Biological characteristics and treatment outcomes of metastatic or recurrent neuroendocrine tumors: tumor grade and metastatic site are important for treatment strategy

Outcome prediction of SSTR-RADS-3A and SSTR-RADS-3B lesions in patients with neuroendocrine tumors based on 68Ga-DOTATATE PET/MR

PURPOSE

Somatostatin receptor (SSTR)-targeted PET imaging has emerged as a common approach to evaluating those patients with well-differentiated neuroendocrine tumors (NETs). The SSTR reporting and data system (SSTR-RADS) version 1.0 provides a means of categorizing lesions from 1 to 5 according to the likelihood of NET involvement, with SSTR-RADS-3A (soft-tissue) and SSTR-RADS-3B (bone) lesions being those suggestive of but without definitive NET involvement. The goal of the present study was to assess the ability of 68Ga-DOTATATE PET/MR imaging data to predict outcomes for indeterminate SSTR-RADS-3A and 3B lesions.

METHODS

NET patients with indeterminate SSTR-RADS-3A or SSTR-RADS-3B lesions who underwent 68Ga-DOTATATE PET/MR imaging from April 2020 through August 2023 were retrospectively evaluated. All patients underwent follow-up through December 2023 (median, 17 months; (3-31 months)), with imaging follow-up or biopsy findings ultimately being used to classify lesions as malignant or benign. Lesion maximum standardized uptake value (SUVmax) along with minimum and mean apparent diffusion coefficient (ADCmin and ADCmean) values were measured and assessed for correlations with outcomes on follow-up.

RESULTS

In total, 33 indeterminate SSTR-RADS-3 lesions from 22 patients (19 SSTR-RADS-3A and 14 SSTR-RADS-3B) were identified based upon baseline 68Ga-DOTATATE PET/MR findings. Over the course of follow-up, 16 of these lesions (48.5%) were found to exhibit true NET positivity, including 9 SSTR-RADS-3A and 7 SSTR-RADS-3B lesions. For SSTR-RADS-3A lymph nodes, a diameter larger than 0.7 cm and an ADCmin of 779 × 10-6mm2/s or lower were identified as being more likely to be associated with metastatic lesions. Significant differences in ADCmin and ADCmean were identified when comparing metastatic and non-metastatic SSTR-RADS-3B bone lesions (P < 0.05), with these parameters offering a high predictive ability (AUC = 0.94, AUC = 0.86).

CONCLUSION

Both diameter and ADCmin can aid in the accurate identification of the nature of lesions associated with SSTR-RADS-3A lymph nodes, whereas ADCmin and ADCmean values can inform the accurate interpretation of SSTR-RADS-3B bone lesions.

Management and Survival Analysis of Gastrointestinal Neuroendocrine Tumors by Different Tumor Characteristics: Tertiary Center Experience

BACKGROUND

Gastrointestinal neuroendocrine tumor (GI-NET) is a group of neoplasia consisting of amine and acid producing cells with different hormonal profiles. Although the entire GIS accounts for about 2% of tumors, recent research reveals that the incidence rate has increased. Given the increasing incidence in GI-NETs, more and more extensive research is needed on this subject. In this regard, the demographic and clinicopathological features of the patients diagnosed with GI-NET and their relationship with survival were investigated in the present study.

METHODS

Thirty-four patients diagnosed with GI-NETs between January 2009 and December 2019 at the Department of Gastroenterology, Inonu University Faculty of Medicine were analyzed retrospectively. Gender, age, tumor localization, metastasis status, tumor number, tumor diameter, tumor grade, Ki-67 index, and the relationships of these factors with overall survival were examined.

RESULTS

Of the patients, 61.8% included in the study were male and 38.2% were female. The average age of the patients was 60.74 years. The most common tumor location was in the stomach (26.5%) and liver (26.5%). Apart from this, 17.6% of NETs were seen in the pancreas, 11.8% in the colon, 8.8% in the rectum, 5.9% in the small intestine, and 2.9% in the appendix. No significant relationship was observed between tumor location and gender (p = .326) and age (p = .641). The tumor diameter ranged from 0.2 cm to 13.91 cm, but the average tumor diameter was 3.84 cm. Solitary tumor was found in 51.5% of cases and multiple tumors in 48.5% of cases. The most common grade was Grade 1 with 41.2% of occurrence. The average of Ki-67 index was 18.36%. There was metastasis in 52.9% of cases. The rate of medical treatment was 48.5%. The median overall survival time of the patients was 23.1 months. In addition, 1-year overall survival was 74.9%, 2-year overall survival was 44.6%, and 5-year overall survival was 35.7%. A statistically significant difference was found between tumor grade and the presence of metastasis, and the overall survival (p = .003 and p = .005).

CONCLUSIONS

The tumor grade and the presence of metastasis in gastrointestinal neuroendocrine tumors were found to be the most important prognostic factors affecting overall survival.

Pediatric Neuroendocrine Neoplasms: Rare Malignancies with Incredible Variability

Neuroendocrine neoplasms (NENs) encompass a variety of neuroendocrine tumors (NETs) and neuroendocrine carcinomas (NECs) which can arise anywhere in the body. While relatively rare in the pediatric population, the incidence of NENs has increased in the past few decades. These neoplasms can be devastating if not diagnosed and treated early, however, symptoms are variable and can be indolent for many years. There is a reported median of 10 years from the appearance of the first symptoms to time of diagnosis. Considering some of these neoplasms have a mortality rate as high as 90%, it is crucial healthcare providers are aware of NENs and remain vigilant. With better provider education and easily accessible resources for information about these neoplasms, awareness can be improved leading to earlier disease recognition and diagnosis. This manuscript aims to provide an overview of both the most common NENs as well as the rarer NENs with high lethality in the pediatric population. This review provides up to date evidence and recommendations, encompassing recent changes in classification and advances in treatment modalities, including recently completed and ongoing clinical trials.

Iodine-125 seed implantation combined chemotherapy for metastatic pancreatic adenocarcinoma with primary colon cancer: A case report

RATIONALE

Colon cancer has a distinct migration aptitude. However, pancreatic metastasis is rare and treatment of inoperable pancreatic cancers is seldom seen.

PATIENT CONCERNS

A 47-year-old woman presented 2-month history of abdominal pain and abdominal distention, with anal cessation of exhaust and defecation for 4 days. A colon cancer radical resection was performed when she diagnosed with colon cancer. After 26 months, the patient complained shoulder and back pain. Multiple intraperitoneal metastases and nonisolated pancreatic metastasis of colon cancer were diagnosed.

DIAGNOSIS

Metastatic pancreatic adenocarcinoma (MPA) with primary colon cancer.

INTERVENTION

Iodine-125 seed implantation combined chemotherapy.

OUTCOMES

She remains free of cancer metastasis and recurrence, and has a good quality of life during the period.

LESSONS SUBSECTIONS

Iodine-125 seed implantation is an effective and safe strategy for unresectable metastatic pancreatic cancer. Iodine-125 seed implantation combined with chemotherapy improve survival for advanced pancreatic metastasis of colon cancer.

Impact of the initial site of metastases on post-recurrence survival for neuroendocrine cervical cancer

Objective

To summarize the risk factors and emphasize the prognostic importance of the site of recurrent neuroendocrine cervical cancer (NECC).

Methods

We enrolled 88 patients who developed recurrence after radical surgery for pathological stage I–IVa primary NECC between January 2003 and 30 December 2020 and classified these cases into 7 groups based on the initial recurrence. The risk factors for post-recurrence survival (PRS) were analyzed by Kaplan–Meier and Cox regression methods.

Results

Among 88 NECC patients, nearly all patients (95.50%) experienced progression within 3 years. The time to progression was significantly longer in patients with lung recurrence than in patients without lung recurrence (p = 0.008). After the first recurrence, the median follow-up was 11.1 months (range 2.37–65.50 months), and the 5-year PRS was only 20.6%. The depth of invasion in the primary surgery, number of recurrent sites, abdominal organ recurrence were correlated with PRS by univariate analysis. Multivariate analyses revealed that the number of recurrent sites (p = 0.025) and abdominal organ recurrence (p = 0.031) were independent prognostic factors. Notably, the combination of immune checkpoint inhibitors and chemotherapy, with or without surgery, showed a 43.8% objective response rate in recurrent NECC.

Conclusion

Patients with abdominal organ recurrence need more sophisticated therapy. The combination of immune therapy and chemotherapy might be an opportunity for recurrent NECC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09737-4.

Clinicopathological Characteristics of Nonfunctional Pancreatic Neuroendocrine Neoplasms and the Effect of Surgical Treatment on the Prognosis of Patients with Liver Metastases: A Study Based on the SEER Database

Background

The incidence of nonfunctional pancreatic neuroendocrine neoplasms (NF-pNENs) has been increasing annually. This study is aimed at investigating the clinicopathological characteristics and high-risk factors of NF-pNENs and the influence of surgical treatment on the prognosis of NF-pNEN patients with liver metastases.

Methods

pNEN patients in this study were obtained from the Surveillance, Epidemiology, and End Results (SEER) database. This study analyzed patients diagnosed with NF-pNENs from 2000 to 2017 who met the inclusion criteria. A retrospective analysis of the clinicopathological characteristics of NF-pNEN patients was conducted. Kaplan-Meier method was used to calculate the survival time. A multivariate Cox regression model was used to analyze the survival outcomes and risk factors.

Results

From 2000 to 2017, the SEER database registered 10576 patients with pNENs and 1774 patients with liver metastases. Cox analysis revealed that age, sex, primary site, grade, tumor stage, surgery, tumor size, and liver metastasis were risk factors of prognosis, with grade being the most influential index. Patients with NF-pNENs with liver metastasis and no metastasis had different primary site, grade, and tumor size. In general, a higher grade was associated with a larger tumor and a greater risk of liver metastasis. Meanwhile, patients with liver metastasis showed that those with tumors originated from the tail of the pancreas had better prognoses than those with tumors originated from other parts. Surgical treatment can improve the prognosis of patients with liver metastases, despite the tumor grade.

Conclusions

The incidence of pNENs has been increasing annually, and the liver has been the most common site of metastasis. Liver metastasis in patients with NF-pNENs, related to tumor size and grade, affected their long-term survival. Surgery significantly improved the prognosis of patients with liver metastases secondary to NF-pNENs with different grades.

Outcomes after high-dose radiation in the management of neuroendocrine neoplasms

BACKGROUND

Neuroendocrine neoplasms (NENs) comprise a rare and heterogenous group of cancers, for which the role of radiation therapy continues to evolve. The purpose of this study is to analyze oncologic outcomes after the use of high-dose radiation in management of NENs at a tertiary hospital.

MATERIALS AND METHODS

We performed a retrospective review of patients who received high-dose radiation with intent to cure or provide durable local control (defined as biologically effective dose (BED) ≥40, α/β = 10) for a localized or metastatic NEN from 2006 to 2019. Evaluation of disease status after radiation was performed according to Response Evaluation Criteria in Solid Tumors (RECIST) criteria when possible. Patients were grouped by differentiation (well-differentiated (WD) or poorly-differentiated (PD)) and stage (localized/locally advanced disease (L) or metastatic (M)) in analysis of probabilities of progression after radiation.

RESULTS

45 patients completed a radiation course with BED ≥40 for a NEN (median BED 72). With a median follow-up of 24 months after radiation, the 2-year actuarial rates of local relapse-free survival, new metastasis-free survival, progression-free survival, and overall survival after radiation were 98%, 45%, 41%, and 69%, respectively. 25 patients (56%) developed new metastases after completion of radiation, including 33% (n = 3) of patients with WD-L disease, 44% (n = 8) of WD-M, 77% (n = 10) of PD-L, and 80% (n = 4) of PD-M, with progressively shorter median times to progression (26, 9, 8, and 3 months, respectively; p = 0.093). Of the 25 patients evaluable by RECIST, 68% (n = 17) achieved either a complete or partial best response in the irradiated lesion.

CONCLUSIONS

These data suggest that focal, high-dose radiation has a role in the management of selected patients with NENs. Local failure is rare in patients with both well-differentiated and poorly-differentiated disease, although the predominant pattern of failure remains development of new metastases.

Systemic Treatment of Advanced Gastroenteropancreatic Neuroendocrine Tumors in Korea: Literature Review and Expert Opinion

Neuroendocrine tumors (NETs) are a group of malignancies arising from neuroendocrine cells and frequently originate in the gastrointestinal tract and pancreas. Although curative resection is the main treatment for localized disease, systemic therapy is needed for relapsed or metastatic/unresectable gastroenteropancreatic NETs (GEP-NETs). Although there are several NET treatment guidelines from various countries, the geographical discrepancies between patient clinical characteristics, the regulatory approval status for therapeutic agents, and medical practices necessitate specific guidelines for Korean patients. We here provide a consensus review of the diagnosis, staging and systemic treatment of Korean GEP-NET patients. Systemic therapy options and the current Korean expert consensus on these treatments, including somatostatin analogs, targeted therapies such as everolimus and sunitinib, peptide receptor radionuclide treatments, and cytotoxic chemotherapies are addressed.

Innumerable hemorrhagic brain metastases from a neuroendocrine tumor grade-1 with prolonged natural history

BACKGROUND

Neuroendocrine tumors (NET) are rare tumors with a low incidence of brain metastasis, especially in grade 1 NET. The most common source of brain metastasis is the lung. We present an unusual case of NET grade 1 with multiple hemorrhagic brain metastases.

CASE DESCRIPTION

A 46-year-old woman, who initially presented with a seizure, was diagnosed with multiple brain and lung lesions. She was offered a biopsy for diagnosis, but she refused and lost to follow up. Eighteen years later, she developed progressive quadriparesis and confusion. A biopsy of the left frontal lobe lesions showed NET grade 1. A lung biopsy of the left upper lobe was consistent with the same diagnosis. The patient's functional status was poor with Eastern Cooperative Oncology Group (ECOG) grade 4. She only received palliative whole-brain radiation therapy (WBRT) and died 3 months after discharge.

CLINICAL DISCUSSION

NET is a spectrum that encompasses benign to malignant cells. There is a female predominance in lower grades and male predominance in higher grades. No effective management for brain metastases was described, and the prognosis remains poor.

CONCLUSION

Multiple brain metastases can be the first presentation of patients with NET. Early diagnosis and treatment may have a more favorable impact on the outcome of this disease. The longstanding numerous hemorrhagic NET brain metastases is exceedingly rare. The neuroimaging appearance is similar to other neoplastic and non-neoplastic lesions. An important differential diagnosis to consider is metastatic melanoma and choriocarcinoma, familial cavernous malformation, diffuse axonal injury, cerebral vasculitis, and amyloid angiopathy.

Initial clinical evaluation of indigenous 90Y-DOTATATE in sequential duo-PRRT approach (177Lu-DOTATATE and 90Y-DOTATATE) in neuroendocrine tumors with large bulky disease: Observation on tolerability, 90Y-DOTATATE post- PRRT imaging characteristics (bremsstrahlung and PETCT) and early adverse effects

¹⁷⁷Lu-DOTATATE peptide receptor radionuclide therapy (PRRT) alone has lesser potential in the clinical setting of neuroendocrine tumor (NET) with large bulky disease and nonhomogeneous somatostatin receptors (SSTR) distribution, owing to lower energy (Eβmax 0.497 MeV) and a shorter particle penetration range (maximum 2–4 mm) of ¹⁷⁷Lu. In large bulky NETs, ⁹⁰Yttrium (⁹⁰Y) has the theoretical advantages because of a longer beta particle penetration range (a maximum soft tissue penetration of 11 mm). Therefore, a combination of ¹⁷⁷Lu and ⁹⁰Y is a theoretically sound concept that can result in better response in metastatic NET with large-bulky lesion and non-homogeneous SSTR distribution. The aim of the study was to determine the feasibility of combining ⁹⁰Y-DOTATATE with ¹⁷⁷Lu-DOTATATE PRRT as sequential duo-PRRT in metastatic NET with (≥5 cm) including the post ⁹⁰Y-DOTATATE-PRRT imaging and also to determine early toxicity of the duo-PRRT approach. A total of 9 patients received combination of ¹⁷⁷Lu-DOTATATE with ⁹⁰Y-DOTATATE (indigenously prepared and approved) through sequential duo-PRRT approach. These 9 NET patients were included and analyzed in this study. All 9 patients had undergone post-PRRT ⁹⁰Y-DOTATATE imaging, including a whole-body planar bremsstrahlung imaging followed by regional single-photon emission computed tomography (SPECT)-computed tomography (CT) imaging and also a regional positron emission tomography–computed tomography imaging. Grading of ⁹⁰Y-DOTATATE and ¹⁷⁷Lu-DOTATATE uptake was done on post-PRRT imaging by both modalities. The size of the lesions ranged from 5.5 cm to 16 cm with average size of 10 cm before sequential duo-PRRT was decided. Sequential duo-PRRT was administered because of stable, unresponsive disease following ¹⁷⁷Lu-DOTATATE in 5 patients (55.6%), progressive disease after ¹⁷⁷Lu-DOTATATE in 2 patients (22.2%), and with neoadjuvant intent in 2 patients (22.2%). The total cumulative dose of ¹⁷⁷Lu-DOTATATE before duo-pRRT ranged from 11.84 GBq to 37 GBq per patient and average administered dose of 27.21 GBq per patient in this study. Out of 9 patients, 8 patients received single cycle of ⁹⁰Y-DOTATATE (ranging from 2.66 GBq to 3.4 GBq per patient with average administered dose of 3.12 GBq per patient). One patient received two cycles of ⁹⁰Y-DOTATATE (total dose of 6.2 GBq). Out of 9 patients, 8 patients showed excellent tracer concentration in lesions on post-PRRT ⁹⁰Y-DOTATATE imaging and the remaining 1 patient showed fairly adequate ⁹⁰Y-DOTATATE tracer uptake in lesion on visual analysis. There was matched ⁹⁰Y-DOTATATE uptake with ⁶⁸Ga-DOTATATE and also with ¹⁷⁷LuDOTATATE in all 9 patients. The sequential duo-PRRT was well tolerated by all patients. Two patients (22.2%) developed mild nausea, one patient (11.1%) developed transient mild-grade hemoglobin toxicity, and one patient (11.1%) developed mild-grade gastrointestinal symptoms (loose motion and abdominal pain). No nephrotoxicity, hepatotoxicity, and other hematological toxicity was observed. The combination of the indigenous ⁹⁰Y-DOTATATE with ¹⁷⁷Lu-DOTATATE PRRT in NET as sequential duo-PRRT was well tolerated, feasible and safe in stable, unresponsive/progressive disease following single isotope ¹⁷⁷Lu-DOTATATE therapy and also in neoadjuvant PRRT setting with large bulky lesion (≥≥5cm). Post-PRRT ⁹⁰Y-DOTATATE imaging showed excellent ⁹⁰Y-DOTATATE uptake in nearly all NET patients. Mild-grade early adverse effects were easily manageable and controllable in this sequential duo-PRRT approach.

Synchronous NET and colorectal cancer development: a case report

Background

The incidence of synchronous gastrointestinal neuroendocrine tumors (GI-NETs) and colorectal cancer is very low.

Case presentation

We present a 72-year-old man diagnosed with a rectal neuroendocrine tumor (NET) with multiple organ metastases and simultaneous sigmoid colon cancer. Although the NET was his prognostic factor, he underwent a laparoscopic sigmoidectomy at first because it was expected that the colon cancer would cause obstruction or bleeding during NET treatment. Subsequently, he started taking everolimus.

Conclusions

We should consider surgical resection of the synchronous cancer before systemic therapy for a GI-NET regardless of the difference in prognosis between synchronous tumors, if the cancer may impair the continuation of systemic therapy.

Treatment Patterns and Survival among Patients with Metastatic Gastroenteropancreatic Neuroendocrine Tumours in Sweden - a Population-based Register-linkage and Medical Chart Review Study

Background: Gastroenteropancreatic neuroendocrine tumours (GEP-NETs) are neoplasms derived from the endocrine system in the gastrointestinal tract and pancreas. Treatment options include surgery; pharmacological treatments like somatostatin analogues (SSA), interferon alpha, molecular targeted therapy and chemotherapy; and peptide receptor radionuclide therapy.

The objective of this study was to describe treatment patterns and survival among patients with metastatic GEP-NET grade 1 or 2 in Sweden.

Methods: Data was obtained via linkage of nationwide registers. Patients diagnosed with metastatic GEP-NET grade 1 or 2 in Sweden between 2005 and 2013 were included (n=811; National population). In addition, medical chart review was performed for the subpopulation diagnosed at Sahlgrenska University Hospital, Gothenburg (n=127; Regional population). Treatment patterns, including treatment sequences, and overall survival were assessed.

Results: Most patients had small intestinal NET (76%). In the regional population, 72% had grade 1 tumours; 50% had functioning tumours. The two most common first-line treatments were surgery (57%) and SSA (25%). After first-line surgery, 46% received SSA, while 40% had no further treatment. After first-line SSA, 52% received surgery, while 27% had no further treatment. Overall median survival time from date of diagnosis was 7.0 years (95% CI 6.2-not reached). Among patients with distant metastases, pancreatic NET (vs. small intestinal NET) was associated with poorer survival (HR 1.9; 95% CI 1.1-3.3), as were liver metastases (HR 3.2; 95% CI 1.5-7.0).

Conclusions: First-line surgery was typically followed by SSA or no further treatment. Among patients with distant metastases, pancreatic NET or liver metastases were associated with a poorer survival.

Poorly differentiated neuroendocrine rectal carcinoma with uncommon immune-histochemical features and clinical presentation with a subcutaneous metastasis, treated with first line intensive triplet chemotherapy plus bevacizumab FIr-B/FOx regimen: an experience of multidisciplinary management in clinical practice

Background

Neuroendocrine tumors (NETs) are heterogeneous, widely distributed tumors arising from neuroendocrine cells. Gastrointestinal (GI)-NETs are the most common and NETs of the rectum represent 15, 2% of gastrointestinal malignancies. Poorly differentiated neuroendocrine carcinomas of the GI tract are uncommon. We report a rare case of poorly differentiated locally advanced rectal neuroendocrine carcinoma with nodal and a subcutaneous metastasis, with a cytoplasmic staining positive for Synaptophysin and Thyroid Transcription Factor-1.

Case presentation

A 72-year-old male presented to hospital, due to lumbar, abdominal, perineal pain, and severe constipation. A whole-body computed tomography scan showed a mass of the right lateral wall of the rectum, determining significant reduction of lumen caliber. It also showed a subcutaneous metastasis of the posterior abdominal wall. Patient underwent a multidisciplinary evaluation, diagnostic and therapeutic plan was shared and defined. The pathological examination of rectal biopsy and subcutaneous nodule revealed features consistent with small-cell poorly differentiated neuroendocrine carcinoma. First line medical treatment with triplet chemotherapy and bevacizumab, according to FIr-B/FOx intensive regimen, administered for the first time in this young elderly patient affected by metastatic rectal NEC was highly active and tolerable, as previously reported in metastatic colo-rectal carcinoma (MCRC). A consistent rapid improvement in clinical conditions were observed during treatment. After 6 cycles of treatment, CT scan and endoscopic evaluation showed clinical complete response of rectal mass and lymph nodes; patient underwent curative surgery confirming the pathologic complete response at PFS 9 months.

Discussion and conclusions

This case report of a locally advanced rectal NEC with an unusual subcutaneous metastasis deserves further investigation of triplet chemotherapy-based intensive regimens in metastatic GEP NEC.

Surgical Resection for Metastatic Tumors in the Pancreas: A Single-Center Experience and Systematic Review

BACKGROUND

Metastatic lesion to the pancreas accounts for approximately 2% of pancreatic neoplasms. There is no prospective, randomized or case-controlled study evaluating the role of pancreatic metastasectomy.

METHODS

The PubMed, EMBASE, and Cochrane Library electronic databases were searched for studies published between January 1, 2001 and December 31, 2017. Studies with five or more patients who received pancreatic metastasectomy and data from our institution (29 patients) were included. The Kaplan-Meier method was used for survival analysis.

RESULTS

A total of 414 patients from 20 institutions who underwent pancreatic resections were included. Of the reported 31 kinds of primary neoplasms, renal-cell carcinoma (RCC) comprised the most (54.3%). At the time of diagnosis, although 40.3% patients were asymptomatic, abdominal pain (34.8%) and jaundice (20.6%) were relatively common. As for surgical type, pancreatoduodenectomy, total pancreatectomy, distal pancreatectomy, and enucleation took up 37.9%, 11.4%, 43.5%, and 7.2% respectively. The mortality and morbidity rates were 1.4% and 48.3% respectively. Patients with symptoms at the time of diagnosis had significantly shorter survival compared with asymptomatic patients (p = 0.017). Those with RCC as primary tumor had significantly longer survival compared with non-RCC patients (p < 0.001). Positive margin also predicts worse prognosis (p = 0.035).

CONCLUSIONS

Pancreatic metastasectomy is safe and associated with acceptable short- and intermediate-term results. In the conditions of RCC as the primary tumor, being asymptomatic, or negative resection margin, a better prognosis after resection can be achieved.

International Union of Basic and Clinical Pharmacology. CV. Somatostatin Receptors: Structure, Function, Ligands, and New Nomenclature

Somatostatin, also known as somatotropin-release inhibitory factor, is a cyclopeptide that exerts potent inhibitory actions on hormone secretion and neuronal excitability. Its physiologic functions are mediated by five G protein-coupled receptors (GPCRs) called somatostatin receptor (SST)1-5. These five receptors share common structural features and signaling mechanisms but differ in their cellular and subcellular localization and mode of regulation. SST₂ and SST₅ receptors have evolved as primary targets for pharmacological treatment of pituitary adenomas and neuroendocrine tumors. In addition, SST₂ is a prototypical GPCR for the development of peptide-based radiopharmaceuticals for diagnostic and therapeutic interventions. This review article summarizes findings published in the last 25 years on the physiology, pharmacology, and clinical applications related to SSTs. We also discuss potential future developments and propose a new nomenclature.

Fundamental study of radiogallium-labeled aspartic acid peptides introducing octreotate derivatives

OBJECTIVE

Somatostatin receptors are highly expressed in neuroendocrine tumors, and many radiolabeled somatostatin analogs for diagnosis and treatment have been developed. To simultaneously detect not only primary cancer but also bone metastases, this study aimed to develop a positron emission tomography probe using generator-produced nuclide Gallium-68 (T_1/2 = 68 min), in which a carrier for primary cancer, a carrier for bone metastases lesions, and a stable gallium complex are introduced into the one molecule. Based on this strategy, the somatostatin receptor-targeted peptide, [Tyr³]-octreotate (TATE), aspartic acid peptide (D_n) with high binding affinity for hydroxyapatite, and Ga-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) as a stable gallium complex were selected. The novel complexes, Ga-DOTA-D_n-TATE (n = 0, 2, 5, 8, or 11), were designed, synthesized, and evaluated. The radiogallium complexes were prepared using the easy-to-handle radioisotope ⁶⁷Ga due to relatively long half-life.

METHODS

The radiogallium complex precursor DOTA-D_n-TATE was synthesized by the Fmoc-based solid-phase method and by the air oxidation method to form the disulfide bond. [⁶⁷Ga]Ga-DOTA-D_n-TATE was synthesized by reacting DOTA-D_n-TATE and ⁶⁷Ga. Hydroxyapatite binding assays, in vitro cellular uptake experiments in AR42J tumor cells, in biodistribution experiments in AR42J tumor-bearing mice, were performed using [⁶⁷Ga]Ga-DOTA-D_n-TATE.

RESULTS

The radiochemical purities of [⁶⁷Ga]Ga-DOTA-D_n-TATE were > 96.0%. In in vitro and in vivo experiments, [⁶⁷Ga]Ga-DOTA-D₁₁-TATE had a high affinity for hydroxyapatite and highly accumulated in bone. However, the uptake of [⁶⁷Ga]Ga-DOTA-D₁₁-TATE into somatostatin receptor-positive AR42J cells was lower than that of [⁶⁷Ga]Ga-DOTA-TATE, and the accumulation of [⁶⁷Ga]Ga-DOTA-D₁₁-TATE in tumor was significantly low.

CONCLUSION

Ga-DOTA-D₁₁-TATE may not be recognized by somatostatin receptor by the introduction of D₁₁, and the charge adjustment may be important for somatostatin receptor-positive cell uptake.

Surgery Provides Long-Term Survival in Patients with Metastatic Neuroendocrine Tumors Undergoing Resection for Non-Hormonal Symptoms

INTRODUCTION

Patients with metastatic neuroendocrine tumor (NET) often have an indolent disease course yet the outcomes for patients with metastatic NET undergoing surgery for non-hormonal (NH) symptoms of GI obstruction, bleeding, or pain is not known.

METHODS

We identified patients with metastatic gastroenteropancreatic NET who underwent resection from 2000 to 2016 at 8 academic institutions who participated in the US Neuroendocrine Tumor Study Group.

RESULTS

Of 581 patients with metastatic NET to liver (61.3%), lymph nodes (24.1%), lung (2.1%), and bone (2.5%), 332 (57.1%) presented with NH symptoms of pain (n = 223, 67.4%), GI bleeding (n = 54, 16.3%), GI obstruction (n = 49, 14.8%), and biliary obstruction (n = 22, 6.7%). Most patients were undergoing their first operation (85.4%) within 4 weeks of diagnosis. The median overall survival was 110.4 months, and operative intent predicted survival (p < 0.001) with 66.3% undergoing curative resection. Removal of all metastatic disease was associated with the longest median survival (112.5 months) compared to debulking (89.2 months), or palliative resection (50.0 months; p < 0.001). The 1-, 3-, and 12-month mortality was 3.0%, 4.5%, and 9.0%, respectively. Factors associated with 1-year mortality included palliative operations (OR 6.54, p = 0.006), foregut NET (5.62, p = 0.042), major complication (4.91, p = 0.001), and high tumor grade (11.2, p < 0.001). The conditional survival for patients who lived past 1 year was 119 months.

CONCLUSIONS

Patients with metastatic NET and NH symptoms that necessitate surgery have long-term survival, and goals of care should focus on both oncologic and quality of life impact. Surgical intervention remains a critical component of multidisciplinary care of symptomatic patients.

Radionuclide Therapy for Neuroendocrine Tumors

Peptide receptor radionuclide therapy (PRRT) is a form of systemic radiotherapy that allows targeted delivery of radionuclides to tumor cells expressing high levels of somatostatin receptors. The two radiopeptides most commonly used for PRRT, ⁹⁰Y-DOTATOC and ¹⁷⁷Lu-DOTATATE, have been successfully employed for more than a decade for the treatment of advanced neuroendocrine tumors (NETs). Recently, the phase III, randomized NETTER-1 trial has compared ¹⁷⁷Lu-DOTATATE versus high-dose octreotide LAR in patients with progressive, metastatic midgut NETs, demonstrating exceptional tolerability and efficacy. This review summarizes recent developments in the field of radionuclide therapy for gastroenteropancreatic and lung NETs and considers possible strategies to further enhance its clinical efficacy.

Incidental metastatic mediastinal atypical carcinoid in a patient with parathyroid adenoma: a case report

Background

Atypical carcinoid arising from the mediastinal tissue is a rare neuroendocrine tumor and an association with parathyroid adenoma is very unusual. We report an unusual case of atypical carcinoid of mediastinum with metastasis in a patient presenting with parathyroid adenoma, which is the first case to be reported from Pakistan.

Case presentation

A 51-year-old Pakistani man was seen in postoperative intensive care after right parathyroidectomy and mediastinal mass resection for the management of postoperative hypocalcaemia. He had a background history of dyspnea. Examination was unremarkable. Preoperative laboratory evaluation revealed a calcium level of 12.7 mg/dl, phosphate of 1.9 mg/dl, serum albumin of 4.8 g/dl, alkaline phosphate of 94 U/L, and serum intact parathyroid hormone level 413.8 pg/ml. A technetium-99m sestamibi parathyroid scan showed right parathyroid increased tracer uptake. Further workup revealed a large mediastinal mass which was diagnosed as atypical carcinoid after Tru-Cut biopsy. He underwent right-sided parathyroidectomy and resection of the mediastinal mass. The histopathology confirmed it to be a parathyroid adenoma and atypical carcinoid tumor of his mediastinum with metastasis in his lymph node and parathyroid gland. Somatostatin receptor scintigraphy revealed a well-defined focus in his left hypochondriac region consistent with a somatostatin receptor scintigraphy-avid tumor. He was started on everolimus and planned for octreotide therapy.

Conclusions

We describe an incidental finding of atypical carcinoid of the mediastinum in a patient diagnosed as having parathyroid adenoma. Clinical manifestations of neuroendocrine syndromes are challenging. Some tumors cluster in a non-classic description with other common neoplasms. They rarely present in isolation, remain clinically silent, and need aggressive workup with the aid of imaging and histopathology.

Somatostatin analogues in acromegaly and gastroenteropancreatic neuroendocrine tumours: past, present and future

Acromegaly is a hormonal disorder that arises when the pituitary gland secretes excess growth hormone (GH), which in turn stimulates a concomitant increase in serum insulin-like growth factor 1 (IGF-1) levels. Gastroenteropancreatic neuroendocrine tumours (GEP-NET) constitute a heterogeneous group of tumours that can secrete serotonin and a variety of peptide hormones that may cause characteristic symptoms known as carcinoid syndrome or other symptoms and hormonal hypersecretion syndromes depending on the tumour's site of origin. Current medical therapy for the treatment of acromegaly and GEP-NET involves the administration of somatostatin analogues that effectively suppress excess hormone secretion. After its discovery in 1979, octreotide became the first synthetic biologically stable somatostatin analogue with a short-acting formulation of octreotide introduced into clinical practice in the late 1980s. Lanreotide, another somatostatin analogue, became available in the mid-1990s initially as a prolonged-release formulation administered every 10 or 14 days. Long-acting release formulations of both octreotide (Sandostatin LAR and Novartis) and lanreotide (Somatuline Autogel, Ipsen), based on microparticle and nanoparticle drug-delivery technologies, respectively, were later developed, which allowed for once-monthly administration and improved convenience. First-generation somatostatin analogues remain one of the cornerstones of medical therapy in the management of pituitary and GEP-NET hormone hypersecretion, with octreotide having the longest established efficacy and safety profile of the somatostatin analogue class. More recently, pasireotide (Signifor), a next-generation multireceptor-targeted somatostatin analogue, has emerged as an alternative therapeutic option for the treatment of acromegaly. This review summarizes the development and clinical success of somatostatin analogues.

Assessment of intracranial metastases from neuroendocrine tumors/carcinoma

BACKGROUND

The most common sites of origin for neuroendocrine carcinoma are gastrointestinal tract and its accessory glands, and lungs.

MATERIALS AND METHODS

One-hundred fifty cases diagnosed with metastatic brain lesions were retrieved from hospital records within 5 years. For these cases, the primary neoplasm, histopathological classification, metastasis, treatment, and fate all were studied.

RESULTS

Intracranial deposits were detected in 10%. The primary lesion was in the lungs in 87% of patients, and 1 patient in the breast and 1 in esophagus. Pathological classification of the primary lesion was Grade 2 (MIB-1: 3-20%) in 1 patient and neuroendocrine carcinoma (MIB-1: ≥21%) in 14 patients. The median period from onset of the primary lesion up to diagnosis of brain metastasis was 12.8 months. About 33% of patients had a single metastasis whereas 67% patients had multiple metastases. Brain metastasis was extirpated in 33% of patients. Stereotactic radiotherapy alone was administered in 20% of patients, and brain metastasis was favorably controlled in most of the patients with coadministration of cranial irradiation as appropriate. The median survival period from diagnosis of brain metastasis was 8.1 months.

CONCLUSION

Most of patients with brain metastasis from neuroendocrine carcinoma showed the primary lesion in the lungs, and they had multiple metastases to the liver, lymph nodes, bones, and so forth at the time of diagnosis of brain metastasis. The guidelines for accurate diagnosis and treatment of neuroendocrine carcinoma should be immediately established based on further analyses of those patients with brain metastasis.

Elevated Alkaline Phosphatase Prior to Transarterial Chemoembolization for Neuroendocrine Tumors Predicts Worse Outcomes

INTRODUCTION

We hypothesized that an elevated preoperative alkaline phosphatase (AP) predicted worse outcomes for patients undergoing transarterial chemoembolization (TACE) for neuroendocrine tumor (NET) liver metastases.

METHODS

We reviewed all patients who underwent TACE for metastatic NET between 2009 and 2013. Survival was evaluated using preprocedure variables.

RESULTS

One hundred and nine patients underwent 210 TACE procedures. The average age was 57.7 years (range 20-78). Primary sites included pancreas (N = 20), other gastrointestinal (N = 52), lung (N = 9), and unknown (N = 28). The tumor was grade 1 in 68 (62 %), grade 2 in 21 (19 %), and grade 3 in 3 (3 %). Extrahepatic disease was present in 54 (50 %) and greater than 50 % hepatic tumor burden by imaging in 63 (58 %). Elevated bilirubin occurred in 8 (7 %), elevated AP in 22 (20 %), elevated ALT in 21 (19 %), and elevated AST in 41 (38 %). Univariate predictors included tumor grade (43 vs 27 vs 21 months, p = 0.015), hepatic tumor burden (59 vs 37 months, p = 0.009), and elevated AP (59 vs 23 months, p < 0.001). On multivariate analysis, only elevated AP (p = 0.001) predicted worse survival.

CONCLUSIONS

Elevated AP prior to TACE for metastatic NET portends a worse survival outcome, even more so than tumor grade or extent of hepatic disease.

Clinicopathological analysis in patients with neuroendocrine tumors that metastasized to the brain

Background

A neuroendocrine tumor (NET) can develop anywhere in the body, but is mainly found in the pancreas, gastrointestinal tract, and lungs. This report is a retrospective study of the clinicopathological features of NET patients with brain metastasis whose tissue diagnosis was made at our hospital.

Methods

Patients with brain metastasis evidenced by clinical records and images were accumulated among 302 patients in whom tissue diagnosis of NETs was made at our hospital between 2008 and 2013. In the patients, the primary lesion, pathological classification, pattern of metastasis, details of treatment, and outcomes were analyzed.

Results

Brain metastasis was observed in 31 patients (10.3 %). The primary lesion was in the lungs in 26 patients (83.9 %), and the mammary glands, esophagus, and uterus in 1 patient each. Primary lesions were unknown in 2 patients, including 1 patient in whom NETs were detected in the lymph nodes alone. Pathological classification of the primary lesion was NET Grade 2 (Ki-67: 3 to 20 %) in 3 patients and neuroendocrine carcinoma (NEC, Ki-67: ≥21 %) in 26 patients. The median period from onset of the primary lesion up to diagnosis of brain metastasis was 12.8 months, and the brain lesion preceded brain metastasis in 6 patients. Ten patients had a single metastasis whereas 21 patients had multiple metastases, but no characteristics were observed in their images. Brain metastasis was extirpated in 10 patients. Stereotactic radiotherapy alone was administered in 6 patients, and brain metastasis was favorably controlled in most of the patients with coadministration of cranial irradiation as appropriate. The median survival period from diagnosis of brain metastasis was 8.1 months, and the major cause of death was aggravation of the primary lesion or metastatic lesions in other organs.

Conclusion

Most of NET patients with brain metastasis showed the primary lesion of NEC in the lungs, and they had multiple metastases to the liver, lymph nodes, bones, and so forth at the time of diagnosis of brain metastasis. The guidelines for accurate diagnosis and treatment of NETs should be immediately established based on further analyses of NET patients with brain metastasis.

Reviewing the Osteotropism in Neuroendocrine Tumors: The Role of Epithelial-Mesenchymal Transition

BACKGROUND

Neuroendocrine tumors (NETs) metastasize to the bone. However, the incidence, clinical features, management and pathogenesis of bone involvement in NET patients have been poorly investigated.

METHODS

We reviewed all published reports of histologically confirmed bone metastatic NETs and explored clinical, radiological, prognostic and therapeutic characteristics in a population of 152 patients. We then evaluated immunohistochemical expression of a panel of eight epithelial-mesenchymal transition (EMT)-related factors including SNAIL, TGF-β1, CTGF, IL-11, PTHrP, EpCAM, CXCR4 and RANK in an independent cohort of 44 archival primary NETs. Biomarker expression was correlated with clinicopathological variables, including skeletal involvement, and tested for survival prediction.

RESULTS

We found that 55% of NET patients with bone metastases were male, with a median age of 55 years at diagnosis. Metastases were restricted to the skeleton in 34% of the NET population, and axial and osteoblastic lesions were prevalent. NETs differently expressed proteins involved in EMT activation. High CXCR4 (p < 0.0001) and low TGF-β1 levels (p = 0.0015) were significantly associated with increased risk of skeletal metastases, suggesting that EMT is implicated in NET osteotropism. By applying an algorithm measuring distinct immunohistochemical predictors of osteotropism on primary tumors, we were able to identify NET patients with bone metastases with a sensitivity and specificity of 91 and 100%, respectively (p < 0.0001). Patients whose primary tumors expressed CTGF (p = 0.0007) as well as the truncated form of EpCAM (p = 0.06) showed shorter survival.

CONCLUSION

Although underestimated, bone metastases are a prominent feature of NETs, and the tumor expression of EMT markers at diagnosis may predict concurrent or subsequent skeleton colonization.

Bone metastases in well-to-moderately differentiated neuroendocrine tumors: a single institutional review from the Ohio State University Medical Center

OBJECTIVE

In this study, we look at the clinical features associated with bone metastasis in patients with well-to-moderately differentiated neuroendocrine tumors (NETs), specifically primary tumor characteristics, complications, elevated hormone levels, and survival.

METHODS

A retrospective study at the Ohio State University was performed on patients diagnosed with well-to-moderately differentiated NETs from 2000 to 2010 who were found to have bone metastases. A control group of patients with metastatic NETs without bone metastases was matched with regard to demographic and clinical data.

RESULTS

Of 341 patients with well-to-moderately differentiated NETs, 40 patients were found with bone metastases within the 10-year study period. Patients with bone metastases had shorter survival (median, 52 months) compared to the control group (median, 98 months; P = 0.024). Of 26 patients with bone metastases who died, 6 (23%) patients had a cause of death related to their bone metastatic disease. There were 8 patients with spinal cord compression, and 6 with pathologic fractures.

CONCLUSIONS

Our study suggests that patients with well-to-moderately differentiated NETs metastatic to bone have larger tumors, more frequently elevated pancreastatin, and shorter survival than patients without bone metastases, with complications of bone metastases significantly contributing to mortality and morbidity.

Diagnosis and prediction of neuroendocrine liver metastases: a protocol of six systematic reviews

Background

Patients with hepatic metastases from neuroendocrine tumors (NETs) benefit from an early diagnosis, which is crucial for the optimal therapy and management. Diagnostic procedures include morphological and functional imaging, identification of biomarkers, and biopsy.

Objective

The aim of six systematic reviews discussed in this study is to assess the predictive value of Ki67 index and other biomarkers, to compare the diagnostic accuracy of morphological and functional imaging, and to define the role of biopsy in the diagnosis and prediction of neuroendocrine tumor liver metastases.

Methods

An objective group of librarians will provide an electronic search strategy to examine the following databases: MEDLINE, EMBASE and The Cochrane Library (Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials (CENTRAL), Database of Abstracts of Reviews of Effects). There will be no restriction concerning language and publication date. The qualitative and quantitative synthesis of the systematic review will be conducted with randomized controlled trials (RCT), prospective and retrospective comparative cohort studies, and case-control studies. Case series will be collected in a separate database and only used for descriptive purposes.

Results

This study is ongoing and presents a protocol of six systematic reviews to elucidate the role of histopathological and biochemical markers, biopsies of the primary tumor and the metastases as well as morphological and functional imaging modalities for the diagnosis and prediction of neuroendocrine liver metastases.

Conclusions

These systematic reviews will assess the value and accuracy of several diagnostic modalities in patients with NET liver metastases, and will provide a basis for the development of clinical practice guidelines.

Trial Registration

The systematic reviews have been prospectively registered with the International Prospective Register of Systematic Reviews (PROSPERO): CRD42012002644; http://www.metaxis.com/prospero/full_doc.asp?RecordID=2644 (Archived by WebCite at http://www.webcitation.org/6LzCLd5sF), CRD42012002647; http://www.metaxis.com/prospero/full_doc.asp?RecordID=2647 (Archived by WebCite at http://www.webcitation.org/6LzCRnZnO), CRD42012002648; http://www.metaxis.com/prospero/full_doc.asp?RecordID=2648 (Archived by WebCite at http://www.webcitation.org/6LzCVeuVR), CRD42012002649; http://www.metaxis.com/prospero/full_doc.asp?RecordID=2649 (Archived by WebCite at http://www.webcitation.org/6LzCZzZWU), CRD42012002650; http://www.metaxis.com/prospero/full_doc.asp?RecordID=2650 (Archived by WebCite at http://www.webcitation.org/6LzDPhGb8), CRD42012002651; http://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42012002651#.UrMglPRDuVo (Archived by WebCite at http://www.webcitation.org/6LzClCNff).

Long-term management of a patient with well-differentiated pulmonary neuroendocrine carcinoma: a case report

Pulmonary neuroendocrine tumors (NET) are rare, and very few published reports have described the long-term treatment of patients with this disease. Current treatment options for patients with metastatic well-differentiated pulmonary NET are limited. This case report details the long-term treatment of a 62-year-old female patient with well-differentiated pulmonary NET and multiple liver metastases. The heavily pretreated patient achieved radiographic stability in measurable disease, improvement in nonmeasurable disease, and symptomatic improvement over 3 years while receiving the combination of everolimus and octreotide long-acting repeatable (LAR). Treatment was well tolerated without mucositis, rash, or pneumonitis. This case report suggests that the combination of everolimus and octreotide LAR may be a novel treatment option for heavily pretreated patients with metastatic well-differentiated pulmonary NET, but these findings require further analysis in clinical trials.

Pancreatic neuroendocrine tumors: biology, diagnosis,and treatment

Pancreatic neuroendocrine tumors (PNETs), a group of endocrine tumors arising in the pancreas, are among the most common neuroendocrine tumors. The genetic causes of familial and sporadic PNETs are somewhat understood, but their molecular pathogenesis remains unknown. Most PNETs are indolent but have malignant potential. The biological behavior of an individual PNET is unpredictable; higher tumor grade, lymph node and liver metastasis, and larger tumor size generally indicate a less favorable prognosis. Endocrine testing, imaging, and histological evidence are necessary to accurately diagnose PNETs. A 4-pronged aggressive treatment approach consisting of surgery, locoregional therapy, systemic therapy, and complication control has become popular in academic centers around the world. The optimal application of the multiple systemic therapeutic modalities is under development; efficacy, safety, availability, and cost should be considered when treating a specific patient. The clinical presentation, diagnosis, and treatment of specific types of PNETs and familial PNET syndromes, including the novel Mahvash disease, are summarized.

The expanding role of somatostatin analogs in the management of neuroendocrine tumors

BACKGROUND

Neuroendocrine tumors (NETs) are neoplasms arising most often in the GI tract, pancreas, or lung. Diagnosis of NETs is often delayed until the disease is advanced, because of the variable and nonspecific nature of the initial symptoms. Surgical resection for cure is therefore not an option for most patients.

METHODS

Somatostatin analogues represent the cornerstone of therapy for patients with NETs. This article reviews the important role that somatostatin analogues continue to play in the treatment of patients with NETs.

RESULTS

Octreotide was the first somatostatin analogue to be developed; more than 30 years of data have accumulated demonstrating its efficacy and safety. Lanreotide is another somatostatin analogue in clinical use, and pasireotide is a promising somatostatin analogue in development. Newer long-acting depot formulations are now available offering once-monthly administration. Although octreotide was initially developed for symptom control, recent results indicate that it also has an antiproliferative effect, significantly increasing time to progression in patients with midgut NETs. Combinations of octreotide with other targeted therapies may further improve patient outcomes. Findings in recent studies of the combination of octreotide and the mTOR inhibitor everolimus are encouraging. The combinations of octreotide with other agents (eg, interferon-α, bevacizumab, cetuximab, AMG-706, and sunitinib) are being investigated.

CONCLUSIONS

Somatostatin analogues have been used to treat the symptoms of NETs for decades and also have an antineoplastic effect, markedly prolonging progression-free survival. Somatostatin analogues are likely to remain the cornerstone of treatment for most patients with advanced NETs. Promising new combination therapies are undergoing clinical investigation.

Phase 2 study of everolimus monotherapy in patients with nonfunctioning neuroendocrine tumors or pheochromocytomas/paragangliomas

BACKGROUND

The current study was conducted to evaluate the efficacy and safety of everolimus in the treatment of patients with nonfunctioning neuroendocrine tumors (NETs) or pheochromocytomas/paragangliomas.

METHODS

Patients with histologically confirmed nonfunctioning NETs or pheochromocytomas/paragangliomas and with documented disease progression before study enrollment were eligible for the current study. Everolimus was administered daily at a dose of 10 mg for 4 weeks. Response was assessed by Response Evaluation Criteria In Solid Tumors (RECIST; version 1.0) every 8 weeks. The primary endpoint was the 4-month progression-free survival rate (PFSR). The hypothesis of the current study was that the 4-month PFSR would increase from 50% to 65%. Safety was evaluated using the National Cancer Institute's Common Terminology Criteria for Adverse Events (version 3.0).

RESULTS

A total of 34 patients were enrolled. Of these, 27 patients had nonfunctioning NETs, 5 had pheochromocytomas, and 2 had paragangliomas. The 4-month PFSR was 78%. Partial response (PR) was observed in 3 patients. Twenty-eight patients had stable disease (SD) and 2 patients developed progressive disease (PD). The response rate (RR) and overall disease control rate (DCR) were 9.0% (95% confidence interval [95% CI], 0%-18.6%) and 93.9% (95% CI, 85.8%-100%), respectively. The PFS was 15.3 months (95% CI, 4.6 months-26.0 months). Of the patients with nonfunctioning NETs, 3 achieved a PR and 23 had SD (RR, 11.1%; DCR, 100%); the PFS was 17.1 months (95% CI, 11.1 months-23.0 months) and the 4-month PFSR was 90.0%. Twenty-one patients (80.8%) demonstrated tumor shrinkage. In 7 patients with pheochromocytomas/paragangliomas, 5 achieved SD, and 2 developed PD. The PFS was 3.8 months (95% CI, 0.5 months-7.0 months) and the 4-month PFSR was 42.9%. Four patients demonstrated tumor shrinkage. The major grade 3/4 adverse events were thrombocytopenia (14.7%), hyperglycemia (5.9%), stomatitis (5.9%), and anemia (5.9%).

CONCLUSIONS

Everolimus was associated with high therapeutic efficacy and tolerability in patients with nonfunctioning NETs, and demonstrated modest efficacy in patients with pheochromocytomas/paragangliomas.

[Pharmacologic therapy for neuroendocrine tumours]

Neuroendocrine tumours are heterogeneous and rare malignancies arising from endocrine cells located in various anatomical locations. Neuroendocrine tumours can be functional and may produce a wide variety of mediators, however, the majority of neuroendocrine tumours do not produce biologically active hormones (non-functioning tumours). On the basis of their pathological and biological characteristics they can be well differentiated as low malignant and poorly differentiated highly malignant tumours. In the case of the advanced low malignant tumours the application of somatostatin analogues not only may control symptoms but they also have direct anti-tumour effect. The use of higher doses of somatostatin analogues or new subtype selective agonists, and chimeric or pan-somatostatin analogues will probably improve the clinical management of the patients who fail to respond to standard somatostatin analogue treatment. Data show that somatostatin analogues and interferon have a synergistic effect. The currently used chemotherapy in progressive neuroendocrine tumors is mainly devoted to poorly differentiated tumours, but also to well differentiated carcinomas which are either not eligible or resistant to other therapies. However, the new anti-tumoural agents, could eventually replace these old recipes in the near future. Clinical trials show that telozomide with capecitabine result in more favorable toxic profile and higher and longer response rate in the case of well-differentiated tumours. Targeted therapy became a new possibility in neuroendocrine tumours too. The monoclonal antibody bevacizumab, which affects the vascular endothelial growth factor receptors, has beneficial effects both in monotherapies and in combination with somatostatin analogues or with oxaliplatine and capecitabine. Recently, the low molecular multikinase inhibitor, sunitinib has demonstrated efficacy in pancreas neuroendocrine tumors, which was proven in a phase 3 trial. The mammalian target of the rapamycin inhibitor everolimus, currently investigated in phase 3 trials, was also efficient in the same subtype. Further trials are needed to determine that in the case of other types of neuroendocrine tumours which targeted therapy could be efficient. Radioisotope-labeled peptide receptor therapy with ¹³¹I-MIBG, ⁹⁰Y-DOTA-TOC or ¹⁷⁷Lu-DOTA-TOC may offer a highly effective option for patients with progressive and advanced stage of neuroendocrine tumours. The purpose of this review is to review and analyze data available regarding contemporary chemotherapeutic management of neuroendocrine tumours in order to determine which therapy should be applied in the therapeutic arsenal.

Treatment of liver metastases in patients with neuroendocrine tumors: a comprehensive review

Patients diagnosed with Neuroendocrine Tumors (NET) often are also diagnosed with Neuroendocrine Liver Metastases (NLM) during the course of their disease. NLM can cause significant morbidity and mortality, oftentimes much more than compared to patients with NET. Treatment options have been limited in the past, focusing on surgical resections, for which only a minority of patients are candidates. However, developments of new treatment modalities have progressed rapidly and patients with NLM now have significantly more options, including surgical-directed therapies; liver-directed therapies; and nonsurgical, non-liver-directed therapies. This review provides information about the roles of hepatic resection, orthotopic liver resection, radiofrequency ablation, hepatic artery embolization and hepatic artery chemoembolization, hepatic artery radioembolization and selective internal radiation therapy, peptide receptor radionuclide therapy, systemic chemotherapy, biotherapies including somatostatin analogs and interferon-α, vascular endothelial growth factor and mTOR targets, and microRNA-regulated pathways. Given these new options, the clinician can tailor therapy specific to the patient diagnosed with NLM, thereby giving the patient the best possible chance of prolonged survival.