Peptide Receptor Radionuclide Therapy Improves Survival in Patients Who Progress After Resection of Gastroenteropancreatic Neuroendocrine Tumors.

Background: Peptide receptor radionuclide therapy (PRRT) is an effective treatment for advanced gastroenteropancreatic (GEP) neuroendocrine tumors (NETs). We investigated a 2-decade experience with PRRT to determine whether PRRT confers a survival advantage to patients who progress after surgery versus other therapies.

Methods: We identified patients from our clinic who had resection/cytoreduction of GEP-NETs, then disease progression by Response Evaluation Criteria in Solid Tumors (RECIST) 1.

Chemokine Receptor CXCR4 Radioligand Targeted Therapy Using 177Lutetium-pentixather for Pulmonary Neuroendocrine Cancers.

Intermediate to high-grade lung neuroendocrine tumors (NETs; i.e., atypical carcinoid tumors) and neuroendocrine carcinomas (NECs) are currently difficult to cure.

Is There a Role for Surgical Resection of Grade 3 Neuroendocrine Neoplasms?

Background: Grade 3 (G3) gastroenteropancreatic (GEP) neuroendocrine neoplasms (NENs) are aggressive tumors with poor survival outcomes for which medical management is generally recommended. This study sought to evaluate outcomes of surgically treated G3 GEP-NEN patients.

Methods: A single-institutional prospective NEN database was reviewed.

Establishment of Novel Neuroendocrine Carcinoma Patient-Derived Xenograft Models for Receptor Peptide-Targeted Therapy.

Gastroenteropancreatic neuroendocrine neoplasms (GEP NENs) are rare cancers consisting of neuroendocrine carcinomas (NECs) and neuroendocrine tumors (NETs), which have been increasing in incidence in recent years. Few cell lines and pre-clinical models exist for studying GEP NECs and NETs, limiting the ability to discover novel imaging and treatment modalities. To address this gap, we isolated tumor cells from cryopreserved patient GEP NECs and NETs and injected them into the flanks of immunocompromised mice to establish patient-derived xenograft (PDX) models.

Safety and Efficacy of Peptide-Receptor Radionuclide Therapy in Elderly Neuroendocrine Tumor Patients.

Peptide receptor radionuclide therapy (PRRT) is a well-established treatment in somatostatin receptor-expressing neuroendocrine tumours (NETs). The safety and efficacy of PRRT in >79 years old patients (EP) have not been systematically investigated. All patients with inoperable/metastatic/progressive G1/G2 NET, >79 years (EP), treated with PRRT at the University Hospital of Basel between 2006 and 2018, were enrolled in this retrospective matched cohort study.

Management of Duodenal Neuroendocrine Tumors: Surgical versus Endoscopic Mucosal Resection.

Background: Management of duodenal neuroendocrine tumors (DNETs) is not standardized, with smaller lesions (< 1-2 cm) generally treated by endoscopic mucosal resection (EMR) and larger DNETs by surgical resection (SR). This study reviewed how patients were selected for treatment and compared outcomes.

Patients And Methods: Patients with DNETs undergoing resection were identified through institutional databases, and clinicopathologic data recorded.

Potential for Increasing Uptake of Radiolabeled Ga-DOTATOC and I-MIBG in Patients with Midgut Neuroendocrine Tumors Using a Histone Deacetylase Inhibitor Vorinostat.

Histone deacetylase (HDAC) inhibitors have been shown in preclinical studies to upregulate norepinephrine transporters in neuroblastoma and pheochromocytoma, and somatostatin receptors in pulmonary carcinoid, small cell lung cancer, and pancreatic neuroendocrine malignancies. This pilot imaging study in humans focuses on midgut neuroendocrine carcinoma metastatic to the liver, evaluating the effect of pretreatment with the HDAC inhibitor vorinostat on uptake of I-MIBG and Ga-DOTATOC. Multiple midgut neuroendocrine liver metastases in clinically stable subjects were imaged with I-MIBG and Ga-DOTATOC before and after a 4-d course of vorinostat.

Opportunities to Improve Symptom Control with Somatostatin Congeners in GEP-NETs: A Review of Key Issues.

Octreotide acetate (octreotide) is the most prescribed and most studied somatostatin congener, or analog, for gastroenteropancreatic neuroendocrine tumors (GEP-NETs) and carcinoid syndrome, the latter of which may be characterized by debilitating diarrhea and flushing. Approved in the U.S.

Presacral neuroendocrine tumors associated with the Currarino syndrome.

Currarino syndrome (CS) is an autosomal dominant syndrome caused by mutations in MNX1 and characterized by anorectal abnormalities, partial sacral agenesis, and presacral masses. The presacral masses are typically benign; however, malignant degeneration can occur, and presacral neuroendocrine tumors (NETs) have been reported in six cases. We report three individuals from two families affected by CS in which multiple individuals developed presacral NETs.

Addition of I-MIBG to PRRT (Y-DOTATOC) for Personalized Treatment of Selected Patients with Neuroendocrine Tumors.

Peptide receptor radionuclide therapy (PRRT) is an effective treatment for metastatic neuroendocrine tumors. Delivering a sufficient tumor radiation dose remains challenging because of critical-organ dose limitations. Adding I-metaiodobenzylguanidine (I-MIBG) to PRRT may be advantageous in this regard.

Prospective Analysis of the Impact of 68Ga-DOTATOC Positron Emission Tomography-Computerized Axial Tomography on Management of Pancreatic and Small Bowel Neuroendocrine Tumors.

Objectives: A prospective clinical trial evaluated the effect of Ga-DOTATOC positron emission tomography-computerized axial tomography (PET-CT) on change in management of patients with lung, pancreatic, and small bowel neuroendocrine tumors. The primary eligibility criterion was a histologically proven tumor with positive somatostatin receptor subtype 2A immunohistochemistry. The primary and secondary end points were change in patient management and safety.

The North American Neuroendocrine Tumor Society Consensus Guidelines for Surveillance and Medical Management of Pancreatic Neuroendocrine Tumors.

This article is the result of the North American Neuroendocrine Tumor Society consensus conference on the medical management of pancreatic neuroendocrine tumors from July 19 to 20, 2018. The guidelines panel consisted of medical oncologists, pathologists, gastroenterologists, endocrinologists, and radiologists. The panel reviewed a series of questions regarding the medical management of patients with pancreatic neuroendocrine tumors as well as questions regarding surveillance after resection.

It Is Time to Rethink Biomarkers for Surveillance of Small Bowel Neuroendocrine Tumors.

Background: Tumor biomarkers (TBMs) reflect disease burden and correlate with survival for small bowel neuroendocrine tumors (SBNETs). This study sought to determine the performance of chromogranin A (CgA), pancreastatin (PST), neurokinin A (NKA), and serotonin (5HT) during follow-up assessment of resected SBNETs.

Methods: An institutional database identified patients undergoing surgery for SBNETs.

Evolution of Neuroendocrine Tumor Therapy.

To better understand developments in treatment of neuroendocrine tumors of the gastroenteropancreatic system, and the pivotal roles of native somatostatin and its long-acting analogues play in normal peptide regulation and neuropeptide excess associated with neuroendocrine tumors (NETs), this article delineates and defines distinct eras in the history and discovery of gastrointestinal endocrinology. We highlight the collaboration between academia and industry in basic science and the clinical research that advanced Lu-177-DOTATATE to approval as standard of care therapy for low-grade NETs. Examples of new radioisotopes and therapy compounds currently in development for diagnosis and therapy for high-grade NETs are also discussed.

Time to Sustained Improvement in Bowel Movement Frequency with Telotristat Ethyl: Analyses of Phase III Studies in Carcinoid Syndrome.

Background: Telotristat ethyl is approved to treat carcinoid syndrome diarrhea in combination with somatostatin analogs. In TELESTAR and TELECAST phase III studies, patients with carcinoid syndrome received telotristat ethyl 250 or 500 mg 3 times per day (tid) or placebo tid in addition to somatostatin analogs. The aim of this prespecified analysis was to examine the time to reductions in bowel movements (BMs) in the TELESTAR and TELECAST studies using survival analysis methods.

Impact of liver tumour burden, alkaline phosphatase elevation, and target lesion size on treatment outcomes with Lu-Dotatate: an analysis of the NETTER-1 study.

Purpose: To assess the impact of baseline liver tumour burden, alkaline phosphatase (ALP) elevation, and target lesion size on treatment outcomes with Lu-Dotatate.

Methods: In the phase 3 NETTER-1 trial, patients with advanced, progressive midgut neuroendocrine tumours (NET) were randomised to 177Lu-Dotatate (every 8 weeks, four cycles) plus octreotide long-acting release (LAR) or to octreotide LAR 60 mg. Primary endpoint was progression-free survival (PFS).

Gene Expression Signatures Identify Novel Therapeutics for Metastatic Pancreatic Neuroendocrine Tumors.

Purpose: Pancreatic neuroendocrine tumors (pNETs) are uncommon malignancies noted for their propensity to metastasize and comparatively favorable prognosis. Although both the treatment options and clinical outcomes have improved in the past decades, most patients will die of metastatic disease. New systemic therapies are needed.

The Pancreas as a Site of Metastasis or Second Primary in Patients with Small Bowel Neuroendocrine Tumors.

Background: The small bowel and pancreas are the most common primary sites of neuroendocrine tumors (NETs) giving rise to metastatic disease. Some patients with small bowel NETs (SBNETs) present with synchronous or metachronous pancreatic NETs (PNETs), and it is unclear whether these are separate primaries or metastases from one site to the other.

Methods: A surgical NET database including patients undergoing operations for SBNETs or PNETs was reviewed.

Clinical, Diagnostic, and Treatment Characteristics of -Related Metastatic Pheochromocytoma and Paraganglioma.

Pheochromocytoma and paraganglioma (PHEO/PGL) are rare neuroendocrine tumors which may cause potentially life-threatening complications, with about a third of cases found to harbor specific gene mutations. Thus, early diagnosis, treatment, and meticulous monitoring are of utmost importance. Because of low incidence of succinate dehydrogenase complex subunit A ()-related metastatic PHEO/PGL, currently there exists insufficient clinical information, especially with regards to its diagnostic and treatment characteristics.

Long-Term Safety Experience with Telotristat Ethyl Across Five Clinical Studies in Patients with Carcinoid Syndrome.

Background: Patients with neuroendocrine tumors (NETs) and carcinoid syndrome experience considerable morbidity and mortality; carcinoid syndrome may be associated with shorter survival. Carcinoid syndrome is linked to tumoral secretion of serotonin and other bioactive substances. The subsequent debilitating diarrhea and urgency to defecate pose significant health risks.

Effective cytoreduction can be achieved in patients with numerous neuroendocrine tumor liver metastases (NETLMs).

Background: Cytoreductive surgery for neuroendocrine tumor liver metastases improves survival and symptomatic control. However, the feasibility of adequate cytoreduction in patients with many liver metastases remains uncertain. We compared patient outcomes based on the number of lesions treated to better define the efficacy of cytoreductive surgery for numerous neuroendocrine tumor liver metastases.

The Distal Predilection of Small Bowel Neuroendocrine Tumors.

Background: The small bowel (SB) is the most common site of neuroendocrine tumors (NETs) of the GI tract. These are described as being predominantly jejunoileal, but their exact locations within the SB have not been well defined. We sought to determine prospectively the spectrum of SBNET locations.

Technical Note: Single time point dose estimate for exponential clearance.

Objective: Although personalized dosimetry may be desirable for radionuclide therapy treatments, the multiple time samples required to determine the total integrated activity puts a burden on patients and clinic resources. The aim of this paper is to demonstrate that when some prior knowledge is known about the tracer kinetic parameters, the total integrated activity (and thus radiation dose) can be estimated from a single time sample.

Methods: Mathematical derivations have been performed to generate equations for the total integrated activity in terms of a single time sample of activity for monoexponential and biexponential clearance.