Peptide receptor radionuclide therapy for patients with advanced pancreatic neuroendocrine tumors

PET/MRI: pictorial review of hepatobiliary and pancreatic applications

PET and MRI both play valuable roles in the management of hepatobiliary and pancreatic (HBP) malignancies. Simultaneous PET/MRI combines the excellent soft-tissue resolution and anatomic details from MRI with functional information from PET in a single comprehensive examination. MRI is the main imaging modality in evaluating HCC, playing important roles in screening, characterization, local extent, and evaluating tumor response, whereas 18F-fluorodeoxyglucose (FDG) PET can help evaluate for lymph node involvement and metastatic disease. In cholangiocarcinoma and pancreatic malignancies, both PET and MRI have excellent utility in initial staging as well as assessing treatment response. In all HBP malignancies, FDG-PET/MRI is a unique problem-solving tool in complex cases and diagnostic challenges, especially after locoregional therapy and when differentiating residual or recurrent viable disease from inflammatory and other benign processes. In this manuscript, we review the role of PET/MRI in the diagnosis, staging, assessing treatment response, and characterizing post-treatment processes. With the introduction of multiple new tracers, the value of PET/MRI has not yet been fully realized, and more studies are needed to demonstrate the utility and efficacy of PET/MRI in improving patient care in hepatobiliary and pancreatic oncology.

Sequencing Treatments in Patients with Advanced Well-Differentiated Pancreatic Neuroendocrine Tumor (pNET): Results from a Large Multicenter Italian Cohort

Background: The optimal treatment sequencing for advanced, well-differentiated pancreatic neuroendocrine tumors (pNETs) is unknown. We performed a multicenter, retrospective study to evaluate the best treatment sequence in terms of progression-free survival to first-line (PFS1) and to second-line (PFS2), and overall survival among patients with advanced, well-differentiated pNETs. Methods: This multicenter study retrospectively analyzed the prospectively collected data of patients with sporadic well-differentiated pNETs who received at least two consecutive therapeutic lines, with evidence of radiological disease progression before change of treatment lines. Results: Among 201 patients, 40 (19.9%) had a grade 1 and 149 (74.1%) a grade 2 pNET. Primary tumor resection was performed in 98 patients (48.8%). First-line therapy was performed in 128 patients with somatostatin analogs (SSA), 35 received SSA + radioligand therapy (RLT), 21 temozolomide-based chemotherapy, and 17 SSA + targeted therapy. PFS was significantly longer in patients with grade 1 pNETs compared to those with grade 2, in patients who received primary tumor surgery, and in patients treated with RLT compared to other treatments. At multivariate analysis, the use of upfront RLT was independently associated with improved PFS compared to SSA. Second-line therapy was performed in 94 patients with SSA + targeted therapy, 35 received chemotherapy, 45 SSA + RLT, and 27 nonconventional-dose SSA or SSA switch. PFS was significantly longer in patients treated with RLT compared to other treatments. At multivariate analysis, the type of second-line therapy was independently associated with the risk for progression. OS was significantly longer in patients who received primary tumor surgery, with Ki67 < 10%, without extrahepatic disease, and in patients who received SSA-RLT sequence compared to other sequences. Conclusions: In this large, multicenter study, RLT was associated with better PFS compared to other treatments, and the SSA-RLT sequence was associated with the best survival outcomes in patients with pNETs with Ki67 < 10%. Primary tumor surgery was also associated with improved survival.

SEOM-GETNE clinical guidelines for the diagnosis and treatment of gastroenteropancreatic and bronchial neuroendocrine neoplasms (NENs) (2022)

Neuroendocrine neoplasms (NENs) are a heterogeneous family of tumors of challenging diagnosis and clinical management. Their incidence and prevalence continue to rise mainly due to an improvement on diagnostic techniques and awareness. Earlier detection, along with steadfast improvements in therapy, has led to better prognosis over time for advanced gastrointestinal and pancreatic neuroendocrine tumors. The aim of this guideline is to update evidence-based recommendations for the diagnosis and treatment of gastroenteropancreatic and lung NENs. Diagnostic procedures, histological classification, and therapeutic options, including surgery, liver-directed therapy, peptide receptor radionuclide therapy, and systemic hormonal, cytotoxic or targeted therapy, are reviewed and discussed, and treatment algorithms to guide therapeutic decisions are provided.

Controversy Over Liver Transplantation or Resection for Neuroendocrine Liver Metastasis: Tumor Biology Cuts the Deal

BACKGROUND

In patients with neuroendocrine liver metastasis (NELM), liver transplantation (LT) is an alternative to liver resection (LR), although the choice of therapy remains controversial. In this multicenter study, we aim to provide novel insight in this dispute.

METHODS

Following a systematic literature search, 15 large international centers were contacted to provide comprehensive data on their patients after LR or LT for NELM. Survival analyses were performed with the Kaplan-Meier method, while multivariable Cox regression served to identify factors influencing survival after either transplantation or resection. Inverse probability weighting and propensity score matching was used for analyses with balanced and equalized baseline characteristics.

RESULTS

Overall, 455 patients were analyzed, including 230 after LR and 225 after LT, with a median follow-up of 97 months [95% confidence interval (CI): 85-110 months]. Multivariable analysis revealed G3 grading as a negative prognostic factor for LR [hazard ratio (HR)=2.22, 95% CI: 1.04-4.77, P =0.040], while G2 grading (HR=2.52, 95% CI: 1.15-5.52, P =0.021) and LT outside Milan criteria (HR=2.40, 95% CI: 1.16-4.92, P =0.018) were negative prognostic factors in transplanted patients. Inverse probability-weighted multivariate analyses revealed a distinct survival benefit after LT. Matched patients presented a median overall survival (OS) of 197 months (95% CI: 143-not reached) and a 73% 5-year OS after LT, and 119 months (95% CI: 74-133 months) and a 52.8% 5-year OS after LR (HR=0.59, 95% CI: 0.3-0.9, P =0.022). However, the survival benefit after LT was lost if patients were transplanted outside Milan criteria.

CONCLUSIONS

This multicentric study in patients with NELM demonstrates a survival benefit of LT over LR. This benefit depends on adherence to selection criteria, in particular low-grade tumor biology and Milan criteria, and must be balanced against potential risks of LT.

Current and upcoming radionuclide therapies in the direction of precision oncology: A narrative review

As new molecular tracers are identified to target specific receptors, tissue, and tumor types, opportunities arise for the development of both diagnostic tracers and their therapeutic counterparts, termed "theranostics." While diagnostic tracers utilize positron emitters or gamma-emitting radionuclides, their theranostic counterparts are typically bound to beta and alpha emitters, which can deliver specific and localized radiation to targets with minimal collateral damage to uninvolved surrounding structures. This is an exciting time in molecular imaging and therapy and a step towards personalized and precise medicine in which patients who were either without treatment options or not candidates for other therapies now have expanded options, with tangible data showing improved outcomes. This manuscript explores the current state of theranostics, providing background, treatment specifics, and toxicities, and discusses future potential trends.

Comparison of nomogram for Primary Nonfunctional Pancreatic Neuroendocrine Tumors based on the 7th vs 8th edition of the AJCC cancer staging manual

BACKGROUND

Our study aimed to construct and validate prognostic nomograms for predicting survival for patients with Nonfunctional Pancreatic neuroendocrine tumor (NF-pNET).

METHODS

This retrospective study included 1824 patients diagnosed with NF-pNET in the Surveillance, Epidemiology and End Results database between 2004 and 2016. Randomization divided the patients into training (n = 1278) and validation (n = 546) cohorts. Prognostic factors were determined using Cox regression analyses, nomograms based on AJCC 7th and 8th staging system were constructed separately. The prediction models were validated using internal validation and external validation.

RESULTS

Age, year of diagnosis, primary tumor site, grade, 7th or 8th TNM stage, surgery, tumor size were determined as prognostic indicator to construct two nomograms. Harrell's concordance index (C-index) of two nomograms exhibited a clinical predictive ability of 0.828 (95%CI, 0.808~0.849) vs 0.828 (95% CI, 0.808~0.849) in the internal verification. The c-index in the external validation was 0.812 (95%CI, 0.778~0.864) vs 0.814 (95% CI, 0.779~0.848). The predictive power of the two nomograms is comparable.

CONCLUSIONS

Our nomogram may be a effective tool for predicting overall survival in patients with NF-pNET. The AJCC 8th-edition system provides discrimination similar to that of the 7th-edition system.

DLL3 as an Emerging Target for the Treatment of Neuroendocrine Neoplasms

INTRODUCTION

Neuroendocrine neoplasms (NEN) are heterogeneous malignancies that can arise at almost any anatomical site and are classified as biologically distinct well-differentiated neuroendocrine tumors (NET) and poorly differentiated neuroendocrine carcinomas (NEC). Current systemic therapies for advanced disease, including targeted therapies, chemotherapy, and immunotherapy, are associated with limited duration of response. New therapeutic targets are needed. One promising target is delta-like ligand 3 (DLL3), an inhibitory ligand of the Notch receptor whose overexpression on the surface of NEN is associated with tumorigenesis.

METHODS

This article is a narrative review that highlights the role of DLL3 in NEN progression and prognosis, the potential for therapeutic targeting of DLL3, and ongoing studies of DLL3-targeting therapies. Classification, incidence, pathogenesis, and current management of NEN are reviewed to provide biological context and illustrate the unmet clinical needs.

DISCUSSION

DLL3 is overexpressed in many NENs, implicated in tumor progression, and is typically associated with poor clinical outcomes, particularly in patients with NEC. Targeted therapies using DLL3 as a homing beacon for cytotoxic activity mediated via several different mechanisms (eg, antibody-drug conjugates, T-cell engager molecules, CAR-Ts) have shown promising clinical activity in small-cell lung cancer (SCLC). DLL3 may be a clinically actionable target across NEN.

CONCLUSIONS

Current treatment options for NEN do not provide sustained responses. DLL3 is expressed on the cell surface of many NEN types and is associated with poor clinical outcomes. Initial clinical studies targeting DLL3 therapeutically in SCLC have been promising, and additional studies are expanding this approach to the broader group of NEN.

Radioligand therapy (RLT) as neoadjuvant treatment for inoperable pancreatic neuroendocrine tumors: a literature review

In the last 10 years, several literature reports supported radioligand therapy (RLT) in neoadjuvant settings for pancreatic neuroendocrine tumors (PanNETs). Indeed, primary tumor shrinkage has been frequently reported following RLT in unresectable or borderline resectable PanNETs. Moreover, RLT-induced intratumoral modifications facilitate surgery, both on primary tumor and metastasis, having a great impact on progression free survival (PFS), overall survival (OS) and quality of life (QoL). However, prospective controlled investigations are necessary to confirm preliminary data and to define the best RLT scheme and the ideal patient that, in a multidisciplinary approach, should be referred to neoadjuvant RLT.

Clinical Management of Neuroendocrine Neoplasms in Clinical Practice: A Formal Consensus Exercise

Simple Summary

Well-structured international guidelines are currently available regarding the management of patients with neuroendocrine neoplasms (NENs). However, in relation to the multiplicity of treatments and the relative rarity and heterogeneity of NENs, there are many controversial issues in which clinical evidence is insufficient and for which expert opinion can be of help. A group of experts selected 14 relevant topics and formulated relative statements concerning controversial issues in several areas on diagnosis, prognosis, therapeutic strategies, and patient follow-up. Specific statements have also been formulated regarding patient management on radioligand therapy (RLT), as well as in the presence of co-morbidities or bone metastases. All the statements were drafted, discussed, modified, and then approved. The Nominal Group Technique (NGT) method was used to obtain consensus. The results of this paper can facilitate the clinical approach of patients with NENs in daily practice in areas where there is scarcity or absence of clinical evidence.

Abstract

Many treatment approaches are now available for neuroendocrine neoplasms (NENs). While several societies have issued guidelines for diagnosis and treatment of NENs, there are still areas of controversy for which there is limited guidance. Expert opinion can thus be of support where firm recommendations are lacking. A group of experts met to formulate 14 statements relative to diagnosis and treatment of NENs and presented herein. The nominal group and estimate-talk-estimate techniques were used. The statements covered a broad range of topics from tools for diagnosis to follow-up, evaluation of response, treatment efficacy, therapeutic sequence, and watchful waiting. Initial prognostic characterization should be based on clinical information as well as histopathological analysis and morphological and functional imaging. It is also crucial to optimize RLT for patients with a NEN starting from accurate characterization of the patient and disease. Follow-up should be patient/tumor tailored with a shared plan about timing and type of imaging procedures to use to avoid safety issues. It is also stressed that patient-reported outcomes should receive greater attention, and that a multidisciplinary approach should be mandatory. Due to the clinical heterogeneity and relative lack of definitive evidence for NENs, personalization of diagnostic–therapeutic work-up is crucial.

Toxicity and Tolerability of 177Lu-DOTA-TATE PRRT with a Modified Administered Activity Protocol in NETs of Variable Origin - A Phase 2 Registry Study

BACKGROUND

Peptide receptor radionuclide therapy (PRRT) has been recently approved for advanced, metastatic, or progressive neuroendocrine tumors (NETs).

OBJECTIVE

This study reports the adverse events (AEs) observed with patient-tailored administered activity.

METHODS

Fifty-two PRRT naive patients were treated with 177Lu-DOTATATE. The administered activity ranges between 2.78 and 5.55 GBq/cycle using the patient's unique characteristics (age, symptoms, blood work, and biomarkers).

RESULTS

The protocol was well tolerated with the overwhelming majority of participants being forty- six (88%), completing all 4 induction therapy cycles. The median cumulative administered activity was 19.6 GBq (ranged 3.8-22.3 GBq). A total of 42/52 (81%) reported at least one symptom, and 43/52 (83%) had evidence of biochemical abnormality at enrollment that would meet grade 1 or 2 criteria for AEs. These symptoms only slightly increase with treatment to 50/52 (96%) and 51/52 (98%), respectively. The most common symptoms were mild fatigue (62%), shortness of breath (50%), nausea (44%), abdominal pain (38%), and musculoskeletal pain (37%). The most common biomarker abnormalities were mild anemia (81%), reduced estimated glomerular filtration rate (eGFR) (58%), increased alkaline phosphatase (ALP) (50%), and leukopenia (37%). Of critical importance, no 177Lu-DOTATATE related grade 3 or 4 AEs were observed.

CONCLUSION

Tailoring the administered activity of 177Lu-DOTATATE to the individual patient with a variety of NETs is both safe and well-tolerated. No patient developed severe grade 3 or 4 AEs. Most patients exhibit symptoms or biochemical abnormality before treatment and this only slightly worsens following induction therapy.

Phase II trial demonstrates the efficacy and safety of individualized, dosimetry-based 177Lu-DOTATATE treatment of NET patients

PURPOSE

Radionuclide therapy with ¹⁷⁷Lu-DOTATATE is well established for patients with advanced somatostatin receptor-positive neuroendocrine tumors with a standard schedule of 7.4 GBq at four occasions. However, this approach does not consider individual variability affecting the tumor radiation dose or dose to organs at risk. Therefore, it is important to assess more personalized strategies. The aim of this phase II trial was to evaluate individualized ¹⁷⁷Lu-DOTATATE for which the number of cycles varied based on renal dosimetry.

METHODS

Patients were eligible if they had a progressive, somatostatin receptor-positive neuroendocrine tumor with a Ki 67 labeling index < 20%. They received cycles of 7.4 GBq of ¹⁷⁷Lu-DOTATATE at 10 ± 2-week intervals until a predefined radiation dose to the kidneys was reached. The primary endpoint was objective tumor response (RECIST v 1.1). Secondary endpoints included progression-free survival (PFS), overall survival (OS), and toxicity (CTCAE v. 4.0).

RESULTS

Ninety-six patients who had received a median of 5 cycles (range 1-9) were evaluable for efficacy. The objective tumor response was 16% partial response, 66% stable disease, and 19% progressive disease. The median PFS and OS were 29 months and 47 months, respectively, and were significantly associated with kidney dose, performance status, and Ki 67 levels but not with tumor origin. The overall toxicity was mild, and the most common events were grade 1-2 anemia, thrombocytopenia, fatigue, nausea, and diarrhea. Grade 3-4 toxicity occurred in < 10% of patients and was mostly hematological, with no grade 3-4 renal toxicity.

CONCLUSION

Individualized treatment with ¹⁷⁷Lu-DOTATATE based on renal dosimetry is clearly feasible with low toxicity and promising efficacy, showing the potential to further improve outcome beyond the standard approach, and should be further assessed in randomized trials.

TRIAL REGISTRATION

EudraCT 2011-000,240-16. NCT01456078. https://clinicaltrials.gov/ct2/show/NCT01456078.

Examination of the impact molecular charge has on NTSR1-targeted agents incorporated with cysteine protease inhibitors

Our laboratory has previously reported a strategy of employing cysteine cathepsin (CC) inhibitors as adduct forming, trapping agents to extend the tumor residence time of neurotensin receptor subtype 1 (NTSR1)-targeted radiopharmaceuticals. As a follow-up, we herein report a small library of CC trapping agent (CCTA)-incorporated, NTSR1-targeted conjugates with structural modifications that reduce the number of charged functional groups for both the CCTA and the peptide targeting sequence. These modifications were pursued to reduce the renal uptake and increase the translational potential of the CCTA-incorporated, NTSR1-targeted agents as radiotherapeutics. The biological performance of these constructs was examined using a battery of in vitro and in vivo studies employing the NTSR1-positive HT-29 human colon cancer cell line as our model. In vitro studies confirmed the ability of these constructs to target the NTSR1 and efficiently form intracellular adducts with cysteine proteases. Biodistribution studies using an HT-29 xenograft mouse model revealed that truncation (removal of Lys₆-Pro₇) of the NTSR1-targeted peptide (¹⁷⁷Lu-NE2a) had the greatest (3.7-fold) effect at lowering renal recognition/uptake relative to our previously reported construct. Other charge-reducing modifications to the CCTA resulted in unexpected increases in renal uptake. All of the constructs demonstrated similar levels of in vivo NTSR1-positive tumor targeting with the highest tumor residualization resulting from the construct containing the zwitterionic CCTA (¹⁷⁷Lu-NE2a). In vivo adduct formation of the conjugates was confirmed using autoradiographic SDS-PAGE analysis.

Long-term survival and toxicity in patients with neuroendocrine tumors treated with 177 Lu-octreotate peptide radionuclide therapy

BACKGROUND

Peptide receptor radionuclide therapy (PRRT) has shown favorable results in neuroendocrine tumors (NETs). Long-term safety and efficacy data for ¹⁷⁷ Lu-octreotate PRRT, particularly in combination with chemotherapy, is lacking.

METHODS

The authors conducted a retrospective review of the long-term toxicity and survival outcomes of 104 patients with advanced NETs treated on 4 phase 2 clinical trials with Lutetium-177-octreotate (¹⁷⁷ Lu-octreotate) PRRT, mostly in combination with chemotherapy. Median follow-up was 68 months, which represents the longest follow-up study of ¹⁷⁷ Lu-octreotate PRRT for NETs to date.

RESULTS

Median progression-free survival (PFS) was 37 months, and median overall survival (OS) was 71 months. Five- and 10-year OS were 62% and 29%, and 5- and 10-year PFS were 36% and 21%, respectively, demonstrating ¹⁷⁷ Lu-octreotate can provide durable responses. PRRT was well tolerated with 1.9% of patients developing chronic renal impairment and 1% of patients developing long-term thrombocytopenia. Interestingly, there was a relatively high rate of myelodysplasia (MDS)/leukemia (6.7%), possibly attributable to the longer follow-up (with all except 1 case occurring more than 4 years after PRRT treatment) or to the addition of concurrent chemotherapy.

CONCLUSIONS

Lutetium-177-Octreotate PRRT remains an efficacious and well tolerated treatment in long-term follow-up. For clinicians deciding on the timing of PRRT for individual patients, the 6.7% long-term risk of MDS/leukemia needs to be balanced against the 21% PFS at 10 years.

Orchestrating Treatment Modalities in Metastatic Pancreatic Neuroendocrine Tumors-Need for a Conductor

Pancreatic neuroendocrine tumors (pNETs) are a vast growing disease. Over 50% of these tumors are recognized at advanced stages with lymph node, liver, or distant metastasis. An ongoing controversy is the role of surgery in the metastatic setting as dedicated systemic treatments have emerged recently and shown benefits in randomized trials. Today, liver surgery is an option for advanced pNETs if the tumor has a favorable prognosis, reflected by a low to moderate proliferation index (G1 and G2). Surgery in this well-selected population may prolong progression-free and overall survival. Optimal selection of a treatment plan for an individual patient should be considered in a multidisciplinary tumor board. However, while current guidelines offer a variety of modalities, there is so far only a limited focus on the right timing. Available data is based on small case series or retrospective analyses. The focus of this review is to highlight the right time-point for surgery in the setting of the multimodal treatment of an advanced pancreatic neuroendocrine tumor.

Peptide receptor radionuclide therapy implementation and results in a predominantly gastrointestinal neuroendocrine tumor population: A two-year experience in a nonuniversity setting

Neuroendocrine tumors (NETs) are rare, but the incidence and prevalence of NETs are increasing in the United States. While surgery is the preferred treatment for NETs, it is not a viable option for metastatic disease. Lutathera (177Lu-DOTATATE) is approved by the United States Food and Drug Administration and the European Medicines Agency for the treatment of gastroenteropancreatic (GEP)-NETs in adults. There is limited information on GEP-NET treatment responses to Lutathera.Our institution launched a peptide receptor radionuclide therapy (PRRT) service line using Lutathera with involvement from a multidisciplinary team and complete collaboration between hospital administration and clinical providers. A prospective registry study was also established in order to collect patient demographics and clinical data regarding the treatment of GEP primary NETs with Lutathera.Between August 2018 and July 2020, 35 GEP-NET patients were treated with Lutathera, of which 65.71% received 4 complete cycles and 25.71% received 3 cycles; 5.71% and 2.86% received 2 and 1 cycles of PRRT, respectively. Most adverse events during the course of our study were low grade using the common terminology criteria for adverse events system. Of the patients who completed all 4 cycles: 22% showed partial response to Lutathera, 44% showed stable disease, and 13% showed disease progression based on a qualitative assessment of positron emission tomography/computed tomography imaging.From our experience, Lutathera was well tolerated in patients with GEP-NET. Additional studies are needed to examine long-term clinical and patient-reported outcomes associated with GEP-NET treatment as well as financial considerations for hospitals embarking on a PRRT program.

Challenges in Von Hippel-Lindau's disease: PRRT in patients on hemodialysis

Summary

Von Hippel-Lindau's disease (VHL) is a hereditary tumor syndrome characterized by its prototype lesions, hemangioblastomas, and renal cell carcinomas. Treatment for renal cell carcinomas can ultimately result in long-term dialysis. Pancreatic neuroendocrine tumors (pNET) can also occur in the course of the disease. Currently, peptide receptor radionuclide therapy (PRRT) is the standard treatment for progressive neuroendocrine tumors. However, little is known about treatment with PRRT in patients on dialysis, an infrequent presentation in patients with VHL. We present a 72-year-old man with VHL on hemodialysis and a progressive pNET. He received four cycles of PRRT with a reduced dose. Only mild thrombopenia was seen during treatments. The patient died 9 months after the last PRRT because of acute bleeding in a hemangioblastoma. Hemodialysis is not a limiting factor for PRRT treatment and it should be considered as it seems a safe short-term treatment option for this specific group.

Learning points

Von Hippel-Lindau disease (VHL) is a complex disease in which former interventions can limit optimal treatment for following VHL-related tumors later in life. Metastasized pancreatic neuroendocrine tumors occur as part of VHL disease. Peptide receptor radionuclide therapy seems a safe short-term treatment option in patients on hemodialysis.

Predictive Factors for Resistant Disease with Medical/Radiologic/Liver-Directed Anti-Tumor Treatments in Patients with Advanced Pancreatic Neuroendocrine Neoplasms: Recent Advances and Controversies

Simple Summary

Tumor resistance, both primary and acquired, is leading to increased complexity in the nonsurgical treatment of patients with advanced panNENs, which would be greatly helped by reliable prognostic/predictive factors. The importance in identifying resistance is being contributed to by the increased array of possible treatments available for treating resistant advanced disease; the variable clinical course as well as response to any given treatment approach of patients within one staging or grading system, the advances in imaging which are providing increasing promising results/parameters that correlate with grading/outcome/resistance, the increased understanding of the molecular pathogenesis providing promising prognostic markers, all of which can contribute to selecting the best treatment to overcome resistance disease. Several factors have been identified that have prognostic/predictive value for identifying development resistant disease and affecting overall survival (OS)/PFS with various nonsurgical treatments of patients with advanced panNENs. Prognostic factors identified for patients with advanced panNENs for both OS/PFSs include various clinically-related factors (clinical, laboratory/biological markers, imaging, treatment-related factors), pathological factors (histological, classification, grading) and molecular factors. Particularly important prognostic factors for the different treatment modalities studies are the recent grading systems. Most prognostic factors for each treatment modality for OS/PFS are not specific for a given treatment option. These advances have generated several controversies and new unanswered questions, particularly those related to their possible role in predicting the possible sequence of different anti-tumor treatments in patients with different presentations. Each of these areas is reviewed in this paper.

Abstract

Purpose: Recent advances in the diagnosis, management and nonsurgical treatment of patients with advanced pancreatic neuroendocrine neoplasms (panNENs) have led to an emerging need for sensitive and useful prognostic factors for predicting responses/survival. Areas covered: The predictive value of a number of reported prognostic factors including clinically-related factors (clinical/laboratory/imaging/treatment-related factors), pathological factors (histological/classification/grading), and molecular factors, on therapeutic outcomes of anti-tumor medical therapies with molecular targeting agents (everolimus/sunitinib/somatostatin analogues), chemotherapy, radiological therapy with peptide receptor radionuclide therapy, or liver-directed therapies (embolization/chemoembolization/radio-embolization (SIRTs)) are reviewed. Recent findings in each of these areas, as well as remaining controversies and uncertainties, are discussed in detail, particularly from the viewpoint of treatment sequencing. Conclusions: The recent increase in the number of available therapeutic agents for the nonsurgical treatment of patients with advanced panNENs have raised the importance of prognostic factors predictive for therapeutic outcomes of each treatment option. The establishment of sensitive and useful prognostic markers will have a significant impact on optimal treatment selection, as well as in tailoring the therapeutic sequence, and for maximizing the survival benefit of each individual patient. In the paper, the progress in this area, as well as the controversies/uncertainties, are reviewed.

Potential value of pre- and post-therapy [68Ga]Ga-DOTA-TATE PET/CT in the prognosis of response to PRRT in disseminated neuroendocrine tumors

BACKGROUND

Peptide receptor radionuclide therapy (PRRT) is one of the most effective therapeutic options for the treatment of metastatic, well-differentiated neuroendocrine tumors (NETs). It improves progressive disease-free survival and enables the control of hormone secretion in functioning tumors.Currently, there are no clearly established predictors of response to PRRT. The main factors hindering such a prediction are the heterogeneity of somatostatin receptor expression within and between lesions, lack of standardized parameters for functional imaging, and the use of different PRRT protocols.The main goal of our study was to quantify SUVmax changes in [68Ga]Ga-DOTA-TATE PET/CT scans as a potential predictor of long-term response to PRRT.

MATERIAL AND METHODS

Out of 20 patients treated with PRRT using [177Lu]Lu and/or [177Lu]Lu/[90Y]Y-DOTA-TATE in 2017-2019 due to dissemination of neuroendocrine neoplasm, 12 patients underwent [68Ga]Ga-DOTA-TATE PET/CT on average 3.1 months before and 4.5 months after PRRT and were eligible for the analysis.In total, 76 NET lesions were evaluated. We measured SUVmax for every lesion in both PET/CT scans (before and after PRRT). Those values were corrected by liver SUVmax and liver SUVmean measured in volumetric analysis and specified as SUVlmax and SUVlmean. As a next step, changes in SUVlmax and SUVlmean were assessed based on both PET/CT scans. Finally, results were correlated with the clinical outcome assessed as progressive disease, disease stabilization, or partial response.

RESULTS

The mean follow-up period was 19.9 months. Progressive disease, partial response, and disease stabilization were found in five, two, and five patients, respectively. Among patients with a partial response, the decrease in mean SUVlmax was 66.3% when compared to baseline. In patients with stable disease, the decrease in SUVlmax was 30.3% when compared to baseline. In patients with progressive disease, the mean increase in SUVlmax was 9.1% when compared to baseline. The changes in SUVlmean were -69,8%, -30.8%, and -3.7%, respectively.

CONCLUSIONS

A decrease in the SUVmax value in NET lesions, corrected by normal liver tissue uptake assessed in [68Ga]Ga-DOTA-TATE PET/CT scans, indicates a lower risk for NET progressive disease within 20 months after PRRT and may constitute an additional and independent parameter for the estimation of overall risk for disease progression.

New Isotopes for the Treatment of Pancreatic Cancer in Collaboration With CERN: A Mini Review

The use of radioactivity in medicine has been developed over a century. The discovery of radioisotopes and their interactions with living cells and tissue has led to the emergence of new diagnostic and therapeutic modalities. The CERN-MEDICIS infrastructure, recently inaugurated at the European Center for Nuclear Research (CERN), provides a wide range of radioisotopes of interest for diagnosis and treatment in oncology. Our objective is to draw attention to the progress made in nuclear medicine in collaboration with CERN and potential future applications, in particular for the treatment of aggressive tumors such as pancreatic adenocarcinoma, through an extensive review of literature. Fifty seven out of two hundred and ten articles, published between 1997 and 2020, were selected based on relevancy. Meetings were held with a multi-disciplinary team, including specialists in physics, biological engineering, chemistry, oncology and surgery, all actively involved in the CERN-MEDICIS project. In summary, new diagnostic, and therapeutic modalities are emerging for the treatment of pancreatic adenocarcinoma. Targeted radiotherapy or brachytherapy could be combined with existing therapies to improve the quality of life and survival of these patients. Many studies are still in the pre-clinical stage but open new paths for patients with poor prognosis.

Immunotherapeutics at the spearhead: current status in targeting neuroendocrine neoplasms

PURPOSE

Recent advances in the field of immunotherapy have significantly prolonged the survival of patients with aggressive carcinomas, but the role of immunotherapy in neuroendocrine neoplasms (NENs) remains to be elucidated.

METHODS AND RESULTS

We report a patient diagnosed with a well-differentiated grade 3 pancreatic NEN (pNEN) and type 3 liver metastases who received compassionate nivolumab as a fifth line treatment and achieved a durable partial response of more than 34 months. We have performed a systematic review to the literature on tumor microenvironment and potential biomarkers in the field of NEN including the tumor mutational burden, the tumor infiltrating lymphocytes, the programmed cell death ligand 1, and the mismatch repair system. The potential role of the immune system modulation together with a critical assessment of the recent phase II clinical studies in NEN including monotherapy with anti-PD-1/PD-L1 monoclonal antibodies, and combination therapies including anti-PD-1 along with anti-CTLA-4 monoclonal antibodies are also provided.

CONCLUSION

Immunotherapeutics are gaining a post in the field of NENs in cases progressing during the course of the disease, dictating urgently the identification of biomarkers that will enable selection of NEN patients who may benefit from this treatment.

Advanced Pancreatic Neuroendocrine Neoplasms: Which Systemic Treatment Should I Start With?

PURPOSE OF REVIEW

Pancreatic neuroendocrine neoplasms (panNENs) often present as advanced disease and there is little data to guide treatment sequencing in the advance disease setting. Therefore, we aim to provide a comprehensive summary of the current evidence supporting the use of systemic treatment for patients with diagnosis of advanced and metastatic panNENs, as well as to provide strategies for treatment selection and address challenges for treatment selection and sequencing of therapy.

RECENT FINDINGS

Substantial advances have been made and many clinical trials have been performed over the past two decades expanding therapeutic options available for patients with advanced panNETs. Available systemic treatments for patients with well-differentiated pancreatic neuroendocrine tumors include somatostatin receptors ligands (SRLs), traditional cytotoxic chemotherapy regimens, peptide receptor radiotherapy (PRRT), and biologically targeted therapies, whereas patients with poorly differentiated neurodocrine carcinomas have more limited treatment options. Despite these advances, no clear guidelines exist to support the best sequence of treatments, not only the first-line, but also subsequent lines of therapy in patients with panNENs. Advances in molecular research and discovery of biomarkers for response allowing a more personalized approach to the multimodality therapy of panNENs are still limited. Understanding the impact of previous therapies on subsequent treatment efficacy and toxicity is also an ongoing research question. In the absence of definite predictive markers and paucity of comparative randomized trials, along with the heterogeneity of this patient population, systemic therapy selection in advanced non-resectable disease should be patient centered and often require evaluation within a multidisciplinary setting. The specific clinical context of the patient, with assessment of individual patient clinical and pathological features, somatostatin receptors imaging, and goals of treatment must all be considered when deciding on systemic therapy in the patient. Additional research is needed to address the gap in knowledge regarding optimal sequencing and timing of therapies and to provide individual care.

Multiple endocrine neoplasia type 1 (MEN-1) and neuroendocrine neoplasms (NENs)

Neuroendocrine neoplasms (NENs) are relatively rare neoplasms with 6.4-times increasing age-adjusted annual incidence during the last four decades. NENs arise from neuroendocrine cells, which release hormones in response to neuronal stimuli and they are distributed into organs and tissues. The presentation and biological behaviour of the NENs are highly heterogeneous, depending on the organ. The increased incidence is mainly due to increased awareness and improved detection methods both in the majority of sporadic NENs (non-inherited), but also the inherited groups of neoplasms appearing in at least ten genetic syndromes. The most important one is multiple endocrine neoplasia type 1 (MEN-1), caused by mutations in the tumour suppressor gene MEN1. MEN-1 has been associated with different tumour manifestations of NENs e.g. pancreas, gastrointestinal tract, lungs, thymus and pituitary. Pancreatic NENs tend to be less aggressive when arising in the setting of MEN-1 compared to sporadic pancreatic NENs. There have been very important improvements over the past years in both genotyping, genetic counselling and family screening, introduction and validation of various relevant biomarkers, as well as newer imaging modalities. Alongside this development, both medical, surgical and radionuclide treatments have also advanced and improved morbidity, quality of life and mortality in many of these patients. Despite this progress, there is still space for improving insight into the genetic and epigenetic factors in relation to the biological mechanisms determining NENs as part of MEN-1. This review gives a comprehensive update of current evidence for co-occurrence, diagnosis and treatment of MEN-1 and neuroendocrine neoplasms and highlight the important progress now finding its way to international guidelines in order to improve the global management of these patients.

Indications of Peptide Receptor Radionuclide Therapy (PRRT) in Gastroenteropancreatic and Pulmonary Neuroendocrine Tumors: An Updated Review

Radionuclide therapy for neuroendocrine tumors is a form of systemic radiotherapy that allows the administration of targeted radionuclides into tumor cells that express a large quantity of somatostatin receptors. The two most commonly used radio-peptides for radionuclide therapy in neuroendocrine tumors are ⁹⁰Y-DOTATOC and ¹⁷⁷Lu-DOTATATE. Radio-peptides have been used for several years in the treatment of advanced neuroendocrine tumors. Recently, the randomized Phase III study NETTER-1 compared¹⁷⁷Lu-DOTATATE versus high-dose (double-dose) octreotide LAR in patients with metastatic midgut neuroendocrine tumors, and demonstrated its efficacy in this setting. Strong signals in favor of efficiency seem to exist for other tumors, in particular for pancreatic and pulmonary neuroendocrine tumors. This focus on radionuclide therapy in gastroenteropancreatic and pulmonary neuroendocrine tumors addresses the treatment modalities, the validated and potential indications, and the safety of the therapy.

Assessment of Therapy-Related Myeloid Neoplasms in Patients With Neuroendocrine Tumors After Peptide Receptor Radionuclide Therapy: A Systematic Review

Importance

Peptide receptor radionuclide therapy (PRRT) is a tumor-targeted treatment that uses radiation to induce tumor cell death in neuroendocrine tumors (NET) via β particle-emitting radionuclide linked to a somatostatin peptide analog. Therapy-related myeloid neoplasm (t-MN) has been reported as a potential long-term and frequently lethal adverse event after PRRT. However, the incidence, time of diagnosis, and nature of t-MN is unclear. Therefore, a systematic review is helpful to study the incidence and characteristics of t-MN after PRRT in patients with NET.

Objective

To systematically evaluate the literature and report the incidence, time of diagnosis, and nature of t-MN after PRRT.

Evidence Review

MEDLINE, Embase, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials for articles and abstracts reporting studies of different designs studying more than 1 patient (randomized clinical trials, prospective phase I or phase II, retrospective studies, and case series) were searched from database inception through April 2019. Studies of interest included patients with NET who were treated with PRRT and reported the incidence of t-MN, if any. The primary outcome was the incidence of t-MN.

Findings

Twenty-eight articles were identified comprising 7334 patients who were treated with PRRT for NET. The main reason of exclusion was not reporting the t-MN incidence. The incidence of t-MN was variable between studies with mean (SD) incidence of 2.61% (4.38%). Of all 134 cases, cytogenetic abnormalities were reported in 32 patients with the most common abnormality being complex cytogenetics, consistent with myeloid neoplasms following exposure to alkylating agents or irradiation.

Conclusions and Relevance

The risk of t-MN after PRRT is small but not insignificant given the poor prognosis after t-MN diagnosis. Close monitoring is warranted to identify such patients early in the disease course when hematologic abnormalities persist.

Bombesin Receptor Family Activation and CNS/Neural Tumors: Review of Evidence Supporting Possible Role for Novel Targeted Therapy

G-protein-coupled receptors (GPCRs) are increasingly being considered as possible therapeutic targets in cancers. Activation of GPCR on tumors can have prominent growth effects, and GPCRs are frequently over-/ectopically expressed on tumors and thus can be used for targeted therapy. CNS/neural tumors are receiving increasing attention using this approach. Gliomas are the most frequent primary malignant brain/CNS tumor with glioblastoma having a 10-year survival <1%; neuroblastomas are the most common extracranial solid tumor in children with long-term survival<40%, and medulloblastomas are less common, but one subgroup has a 5-year survival <60%. Thus, there is an increased need for more effective treatments of these tumors. The Bombesin-receptor family (BnRs) is one of the GPCRs that are most frequently over/ectopically expressed by common tumors and is receiving particular attention as a possible therapeutic target in several tumors, particularly in prostate, breast, and lung cancer. We review in this paper evidence suggesting why a similar approach in some CNS/neural tumors (gliomas, neuroblastomas, medulloblastomas) should also be considered.

Understanding the Treatment Algorithm of Patients with Metastatic Pancreatic Neuroendocrine Neoplasms: A Single-Institution Retrospective Analysis Comparing Outcomes of Chemotherapy, Molecular Targeted Therapy, and Peptide Receptor Radionuclide Therapy in 255 Patients

BACKGROUND

The number of therapeutic options for patients with pancreatic neuroendocrine neoplasms (PNEN) has increased, but the optimal therapeutic algorithm has not been defined due to lack of randomised trials comparing different modalities.

METHODS

We performed a retrospective study in patients with metastatic PNEN treated with ≥1 line of systemic therapy. The relationship between baseline characteristics, treatment type, and time to treatment failure (TTF), time to progression (TTP), and overall survival (OS) was analysed using the Kaplan-Meier method. Univariate and multivariate analyses were performed using the Cox proportional hazards model.

RESULTS

Two hundred and fifty-five patients with metastatic PNEN had 491 evaluable lines of therapy. Independent predictors of TTF included treatment type, Ki-67, tumour grade, and chromogranin A. To reduce selection bias, a subgroup of 114 patients with grade 2 (G2) metastatic pancreatic neuroendocrine tumours (PNET) was analysed separately. These patients had received 234 lines of treatment (105 chemotherapy, 82 molecular targeted therapy, and 47 peptide receptor radionuclide therapy [PRRT]). In the G2 cohort, TTF and TTP were superior for PRRT compared with both chemotherapy and molecular targeted therapy. OS in the G2 cohort was also superior for those that had received PRRT compared with those that had not (median 84 vs. 56 months; HR 0.55, 95% CI: 0.31-0.98, p = 0.04).

CONCLUSIONS

This study suggests that PRRT is associated with superior clinical outcomes relative to other systemic therapies for G2 metastatic PNET. Prospective studies are required to confirm these observations.

Role of Somatostatin Receptor in Pancreatic Neuroendocrine Tumor Development, Diagnosis, and Therapy

Pancreatic neuroendocrine tumors (pNETs) are rare and part of the diverse family of neuroendocrine neoplasms (NENs). Somatostatin receptors (SSTRs), which are widely expressed in NENs, are G-protein coupled receptors that can be activated by somatostatins or its synthetic analogs. Therefore, SSTRs have been widely researched as a diagnostic marker and therapeutic target in pNETs. A large number of studies have demonstrated the clinical significance of SSTRs in pNETs. In this review, relevant literature has been appraised to summarize the most recent empirical evidence addressing the clinical significance of SSTRs in pNETs. Overall, these studies have shown that SSTRs have great value in the diagnosis, treatment, and prognostic prediction of pNETs; however, further research is still necessary.

177Lu-DOTATATE Therapy of Advanced Pancreatic Neuroendocrine Tumors Heavily Pretreated with Chemotherapy: Analysis of Outcome, Safety, and Their Determinants

OBJECTIVE

To retrospectively analyze toxicity, progression-free survival (PFS), overall survival (OS), and their determinants in patients with advanced pancreatic neuroendocrine tumors (PanNETs), previously pretreated with chemothe-r-apy, undergoing peptide receptor radionuclide therapy (PRRT) with 177Lu-DOTATATE.

METHODS

A total of 102 patients with advanced PanNETs, previously pretreated with one (67%) or several (33%) lines of chemotherapy, were included, of whom 90% had progressive disease and the majority (74.5%) had grade 2 tumors. 177Lu-DOTATATE, 7.4 GBq per cycle, was administered with 6- to 8-week intervals in 88% of patients utilizing a dosimetry-guided protocol until an absorbed dose of 23 Gy to the kidneys was reached.

RESULTS

A mean dose of 32 ± 10.9 GBq per patient was administered in 1-10 cycles starting a median of 36 months after PanNET diagnosis. The median follow-up was 34 months, the median PFS was 24 months, and the median OS was 42 months from start of PRRT. Independent risk factors for both progression and death were liver tumor burden >50%, more than one line of previous chemotherapy, and elevated alkaline phosphatase. Resection of the primary tumor was linked to longer survival. Bone marrow toxicity grade 3-4 occurred in 10.8%. One patient (1.0%) developed acute myeloid leukemia. Bone marrow toxicity was unrelated to type and length of previous chemotherapy, amount of administered activity, and absorbed dose to the bone marrow.

CONCLUSION

177Lu-DOTATATE therapy was feasible, highly effective, and safe in patients with advanced PanNETs heavily pretreated with chemotherapy. More than one line of chemotherapy was a therapy-related independent risk factor for shorter PFS and OS.

How We Do It: A Multidisciplinary Approach to 177Lu DOTATATE Peptide Receptor Radionuclide Therapy

Lutetium 177 (¹⁷⁷Lu) DOTA-0-Tyr3-Octreotate (DOTATATE) peptide receptor radionuclide therapy (PRRT) is an effective treatment for advanced gastroenteropancreatic neuroendocrine tumors. This review presents a clinical practice workflow that has been successful since ¹⁷⁷Lu DOTATATE PRRT was approved by the U.S. Food and Drug Administration. The workflow relies heavily on the input of a multidisciplinary team and involves a nuclear medicine consultation service, tumor board, and specific preparations in advance of therapy and day-of-therapy procedures. A systematic checklist designed to ensure appropriate selection of treatment candidates and identification of any concerns to address to safely administer PRRT is provided. All patients were evaluated with gallium 68 DOTATATE PET/CT, and in cases of high-grade tumors, they were also evaluated with fluorine 18 fluorodeoxyglucose PET/CT, with imaging findings reviewed as part of the systematic checklist before PRRT. Adverse effects are discussed and imaging follow-up regimens are reviewed, including alternative diagnostic contrast materials. Approaches to multiple challenging patient scenarios are illustrated through case examples. Finally, alternative theranostic radionuclides and treatment strategies are discussed.

Pulmonary Neuroendocrine Tumors: Adjuvant and Systemic Treatments

OPINION STATEMENT

Bronchial carcinoids are uncommon tumors accounting for 20 to 30% of all neuroendocrine tumors and about 1-2% of all cancers of pulmonary origin. Bronchial carcinoids are well-differentiated neuroendocrine tumors and have a favorable survival outcome when compared with other subtypes of lung cancers. Treatment of bronchial carcinoids is not simple owing to intricacy of symptom presentation and heterogeneity of disease biology. Successful treatment of patients requires a multimodality approach. Resection is curative in the majority of patients with localized tumors and adjuvant treatment is not routinely recommended. Multiple options for systemic therapy exist for patients with advanced disease. To date, very few randomized clinical trials have been done, partly owing to the relative rarity of this malignancy. Somatostatin analogs (SSAs) are reasonable first-line choice for patients with tumors expressing somatostatin receptors. Everolimus is an appropriate first-line choice for somatostatin receptor negative tumors and for any patients with progressive disease. PRRT can also be considered for progressive tumors expressing somatostatin receptors. Based on retrospective series, cytotoxic chemotherapy can be selected in patients with progressive tumors, primarily when cytoreduction is needed. Herein, we will discuss evidence supporting the role of adjuvant and systemic treatment therapies for those with bronchial carcinoid tumors by focusing on various studies.

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. The available literature was reviewed for each of the question and panel members voted on controversial topics, and the recommendations were included in a document circulated to all panel members for a final approval.

Systemic Treatment Selection for Patients with Advanced Pancreatic Neuroendocrine Tumours (PanNETs)

Pancreatic neuroendocrine tumours (PanNETs) are rare diseases and a good example of how research is not only feasible, but also of crucial importance in the scenario of rare tumours. Many clinical trials have been performed over the past two decades expanding therapeutic options for patients with advanced PanNETs. Adequate management relies on optimal selection of treatment, which may be challenging for clinicians due to the fact that multiple options of therapy are currently available. A number of therapies already exist, which are supported by data from phase III studies, including somatostatin analogues and targeted therapies (sunitinib and everolimus). In addition, chemotherapy remains an option, with temozolomide and capecitabine being one of the most popular doublets to use. Peptide receptor radionuclide therapy was successfully implemented in patients with well-differentiated gastro-entero-pancreatic neuroendocrine tumours, but with certain questions waiting to be solved for the management of PanNETs. Finally, the role of immunotherapy is still poorly understood. In this review, the data supporting current systemic treatment options for locally advanced or metastatic PanNETs are summarized. Strategies for treatment selection in patients with PanNETs based on patient, disease, or drug characteristics is provided, as well as a summary of current evidence on prognostic and predictive biomarkers. Future perspectives are discussed, focusing on current and forthcoming challenges and unmet needs of patients with these rare tumours.

Peptide Receptor Radionuclide Therapy for the Treatment of Pancreatic Neuroendocrine Tumors: Recent Insights

Peptide receptor radionuclide therapy (PRRT) is a paradigm shifting approach to the treatment of neuroendocrine tumors. Although there are no prospective randomized trials directly studying PRRT in pancreatic neuroendocrine tumors (panNETs), there are data to suggest benefit in this patient population. Collectively, the data, consisting of two prospective and six retrospective studies, show a median PFS ranging from 20 to 39 months and a median OS ranging from 37 to 79 months. There are ongoing (and upcoming) prospective, randomized trials of PRRT in panNETs, which will provide further evidence to support this approach.

Recent advances in theranostic polymeric nanoparticles for cancer treatment: A review

Nanotheranostics is fast-growing pharmaceutical technology for simultaneously monitoring drug release and its distribution, and to evaluate the real time therapeutic efficacy through a single nanoscale for treatment and diagnosis of deadly disease such as cancers. In recent two decades, biodegradable polymers have been discovered as important carriers to accommodate therapeutic and medical imaging agents to facilitate construction of multi-modal formulations. In this review, we summarize various multifunctional polymeric nano-sized formulations such as polymer-based super paramagnetic nanoparticles, ultrasound-triggered polymeric nanoparticles, polymeric nanoparticles bearing radionuclides, and fluorescent polymeric nano-sized formulations for purpose of theranostics. The use of such multi-modal nano-sized formulations for near future clinical trials can assist clinicians to predict therapeutic properties (for instance, depending upon the quantity of drug accumulated at the cancerous site) and observed the progress of tumor growth in patients, thus improving tailored medicines.

Renal Neuroendocrine Neoplasms: A Single-center Experience

BACKGROUND

Primary neuroendocrine neoplasms (NENs) of the kidney are exceedingly rare malignancies and the available literature is very limited. The natural history and response to treatments is not well characterized. We aimed to describe the presenting features, demographics, tumor characteristics, and treatment outcomes of patients with renal NENs.

PATIENTS AND METHODS

We performed a retrospective analysis of all Mayo Clinic patient records with a tissue diagnosis of a primary renal NEN. Baseline patient and surgical pathologic features and treatment modalities were collected. Time to recurrence after resection and overall survival (OS) were estimated using with survival analysis. Surveillance, Epidemiology, and End Results data were used to estimate the population-wide incidence and OS.

RESULTS

A total of 17 patients were included in the present study, with a median follow-up of 62.8 months. Distant metastasis was present in 29% at diagnosis, with 76% experiencing distant metastasis at any point; 24% had a horseshoe kidney. Of the 17 patients, 14 had undergone surgical resection with no evidence of disease postoperatively. Ten of these patients had documented recurrence. The median time to recurrence was 18 months (95% confidence interval, 9-46 months). Only 1 of the 10 patients showed a radiographic response to systemic therapy. Of 9 patients, 4 had stable disease with somatostatin analogs. The median OS was 143 months (95% confidence interval, 50-143 months).

CONCLUSIONS

Renal NENs are rare malignancies affecting mostly middle-age patients, with distant metastasis being common. Approximately one half of patients experience stable disease with somatostatin analogs. The OS usually exceeds 5 years.

Systemic Therapies for Metastatic Pancreatic Neuroendocrine Tumors

OPINION STATEMENT

Over the years, there have been significant advances in systemic treatments for metastatic pancreatic neuroendocrine tumors (panNETs). Despite these advancements, uncertainty remains regarding how to best sequence available therapies. For well-differentiated and metastatic panNETs that are somatostatin receptor (SSTR) avid on functional imaging, first-line therapy typically consists of somatostatin analogs (SSAs), given their favorable toxicity profile and overall low burden for patients. When progression of disease is observed on an SSA, multiple treatment options are available, including the targeted agents everolimus and sunitinib, peptide receptor radionuclide therapy (PRRT), as well as chemotherapy, with the latter often preferred for those panNETs of heavy tumor burden, higher grade, and/or more aggressive behavior clinically and/or radiographically. Here, we review panNET classification, currently available systemic treatments, therapy sequencing, and areas of active investigation to further our treatments for the disease.

LARGE CELL METASTATIC PANCREATIC NEUROENDOCRINE CARCINOMA TREATED WITH SOMATOSTATIN ANALOGUES - CASE REPORT AND LITERATURE REVIEW

We report the case of a 55-year-old-male with a large cell metastatic pancreatic neuroendocrine carcinoma treated for 14 months with lanreotide autogel having a stable disease (SD) and not responding to chemotherapy. The somatostatin analogues (SSA) were introduced after an episode of diarrhea and controlled the disease. Progression-free survival (PFS) as determined by Computerized Tomography (CT) scans was obtained for 14 months. After more than a year, the patient's health state deteriorated along with progressive disease. The capecitabine-temozolomide regimen was challenged, but after three cycles, a rapid clinical decline was noted.

CONCLUSION

This unexpected event (diarrhea) in the course of the disease could represent the beginning of carcinoid syndrome. While the lanreotide autogel helped the episode of diarrhea pass, it also helped gain control over the disease itself.