New somatostatin molecule for management of endocrine tumours

A Proposed Classification System and Therapeutic Strategy for Chyle Leak After Laparoscopic Living-Donor Nephrectomy: A Single-Center Experience and Review of the Literature

OBJECTIVES

Chyle leak or chylous ascites remains a rare complication after laparoscopic living-donor nephrectomy. Its cause and management have not been well elucidated in the literature. Thus, the aim of this study was to review the incidence of chyle leak/chylous ascites after laparoscopic living-donor nephrectomy in our institute and in the literature to propose a classification system with its associated treatment strategy.

MATERILAS AND METHODS

In this retrospective review of laparoscopic living-donor nephrectomy patients from January 2005 to April 2016, we identified patients with chyle leak/chylous ascites along with the care performed. A proposed classification system based on our experience and literature is described.

RESULTS

Chylous leak developed in 4 donors (2.25%). Of the 4 donors, 3 were treated nonoperatively with diet modification and subcutaneous octreotide injection. One patient required surgical intervention after not responding to second-line therapy with total parenteral nutrition.

CONCLUSIONS

Chyle leak/chylous ascites after laparoscopic living-donor nephrectomy is rare, but a delayed diagnosis may lead to morbidity secondary to malnutrition and immunosuppression. Meticulous surgical dissection is essential to seal the lymphatic tubes during laparoscopic living-donor nephrectomy. The proposed classification system provides a practical and tailored guide to management based on the drainage volume of chyle leak and a guide to the earlier identification of refractory cases.

Underscoring the influence of inorganic chemistry on nuclear imaging with radiometals

Over the past several decades, radionuclides have matured from largely esoteric and experimental technologies to indispensible components of medical diagnostics. Driving this transition, in part, have been mutually necessary advances in biomedical engineering, nuclear medicine, and cancer biology. Somewhat unsung has been the seminal role of inorganic chemistry in fostering the development of new radiotracers. In this regard, the purpose of this Forum Article is to more visibly highlight the significant contributions of inorganic chemistry to nuclear imaging by detailing the development of five metal-based imaging agents: (64)Cu-ATSM, (68)Ga-DOTATOC, (89)Zr-transferrin, (99m)Tc-sestamibi, and (99m)Tc-colloids. In a concluding section, several unmet needs both in and out of the laboratory will be discussed to stimulate conversation between inorganic chemists and the imaging community.

Prevalence of gastritis in patients with acromegaly: untreated and during treatment with octreotide

OBJECTIVE

It has previously been suggested that acromegalic patients treated with the somatostatin analogue octreotide invariably have chronic gastritis. We have examined the prevalence of gastritis in a large group of acromegalic patients, untreated and during treatment with octreotide.

DESIGN

We studied three groups of acromegalic patients: (A) untreated; (B) octreotide-treated; (C) a subgroup of these studied both before and during octreotide therapy.

PATIENTS

Forty-eight patients, grouped as above, with active acromegaly were examined for the presence of gastritis.

MEASUREMENTS

Gastroscopy and histological examination of gastric biopsies for the presence of gastritis and Helicobacter organisms were undertaken. The principal outcome was quantification of the prevalence of gastritis in the various study groups.

RESULTS

Group A: 10 of the 33 patients (30%) had gastritis before any therapy with octreotide. Group B: 17 of 36 patients (47%) on octreotide treatment for 6-59 months (mean 20.5) had gastritis, and this was present in five out of the sub-group of eight patients (62%) treated for over 3 years. Group C: three of 21 patients (14%) developed gastritis during treatment with octreotide for between 6 and 23 months (mean 12.4). There was a highly significant association between the presence of gastritis and the presence of Helicobacter pylori organisms.

CONCLUSIONS

Octreotide therapy of acromegaly may predispose to the development of gastritis, but this remains statistically unproven. Certainly, gastritis is not an invariable consequence of octreotide therapy, even after prolonged periods of treatment. The presence of gastritis is associated with H. pylori infection.

Difficulties in localization and treatment of insulinomas in type 1 multiple endocrine adenomatosis (MEA)

A 15 year old girl with a family history of type 1 multiple endocrine adenomatosis presented with reversible neurological disturbances, hypoglycaemia and hyperinsulinaemia. Initial radiology was normal, but portal venous sampling suggested an insulinoma in the tail of the pancreas which was removed with conservation of the spleen. Hypoglycaemia persisted despite high doses of diazoxide and intravenous dextrose. A second laparotomy revealed a pancreatic endocrine tumour and sub-total pancreatectomy was performed. Histology revealed islet cell microadenomatosis. Hypoglycaemia persisted despite treatment with somatostatin analogues and 40% intravenous dextrose was required to maintain normoglycaemia. A possible lesion near the splenic hilum on computed tomographic scan was reported as a splenunculus although further peripheral, hepatic and portal venous sampling suggested hepatic or systemic lesions. A positron emission scan and selective visceral angiography suggested a lesion in the left upper quadrant. Acute lactic acidosis, rhabdomyolysis and renal failure supervened. Post mortem revealed the putative 'splenunculus' to be a residual insulinoma, whilst the splenic vein was thrombosed, accounting in part for discrepant venous sampling data. Hyperinsulinaemia in type 1 multiple endocrine adenomatosis may require more aggressive surgical and hormonal intervention than when dealing with solitary insulinomas. Insulinomas may mimic developmental abnormalities on computed tomographic scanning.

Octapeptide analogues of somatostatin inhibit the clonal growth and vasoactive intestinal peptide-stimulated cyclic AMP formation in human small cell lung cancer cells

Two endocrinologically active octapeptide analogues (BIM-23014 C and BIM-23034) of somatostatin (SRIF) containing either an N- or C-terminal 3-(2-naphthyl)-D-Ala residue were examined for their ability to inhibit the in vitro receptor binding, clonal growth, and vasoactive intestinal peptide (VIP)-stimulated cyclic AMP formation in human small cell lung cancer cell (SCLC) line NCI-H345. Both SRIF peptides inhibited [125I]SRIF(Tyr11)-14 binding with IC50 values in the low nM range. Colony formation in the in vitro SCLC growth assay was also inhibited in the same concentration range, as was VIP-stimulated cyclic AMP formation. Therefore, octapeptide analogues of SRIF function as SCLC SRIF receptor agonists.

The clinical use of somatostatin analogues in the treatment of cancer

Somatostatin is a regulatory hormone or tissue factor which plays an inhibitory role in the normal regulation of several organ systems, including the central nervous system, hypothalamus and pituitary gland, the gastrointestinal tract and the exocrine and endocrine pancreas. Sandostatin is an analogue of somatostatin which has characteristics which makes it a better compound for clinical use than native somatostatin: it inhibits GH preferentially over insulin. It has a long half-life in the circulation, causing a prolonged inhibitory effect in somatostatin-responsive target organs. It is active after subcutaneous administration and rebound hypersecretion does not occur. Sandostatin is very well tolerated by most patients. Somatostatin receptors remain present on a variety of tumours which arise in tissues that contain these receptors normally. High numbers of somatostatin receptors have been found on GH-secreting pituitary tumours and on most metastatic endocrine pancreatic tumours and carcinoids. Sandostatin treatment ameliorates clinical symptoms in most acromegalic patients while GH hypersecretion and elevated concentrations of circulating IGF-I are well controlled. In most patients hormonal hypersecretion from endocrine pancreatic tumours and carcinoids is also suppressed during Sandostatin therapy. This results in an instant improvement in the quality of life. There is preliminary evidence of control of tumour growth. The presence of high numbers of somatostatin receptors on tumours enables in vivo receptor-imaging, with 123iodine coupled to a somatostatin analogue. This newly developed technique provides for the first time the possibility of localization of the primary tumours and their metastases and a prediction of which patients may respond to treatment with Sandostatin. Theoretically this somatostatin-receptor imaging technique represents a new approach which may be extended to other receptor-containing tumours. Therefore it may provide a new, powerful alternative to tumour localization performed with monoclonal antibody technology. Another potential development is the use of beta-emitting isotopes coupled to somatostatin analogues for therapeutic irradiation. Somatostatin analogues exert potent inhibitory effects on the growth of a variety of experimental tumour models in animals. Several mechanisms of action have been proposed including the direct antiproliferative effects of somatostatin and its analogues in a variety of tumour cell cultures. Most well-differentiated human brain tumours like meningiomas and low-grade astrocytomas contain somatostatin receptors, while undifferentiated brain tumours mainly contain EGF receptors. Fifteen percent of human breast carcinomas contain somatostatin receptors; those which do have a better prognosis. It can be concluded that somatostatin is an endogenous, naturally occurring inhibitory growth factor.(ABSTRACT TRUNCATED AT 400 WORDS)

The relationship between somatostatin, epidermal growth factor, and steroid hormone receptors in breast cancer

The somatostatin (SS) and the epidermal growth factor (EGF) receptor content have been established in 36 primary breast cancers by receptor autoradiography on adjacent tissue sections. Iodine 125 (125I)-EGF was used as radioligand for EGF receptor visualization whereas an iodinated SS-28 analogue or an octapeptide SS analogue were used to measure SS receptors. Six of 36 tumors contained SS receptors, whereas ten of the 36 tumors were shown to contain EGF receptors. None of the tumor samples containing SS receptors were simultaneously EGF receptor positive. In contrast, all SS receptor-positive tumors simultaneously contained steroid receptors. The positive correlation between SS receptors and steroid receptors as well as the negative correlation between SS receptors and EGF receptors therefore suggest that the small percentage of SS receptor-positive breast tumors are a group of differentiated breast tumors with a good prognosis. In these cases, combined hormonetherapy including SS analogs may be of potential interest.

Coincidence of EGF receptors and somatostatin receptors in meningiomas but inverse, differentiation-dependent relationship in glial tumors

Somatostatin (SS) receptors as well as EGF receptors have been shown to be present in various brain tumors such as meningiomas or glia-derived tumors. Using receptor autoradiography for both receptors, their localization on adjacent tumor sections was investigated and a correlation was attempted. In glia-derived tumors, there was an inverse relationship for the incidence of the two receptors in individual tumors: in a majority of cases (five of eight) of well-differentiated astrocytomas (I-II), SS receptors were present, but in none of the cases (zero of eight) EGF receptors were detected. In undifferentiated glioblastomas, the reverse situation was observed, no SS receptors were found (0 of 14) but EGF receptors were present in a majority of tumors (8 of 14). In astrocytomas III both types of receptors were normally seen. These data suggest that in glia-derived tumors, SS receptors are markers for the well-differentiated cases as opposed to EGF receptors. In meningiomas, SS receptors are found in all (27 of 27) tumors and EGF receptors in a large percentage (23 of 27) of the same tumors. However, in some cases a coincidence of both receptors on the same cell can be excluded. Furthermore, no effect of the SS analog SMS 201-995 on basal or EGF-stimulated growth of meningiomas in culture could be detected. Nevertheless, the coexistence of the two receptor types in meningiomas may be suggestive for a potential functional interaction between EGF and SS.

Action of somatostatin analogue (SMS 201-995) on the growth-promoting effect resulting from sustained achlorhydria in rat gastric mucosa, with special reference to endocrine cell behaviour

We investigated whether a new long-acting somatostatin analogue (SMS 201-995) could antagonize the trophic effect induced by hypergastrinaemia, resulting from chronic omeprazole treatment, on the rat gastric mucosa and particularly on endocrine cell growth. SMS was administered concomitantly with omeprazole for 70 days. Gastric morphometric and cell proliferative parameters, gastric acid secretion and plasma gastrin levels were examined. New findings with omeprazole pointed out: (i) a trophic effect on the antral mucosa and (ii) that the increase observed in gastrin cell number was not due to stimulation of gastrin cell production by omeprazole but more likely to a prolongation of the gastrin cells' life span. As compared to omeprazole alone, simultaneous SMS administration significantly decreased the parietal cell (P less than 0.05) and gastrin cell (P less than 0.01) labelling indices, mucosal height of total glandular stomach (P less than 0.05) and antral mucosal height (P less than 0.05). It tended to lower fundic mucosal height and fundic argyrophil cell density (P less than 0.2 and P less than 0.1, respectively). SMS, in our conditions, did not accentuate the inhibitory effect of omeprazole on gastric acid secretion nor reduce high plasma gastrin levels. We conclude that SMS modestly counteracts the growth-promoting effect observed in rat gastric mucosa after prolonged omeprazole treatment.

High affinity binding of [125I-Tyr11]somatostatin-14 to human small cell lung carcinoma (NCI-H69)

The in vitro binding of [125I-Tyr11]somatostatin-14 (SRIF-14) to membranes prepared from cultured human small cell lung carcinoma (SCLC) cells (NCI-H69) has been characterized. Binding to SCLC was monophasic and of high affinity (Kd = 0.59 +/- 0.02 nM, n = 3). The estimated Bmax was 173 +/- 2.4 fmol/mg protein. Receptors were also present on solid NCI-H69 tumors grown in vivo in the athymic nude mouse. However, the concentration was only about 10% of that observed in cell culture. Biologically-active SRIF analogues were potent inhibitors of [125I-Tyr11]SRIF-14 binding, and an analysis of the pharmacological specificity indicated that the SCLC receptor was of the peripheral (e.g., non-neural) subtype. The presence of SRIF receptors on SCLC membranes may indicate that SRIF has a role in regulation of SCLC function.

Management of Zollinger-Ellison syndrome with gastric antisecretory drugs

Antisecretory drugs are major tools for management of the Zollinger-Ellison syndrome (ZES). Cimetidine was first used as a successful substitute of total gastrectomy. However with high dosage side effects and an escape from control were observed. As a more potent H2-receptor antagonist ranitidine has obvious advantages and is still largely used. Famotidine is more promising with a longer duration of action and given at lower dosages. Omeprazole could be considered as a treatment of choice with specific action on the proton pump and no side effects. However, with this drug the danger of permanent hypergastrinaemia being associated with fundic carcinoïd induction should be appreciated. Long-acting somatostatin has theoretical advantages in reducing simultaneously acid and gastrin secretion with a potential antitrophic effect. Larger studies are needed to precisely assess the therapeutic potential of the last three drugs.

Somatostatin, anaesthesia, and the carcinoid syndrome. Peri-operative administration of a somatostatin analogue to suppress carcinoid tumour activity

A patient with carcinoid syndrome on long-term antiserotonin therapy with parachlorophenylalanine, experienced a flushing attack with hypotension during the prophylactic administration of aprotonin prior to the induction of anaesthesia. When she was subsequently prepared with a long-acting somatostatin analogue, octreotide (Sandostatin, Sandoz SMS 201-995), plasma levels of tumour-released hormones were reduced and anaesthesia for resection of hepatic metastases was uneventful. The advantages of an anaesthetic approach based on inhibition of carcinoid tumour activity, rather than antagonism of released hormones, are discussed.

Clinical and hormonal effects of a long-acting somatostatin analogue in pancreatic endocrine tumors and in carcinoid syndrome

Nine patients with pancreatic apudomas (seven gastrinomas, one glucagonoma, one tumor secreting a substance P-like component) and nine with metastasized carcinoid tumors were treated with a somatostatin analogue (SMS 201-995), administered subcutaneously twice daily for 3 days. Treatment was pursued for 2 to 12 months in nine patients in whom SMS was clinically and/or biologically beneficial. In gastrinomas, SMS decreased plasma gastrin in all but one patient, inhibited the residual gastric acid secretion under H2-blockers and improved diarrhea; in the glucagonoma patient, glucagonemia decreased and skin lesions disappeared. In carcinoid syndrome, clinical efficacy was partial and inconstant; daily 5-hydroxyindole acetic acid (5-HIAA) output was slightly decreased. Plasma substance P levels decreased in six patients with initially high concentrations. No antitumoral activity or side effects have been so far evidenced. SMS 201-995 is a useful, well-tolerated agent in secreting pancreatic apudomas and to a lesser extent in carcinoid syndrome, where high-dosage regimens may be required.

Pharmacological studies of somatostatin and somatostatin-analogues: therapeutic advances and perspectives

This article is aimed at reviewing and analyzing studies that are related to the possible therapeutic use of a potent and ubiquitously-distributed hormone--somato-statin (SS-14), and its analogues. Administration of these substances has provided beneficial effects in treating acromegaly, gastro-intestinal hemorrhagic and hypersecretory disorders, acute pancreatitis, diabetes mellitus, and certain types of cancer. Further studies with SS-14-analogues might provide new therapies for treating certain life-threatening disorders of man.

Absorption of an aqueous solution of a new synthetic somatostatin analogue administered to man by gavage

To determine the local gastrointestinal absorption of a new synthetic somatostatin analogue (SMS 201-995 = Sandostatin), an intestinal tube was passed in eight healthy volunteers and on different days an aqueous solution was administered at four different locations: stomach, proximal duodenum, ligament of Treitz and jejunum. In a follow-up study, an oro-ileal tube was passed in six of the original volunteers and the drug solution was administered in to the terminal ileum. The aqueous solution of SMS was rapidly absorbed from the gastrointestinal tract after local application, and it was well tolerated. Absorption of the drug from the different sites was comparable, although there was a tendency to decreased peptide absorption after ileal administration. Absorption of the drug was quite variable between the subjects and the different locations. The dose-corrected systemic availability relative to subcutaneous administration in another study was 0.28%. However, significant plasma SMS concentrations were achieved, suggesting that oral delivery of the polypeptide may eventually be possible for long-term treatment of a variety of disorders.

Surgery for peptic ulceration associated with hypergastrinaemia

Between 1971 and 1983, 31 males and 13 females were found to have peptic ulceration associated with hypergastrinaemia. An antral G-cell lesion was present in 11 (25 per cent) and a gastrinoma in 14 (32 per cent). There were 11 patients with multiple endocrine adenomatosis (MEA) (25 per cent) and 4 (9 per cent) with primary hyperparathyroidism. Four patients (9 per cent) were unclassified. Length of history and level of gastrin did not differentiate between the groups and an average of 2.5 operations was performed per patient, while the overall mortality was 27.3 per cent. The patients with G-cell lesions were significantly younger than all the other groups (P less than 0.01). Partial gastrectomy adequately treated G-cell hyperplasia. Total gastrectomy was required to treat pancreatic gastrinomata but additional pancreatic resection did not improve the outcome. In MEA, parathyroidectomy did not influence the treatment of a gastrinoma. This is the first recorded experience of surgery for hypergastrinaemia in the United Kingdom and the outcome of such a retrospective study may be a guide to the future management of these conditions.