimulated ACTH release was only slightly smaller than the effect of combined administration of AVP and CRH (80 + 100 pmol iv). The ACTH-stimulating effect of GRP (700 pmol icv) was inhibited about 60% by pretreatment with either CRH or AVP antiserum and prevented by combined pretreatment with the antisera. The results indicate that: 1) GRP affects ACTH secretion indirectly at a suprapituitary level--possibly in the hypothalamus--by stimulating the release of AVP and CRH to the pituitary portal blood; and 2) GRP acts directly at the pituitary level to augment the effect of AVP and CRH on the corticotrophs. We suggest that GRP is involved in the multifactorial regulation of ACTH secretion.

Histamine as a neuroendocrine regulator of the stress-induced release of peripheral catecholamines.

The involvement of hypothalamic histaminergic neurons in the stress-induced release of peripheral catecholamines was studied in conscious, freely moving male rats. Blood samples were obtained via a catheter in a femoral artery. Intracerebroventricular infusion of histamine (HA; 30 micrograms) increased the plasma concentrations of norepinephrine (NE) and epinephrine (E) 3- and 9-fold, respectively. The plasma level of dopamine was not affected. The effect of HA was prevented by prior intracerebroventricular infusion of the H1-receptor antagonist mepyramine (100 micrograms) or the H2-receptor antagonist cimetidine (100 micrograms). Restraint stress applied for 5 min caused an immediate but transient increase in the plasma concentrations of NE and E which were increased 5- and 11-fold, respectively. The plasma level of dopamine was not altered significantly by restraint stress. The effect of stress on NE and E was almost prevented by prior icv infusion of mepyramine or cimetidine. The HA receptor antagonists had no effect on the basal plasma catecholamine level. We conclude that neuronal HA is an important mediator of the restraint stress-induced release of peripheral catecholamines by an action on H1- and H2-receptors within the central nervous system.

Dehydration stimulates hypothalamic gene expression of histamine synthesis enzyme: importance for neuroendocrine regulation of vasopressin and oxytocin secretion.

Dehydration associated with hyperosmolality and decreased extracellular volume stimulates arginine vasopressin (AVP) and oxytocin (OT) secretion from magnocellular neurons of the hypothalamus. The effects of hyperosmolality and decreased extracellular volume on the magnocellular neurons are mainly indirect and seem to be mediated centrally via several neurotransmitters and neuropeptides. Because histamine (HA), which serves as a central neurotransmitter, releases AVP and OT from the neurohypophysis when administered centrally, we investigated the possible role of HA in dehydration-induced AVP and OT secretion. To do this, we studied 1) the effect of dehydration on messenger RNA (mRNA) expression of the HA synthesis enzyme, histidine decarboxylase (HDC), in the tuberomammillary nucleus of the hypothalamus; and 2) the effect of HA synthesis inhibition during dehydration on AVP and OT mRNA expression in the supraoptic nucleus of the hypothalamus as well as on plasma AVP and OT levels. Forty-eight hours of dehydration increased the mRNA level of HDC in the tuberomammillary nuclei, whereas 24 h of dehydration had no effect. Pretreatment with the HA synthesis inhibitor alpha-fluoromethylhistidine (alpha FMH) increased the expression of HDC mRNA in 24-h dehydrated rats, but had no effect in euhydrated rats. In rats dehydrated for 48 h, the already increased level of HDC mRNA was not increased further by alpha FMH. Twenty-four and 48 h of dehydration increased AVP and OT mRNA levels in the supraoptic nucleus. This effect was inhibited by alpha FMH pretreatment. Dehydration increased the plasma levels of AVP and OT to an extent which depended on the duration of dehydration. Pretreatment with alpha FMH inhibited the hormone responses to 24 h of dehydration, but did not affect the responses to 48 h of dehydration. Twenty-four and 48 h of dehydration had no significant effect on the contents of AVP and OT in the neurohypophysis, whereas pretreatment with alpha FMH combined with 48 h of dehydration led to depletion of AVP stores in the neurohypophysis. Based on the present findings, we conclude that hypothalamic histaminergic neurons are involved in the regulation of dehydration-induced stimulation of magnocellular AVP and OT neurons.

Dehydration-induced release of vasopressin involves activation of hypothalamic histaminergic neurons.

The hypothalamic neurotransmitter histamine (HA) induces arginine vasopressin (AVP) release when administered centrally. We studied and characterized this effect of HA with respect to receptor involvement. In addition, we studied the possible role of hypothalamic histaminergic neurons in the mediation of a physiological stimulus (dehydration) for AVP secretion. Intracerebroventricular administration of HA, the H1-receptor agonists 2(3-bromophenyl)HA and 2-thiazolylethylamine, or the H2-receptor agonists amthamine or 4-methyl-HA stimulated AVP secretion. The stimulatory action of HA on AVP was inhibited by pretreatment with the H1-receptor antagonist mepyramine or the H2-receptor antagonist cimetidine. Twenty-four hours of dehydration elevated the plasma osmolality from 298 +/- 3 to 310 +/- 3 mmol/liter and increased the plasma AVP concentration 4-fold. The hypothalamic content of HA and its metabolite tele-methyl-HA was elevated in response to dehydration, indicating an increased synthesis and release of hypothalamic HA. Dehydration-induced AVP secretion was lowered when neuronal HA synthesis was inhibited by the administration of (S) alpha-fluoromethylhistidine or when the animals were pretreated with the H3-receptor agonist R(alpha)methylhistamine, which inhibits the release and synthesis of HA, the H1-receptor antagonists mepyramine and cetirizine, or the H2-receptor antagonists cimetidine and ranitidine. We conclude that HA, via activation of both H1- and H2-receptors, stimulates AVP release and that HA is a physiological regulator of AVP secretion.

Histaminergic activation of the hypothalamic-pituitary-adrenal axis.

Centrally administered histamine (HA) stimulates the secretion of adenohypophysial POMC-derived peptides, which subsequently cause release of corticosterone. The effect of HA on POMC-derived peptide release is indirect, and it is possible that hypothalamic neurons containing corticotropin-releasing hormone (CRH), arginine vasopressin (AVP), or oxytocin (OT) are involved in the mediation of this response. We studied the effect of HA on: 1) expression of CRH, AVP, and OT messenger RNA (mRNA) at the hypothalamic level; 2) expression of c-fos and POMC mRNA at the pituitary level; and 3) peripheral plasma levels of AVP, OT, ACTH, beta-endorphin (beta-END), and corticosterone. HA (270 nmol) infused intracerebroventricularly increased the expression of CRH, AVP, and OT mRNA in the paraventricular nucleus as well as that of OT mRNA in the supraoptic nucleus of the hypothalamus. At the pituitary level the expression of mRNA for c-fos and POMC increased in the anterior but not in the intermediate lobe in response to HA. Plasma levels of AVP, OT, ACTH, beta-END, and corticosterone all increased in response to central HA administration. Circulating levels of AVP and OT peaked after 5 min, ACTH and beta-END after 15 min, whereas corticosterone levels were highest after 30 min. In concert with our earlier discoveries, the present data support the hypothesis that HA-induced secretion of ACTH and beta-END is mediated via central activation of hypothalamic neuroendocrine neurons containing CRH, AVP, and/or OT.

Mediation of the stress-induced prolactin release by hypothalamic histaminergic neurons and the possible involvement of vasopressin in this response.

We investigated the role of histamine (HA) in the neuroendocrine regulation of PRL secretion in conscious male rats. Blood samples were obtained by decapitation of the animals at 0 min. Intracerebroventricular infusion of HA (34-540 nmol at -15 min) stimulated PRL secretion dose dependently with an ED50 of approximately 135 nmol. Inhibition of neuronal HA synthesis by the specific histidine decarboxylase-inhibitor (S)alpha-fluoro-methylhistidine (alpha FMH; 100 mumol/kg ip at -6 h or 400 mumol/kg ip at -20 h and -6 h) caused a 50% reduction (P less than 0.01) in the PRL response to 5 min of restraint stress. Inhibition of neuronal HA metabolism by the specific histamine-methyltransferase-inhibitor SKF-91488 (400 and 800 nmol icv at -20 min) augmented the restraint stress-induced PRL release 26% and 37%, respectively (P less than 0.05). The two enzyme inhibitors had no or only modest effect on the basal PRL secretion. Pretreatment with a specific antiserum (0.5 ml) to arginine vasopressin (AVP) or an AVP antagonist (25 nmol) administered iv at -20 min inhibited the PRL response to HA (270 nmol icv) 80% and 45%, respectively (P less than 0.01) and inhibited the PRL response to restraint stress 70% (P less than 0.01). In contrast, pretreatment with a specific oxytocin (OT) antagonist (50 nmol) had no effect on the HA- or stress-induced PRL release. The AVP antiserum showed less than 0.0003% cross-reactivity with OT, and radiolabeled OT did not bind to serial dilutions of plasma from rats treated with the AVP antiserum. The AVP antiserum or the AVP antagonist almost prevented the PRL release induced by iv infusion of 800 pmol AVP or a posterior pituitary extract. Infusion of AVP (24-800 pmol iv at -15 min) stimulated PRL secretion dose dependently. However, the dose of AVP (800 pmol) required to induce an increase in plasma PRL similar to that obtained by HA-stimulation, led to a rise in plasma AVP which was approximately 1000-fold higher than that induced by HA, which increased plasma AVP 2-fold. Restraint stress had no effect on the plasma AVP level. We conclude that neuronal HA participates in the mediation of the PRL response to stress and that the stress- and HA-induced release of PRL may involve AVP, whereas an involvement of OT seems unlikely.(ABSTRACT TRUNCATED AT 400 WORDS)

Histaminergic and catecholaminergic interactions in the central regulation of vasopressin and oxytocin secretion.

Activation of histaminergic and noradrenergic/adrenergic neurons in the brain stimulates the release of the neurohypophysial hormones arginine vasopressin (AVP) and oxytocin (OT) and are involved the mediation of the hormone responses to physiological stimuli such as dehydration and suckling. We therefore investigated whether the two neuronal systems interact in their regulation of AVP and OT secretion in conscious male rats. When administered intracerebroventricularly (i.c.v.), histamine (HA) as well as the H1 receptor agonist 2-thiazolylethylamine or the H2 receptor agonist 4-methylHA stimulated AVP and OT secretion. Prior i.c.v. infusion of antagonists specific to alpha or beta adrenergic receptors or their subtypes did not significantly affect the hormone response to HA or the histaminergic agonists. Infused i.c.v. norepinephrine (NE) or epinephrine (E) increased AVP and OT secretion. Prior i.c.v. infusion of the H1 receptor antagonist mepyramine or the H2 receptor antagonist cimetidine significantly inhibited the AVP and OT responses to NE and the AVP response to E, whereas only cimetidine inhibited the OT response to E significantly. Systemic pretreatment with imetit, which by activation of presynaptic H3 receptors inhibits neuronal synthesis and release of HA, decreased the AVP and OT responses to NE and E significantly. In the doses used, HA and E had no significant effect on mean arterial blood pressure. NE increased mean arterial blood pressure 10% at 1 and 2.5 min, whereafter the blood pressure returned to basal level within 10 min. The results indicate that noradrenergic and adrenergic neurons stimulate AVP and OT secretion via an involvement of histaminergic neurons, which may occur at magnocellular neurons in the supraoptic and paraventricular nuclei of the hypothalamus. The stimulatory effect of the amines on neurohypophysial hormone secretion seems to be independent of a central action on blood pressure. In contrast, a functionally intact noradrenergic and adrenergic neuronal system seems not to be a prerequisite for a HA-induced release of AVP and OT. The present findings further substantiate the role of histaminergic neurons in the central regulation of neurohypophysial hormone secretion.

Histamine stimulates c-fos expression in hypothalamic vasopressin-, oxytocin-, and corticotropin-releasing hormone-containing neurons.

The stimulatory action of centrally administered histamine (HA) on secretion of the anterior pituitary hormones ACTH, beta-endorphin, and PRL is indirect, and previous studies have suggested that hypothalamic neurons containing CRH, arginine vasopressin (AVP), and oxytocin (OT) are involved in this response. We studied the effect of HA on neuronal activation in the hypothalamus by investigating the expression of c-fos, which is a protooncogene activated early when neurons are stimulated. The expression of c-fos was evaluated by detection of c-fos immunoreactivity (c-fos-IR) using immunohistochemistry and by measurement of c-fos mRNA using in situ hybridization techniques. In addition, the identity of the HA-stimulated neurons was investigated by dual antigen immunohistochemistry visualizing AVP-, OT-, or CRH-IR in the neurons showing increased c-fos expression. HA (270 nmol) infused intracerebroventricularly increased c-fos-IR in the hypothalamus, especially in the periventricular hypothalamic areas and certain hypothalamic nuclei, including the paraventricular nucleus (PVN) and supraoptic nucleus (SON). c-fos-immunoreactive nuclei were observed throughout the SON, whereas in the PVN, c-fos-IR was particularly pronounced in the subnuclei known to contain AVP, OT, and CRH neurons. Double labeling experiments confirmed that c-fos was expressed in AVP-, OT-, and CRH-immunoreactive as well as other neurons. In addition, HA intracerebroventricularly induced a moderate expression of c-fos-IR in the arcuate nucleus. In situ hybridization showed increased levels of c-fos mRNA in both the PVN and SON after HA infusion. We conclude that HA-induced secretion of ACTH, beta-endorphin, and PRL may be mediated via activation of hypothalamic AVP, OT, and CRH neurons.

Insulin/hypoglycemia-induced adrenocorticotropin and beta-endorphin release: involvement of hypothalamic histaminergic neurons.

We have previously found that histamine (HA) is involved in the mediation of restraint- and ether stress-induced release of the POMC-derived peptides ACTH and beta-endorphin (beta-END). In the present study we investigated the possible involvement of hypothalamic histaminergic neurons in the mediation of insulin/hypoglycemia-induced release of ACTH and beta-END in conscious male rats. To do so, hypoglycemia stress was performed during 1) inhibition of HA synthesis, 2) activation of inhibitory presynaptic HA H3-auto-receptors, or 3) blockade of postsynaptic HA H1- or H2-receptors. Hypoglycemia (plasma glucose, 2.2 +/- 0.3 nmol) induced by insulin (3 IU/kg, ip) caused a 3- to 5-fold increase in the plasma concentrations of ACTH and beta-END. A negative exponential correlation was found between the plasma glucose concentration and the ACTH and beta-END levels. Pretreatment of the animals with the HA synthesis inhibitor alpha-fluoromethylhistidine (1.0 mumol) intracerebroventricularly (icv) in a lateral ventricle, inhibited the ACTH and beta-END responses to insulin/hypoglycemia by 60%. When administered ip (100 mumol/kg), the synthesis inhibitor decreased the beta-END response 50%, but did not affect ACTH secretion significantly. Pretreatment of the rats with the H3-receptor agonist R(alpha)methylhistamine (50 mumol/kg, ip, twice) inhibited the secretory responses of ACTH and beta-END to insulin/hypoglycemia by 60-80%. This inhibitory effect of R(alpha)methylhistamine was reversed by prior administration of the specific H3-receptor antagonist thioperamide. Administration of the H1-antagonists mepyramine and cetirizine dose-dependently inhibited the ACTH and beta-END responses to insulin/hypoglycemia, with the highest dose (mepyramine, 350 nmol, icv; cetirizine, 40 mumol/kg, ip) inhibiting the response by 80-100%. The H1-antagonist SKF-93944 (226 nmol, icv) inhibited the ACTH response, but had no effect on the beta-END response. Administration of the H2-antagonists cimetidine (400 nmol, icv) and ranitidine (400 nmol, icv) inhibited the ACTH and beta-END responses to insulin/hypoglycemia by 50-80%. We conclude that histaminergic neurons are involved in the mediation of the insulin/hypoglycemia-induced release of ACTH and beta-END and that the effect is mediated via activation of primarily postsynaptic H1-receptors and, to a lesser extent, H2-receptors.