Peptide receptor radionuclide therapy with 177Lu-DOTA-TATE as a promising treatment of malignant insulinoma: a series of case reports and literature review

Peptide Receptor Radionuclide Therapy Is Effective for Clinical Control of Symptomatic Metastatic Insulinoma: A Long-Term Retrospective Analysis

Metastatic insulinoma is a rare malignant neuroendocrine tumor characterized by inappropriate insulin secretion, resulting in life-threatening hypoglycemia, which is often difficult to treat. There is currently very limited information about the efficacy of peptide receptor radionuclide therapy (PRRT) for clinical control of hypoglycemia. The aim of this long-term retrospective study was to evaluate the therapeutic efficacy of PRRT for improving hypoglycemia, to evaluate the change of medication after PRRT, and to calculate progression-free survival (PFS) and overall survival (OS). Methods: Inclusion criteria were histologically proven somatostatin receptor-positive metastatic malignant insulinoma and at least 2 cycles of [90Y]Y-DOTATOC or [177Lu]Lu-DOTATOC therapy from early 2000 to early 2022. A semiquantitative scoring system was used to quantify the severity and frequency of hypoglycemic episodes under background antihypoglycemic therapy (somatostatin analog, diazoxide, everolimus, corticosteroids): score 0, no hypoglycemic episodes; score 1, hypoglycemic events requiring additional conservative treatment with optimization of nutrition; score 2, severe hypoglycemia necessitating hospitalization and combined medication or history of hypoglycemic coma. Hypoglycemic score before and after PRRT was analyzed. Time of benefit was defined as a time range of fewer hypoglycemic episodes in the observation period than at baseline. Information on antihypoglycemic medication before and after therapy, PFS, and OS was recorded. Results: Twenty-six of 32 patients with a total of 106 [90Y]Y-DOTATOC/[177Lu]Lu-DOTATOC cycles were included. The average observation period was 21.5 mo (range, 2.3-107.4 mo). Before therapy, 81% (n = 21) of the patients had a hypoglycemia score of 2 and 19% (n = 5) had a score of 1. After PRRT, 81% of patients (n = 21) had a decreased score, and the remaining 5 patients showed a stable situation. There was temporary worsening of hypoglycemia just after injection of [90Y]Y-DOTATOC/[177Lu]Lu-DOTATOC in 19% of patients. The average time of benefit in the observation period was 17.2 mo (range, 0-70.2 mo). Antihypoglycemic medication reduction was achieved in 58% (n = 15) of patients. The median OS and PFS after the start of PRRT were 19.7 mo (95% CI, 6.5-32.9 mo) and 11.7 mo (95% CI, 4.9-18.5 mo), respectively. Conclusion: To our knowledge, our study included the largest cohort of patients with malignant insulinoma to be evaluated. Long-lasting symptom control and reduction of antihypoglycemic medications were shown in most patients after late-line PRRT.

Ectopic insulinoma: a systematic review

Knowledge of ectopic insulinomas comes from single cases. We performed a systematic review through PubMed, Web of Science, Embase, eLibrary and ScienceDirect of all cases reported in the last four decades. We also describe one unreported patient. From 28 patients with ectopic insulinoma, 78.6% were female and mean age was 55.7 ± 19.2 years. Hypoglycaemia was the first symptom in 85.7% while 14.3% complained of abdominal pain or genital symptoms. Median tumour diameter was 27.5 [15-52.5] mm and it was localised by CT (73.1%), MRI (88.9%), [68Ga]Ga-DOTA-exedin-4 PET/CT (100%), 68Ga-labelled-DOTA-conjugated somatostatin analogue PET/TC (100%), somatostatin receptor scintigraphy (40%) and endoscopic ultrasound (50%). Ectopic insulinomas were located at duodenum (n = 3), jejunum (n = 2), and one respectively at stomach, liver, appendix, rectum, mesentery, ligament of Treitz, gastrosplenic ligament, hepatoduodenal ligament and splenic hilum. Seven insulinomas were affecting the female reproductive organs: ovary (n = 5), cervix (n = 2) and remaining tumours were at retroperitoneum (n = 3), kidney (n = 2), spleen (n = 1) and pelvis (n = 1). 89.3% underwent surgery (66.7% surgery vs. 33.3% laparoscopy) and 16% underwent an ineffective pancreatectomy. 85.7% had localized disease at diagnosis and 14.3% developed distant metastasis. Median follow-up time was 14.5 [4.5-35.5] months and mortality was reported in 28.6% with median time until death of 60 [5-144] months. In conclusion, ectopic insulinomas are presented as hypoglycaemia with female preponderance. Functional imaging [68Ga]Ga-DOTA-exedin-4 PET/CT and 68Ga-labelled-DOTA-conjugated somatostatin analogue PET/TC have very high sensitivity. Clinicians should be alert to the possibility of extra-pancreatic insulinomas when classic diagnostic tests and intraoperative pancreas exploration failed to locate the tumour.

A case of frequent hypoglycemic attacks successfully controlled with capecitabine plus temozolomide and 177Lu-DOTATATE peptide receptor radionuclide therapy in a patient with recurrent pancreatic insulinoma

A 59-year-old woman with metastatic pancreatic insulinoma, having undergone several treatment regimens including sunitinib, everolimus, lanreotide and streptozocin plus 5-fluorouracil, was admitted to our hospital because of frequent hypoglycemic attacks. These were refractory to medical treatment using diazoxide and required frequent daily intravenous glucose infusions. She was started on capecitabine and temozolomide (CAPTEM), followed by initiation of 177Lu-DOTATATE peptide receptor radionuclide therapy (PRRT). The frequency of hypoglycemic attacks decreased after treatment began and she was discharged on day 58 post-admission, without requiring daily glucose infusions. CAPTEM and PRRT were continued without any major adverse events. Computed tomography revealed shrinkage of primary and metastatic lesions, an anti-tumor effect that continued 8 months after treatment was initiated. Hypoglycemic attacks caused by insulinomas are often refractory to conventional therapy; however, combination treatment using CAPTEM and PRRT has demonstrated a positive and significant response, successfully restoring glycemic control.

Report of a Novel Molecular Profile in Malignant Insulinoma

Pancreatic neuroendocrine tumors, or pNETs, represent a rare and clinically heterogenous subset of pancreatic neoplasms. One such pNET, the insulinoma, is found to be malignant in just 4% of all insulinomas. Due to the exceedingly uncommon occurrence of these tumors, there is controversy regarding the optimal evidence-based management for these patients. We therefore report on a 70-year-old male patient admitted with 3 months of episodic confusion with concurrent hypoglycemia. The patient was found to have inappropriately elevated endogenous insulin levels during these episodes, and somatostatin-receptor subtype 2 selective imaging revealed a pancreatic mass metastatic to local lymph nodes, spleen, and the liver. Fine needle aspiration of pancreatic and liver lesions confirmed the diagnosis of a low grade pancreatic neuroendocrine tumor. Molecular analysis of tumor tissue revealed a novel mutational profile consistent with pNET. The patient was initiated on octreotide therapy. However, treatment with octreotide alone demonstrated limited efficacy in controlling the patient's symptoms, prompting consideration of other therapies.

Complete Resolution of Disease After Peptide Receptor Radionuclide Therapy in a Patient of Metastatic Insulinoma

ABSTRACT

A 48-year-old man, a case of metastatic insulinoma, who failed transarterial chemoembolization of liver metastases underwent multiple cycles of peptide receptor radionuclide therapy with 177Lu-DOTATATE, following which a complete morphologic and metabolic response was demonstrated on 68Ga-DOTATATE PET/CT. Patient had a remarkable improvement in his quality of life as intractable hypoglycemic episodes resolved after treatment. Peptide receptor radionuclide therapy is a promising targeted radionuclide therapy in patients of metastatic insulinomas that can result in reduced tumor burden and improved quality of life, particularly those who fail the conventional treatment modalities as seen in the present case.

Case Report: Hypoglycemia Due to Metastatic Insulinoma in Insulin-Dependent Type 2 Diabetes Successfully Treated With 177 Lu-DOTATATE

We describe a 96-year-old man with insulin-dependent type 2 diabetes mellitus who, despite insulin cessation, presented with recurrent hypoglycemia associated with confirmed inappropriate endogenous hyperinsulinemia. ⁶⁸Ga-DOTATATE-PET/CT scans demonstrated increased uptake in the pancreatic tail with multiple large intensely active liver metastases. Liver biopsy confirmed the diagnosis of well-differentiated metastatic neuroendocrine tumor. He was unsuitable for surgical resection and long-acting somatostatin analog therapy was ineffective. Subsequent management with four cycles of Lutate [177-Lutetium-DOTA⁰-Tyr³-octreotate (¹⁷⁷Lu-DOTATATE)] resulted in resolution of hypoglycemia and ongoing clinical, biochemical, and radiological response 6 years after. This case is unique due to not only the paradoxical entity of insulinoma in insulin-dependent diabetes but also the positive sustained outcome after ¹⁷⁷Lu-DOTATATE, given that unresectable metastatic insulinoma carries a poor prognosis. We review published cases of metastatic insulinoma in patients with diabetes mellitus as well as the literature to-date investigating efficacy and safety of Lutate therapy in metastatic insulinoma.

Peptide receptor radionuclide therapy as a tool for the treatment of severe hypoglycemia in patients with primary inoperable insulinoma

Objectives

Severe hypoglycemia in a course of inoperable insulinoma may be life-threating and often it is not well controlled, even by high doses of diazoxide requiring second line treatment. Among available methods PRRT is characterized by relatively low toxicity and is connected with favorable antitumor effect. The aim of the study was an evaluation of the PRRT effectiveness in control of hypoglycemia in patients with primary inoperable insulinoma.

Methods

Three patients (female with metastatic insulinoma, male with primary inoperable pancreatic tumor, female with MEN1 syndrome and hepatic metastases) were treated with PRRT due to severe hypoglycemia poorly controlled by diazoxide in course of primary inoperable insulinoma.

Results

Patient 1 baseline fasting glucose concentration increased from 2.4 mmol/L [3.30–5.60] to 5.9 mmol/L after PRRT. In patient 2 fasting glucose level 2.30 mmol/L increased after PRRT to 7.0 mmol/L, while baseline insulin level initially 31.15 uU/mL [2.6–24.9] decreased to 15.4 uU/mL. In patients 3, baseline fasting glucose level 2.5 mmol/L increased after PRRT to 7.9 mmol/L, and insulin decreased from 57.9 uU/mL to 6.3 uU/mL. In imaging there was partial response (PR) in patient 1 and 2 and stabilization of the tumor size in patient 3. In patient 2 reduction of tumor infiltration let for curative surgery performed 4 months after PPRT.

Conclusions

PRRT may be effective as a first or second line treatment in management of hypoglycemia for patients with hormonally active inoperable insulinoma.

Carcinoid Syndrome and Hyperinsulinemic Hypoglycemia Associated with Neuroendocrine Neoplasms: A Critical Review on Clinical and Pharmacological Management

The carcinoid syndrome (CS) and hyperinsulinemic hypoglycemia (HH) represent two of the most common clinical syndromes associated with neuroendocrine neoplasms (NENs). The former is mainly related to the serotonin secretion by a small bowel NEN, whereas the latter depends on an insulin hypersecretion by a pancreatic insulinoma. Both syndromes/conditions can affect prognosis and quality of life of patients with NENs. They are often diagnosed late when patients become strongly symptomatic. Therefore, their early detection and management are a critical step in the clinical management of NEN patients. A dedicated and experienced multidisciplinary team with appropriate therapeutic strategies is needed and should be encouraged to optimize clinical outcomes. This review aims to critically analyze clinical features, evidence and treatment options of CS and HH and therefore to improve their management.

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.

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.

Perspectives on the current pharmacotherapeutic strategies for management of functional neuroendocrine tumor syndromes

Introduction: In the past, controlling the hormone-excess-state was the main determinant of survival in Functional-Neuroendocrine-Neoplasm-syndromes (F-NENs). This was difficult because the pharmacological-armamentarium available was limited. Recently, new therapeutic strategies have increased but it also generated controversies/uncertainties.Areas covered: The authors briefly review: established/proposed F-NENs; the rationale for treatments; the recommended initial-pharmacotherapeutic-approach to controlling F-NENs hormone-excess-state; the secondary-approaches if the initial approach fails or resistance develops; and the approach to deal with the malignant nature of the NEN. Also discussed are controversies/uncertainties related to new treatments.Expert opinion: Unfortunately, except for patients with insulinomas (>90-95%), gastrinomas (<20-40%), a minority with the other F-panNENs and 0-<1% with Carcinoid-syndrome is curative-surgery possible. Except for insulinomas, gastrinomas, and ACTHomas, long-acting somatostatin-analogs are the initial-pharmacological-treatments for hormone-excess-state. For insulinomas prior to surgery/malignancy, diazoxide is the initial drug-treatment; for gastrinomas, oral PPIs; and for ACTHomas, steroidogenesis inhibitors. There are now several secondary pharmacotherapeutic treatments. Surgery and liver-directed therapies also have a role in selected patients. Particularly promising is the recent results with PRRT for the hormone-excess-state, independent of its anti-growth effect. The sequence to use various agents and the approach to syndrome diagnosis while taking various agents remains unclear/controversial in many cases.

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.

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.

La néoplasie endocrinienne multiple de type 1 : mise au point après le congrès de l’ENETS 2019

Multiple Endocrine Neoplasia Type 1 (NEM1) is related to mutations of the menin gene. It is an autosomal dominant disease. Its prevalence is about 1/30 000 with a hugh penetrance. There is no genotype-phenotype correlation. This hereditary syndrome is characterized by the presence of tumors of the endocrine system (parathyroid, endocrine pancreas, pituitary and adrenal gland). Other disorders have also been described (bronchial and thymic carcinoid tumor, breast cancer, skin lesions). Management must take into account the specificities of these pathologies in NEM1 compared to sporadic forms (young age at diagnosis, multiple lesions within the same gland, multi-focal disease). © 2019 Published by Elsevier Masson SAS. All rights reserved. Cet article fait partie du numéro supplément Les Must de l'Endocrinologie 2019 réalisé avec le soutien institutionnel de Ipsen-Pharma.

The functioning side of the pancreas: a review on insulinomas

PURPOSE

Insulinomas are a rare type of neuroendocrine tumors, originating in the pancreas, difficult to diagnose and to treat. Due to its rarity, insulinomas are a not well-known pathological entity; thus, the diagnostic process is frequently a medical challenge with many possible differential diagnoses. The diagnostic process varies between non-invasive procedures, such as the fasting test or imaging techniques, and invasive ones. Insulinomas are rarely malignant, but the glycemic imbalance correlated with this tumor can frequently alter the quality of life of the patients and the consequent hypoglycemia can be extremely dangerous. Moreover, insulinomas can be associated with different genetic syndromes, such as Multiple Endocrine Neoplasia 1, accompanied by other specific symptoms. There are many different treatment strategies, depending on the need to control symptoms or control diseases progression, the only curative one being surgery.

METHODS AND RESULTS

We reviewed the evidences present in the literature on insulinomas and reported its main clinical characteristics and management strategies.

CONCLUSION

The aim of this review of the literature is to present the current knowledge on insulinomas, exploring the main clinical characteristics, the diagnostic tools, and the therapeutic strategies.