Faculty Bibliography

BACKGROUND:Surgery is the definitive treatment of Cushing's syndrome (CS) but medications may also be used as a first-line therapy. Whether preoperative medical treatment (PMT) affects postoperative outcome remains controversial. OBJECTIVE:(1) Evaluate how frequently PMT is given to CS patients across Europe; (2) examine differences in preoperative characteristics of patients who receive PMT and those who undergo primary surgery and (3) determine if PMT influences postoperative outcome in pituitary-dependent CS (PIT-CS). PATIENTS AND METHODS/METHODS:1143 CS patients entered into the ERCUSYN database from 57 centers in 26 countries. Sixty-nine percent had PIT-CS, 25% adrenal-dependent CS (ADR-CS), 5% CS from an ectopic source (ECT-CS) and 1% were classified as having CS from other causes (OTH-CS). RESULTS: < 0.01). Within 6 months of surgery, no differences in morbidity or remission rates were observed between SX and PMT groups. CONCLUSIONS:PMT may confound the interpretation of immediate postoperative outcome. Follow-up is recommended to definitely evaluate surgical results.

Somatostatin receptors are a pivotal target for treatment of pancreatic neuroendocrine tumors (pNET), either with somatostatin analogues (SSA) or radiolabeled SSA. The highest affinity target for the most commonly used SSA is the somatostatin receptor type 2 (sst

Mesenteric fibrosis (MF) surrounding a mesenteric mass is a hallmark feature of small intestinal neuroendocrine tumours (SI-NETs). Since this can induce intestinal obstruction, oedema and ischaemia, prophylactic resection of the primary tumour and mesenteric mass is often recommended. This study assessed the predictors for mesenteric metastasis and fibrosis and the effect of MF and palliative surgery on survival. A retrospective analysis of 559 patients with pathologically proven SI-NET and available CT-imaging data was performed. Clinical characteristics, presence of mesenteric mass and fibrosis on CT imaging and the effect of palliative abdominal surgery on overall survival were assessed. We found that MF was present in 41.4%. Older age, 5-HIAA excretion ≥67 μmol/24 h, serum CgA ≥121.5 μg/L and a mesenteric mass ≥27.5 mm were independent predictors of MF. In patients ≤52 years, mesenteric mass was less often found in women than in men (39% vs 64%, P = 0.002). Corrected for age, tumour grade, CgA and liver metastasis, MF was not a prognostic factor for overall survival. In patients undergoing palliative surgery, metastasectomy of mesenteric mass or prophylactic surgery did not result in survival benefit. In conclusion, we confirmed known predictors of MF and mesenteric mass and suggest a role for sex hormones as women ≤52 years have less often a mesenteric mass. Furthermore, the presence of MF has no effect on survival in a multivariate analysis, and we found no benefit of metastasectomy of mesenteric mass or prophylactic surgery on overall survival.

Small intestinal neuroendocrine tumours (SI-NETs) are neoplasms characterized by their ability to secrete biogenic amines and peptides. These cause distinct clinical pathology including carcinoid syndrome, marked by diarrhoea and flushing, as well as fibrosis, notably mesenteric fibrosis. Mesenteric fibrosis often results in significant morbidity by causing intestinal obstruction, oedema and ischaemia. Although advancements have been made to alleviate symptoms of carcinoid syndrome and prolong the survival of patients with SI-NETs, therapeutic options for patients with mesenteric fibrosis are still limited. As improved insight in the complex pathogenesis of mesenteric fibrosis is key to the development of new therapies, we evaluated the literature for known and putative mediators of fibrosis in SI-NETs. In this review, we discuss the tumour microenvironment, growth factors and signalling pathways involved in the complex process of fibrosis development and tumour progression in SI-NETs, in order to elucidate potential new avenues for scientific research and therapies to improve the management of patients suffering from the complications of mesenteric fibrosis.

Context:Pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine, usually benign, tumors. Currently, the only reliable criterion of malignancy is the presence of metastases. Objective:The aim of this study was to identify genes associated with malignancy in PPGLs. Design:Transcriptomic profiling was performed on 40 benign and 11 malignant PPGLs. Genes showing a significantly different expression between benign and malignant PPGLs with a ratio ≥4 were confirmed and tested in an independent series by quantitative real-time polymerase chain reaction (qRT-PCR). Immunohistochemistry was performed for the validated genes on 109 benign and 32 malignant PPGLs. Functional assays were performed with hPheo1 cells. Setting:This study was conducted at the Department of Pathology of the Erasmus MC University Medical Center Rotterdam Human Molecular Genetics laboratory of the de Duve Institute, University of Louvain. Patients:PPGL samples from 179 patients, diagnosed between 1972 and 2015, were included. Main outcome measures:Associations between gene expression and malignancy were tested using supervised clustering approaches. Results:Ten differentially expressed genes were selected based on messenger RNA (mRNA) expression array data. Contactin 4 (CNTN4) was overexpressed in malignant vs benign tumors [4.62-fold; false discovery rate (FDR), 0.001]. Overexpression at the mRNA level was confirmed using qRT-PCR (2.90-fold, P = 0.02; validation set: 4.26-fold, P = 0.005). Consistent findings were obtained in The Cancer Genome Atlas cohort (2.7-fold; FDR, 0.02). CNTN4 protein was more frequently expressed in malignant than in benign PPGLs by immunohistochemistry (58% vs 17%; P = 0.002). Survival after 7 days of culture under starvation conditions was significantly enhanced in hPheo1 cells transfected with CNTN4 complementary DNA. Conclusion:CNTN4 expression is consistently associated with malignant behavior in PPGLs.

Context:The disease course of adrenocortical carcinoma (ACC) patients is heterogeneous. A marker for prognosis and treatment response would facilitate choices for diagnosis and therapy. In other cancer types, circulating cell-free tumor DNA predicted tumor dynamics. Case Descriptions:The present pilot study included six patients. Next-generation sequencing (NGS) showed mutations in three ACC cases. From these patients, blood was drawn before (1 to 2 weeks) and after surgery and cell-free circulating DNA (cfDNA) was isolated. Tumor-specific mutations were found in the cfDNA of one of the three patients, with metastasized ACC at diagnosis. NGS of the tumor showed an NRAS mutation (c.182A>G:p.Q61R) in 78%, a TP53 mutation (c.856G>A:p.E286K) in 60%, and a TERT gene mutation (1295250C>T) in 28% of the reads. The preoperative cfDNA showed the same mutations at a frequency of 64%, 32%, and 2%, respectively. The postoperative cfDNA showed the same mutations but at lower frequencies (52%, 16%, and 3%, respectively). The patient was postoperatively treated with mitotane and chemotherapy. No mutations were detected in the corresponding leukocyte DNA or in the cfDNA from the two other patients. Conclusions:To the best of our knowledge, we report for the first time mutations occurring at high levels in cfDNA collected before and after surgery from one of three patients, after previous identification in the tumor. However, in the cfDNA from two patients with known mutations, we were unable to reliably detect mutations in the cfDNA. Our results indicate that mutation detection in cfDNA can vary among ACC patients, and other approaches might be required to detect the tumor response and monitor progressive disease.

Purpose: Bronchial and gastroenteropancreatic neuroendocrine tumors (NET) are slow-growing tumors, which frequently express somatostatin receptors on their cell membranes. These receptors are targets for therapy with Lutetium-177-labeled somatostatin analogues. We have treated over 1,200 patients with peptide receptor radionuclide therapy (PRRT) with [¹⁷⁷Lu-DOTA⁰,Tyr³]octreotate (¹⁷⁷Lu-DOTATATE) since the year 2000 and present the results on efficacy, survival, and toxicity of this therapy.Experimental Design: For safety analysis, 610 patients treated with a cumulative dose of at least 100 mCi (3.7 GBq) ¹⁷⁷Lu-DOTATATE were included. A subgroup of 443 Dutch patients who were treated with a cumulative dose of at least 600 mCi (22.2 GBq) ¹⁷⁷Lu-DOTATATE before 2013 was further analyzed for efficacy and survival.Results: The objective response rate of the total group of patients was 39%. Stable disease was reached in 43% of patients. Progression-free survival (PFS) and overall survival (OS) for all NET patients were 29 months [95% confidence interval (CI), 26-33 months] and 63 months (95% CI, 55-72 months). Long-term toxicity included acute leukemia in four patients (0.7%) and myelodysplastic syndrome in nine patients (1.5%). No therapy-related long-term renal or hepatic failure occurred.Conclusions: PRRT with ¹⁷⁷Lu-DOTATATE is a favorable therapeutic option in patients with metastatic bronchial and gastroenteropancreatic NETs that express somatostatin receptors. PRRT with ¹⁷⁷Lu-DOTATATE is safe with few side-effects and shows good response rates with PFS of 29 months and OS of 63 months. Clin Cancer Res; 23(16); 4617-24. ©2017 AACR.

BACKGROUND:Serotonin secretion occurs in approximately 1%-4% of patients with a pancreatic neuroendocrine tumour (PNET), but the incidence is not well defined. The aim of this study was to determine the incidence of serotonin secretion with and without carcinoid syndrome and the prognostic value for overall survival (OS). METHODS:Data were collected from 255 patients with a PNET if 24-hours urinary 5-hydroxyindoleacetic acid excretion (5-HIAA) was assessed. Patients were diagnosed with serotonin secretion if 24-hours urinary 5-HIAA excretion was more than 3× the upper limit of normal (ULN) of 50 μmol/24 hours during follow-up. The effect of serotonin secretion on OS was estimated with uni- and multivariate analyses using a Cox regression. RESULTS:Two (0.8%) patients were diagnosed with carcinoid syndrome, and another 20 (7.8%) had a serotonin-secreting PNET without symptoms. These patients mostly had ENETS stage IV disease with high chromogranin A (CgA). Serotonin secretion was a negative prognostic factor in univariate analysis (HR 2.2, 95% CI: 1.27-3.81), but in multivariate analysis, only CgA>10× ULN (HR: 1.81, 95% CI: 1.10-2.98) and neuron-specific enolase (NSE) >ULN (HR: 3.51, 95% CI: 2.26-5.46) were predictors for OS. Immunohistochemical staining for serotonin was positive in 28.6% of serotonin-secreting PNETs (one with carcinoid syndrome) and negative in all controls. CONCLUSION/CONCLUSIONS:Carcinoid syndrome is rare in patients with a PNET, but serotonin secretion occurs often. This is a negative prognostic factor for OS, but after correction for CgA and NSE, it is no longer a predictor and probably only a "not-so innocent bystander" in patients with high tumour burden.

Pheochromocytoma/paraganglioma (PPGL) syndromes associated with polycythemia have previously been described in association with mutations in the von Hippel-Lindau gene. Recently, mutations in the prolyl hydroxylase gene (PHD) 1 and 2 and in the hypoxia-inducible factor 2 α (HIF2A) were also found to be associated with multiple and recurrent PPGL. Such patients also presented with PPGL and polycythemia, and later on, some presented with duodenal somatostatinoma. In additional patients presenting with PPGL and polycythemia, no further mutations have been discovered. Because the functional imaging signature of patients with PPGL-polycythemia syndromes is still unknown, and because these tumors (in most patients) are multiple, recurrent, and metastatic, the goal of our study was to assess the optimal imaging approach using 4 different PET radiopharmaceuticals and CT/MRI in these patients. Methods: Fourteen patients (10 women, 4 men) with confirmed PPGL and polycythemia prospectively underwent ⁶⁸Ga-DOTATATE (13 patients), ¹⁸F-FDG (13 patients), ¹⁸F-fluorodihydroxyphenylalanine (¹⁸F-FDOPA) (14 patients), ¹⁸F-fluorodopamine (¹⁸F-FDA) (11 patients), and CT/MRI (14 patients). Detection rates of PPGL lesions were compared between all imaging studies and stratified between the underlying mutations. Results:¹⁸F-FDOPA and ¹⁸F-FDA PET/CT showed similar combined lesion-based detection rates of 98.7% (95% confidence interval [CI], 92.7%-99.8%) and 98.3% (95% CI, 90.9%-99.7%), respectively. The detection rates for ⁶⁸Ga-DOTATATE (35.3%; 95% CI, 25.0%-47.2%), ¹⁸F-FDG (42.3; 95% CI, 29.9%-55.8%), and CT/MRI (60.3%; 95% CI, 48.8%-70.7%) were significantly lower (P < 0.01), irrespective of the mutation status. Conclusion:¹⁸F-FDOPA and ¹⁸F-FDA are superior to ¹⁸F-FDG, ⁶⁸Ga-DOTATATE, and CT/MRI and should be the radiopharmaceuticals of choice in this rare group of patients.

The treatment of hormone hypersecretory syndromes caused by neuroendocrine tumors (NETs) can be a major challenge. NETs originating from the small intestine often secrete serotonin causing flushing, diarrhea and valve fibrosis, leading to dehydration or heart failure in severe cases. NETs from the pancreas can secrete a wider variety of hormones, like insulin, glucagon and gastrin leading to distinct clinical syndromes. Historically mortality in patients with functioning NETs was high due to the complications caused by the hypersecretion of hormones. This has been reduced with several drugs: proton-pump inhibitors decrease acid secretion caused by gastrinomas. Somatostatin analogs can inhibit the secretion of multiple hormones and these are now the cornerstone for treating patients with a gastroenteropancreatic NET. However, peptide receptor radionuclide therapy (PRRT) with radiolabeled somatostatin analogs and everolimus can also decrease symptoms of hypersecretion and increase progression-free survival. Several factors affect the survival in patients with a functioning NET. Complications of hypersecretion negatively impact survival; however, secretion of hormones is also often a sign of a well-differentiated NET and due to the symptoms, functioning NETs can be detected in an earlier stage suggesting a positive effect on prognosis. The effect on survival is also dependent on the type of hormone being secreted. This review aims to study the effect of hormone secretion on the prognosis of NETs with the contemporary treatments options available today.