Concomitant inhibition of PI3K/mTOR signaling pathways boosts antiproliferative effects of lanreotide in bronchopulmonary neuroendocrine tumor cells

Introduction: Somatostatin analogues (SSAs) are commonly used in the treatment of hormone hypersecretion in neuroendocrine tumors (NETs), however the extent to which they inhibit proliferation is much discussed. Objective: We studied the antiproliferative effects of novel SSA lanreotide in bronchopulmonary NETs (BP-NETs). We focused on assessing whether pretreating cells with inhibitors for phosphatidylinositol 3-kinase (PI3K) and mammalian target for rapamycin (mTOR) could enhance the antiproliferative effects of lanreotide. Methods: BP-NET cell lines NCI-H720 and NCI-H727 were treated with PI3K inhibitor BYL719 (alpelisib), mTOR inhibitor everolimus and SSA lanreotide to determine the effect on NET differentiation markers, cell survival, proliferation and alterations in cancer-associated pathways. NT-3 cells, previously reported to express somatostatin receptors (SSTRs) natively, were used as control for SSTR expression. Results: SSTR2 was upregulated in NCI-H720 and NT-3 cells upon treatment with BYL719. Additionally, combination treatment consisting of BYL719 and everolimus plus lanreotide tested in NCI-H720 and NCI-H727 led to diminished cell proliferation in a dose-dependent manner. Production of proteins activating cell death mechanisms was also induced. Notably, a multiplexed gene expression analysis performed on NCI-H720 revealed that BYL719 plus lanreotide had a stronger effect on the downregulation of mitogens than lanreotide alone. Discussion/Conclusion: We report a widespread analysis of changes in BP-NET cell lines at the genetic/protein expression level in response to combination of lanreotide with pretreatment consisting of BYL719 and everolimus. Interestingly, SSTR expression reinduction could be exploited in therapeutic and diagnostic applications. The overall results of this study support the evaluation of combination-based therapies using lanreotide in preclinical studies to further increase its antiproliferative effect and ultimately facilitate its use in high-grade tumors.

Non-Surgical Interventions for the Prevention of Clinically Relevant Postoperative Pancreatic Fistula-A Narrative Review

Clinically relevant postoperative pancreatic fistula (CR-POPF) is the leading cause of morbidity and mortality after pancreatic surgery. Post-pancreatectomy acute pancreatitis (PPAP) has been increasingly understood as a precursor and exacerbator of CR-POPF. No longer believed to be the consequence of surgical technique, the solution to preventing CR-POPF may lie instead in non-surgical, mainly pharmacological interventions. Five databases were searched, identifying eight pharmacological preventative strategies, including neoadjuvant therapy, somatostatin and its analogues, antibiotics, analgesia, corticosteroids, protease inhibitors, miscellaneous interventions with few reports, and combination strategies. Two further non-surgical interventions studied were nutrition and fluids. New potential interventions were also identified from related surgical and experimental contexts. Given the varied efficacy reported for these interventions, numerous opportunities for clarifying this heterogeneity remain. By reducing CR-POPF, patients may avoid morbid sequelae, experience shorter hospital stays, and ensure timely delivery of adjuvant therapy, overall aiding survival where prognosis, particularly in pancreatic cancer patients, is poor.

Dumping Syndrome: Pragmatic Treatment Options and Experimental Approaches for Improving Clinical Outcomes

Dumping syndrome is a common complication after esophageal, gastric and bariatric surgery and has a significant negative impact on the quality of life of patients. This narrative review describes the clinical syndrome, pathophysiology, diagnosis and reports on standard and pragmatic therapeutical treatment options in order to improve the clinical outcome of patients with dumping syndrome. Dumping syndrome consists of early and late dumping symptoms and can be diagnosed using clinical parameters with the help of the Sigstad's score, questionnaires or by provocative testing. The prevalence of dumping syndrome varies depending on the employed definition of dumping syndrome. Overall, dumping syndrome is more frequent nowadays due to increasing numbers of upper gastrointestinal and bariatric surgeries being performed. First treatment step includes dietary adjustment and dietary supplements, which are often sufficient to manage symptoms for the majority of patients. Next step of therapy includes acarbose, which is effective for late dumping symptoms, but the use is limited due to side effects. Somatostatin analogues are indicated after these two steps have failed. Somatostatin analogues are very effective for controlling early and late dumping, also in the long term. Glucagon like peptide-1 receptor agonists, endoscopic and surgical (re)interventions are reported as treatment options for refractory dumping syndrome; however, their use is not recommended in clinical practice due to the limited evidence on and uncertainty of outcomes. These alternatives should be considered only as last resort options in patients with otherwise refractory and invalidating dumping syndrome.

Questionnaire PLD-complaint-specific assessment identifies need for therapy in polycystic liver disease: A multi-centric prospective study

BACKGROUND AND AIMS

Polycystic liver disease (PLD) can lead to extensive hepatomegaly. Symptom relief is the primary goal of the treatment. The role of the recently developed disease-specific questionnaires for identification of the thresholds and the assessment of therapy needs further investigation.

METHODS

A five-year prospective multi-centric observational study in 21 hospitals in Belgium gathered a study population of 198 symptomatic PLD-patients of whom the disease-specific symptom questionnaire PLD-complaint-specific assessment (POLCA) scores were calculated. The thresholds of the POLCA score for the need for volume reduction therapy were analyzed.

RESULTS

The study group consisted of mostly (82.8%) women with baseline mean age of 54.4 years ±11.2, median liver volume expressed as height-adjusted total liver volume(htLV) of 1994 mL (interquartile range [IQR] 1275; 3150) and median growth of the liver of +74 mL/year (IQR +3; +230). Volume reduction therapy was needed in 71 patients (35.9%). A POLCA severity score (SPI) ≥ 14 predicted the need for therapy both in the derivation (n = 63) and the validation cohort (n = 126). The thresholds to start somatostatin analogues (n = 55) or to consider liver transplantation (n = 18) were SPI scores of ≥14 and ≥ 18 and the corresponding mean htLVs were 2902 mL (IQR 1908; 3964) and 3607 mL (IQR 2901; 4337), respectively. Somatostatin analogues treatment resulted in a decrease in the SPI score -6.0 versus + 4.5 in patients without somatostatin analogues (p < 0.01). Changes in the SPI score were significantly different between the liver transplantation group and no liver transplantation group, +4.3 ± 7.1 versus -1.6 ± 4.9, respectively, (p < 0.01).

CONCLUSION

A polycystic liver disease-specific questionnaire can be used as a guide on when to start a volume reduction therapy and to assess the effect of treatment.

Risk of depression in patients with acromegaly in Korea (2006-2016): a nationwide population-based study

BACKGROUND

An increased prevalence of depression has been reported in patients with acromegaly. However, most studies included a relatively small sample size owing to the rarity of acromegaly. We aimed to investigate the risk of depression in patients with acromegaly using the Korean National Health Information Database (NHID).

METHODS

The data of patients with acromegaly in 2006-2016 were collected from the rare incurable disease registry of the NHID. Patients with acromegaly were matched with control participants without acromegaly for age and sex in a 1:5 ratio.

RESULTS

Patients who did not receive treatment for acromegaly had a significantly increased risk of depression (hazard ratio [HR]: 1.43, 95% confidence interval [CI]: 1.12-1.82). However, the risk of depression did not increase in patients who received treatment for acromegaly. The multiple Cox regression analysis showed that the risk of depression was significantly higher in the untreated group than in the control group during the first 3 years of observation (HR: 1.829, 95% CI: 1.305-2.563). However, after a time lag of over 3 years, the risk of depression decreased in the untreated group, which is similar to that in the control group.

CONCLUSION

Our nationwide study suggests that patients who did not receive treatment for acromegaly have a higher risk of depression compared with controls. The untreated acromegaly patients should be monitored for the development of depression, especially in the early years after diagnosis. These results could serve as a basis for developing screening strategies to mitigate depression in acromegaly patients.

Molecular Theranostics in Radioiodine-Refractory Differentiated Thyroid Cancer

Differentiated thyroid cancer (DTC) is the most common subtype of thyroid cancer and has an excellent overall prognosis. However, metastatic DTC in certain cases may have a poor prognosis as it becomes radioiodine-refractory. Molecular imaging is essential for disease evaluation and further management. The most commonly used tracers are [18F]FDG and isotopes of radioiodine. Several other radiopharmaceuticals may be used as well, with different diagnostic performances. This review article aims to summarize radiopharmaceuticals used in patients with radioiodine-refractory DTC (RAI-R DTC), focusing on their different molecular pathways. Additionally, it will demonstrate possible applications of the theranostics approach to this subgroup of metastatic DTC.

Small Bowel Neuroendocrine Tumors-10-Year Experience of the Ottawa Hospital (TOH)

(1) Aim: The prevalence and incidence of small bowel NETs have increased significantly over the past two decades. This study aims to report the 10-year experience of SB-NET management at a regional cancer center in Canada. (2) Materials and methods: We conducted a retrospective study of the clinical and pathological data of patients diagnosed with biopsy-proven SB-NET at The Ottawa Hospital (TOH), Ottawa, Canada between 2011 and 2021. We report the clinicopathological characteristics of these patients, as well as their outcomes data, including survival rates. (3) Results: Between 2011 and 2021, a total of 177 SB-NET cases were identified with 51% (n = 91) of cases being males. The most common sites of the tumors were the ileum 53% (n = 94), followed by the duodenum 9% (n = 16) and jejunum 7% (n = 12). Approximately 24% (n = 42) of the patients had symptoms for over six months prior to diagnosis and 18% (n = 32) had functioning SB-NET during the course of the disease. The majority of patients had locally advanced or metastatic disease at the time of presentation with stage III, and stage IV representing 42% (n = 75), and 41% (n = 73) respectively. The majority of patients 84% (n = 148) had well-differentiated histology. One hundred twenty patients underwent surgical resection of the primary tumor including 28 patients (16%) with limited metastatic disease. A total of 21 patients (18%) had recurrence after curative surgery. A total of 62 patients (35%) received first-line somatostatin analog (SSA) therapy for unresectable disease and seven patients had PRRT after progression on SSA. Five years OS was 100%, 91%, 97%, and 73% for stages I, II, III, and IV respectively. In univariate analysis, carcinoid symptoms, T stage, and differentiation were significant predictors for worse overall survival, but not RFS. (4) Conclusions: Compared to published historical controls, our study suggests improvement in the 5-year survival rate of SB-NETs over the last 10 years.

Small Bowel Bleeding: Clinical Diagnosis and Management in the Elderly

INTRODUCTION

With the global increase in life expectancy, there is an increase in gastrointestinal presentations in the elderly. Small bowel bleeding (SBB) is a cause of significant morbidity in the elderly requiring multiple hospital visits, investigations and potentially expensive therapy.

AREAS COVERED

In this review we will outline the different modalities which are used for the diagnosis and management of SBB. We will also discuss the common causes of SBB in the elderly.

EXPERT OPINION

SBB in elderly has a significant impact on the quality of life of the elderly. Larger randomized studies in the elderly are urgently required to help guide clinicians on the best and most cost-effective treatment algorithm in this challenging cohort.

Tumour Heterogeneity and the Consequent Practical Challenges in the Management of Gastroenteropancreatic Neuroendocrine Neoplasms

Tumour heterogeneity is a common phenomenon in neuroendocrine neoplasms (NENs) and a significant cause of treatment failure and disease progression. Genetic and epigenetic instability, along with proliferation of cancer stem cells and alterations in the tumour microenvironment, manifest as intra-tumoural variability in tumour biology in primary tumours and metastases. This may change over time, especially under selective pressure during treatment. The gastroenteropancreatic (GEP) tract is the most common site for NENs, and their diagnosis and treatment depends on the specific characteristics of the disease, in particular proliferation activity, expression of somatostatin receptors and grading. Somatostatin receptor expression has a major role in the diagnosis and treatment of GEP-NENs, while Ki-67 is also a valuable prognostic marker. Intra- and inter-tumour heterogeneity in GEP-NENS, however, may lead to inaccurate assessment of the disease and affect the reliability of the available diagnostic, prognostic and predictive tests. In this review, we summarise the current available evidence of the impact of tumour heterogeneity on tumour diagnosis and treatment of GEP-NENs. Understanding and accurately measuring tumour heterogeneity could better inform clinical decision making in NENs.

Diagnosis and management of neuroendocrine tumours

Neuroendocrine tumours (NETs) represent a heterogenous group of tumours, with diversity in their primary tumour sites, functional status (ie hormone secreting or non-functional) and degrees of aggressiveness (ranging from well-differentiated, grade 1 neuroendocrine tumours to poorly differentiated grade 3, neuroendocrine carcinomas). The most common sites are the lung, small bowel, pancreas and appendix. Clinical presentation is variable, ranging from incidental lesions detected on cross-sectional imaging, small bowel obstruction, carcinoid syndrome or other syndromic presentations (eg hypoglycaemia resulting from insulinoma) through to florid carcinoid heart disease. Diagnosis relies on biochemical markers, computed tomography (CT), magnetic resonance imaging (MRI) and somatostatin-receptor based functional imaging. Treatment comprises surgery where curative resection is possible through to approaches where disease stabilisation is the key, involving somatostatin analogues, peptide receptor radionuclide therapy (PRRT), everolimus, sunitinib, liver-directed therapies and sometimes chemotherapy. Although local and systemic complications can occur, they are associated with reasonable 5- and 10-year survival rates, respectively.

Treatment efficacy in a metastatic small intestinal neuroendocrine tumour grade 2 cohort

Small intestinal neuroendocrine tumours (Si-NET) are often studied as a uniform group. Proliferation index Ki-67 influences prognosis and determines tumour grade. We hypothesized that Si-NET grade 2 (G2) tumours, which have a higher Ki-67 than G1 tumours, might benefit less from established treatments for metastatic disease. We conducted a retrospective cohort study of 212 patients with metastatic Si-NET G2 treated in two Swedish hospitals during 20 years (2000-2019). Median cancer-specific survival on first-line somatostatin analogues (SSA) was 77 months. Median progression-free survival (PFS) was 12.4 months when SSA was given as monotherapy and 19 months for all patients receiving first-line SSA. PFS after SSA dose escalation was 6 months in patients with radiological progression. Treatment efficacies of SSA and peptide receptor radionuclide treatment (PRRT) were studied separately in patients with Ki-67 of 3-5%, 5-10% and 10-20%. For SSA, PFS was significantly shorter at higher Ki-67 levels (31, 18 and 10 months, respectively), while there was only a minor difference in PFS for PRRT (29, 25 and 25 months). Median PFS for sequential treatment with interferon-alpha (IFNα), everolimus and chemotherapy was 6, 5 and 9 months. IFNα seemed to be effective in tumours with low somatostatin-receptor expression. In conclusion, established treatments appeared effective in Si-NET G2, despite their higher proliferation index compared to G1 tumours. However, efficacy of SSA but not PRRT was reduced at higher Ki-67 levels. SSA dose escalation provided limited disease stabilization.

The Role of Somatostatin Analogues in the Control of Diarrhea and Flushing as Markers of Carcinoid Syndrome: A Systematic Review and Meta-Analysis

BACKGROUND

Somatostatin analogues (SSAs) are the cornerstone of treatment for carcinoid syndrome (CS)-related symptoms. The aim of this systematic review and meta-analysis is to evaluate the percentage of patients achieving partial (PR) or complete response (CR) with the use of long-acting SSAs in patients with CS.

METHODS

A systematic electronic literature search was conducted in PubMed, Cochrane, and Scopus to identify eligible studies. Any clinical trials reporting data on the efficacy of SSAs to alleviate symptoms in adult patients were considered as potentially eligible.

RESULTS

A total of 17 studies reported extractable outcomes (PR/CR) for quantitative synthesis. The pooled percentage of patients with PR/CR for diarrhea was estimated to be 0.67 (95% confidence interval (CI): 0.52-0.79, I₂ = 83%). Subgroup analyses of specific drugs provided no evidence of a differential response. With regards to flushing, the pooled percentage of patients with PR/CR was estimated to be 0.68 (95% CI: 0.52-0.81, I₂ = 86%). Similarly, no evidence of a significant differential response in flushing control was documented.

CONCLUSIONS

We estimate there is a 67-68% overall reduction in symptoms of CS associated with SSA treatment. However, significant heterogeneity was detected, possibly revealing differences in the disease course, in management and in outcome definition.

Comparison of somatostatin receptor expression in patients with neuroendocrine tumours with and without somatostatin analogue treatment imaged with [18F]SiTATE

Purpose

Somatostatin analogues (SSA) are frequently used in the treatment of neuroendocrine tumours. Recently, [18F]SiTATE entered the field of somatostatin receptor (SSR) positron emission tomography (PET)/computed tomography (CT) imaging. The purpose of this study was to compare the SSR-expression of differentiated gastroentero-pancreatic neuroendocrine tumours (GEP-NET) measured by [18F]SiTATE-PET/CT in patients with and without previous treatment with long-acting SSAs to evaluate if SSA treatment needs to be paused prior to [18F]SiTATE-PET/CT.

Methods

77 patients were examined with standardised [18F]SiTATE-PET/CT within clinical routine: 40 patients with long-acting SSAs up to 28 days prior to PET/CT examination and 37 patients without pre-treatment with SSAs. Maximum and mean standardized uptake values (SUVmax and SUVmean) of tumours and metastases (liver, lymphnode, mesenteric/peritoneal and bones) as well as representative background tissues (liver, spleen, adrenal gland, blood pool, small intestine, lung, bone) were measured, SUV ratios (SUVR) were calculated between tumours/metastases and liver, likewise between tumours/metastases and corresponding specific background, and compared between the two groups.

Results

SUVmean of liver (5.4 ± 1.5 vs. 6.8 ± 1.8) and spleen (17.5 ± 6.8 vs. 36.7 ± 10.3) were significantly lower (p < 0.001) and SUVmean of blood pool (1.7 ± 0.6 vs. 1.3 ± 0.3) was significantly higher (p < 0.001) in patients with SSA pre-treatment compared to patients without. No significant differences between tumour-to-liver and specific tumour-to-background SUVRs were observed between both groups (all p > 0.05).

Conclusion

In patients previously treated with SSAs, a significantly lower SSR expression ([18F]SiTATE uptake) in normal liver and spleen tissue was observed, as previously reported for 68Ga-labelled SSAs, without significant reduction of tumour-to-background contrast. Therefore, there is no evidence that SSA treatment needs to be paused prior to [18F]SiTATE-PET/CT.

Preoperative medical treatments and surgical approaches for acromegaly: A systematic review

OBJECTIVE

Acromegaly is a condition characterized by an overproduction of growth hormone which infers high morbidity and mortality if left untreated. The objective of this review is to analyse and appraise the current evidence for the generalized use of preoperative medications and the various surgical approaches as described in the literature.

DESIGN

A thorough search from MEDLINE via PubMed, EMBASE, and Cochrane Library has been performed which identified a total of 37 papers.

CONCLUSION

The preoperative use of somatostatin receptor agonists (SAs) in acromegaly is a controversial topic with current guidelines suggesting against their generalized routine use. Most authors noticed an insignificant long-term remission of acromegaly when given SAs compared with nil preoperative therapy, except for invasive macroadenomas as SAs have been found to reduce the tumour volume and aid towards the total resection of the adenoma. Furthermore, according to the evidence available, endoscopic transsphenoidal surgery is the optimum method for hypophysectomy in terms of its remission and safety profile.

Second line treatment of acromegaly: Pasireotide or Pegvisomant?

Acromegaly is a chronic disease with an increased mortality in case of persistently active disease. The treatment of acromegaly is mainly based on the surgical resection of the GH secreting pituitary tumor and, in cases with persistent disease, on the medical therapy with first generation somatostatin analogues (first gen-SSAs). Data from national registries, meta-analysis and epidemiology studies showed that 24%-65% of acromegaly patients treated with first gen-SSA did not reach the control of disease, requiring second line therapies, as the second gen-SSAs and the GH receptor antagonist. According to the high efficacy of these treatments and their molecular mechanisms of action, the choice of second line therapies should be personalized. In this review, we summarize the evidence on clinical, molecular and morphological aspects that may predict the response to second line therapies, in order to integrate and translate in the clinical practice for a patient-tailored therapeutic approach.

Immune Checkpoint Inhibitor Therapy in Neuroendocrine Tumors

Neuroendocrine tumors (NETs) occur in various regions of the body and present with complex clinical and biochemical phenotypes. The molecular underpinnings that give rise to such varied manifestations have not been completely deciphered. The management of neuroendocrine tumors (NETs) involves surgery, locoregional therapy, and/or systemic therapy. Several forms of systemic therapy, including platinum-based chemotherapy, temozolomide/capecitabine, tyrosine kinase inhibitors, mTOR inhibitors, and peptide receptor radionuclide therapy have been extensively studied and implemented in the treatment of NETs. However, the potential of immune checkpoint inhibitor (ICI) therapy as an option in the management of NETs has only recently garnered attention. Till date, it is not clear whether ICI therapy holds any distinctive advantage in terms of efficacy or safety when compared to other available systemic therapies for NETs. Identifying the characteristics of NETs that would make them (better) respond to ICIs has been challenging. This review provides a summary of the current evidence on the value of ICI therapy in the management of ICIs and discusses the potential areas for future research.

Pulmonary Function Tests as a Biomarker in Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia Patients Treated With Somatostatin Analogues

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) describes an indolent, under-recognised and poorly understood pulmonary condition with fewer than 200 reported cases across the literature. Currently, cases are diagnosed following a biopsy of the primary lesion, with treatment options centring on symptomatic benefit as opposed to targeting the underlying aetiology. Classically, DIPNECH lesions have been described as slow growing and benign, but with growing awareness of the condition, reports of metastatic disease with significant symptomatic burden have been reported. However, effectively addressing the subset of DIPNECH patients with greater metastatic potential remains an unmet clinical need. Due to the similarities between DIPNECH and carcinoid patients, several centres have considered using somatostatin analogues to not only help symptomatically but also to initiate tumour regression. However, to date, there are limited biomarkers to help evaluate the benefit of such options. In this review, we consider the use of pulmonary function tests (PFTs) to help quantify the benefit of somatostatin analogues. Although much of the evidence stems from small single-centre studies, the use of PFTs within the treatment pathway for both localised and metastatic DIPNECH represents a meaningful improvement from subjective monitoring of disease.

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)]

Updated Polish recommendations for the management of patients with neuroendocrine neoplasms (NENs) of the small intestine (SINENs) and of the appendix (ANENs) are presented here. 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. Najczęściej pierwszą manifestacją ANEN jest jego ostre zapalenie. Typical symptoms of carcinoid syndrome occur in approximately 20-30% of SINENs patients with distant metastases. In laboratory diagnostics the assessment of 5-hydroxyindoleacetic acid concentration is helpful in the diagnosis of carcinoid syndrome. The most commonly used imaging methods are ultrasound examination, computed tomography, magnetic resonance imaging, colonoscopy and somatostatin receptor imaging. 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 dissemination with progression during SSAs treatment, with high expression of somatostatin receptors, radioisotope therapy should be considered first followed by targeted therapies - everolimus. After the exhaustion of the above available therapies, chemotherapy may be considered in selected cases. Recommendations for patient monitoring are also presented.

Efficacy, safety and unmet needs of evolving medical treatments for carcinoid syndrome

This review reports on the currently available medical treatment options for the control of symptoms due to carcinoid syndrome in patients with neuroendocrine tumors. The efficacy and adverse events (AEs) of approved drugs such as somatostatin analogues (SSA), telotristat ethyl (TE) and interferon-alpha, are reviewed. Somatostatin analogues remain the standard treatment of carcinoid syndrome based on the high expression of somatostatin receptors and the resulting inhibition of secretion of bioactive compounds; their use is associated with relatively mild AEs, involving mainly the gastrointestinal system, and being usually transient. Although dose escalation of SSA remains an unapproved option, it is clinically implemented to alleviate symptoms in refractory carcinoid syndrome and supported by the most recent guidelines. The side effects associated with the increased dose are in general mild and consistent with standard dose of SSA. Telotristat ethyl, an oral inhibitor of tryptophan hydroxylase, the rate-limiting enzyme in serotonin biosynthesis, represents a rather novel innovative treatment option in patients with carcinoid syndrome suffering from diarrhea and complements the standard therapy of SSA. Given the low toxicity profile, TE may be considered an early add-on treatment to SSA in patients with uncontrolled carcinoid syndrome. However, further prolonged follow-up of patients treated with TE may be needed to exclude potential AEs, such as liver toxicity or depressed mood, in patients with long-term treatment. Interferon alpha is a cytokine with direct inhibitory effect on hormone secretion and tumor cell proliferation and an approved therapy in carcinoid syndrome but is associated with significant AEs in the majority of the patients requiring frequently dose reduction. The finding of a more favorable tolerability of pegylated interferon needs to be confirmed in a prospective study.

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

Background

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.

Patients and methods

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.

Results

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.

Conclusions

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.

Sequential therapies in gastric gastrinoma

Not required for Clinical Vignette.

The effects of somatostatin analogues on glycaemia in the treatment of neuroendocrine tumours

Long-acting somatostatin analogues (SSAs) are the most commonly used drugs in the management of neuroendocrine tumours (NETs) because of their ability to control symptoms and prolong survival. SSA use is associated with changes in glucose metabolism. However, the impacts on glycaemic control and body mass index (BMI) caused by SSAs in NETs are largely unknown. In the present study, we evaluated the effects of SSA treatment on BMI and glycated haemoglobin (HbA1c) in our cohort of patients with NETs. We also assessed changes in glycaemic control and BMI before and after SSA treatment. In addition, we assessed the incidence of new diabetes or whether there was worsening of glycaemic control for patients with pre-existing diabetes. The study comprised a retrospective study of 279 patients with NETs who were treated with SSAs between January 2014 and January 2019. Glycaemic control was assessed by measuring changes in Hba1c. A number needed to harm analysis was used to look at new cases of diabetes within the study population. Treatment with SSAs was associated with a mean increase in HbA1c of 3.35 ± 6.30 mmol mol^-1 despite a mean decrease in BMI of -1.04 ± 2.79 kg m^-2 . There were 19 new cases of type 2 diabetes mellitus (T2DM) in the population of 209 with a number needed to harm of 12.5. Of the 34 patients with pre-existing T2DM, five had worsening of their mean HbA1c. Treatment with SSAs for NETs is associated with an increase in HbA1c, despite a reduction in BMI and, importantly, a risk of developing T2DM with a number needed to harm of 12.5. This project was registered with the National Health Service Clinical Audit and Registries. It has a CARMS number - 17666.

Preoperative treatment of benign insulinoma: diazoxide or somatostatin analogues?

Surgery is the ideal treatment of insulinoma. However, systemic therapy may be required to prevent severe preoperative hypoglycaemia, when surgery is contraindicated, delayed or refused and in case of unresectable metastatic disease. Diazoxide is commonly used but is not always effective and can cause serious side effects. Somatostatin analogues (octreotide and lanreotide) may be an alternative option. We report the case of a 27-year-old patient with insulinoma in whom diazoxide was compared with lanreotide before operation. A diagnosis of insulinoma was made on the basis of a fasting test and a 2 cm tumour confirmed in the body of the pancreas, with a high uptake of 111-In-pentreotide. Diazoxide was initiated and increased to a maximal tolerated dose of 450 mg/day. Because of dyspnoea and persisting hypoglycaemia, diazoxide was shifted to lanreotide 120 mg. All symptoms resolved without hypoglycaemia. According to the EORTC quality score of life, the score without treatment, under diazoxide, under lanreotide and after surgery were respectively 84.7, 73.3, 90.9 and 99.1. Thus, providing a positive Octreoscan, somatostatin analogues may be a safe, effective and well-tolerated option in patients with insulinoma refractory and/or intolerant to diazoxide or with a high risk of fluid retention.

Pseudo-pheochromocytoma due to obstructive sleep apnea: a case report

SUMMARY

Obstructive sleep apnea (OSA) is a condition of intermittent nocturnal upper airway obstruction. OSA increases sympathetic drive which may result in clinical and biochemical features suggestive of pheochromocytoma. We present the case of a 65-year-old male with a 2.9-cm left adrenal incidentaloma on CT, hypertension, symptoms of headache, anxiety and diaphoresis, and persistently elevated 24-h urine norepinephrine (initially 818 nmol/day (89-470)) and normetanephrine (initially 11.2 µmol/day (0.6-2.7)). He was started on prazosin and underwent left adrenalectomy. Pathology revealed an adrenal corticoadenoma with no evidence of pheochromocytoma. Over the next 2 years, urine norepinephrine and normetanephrine remained significantly elevated with no MIBG avid disease. Years later, he was diagnosed with severe OSA and treated with continuous positive airway pressure. Urine testing done once OSA was well controlled revealed complete normalization of urine norepinephrine and normetanephrine with substantial symptom improvement. It was concluded that the patient never had a pheochromocytoma but rather an adrenal adenoma with biochemistry and symptoms suggestive of pheochromocytoma due to untreated severe OSA. Pseudo-pheochromocytoma is a rare presentation of OSA and should be considered on the differential of elevated urine catecholamines and metanephrines in the right clinical setting.

LEARNING POINTS

Obstructive sleep apnea (OSA) is a common condition among adults. OSA may rarely present as pseudo-pheochromocytoma with symptoms of pallor, palpitations, perspiration, headache, or anxiety. OSA should be considered on the differential of elevated urine catecholamines and metanephrines, especially in patients with negative metaiodobenzylguanidine (MIBG) scan results.

Bronchial Carcinoids: From Molecular Background to Treatment Approach

Simple Summary

Bronchial carcinoids (BCs) are uncommon and usually slow growing neuroendocrine epithelial malignancies that represent less than 2% of all lung cancers. Differences in the extent of molecular alterations between neuroendocrine carcinomas and BCs may underline the differences in the aggressiveness of these lesions. Moreover, although atypical BCs and typical BCs have similar set of mutations, some differential molecular and genetic alterations have been described between these two entities. A better understanding of the genetic and molecular background of BCs would allow a better selection of medical treatments in these patients. Regarding treatment, most BCs can be cured by surgery; however, inoperable tumors are mostly insensitive to chemotherapy and radiotherapy. In advanced BCs, the only drug that has a positive phase III clinical trial in BCs is everolimus. Somatostatin analogues constitute the gold standard for symptomatic relief. Peptide receptor radionuclide therapy has been associated with longer progression free. The efficacy of other treatments such as antiangiogenic agents and immunotherapy is still not established.

Abstract

A better understanding of the genetic and molecular background of bronchial carcinoids (BCs) would allow a better estimation of the risk of disease progression and the personalization of treatment in cases of advanced disease. Molecular studies confirmed that lungs neuroendocrine tumors (NETs) and neuroendocrine carcinomas (NECs) are different entities; thus, no progression of NET to NEC is expected. In BCs, MEN1 gene mutations and deletions and decreased gene expression have been associated with a poor prognosis. ATRX mutation has also been linked to a shorter disease-specific survival. In terms of therapeutic targets, PI3K/AKT/mTOR pathway mutations have been described in 13% of typical carcinoids (TCs) and 39% of atypical carcinoids (ACs), representing a targetable mutation with kinase inhibitors. Regarding treatment, surgical resection is usually curative in localized BCs and adjuvant treatment is not routinely recommended. Multiple options for systemic therapy exist for patients with advanced BCs, although limited by a heterogeneity in the scientific evidence behind their use recommendation. These options include somatostatin analogues, everolimus, peptide receptor radionuclide therapy, chemotherapy, radiotherapy, antiangiogenic agents, and immunotherapy. In this article, we provide a comprehensive review about the molecular and genetic background of BCs, and about the treatment of local and metastatic disease, as well as the main paraneoplastic syndromes that have been associated with this tumor.

Assessment of VEGF and VEGF R1 serum levels in patients with neuroendocrine neoplasms before and after treatment with first-generation somatostatin analogues

INTRODUCTION

Vascular endothelial growth factor (VEGF) is a known promoter of angiogenesis that can support neuroendocrine neoplasm (NEN) development. The aim of the study was to evaluate the serum VEGF and vascular endothelial growth factor receptor 1 (VEGF R1) concentration changes in patients with NEN treated with first-generation long-acting somatostatin analogues (SSA).

MATERIAL AND METHODS

The study comprised 55 controls and 56 NEN patients before and after SSA treatment in various periods of time (months): 1-12 (n = 54), 13-24 (n = 46), 25-36 (n = 35), 37-60 (n = 26), and over 60 months (n = 22). An analysis of medical records and serum VEGF and VEGF R1 concentration measurements of NEN patients, by enzyme-linked immunosorbent assay (ELISA) were made.

RESULTS

During SSA treatment time, a decrease of the VEGF and an increase of VEGF R1 concentrations was observed. We confirmed significant VEGF differences between 2 pairs of SSA-treated NEN patient subgroups: Group 1-12 vs. Group 37-60 (p = 0.039) and Group 1-12 vs. Group > 60 (p = 0.026). We did not note significant differences of VEGF R1 levels between SSA-treated NEN patient subgroups. Among the studied biomarkers, VEGF R1 exhibited the best performance in distinguishing between NEN patients with controls; area under the curve (AUC) = 1 (p < 0.001).

CONCLUSIONS

The examined angiogenesis factors (VEGF and VEGF R1) seem to have limited usage in the assessment of SSA treatment effectiveness in NEN. However, the assessment of serum levels of these factors may help in the differentiation of NEN patients and healthy controls; in particular, VEGF R1 seems to be a good diagnostic biomarker for NEN patients.

Preparation of Long-acting Somatostatin and GnRH Analogues and their Applications in Tumor Therapy

Hormonal drugs are essential treatment options for some hormone-dependent or hormone-sensitive tumors. The common dosage forms of hormonal drugs have a short half-life. Hence, frequent administration is needed, which results in poor patient compliance. Nevertheless, using drug delivery technology, somatostatin analogues (SSAs) and gonadotropin-releasing hormone (GnRH) analogues are prepared into long-acting formulations that can significantly prolong the action time of these drugs, reducing medication frequency and increasing patient compliance. Such drugs are advantageous when treating acromegaly, gastroenteropancreatic neuroendocrine tumors (GEP-NETs), breast cancer, prostate cancer, and other diseases having a relatively long course. SSAs and GnRH analogues are two typical hormonal drugs, the long-acting formulations of which are essential in clinical practice. This review summarized the preparation methods and clinical application of long-acting formulations in cancer. Further, the action mechanism and new research of SSAs and GnRH analogues were discussed, and suggestions related to the development of long-acting SSAs and GnRH analogues were provided.

Somatostatin and Somatostatin Receptors: From Signaling to Clinical Applications in Neuroendocrine Neoplasms

Neuroendocrine neoplasms (NENs) are heterogeneous neoplasms which arise from neuroendocrine cells that are distributed widely throughout the body. Although heterogenous, many of them share their ability to overexpress somatostatin receptors (SSTR) on their cell surface. Due to this, SSTR and somatostatin have been a large subject of interest in the discovery of potential biomarkers and treatment options for the disease. The aim of this review is to describe the molecular characteristics of somatostatin and somatostatin receptors and its application in diagnosis and therapy on patients with NENs as well as the use in the near future of somatostatin antagonists.

Resistance to first-generation somatostatin receptor ligands does not impair the results of gamma knife radiosurgery in acromegaly

OBJECTIVE

Gamma knife radiosurgery (GKRS) has proven to be an effective adjuvant treatment for patients with acromegaly. We performed the present study to investigate, which would be the outcome of GKRS, independently on the response to somatostatin receptor ligand (SRL).

DESIGN

Retrospective, observational study.

PATIENTS

Ninety-six patients with active acromegaly were included.

MEASUREMENTS

The cumulative probability of normalisation of insulin-like growth factor 1 (IGF-1) levels after GKRS was assessed by the Kaplan-Meier method. The association of several clinical characteristics with GKRS outcomes was explored with the use of a Cox proportional-hazard model with the relative hazard ratio and 95% confidence interval (CI).

RESULTS

Resistance to SRL occurred in 39 of the 96 patients (40.6%). After GKRS, patients resistant to SRL had a 5- and 10-year probability of remission of 40.7% (95% CI: 23.7%-57.7%) and 75.9% (95% CI: 57.9%-93.9%), respectively. Patients responding to SRL had a 5- and 10-year probability of remission of 46.8% (95% CI: 32.2%-61.4%) and 58.1% (95% CI: 41.5%-74.7%), respectively. The difference was not significant (p = .48 by the log-rank test). Multivariate Cox analysis confirmed that the only independent variables associated with GKRS outcome were basal growth hormone (GH; p = .001) and IGF-1 multiple of the upper limit of normal levels before GKRS (p = .013).

CONCLUSION

We demonstrate for the first time that the responsiveness to SRL has no effect on the probability to obtain remission of acromegaly after GKRS. The remission of disease occurred more frequently in patients who had lower GH and IGF-1 levels before GKRS.

A Rare Case of a Large Primary Renal Neuroendocrine Tumour: A Case Report and Brief Review of Literature

Primary renal neuroendocrine tumours are very rare clinical entities, and as such, relatively little is known about their clinical progression. Here, we outline the case of a young female patient presenting with abdominal pain and a large 14 cm right renal mass. Initial radiological studies demonstrated localised disease, but during surgical resection, widespread liver metastasis was identified. Histological analysis revealed a grade 2, well-differentiated neuroendocrine tumour pT3a. Whilst surgical resection remains the gold standard for localised disease, further work is required to understand the pathogenesis, prognostic indicators and treatment following metastatic spread. The poor prognosis seen in primary renal neuroendocrine neoplasia highlights the importance of further directed research in this area.

Pharmacological and safety profile of a prolonged-release lanreotide formulation in acromegaly

BACKGROUND

Patients with acromegaly require lifelong medication; a longer dosing interval would reduce treatment burden. This study investigated the pharmacokinetics, pharmacodynamics and safety profile of a new prolonged-release formulation (PRF) of lanreotide every 12 weeks.

RESEARCH DESIGN AND METHODS

In this multicenter, open-label, dose-ascending study, cohorts of nine patients with acromegaly received single doses of lanreotide PRF according to a 3 + 3 + 3 scheme in order to determine the maximum tolerated dose (MTD). Following a 12-week treatment period, patients were followed up for a further 12 weeks. Serum lanreotide, insulin-like growth factor-1 and growth hormone concentrations were analyzed. Adverse events were monitored throughout the study.

RESULTS

The MTD was not reached. Peak lanreotide serum concentration values were similar in all cohorts, whereas area under the curve values from time zero to 85 days increased but were not dose-proportional. The apparent elimination half-life of lanreotide PRF was approximately 54-63 days, in line with the expected prolonged-release characteristics. Growth hormone and insulin-like growth factor-1 levels were generally stable.

CONCLUSIONS

The safety and tolerability profile was in-line with the known safety profile of lanreotide autogel. Lanreotide PRF was well tolerated and the pharmacokinetic profile suggests that a dosing interval of 12 weeks could be achievable.

CLINICAL TRIAL REGISTRATION

www.clinicaltrials.gov identifier is NCT02396953; EudraCT 2014-002389-62.

Somatostatin Analogue Therapy in MEN1-Related Pancreatic Neuroendocrine Tumors from Evidence to Clinical Practice: A Systematic Review

Neuroendocrine neoplasms (NENs) are relatively rare and complex tumors that can be sporadic or hereditary, as in the context of multiple endocrine neoplasia type 1 (MEN1) where patients display a 70% lifelong risk of developing a pancreatic NENs (pNENs). To date, specific personalized treatment for pNENs in patients with MEN1 are lacking. The aim of this study was to systematically analyze the efficacy and safety of somatostatin analogue (SSA) treatment in patients affected by MEN1-related pNENs. We performed a systematic review of the literature, searching for peer-reviewed articles on SSA (octreotide or lanreotide) treatment in MEN1 associated with pNENs. We selected 20 studies with a pooled population of 105 MEN1 patients with pNENs. Females were 58.5%, median age was 44 years (18-73). TNM stage at diagnosis was stage I-II in 84.8% and stage IV in 15.2%. The overall response rate (SD+PR+CR) was achieved in 88.3% of cases, with stable disease in 75.6% and objective response in 12.7% of patients. The safety profile was favorable with both SSA agents. SSAs appear to be an effective and safe treatment option for MEN1-related pNEN, either at localized or advanced stages.

Combination Therapies with PRRT

Peptide receptor radionuclide therapy (PRRT) is a successful targeted radionuclide therapy in neuroendocrine tumors (NETs). However, complete responses remain elusive. Combined treatments anticipate synergistic effects and thus better responses by combining ionizing radiation with other anti-tumor treatments. Furthermore, multimodal therapies often have a balanced toxicity profile. To date, few studies have evaluated the effect of combination therapies with PRRT, some of them phase I/II trials. This review will focus on several clinically tested, tailored approaches to improving the effects of PRRT. The aim is to help clinicians in the treatment planning of NETs to choose the most effective and safe treatment for each patient in the sense of personalized medicine. Current promising combination partners of PRRT are somatostatin analogues (SSAs), chemotherapy, molecular targeted treatment, liver radioembolization, and dual radionuclide PRRT (Lutetium-177-PRRT combined with Yttrium-90-PRRT).

Molecular and Clinical Implications of Somatostatin Receptor Profile and Somatostatin Analogues Treatment in Oral Cavity Squamous Cell Carcinoma

Simple Summary

The treatment of oral squamous cell carcinoma (OSCC) represents a significant problem worldwide. Among cancers with the highest incidence, OSCC renders one of the worst prognoses. Therefore, novel prognostic biomarkers and therapeutic tools to tackle OSCC are urgently needed. Somatostatin-analogues (SSA) are an invaluable therapeutic option in the treatment of several cancers. We aimed to determine the expression levels of all somatostatin-receptors (SSTs) in OSCC, compared to adjacent healthy control tissues, to analyze the relationship of SSTs expression with key clinical and histopathological data, and to explore the direct in vitro effect of different SSAs on OSCC cancer cells. Our findings highlight a potential role of SST₂ as a good prognostic biomarker for recurrence and metastasis in OSCC and unveil that SSA exerts antitumoral effects on OSCC cells, providing a relevant clinical conclusion, which should be soon tested for their use in humans.

Abstract

Oral squamous cell carcinoma (OSCC) incidence has increased by 50% over the last decade. Unfortunately, surgery and adjuvant radiotherapy and chemotherapy are still the mainstream modality of treatment, underscoring the need for alternative therapies. Somatostatin-analogues (SSA) are efficacious and safe treatments for a variety of tumors, but the presence of somatostatin-receptors (SSTs) and pharmacological effects of SSA on OSCC are poorly known. In this study, we demonstrated that SST₂ and SST₃ levels were significantly higher in OSCC, compared to adjacent healthy control tissues. SST₂ expression was associated with less regional metastasis and a lower recurrence rate. Moreover, SST₂ was elevated in OSCC and associated with histopathological good prognosis factors, such as high peritumoral inflammation, smaller depth of invasion, and expansive vs. infiltrative front of tumor invasion. Importantly, treatment with different SSA (octreotide, lanreotide, and pasireotide) significantly reduced cell-proliferation in OSCC primary cell cultures. Altogether, this study demonstrated that SST₂ is overexpressed in OSCC vs. healthy tissues and could represent a novel prognostic biomarker, since its expression is associated with tumors that show better prognostic factors and less recurrent rate. Moreover, our data unveil clear antitumoral effects of SSAs on OSCC, opening new avenues to explore their potential as targeting therapy to OSCC.

Determination of neuron-specific enolase in patients with midgut-type tumour treated with somatostatin analogues

INTRODUCTION

The biochemical diagnosis of neuroendocrine tumours (NETs) uses assays of specific and nonspecific markers. Nonspecific markers include, among others, neuron-specific enolase (NSE). The aim of this study was to evaluate NSE in patients with midgut type tumours treated with somatostatin analogues.

MATERIAL AND METHODS

The study group of patients with NETs of the small intestine included 41 patients. Grade G1 was found in 19 cases, while G2 was seen in the remaining 22 cases. Liver metastases were found in all patients studied. The examined group of patients was treated with somatostatin analogues receiving octreotide LAR at a dose of 30 mg. The control of biochemical parameters was performed every 3 months and imaging examinations every 6 months. The Immuno-Biological Laboratories kit was used for determination of NSE concentration, where reference values were 12.5-25 ng/mL.

RESULTS

In the G1 group of patients, the median value of NSE concentration was 134.67 ng/mL, while in the G2 group, the value was 234.55 ng/mL and was significantly higher than in the G1 group (p = 0.003). In the determination of NSE concentration values according to the degree of liver involvement, in the group of patients with 10% liver involvement, the median value of NSE concentration was 143.21 ng/mL, while in the group with 25% liver involvement, the value was 251.82 ng/mL (p < 0.001). In the analysis of NSE concentration assessment in patients with disease progression, the median value was 234.65 ng/mL compared to the group with disease stabilization, where the median NSE value was significantly lower and amounted to 136.27 ng/mL (p < 0.001).

CONCLUSIONS

In our study, we observed that NSE concentration values were significantly higher among patients with NET midgut type tumour with histological grade G2 and in patients with 25% liver involvement and progression of the disease process.

Somatostatin Receptor Subtype Expression in Patients with Acromegaly and Complicated Clinical Course

Somatostatin analogues are considered to be the first line of treatment in acromegaly. Somatostatin analogues of the first generation mainly target the somatostatin receptor (SSTR) subtype 2 and have been proven efficient in the majority of patients with acromegaly. Pasireotide was the first somatostatin analogue also substantially targeting the SSTR subtype 5. An efficient drug for Cushing’s disease tailored to suboptimal-responding patients with acromegaly then became available. We immunohistochemically investigated SSTR subtypes expression in pituitary adenomas from operated acromegaly patients with clinical relapse and a complicated clinical course. Patients received pasireotide in the course of their disease. The predictive value of SSTR subtypes immunhistochemical analysis for the therapeutic response is discussed.

Clinical challenges and dilemmas in the management of advanced pancreatic neuroendocrine tumour - the first manifestation of von Hippel-Lindau disease in a young patient

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Vigilance for carcinoid heart disease is still required in the era of somatostatin analogues: Lessons from a case series

AIM

Carcinoid heart disease (CHD) is a well-documented complication of neuroendocrine tumors (NETs) due to secreted hormones causing fibrosis. Somatostatin analogues (SSAs) can decrease hormonal secretion and inhibit tumor growth. The reported incidence of CHD has decreased as SSA use has increased. We describe a series of patients who have developed CHD even though they were treated with SSA therapy.

METHODS

Nine patients were seen in four centers in Australia and New Zealand. The average duration of follow-up from diagnosis was 39 months.

RESULTS

Three patients had Grade 1 and six Grade 2 disease by World Health Organization 2010 criteria. All patients had no CHD symptoms at baseline and started SSA therapy soon after diagnosis, yet developed significant, symptomatic cardiac dysfunction in their disease course. The median time from NET diagnosis to SSA initiation was 1 month, and median time from NET diagnosis to CHD diagnosis was 23 months (range 4-52). All patients who were tested had persistently increased hormonal levels (chromogranin A, urinary 5-hydroxyindolacetic acid).

CONCLUSIONS

The good symptomatic control afforded by SSAs should not lead to reduced vigilance in screening for CHD, especially in patients with persistently elevated hormonal assays. Clinicians should consider regular echocardiographic screening in patients with a secretory syndrome.

Giant silent corticotrope pituitary adenoma in a patient with complicated clinical course

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Patterns of Abnormal Glucose Metabolism in Acromegaly and Impact of Treatment Modalities on Glucose Metabolism

Background: Chronic exposure to high levels of growth hormone (GH) and insulin-like growth factor 1 (IGF-1) leads to metabolic complications, most importantly dysglycemia in the form of diabetes mellitus and pre-diabetes. Dysglycemia if diagnosed early in the course of the disease can decrease complications. Treatment modalities in the form of surgery and medical therapy have varied impacts on glucose metabolism.

Objective: To determine the frequency of diabetes mellitus, impaired glucose tolerance, and impaired fasting glucose in Pakistani patients with acromegaly and to establish the impact of the intervention (surgery/medical) on glucose metabolism.

Methods: This study was a retrospective review of patient records. Eighty-nine patients fulfilling the Endocrine Society criteria for acromegaly diagnosis were included. A data of baseline, GH, IGF-1 level, hemoglobin A1C (HbA1C), fasting blood glucose (FBG), and random blood glucose (RBS) levels were reviewed before and after the intervention (surgery/medical therapy). Normal glucose tolerance (NGT), impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and diabetes mellitus (DM) were defined based on the American Diabetes Association (ADA) criteria. Patients were grouped into normoglycemic (NGT) and dysglycemic (IFG, IGT, and DM) based on FBG, RBS, and HbA1C.

Results: Major risk factors for dysglycemia included age (15-45 years), male sex (33.70%), obesity (45.7%), and macroadenoma (77.52%). Both mean GH levels (58.29 vs. 54.36 ng/dl) and IGF-1 levels (862.98 vs. 824.32 ng/dl) were higher among the normoglycemic than dysglycemia. Pre-surgery NGT, IFG, IGT, IFG, and IGT/DM combined were found in 48.31%, 5.61%, 1.1%, 5.61%, and 39.32% of the subjects respectively. Post-surgery, HbA1C improved in 79.5%, deteriorated in 6.8%, and remained the same in 13.6%. Similarly, it improved in 67% post-medical therapy. Both FBG and RBS improved post-surgery and medical therapy. Further, the number of anti-diabetic drugs used also decreased post-surgery.

Conclusion: Dysglycemia is more common among patients with acromegaly as compared to the general population and tends to be poorly controlled in untreated acromegaly. Glycemic control improves significantly after surgery and medical therapy.

Pasireotide in the Personalized Treatment of Acromegaly

The delay in controlling the disease in patients who do not respond to first-line treatment with first generation somatostatin receptor ligands (first-generation SRLs) can be quantified in years, as every modification in the medical therapy requires some months to be fully evaluated. Considering this, acromegaly treatment should benefit from personalized medicine therapeutic approach by using biomarkers identifying drug response. Pasireotide has been positioned mostly as a compound to be used in first-generation SRLs resistant patients and after surgical failure, but sufficient data are now available to indicate it is a first line therapy for patients with certain characteristics. Pasireotide has been proved to be useful in patients in which hyperintensity T2 MRI signal is shown and in those depicting low SST2 and high expression of SST5, low or mutated AIP condition and sparsely granulated immunohistochemical pattern. This combination of clinical and pathological characteristics is unique for certain patients and seems to cluster in the same cases, strongly suggesting an etiopathogenic link. Thus, in this paper we propose to include this clinico-pathologic phenotype in the therapeutic algorithm, which would allow us to use as first line medical treatment those compounds with the highest potential for achieving the fastest control of GH hypersecretion as well as a positive effect upon tumor shrinkage, therefore accelerating the implementation of precision medicine for acromegaly. Moreover, we suggest the development, validation and clinical use of a pasireotide acute test, able to identify patients responsive to pasireotide LAR as the acute octreotide test is able to do for SRLs.

Carcinoid syndroma - diagnosis and management

Neuroendocrine tumors (NETs, originally termed &#8220;carcinoids&#8221;) create a relatively rare group of neoplasms with an approximate incidence rate of 5 to 8 cases per 10 000 persons. NETs predominantly demonstrate indolent disease biology for many years. They become symptomatic when they are large enough or when they metastasize to the liver or the lungs, bones, or other sites. Roughly 30% to 40% of subjects with NETs develop carcinoid syndrome. Signs and symptoms of carcinoid syndrome are bronchospasm, flushing, diarrhea and cramping, cyanosis and pellagra. White plaque-like deposits on the endocardial surface of heart structures are characteristic for carcinoid heart disease. The treatment of patients with carcinoid syndrome is multi-faceted due to the necessity to manage simultaneously the systemic cancer disease as well as the signs of carcinoid syndrome and includes resection or debulking of tumor mass, biological treatment with somatostatin analogues and peptide receptor radionuclide treatment.

Drug-induced Cholelithiasis

BACKGROUND

The prevalence of cholelithiasis in developed countries is high and its cause is multifactorial, with a negligible proportion of drug-induced cholelithiasis.

METHODS

Relevant studies were identified by PubMed, Google Scholar and Science Direct. Reference lists of retrieved articles were also reviewed. The most relevant and up-to-date information was incorporated.

RESULTS

There is a wide range of drugs that can induce lithiasis. While the risk of developing lithiasis is high with some drugs (ceftriaxone, atazanavir, somatostatin analogues), it is lower or even questionable with others. Some drugs precipitate in the bile and may account for up to 100% of the weight of the stone.

CONCLUSION

Cholelithiasis can be induced by a wide range of drugs with different mechanisms of action. The aim of the article is to draw attention to this lesser known fact and the need to take into account the risk of developing lithiasis prior to therapy initiation.

Somatostatin in renal physiology and autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD) is characterized by progressive cyst formation, leading to growth in kidney volume and renal function decline. Although therapies have emerged, there is still an important unmet need for slowing the rate of disease progression in ADPKD. High intracellular levels of adenosine 3′,5′-cyclic monophosphate (cAMP) are involved in cell proliferation and fluid secretion, resulting in cyst formation. Somatostatin (SST), a hormone that is involved in many cell processes, has the ability to inhibit intracellular cAMP production. However, SST itself has limited therapeutic potential since it is rapidly eliminated in vivo. Therefore analogues have been synthesized, which have a longer half-life and may be promising agents in the treatment of ADPKD. This review provides an overview of the complex physiological effects of SST, in particular renal, and the potential therapeutic role of SST analogues in ADPKD.

Detailed Insight into the Interaction of Bicyclic Somatostatin Analogue with Cu(II) Ions

Somatostatin analogues are useful pharmaceuticals in peptide receptor radionuclide therapy. In previous studies, we analyzed a new bicyclic somatostatin analogue (BCS) in connection with Cu(II) ions. Two characteristic sites were present in the peptide chain: the receptor- and the metal-binding site. We have already shown that this ligand can form very stable imidazole complexes with the metal ion. In this work, our aim was to characterize the intramolecular interaction that occurs in the peptide molecule. Therefore, we analyzed the coordination abilities of two cyclic ligands, i.e., P1 only with the metal binding site and P2 with both sites, but without the disulfide bond. Furthermore, we used magnetic circular dichroism (MCD) spectroscopy to better understand the coordination process. We applied this method to analyze spectra of P1, P2, and BCS, which we have described previously. Additionally, we analyzed the MCD spectra of P3 ligand, which has only the receptor binding site in its structure. We have unequivocally shown that the presence of the Phe-Trp-Lys-Thr motif and the disulfide bond significantly increases the metal binding efficiency.

Chromogranin A assessment in patients with neuroendocrine neoplasm of the small bowel and carcinoid syndrome treated with somatostatin analogues

BACKGROUND

Chromogranin A (CgA) is one of the non-specific markers measured in the biochemical diagnostics of neuroendocrine neoplasms (NENs).

OBJECTIVES

To analyze the CgA levels of patients with carcinoid syndrome who are being treated with somatostatin analogues (SSAs), depending on the histologic maturity of the neoplasm, the degree of liver involvement and the stage of the disease.

MATERIAL AND METHODS

The study group comprised of 41 patients, including 29 women (70.7%) and 12 men (29.3%). All of the patients had undergone surgical removal of the primary site. Hepatic metastases were found in all patients and they all were treated with SSAs. Chromogranin A concentration was determined using the enzyme-linked immunosorbent assay (ELISA).

RESULTS

Among the patients with grade 1 tumors, the mean CgA value was 298.83 ng/mL, whereas in the group with grade 2 tumors, the CgA value was 1498.44 ng/mL, which was a statistically significant difference (p < 0.001). In the group of patients with 10% liver involvement, the mean CgA value was 394.44 ng/mL, whereas in the group of patients with 25% liver involvement, this value was 1,770.63 ng/mL, demonstrating significantly higher values (p < 0.001). Among the patients with a progressing disease, the mean CgA concentration value was 1,620.78 ng/mL, whereas in the group of patients with a stable disease, these were considerably lower, amounting to 230.36 ng/mL (p < 0.001).

CONCLUSIONS

Assessing CgA level in patients with carcinoid syndrome is helpful in the diagnostics and monitoring of treatment because CgA values depend on the tumor grade and the severity of the disease.

High-dose Somatostatin Analogues for Progressive Neuroendocrine Tumours

Neuroendocrine tumours are a heterogeneous group of neoplasms with a variety of treatment options, but studies suggest they should in most cases, if they are not curable surgically, be treated initially with monthly long-acting somatostatin analogues. New data recently published suggest that if patients show progression on the current analogues at the recommended doses, increasing the dose or frequency of these analogues may provide a further therapeutic effect, although proper randomised trials will be necessary to confirm this effect.

Advances in the Management of Medullary Thyroid Carcinoma: Focus on Peptide Receptor Radionuclide Therapy

Effective treatment options in advanced/progressive/metastatic medullary thyroid carcinoma (MTC) are currently limited. As in other neuroendocrine neoplasms (NENs), peptide receptor radionuclide therapy (PRRT) has been used as a therapeutic option in MTC. To date, however, there are no published reviews dealing with PRRT approaches. We performed an in-depth narrative review on the studies published in this field and collected information on registered clinical trials related to this topic. We identified 19 published studies, collectively involving more than 200 patients with MTC, and four registered clinical trials. Most cases of MTC were treated with PRRT with somatostatin analogues (SSAs) radiolabelled with 90 yttrium (90Y) and 177 lutetium (177Lu). These radiopharmaceuticals show efficacy in the treatment of patients with MTC, with a favourable radiological response (stable disease, partial response or complete response) in more than 60% of cases, coupled with low toxicity. As MTC specifically also expresses cholecystokinin receptors (CCK2Rs), PRRT with this target has also been tried, and some randomised trials are ongoing. Overall, PRRT seems to have an effective role and might be considered in the therapeutic strategy of advanced/progressive/metastatic MTC.

Maintenance of Acromegaly Control in Patients Switching From Injectable Somatostatin Receptor Ligands to Oral Octreotide

PURPOSE

The phase 3 CHIASMA OPTIMAL trial (NCT03252353) evaluated efficacy and safety of oral octreotide capsules (OOCs) in patients with acromegaly who previously demonstrated biochemical control while receiving injectable somatostatin receptor ligands (SRLs).

METHODS

In this double-blind study, patients (N = 56) stratified by prior SRL dose were randomly assigned 1:1 to OOC or placebo for 36 weeks. The primary end point was maintenance of biochemical control at the end of treatment (mean insulin-like growth factor 1 [IGF-1] ≤ 1.0 × upper limit of normal [ULN]; weeks 34 and 36). Time to loss of IGF-1 response and proportion requiring reversion to injectable SRLs were assessed as broader control measures.

RESULTS

Mean IGF-1 measurements were 0.80 and 0.97 × ULN for OOC and 0.84 and 1.69 × ULN for placebo, at baseline and end of treatment, respectively. Mean growth hormone (GH) changed from 0.66 to 0.60 ng/mL for OOCs and 0.90 to 2.57 ng/mL for placebo. Normalization of IGF-1 levels (≤ 1.0 × ULN) was maintained in 58.2% for OOCs vs 19.4% for placebo (P = .008); GH levels were maintained (< 2.5 ng/mL) in 77.7% for OOC vs 30.4% for placebo (P = .0007). Median time to loss of response (IGF-1 > 1.0 or ≥ 1.3 × ULN definitions) for patients receiving placebo was 16 weeks; for patients receiving OOCs, it was not reached for both definitions during the 36-week trial (P < .0001). Of the patients in the OOC group, 75% completed the trial on oral therapy. The OOC safety profile was consistent with previous SRL experience.

CONCLUSIONS

OOCs may be an effective therapy for patients with acromegaly who previously were treated with injectable SRLs.