Somatostatin Analogue Therapy Research Articles

Clinical management and outcome of head and neck paragangliomas (HNPGLs): A single centre retrospective study.

Head and neck paragangliomas (HNPGLs) are rare, usually benign, slow-growing tumours arising from neural crest-derived tissue. Definitive management pathways for HNPGLs have yet to be clearly defined. To review our experience of the clinical features and management of these tumours and to analyse outcomes of different treatment modalities. Demographic and clinical data were obtained from The Northern Ireland Electronic Care Record (NIECR) as well from a prospectively maintained HNPGL database between January 2011 through December 2023. There were 87 patients; 50 females: 37 males with a mean age of 52.3 ± 14.2 years old (range 17-91 years old). 58.6% (n = 51) of patients had carotid body tumours, 25.2% (n = 22) glomus vagal tumours, 6.8% (n = 6) tumours in the middle ear, 2.2% (n = 2) in the parapharyngeal space and 1.1% (n = 1) in the sphenoid sinus. 5.7% (n = 5) of patients had multifocal disease. The mean tumour size at presentation was 3.2 ± 1.4 cm (range 0.5-6.9 cm). Pathogenic SDHD mutations were identified in 41.3% (n = 36), SDHB in 12.6% (n = 11), SDHC in 2.2% (n = 2) and SDHA in 1.1% (n = 1) of the patients. Overall treatment modalities included surgery alone in 51.7% (n = 45) of patients, radiotherapy in 14.9% (n = 13), observation in 28.7% (n = 25), and somatostatin analogue therapy with octreotide in 4.5% (n = 4) of patients. Factors associated with a significantly higher risk of recurrence included age over 60 years (p = .04), tumour size exceeding 2 cm (p = .03), positive SDHx variants (p = .01), and vagal and jugular tumours (p = .04). The majority of our patients underwent initial surgical intervention and achieved disease stability. Our results suggest that carefully selected asymptomatic or medically unfit patients can be safely observed provided lifelong surveillance is maintained. We advocate for the establishment of a UK and Ireland national HNPGL registry, to delineate optimal management strategies for these rare tumours and improve long term outcomes.

Correlation between tumor invasion and somatostatin receptor subtypes in acromegaly.

The low expression of somatostatin receptor (SSTR) subtypes in somatotropinoma is associated with a poor response to somatostatin analogs (SSAs). However, the correlation between SSTRs and tumor invasion has not yet been clarified. Therefore, the authors aimed to investigate the relationship between SSTRs and tumor invasion, as well as the correlation between tumor invasiveness and pharmacological response to SSAs. A total of 102 patients with acromegaly who underwent surgery between December 2016 and December 2021 at the largest pituitary tumor surgery center in southern China were included in this retrospective study. Patients were divided into the noninvasive tumor group (Knosp grades 0-2 and Hardy-Wilson grade I or II) and invasive group (either Knosp grade 3 or 4 or Hardy-Wilson grade III or IV). The positive response to SSAs was defined by the following criteria after at least 3 months of SSA treatment: 1) ≥ 50% reduction or age- and sex-adjusted normal range of insulin-like growth factor-1 (IGF-1) level; 2) ≥ 80% reduction in or normal range of growth hormone (GH) level; or 3) > 20% reduction in tumor volume. The reference for the normal range of age- and sex-adjusted serum IGF-1 levels was derived from a survey of 2791 healthy adults (1339 males and 1452 females) in China. Demographics and clinical characteristics including tumor size, biochemical assessment, expression levels of SSTRs, and response to preoperative SSAs were compared between the invasive group and noninvasive group. Receiver operating characteristic (ROC) curve analysis was performed to assess the association between SSTR2 and tumor invasion. Compared with the noninvasive group, the invasive group presented with a larger tumor size (9.99 ± 10.41 cm3 vs 3.50 ± 4.02 cm3, p < 0.001), relatively lower SSTR2 expression (p < 0.001), and poorer response to SSAs (36.4% vs 91.7%, p < 0.001). In addition, there was a significant negative correlation between SSTR2 mRNA level and tumor size (r = -0.214, p = 0.031). However, there were no statistically significant differences in the expression of SSTR1, SSTR3, and SSTR5 between the groups. ROC analysis revealed that the low SSTR2 mRNA level was closely associated with tumor invasion (area under the curve 0.805, p < 0.0001). Tumor invasion is negatively correlated with SSTR2 level but is not associated with other SSTR subtypes. Patients with invasive tumors have a poorer response to SSA therapy, which may be due to the low level of SSTR2 expression. Therefore, SSTR2 could be considered as a routine investigative marker for aiding management of postoperative residual tumors.

Somatostatin analog (octreotide) and sirolimus immunosuppressive therapy in the treatment of chyloperitoneum and chylothorax in newborns and infants

Background: Chyloperitoneum (CP) and chylothorax (CT) are rare conditions that have a high mortality rate and unclear treatment options. Their incidence in neonates ranges from 1 in 20000 to 1 in 187000 live births. This study aims to evaluate the effectiveness of synthetic somatostatin analog (octreotide) and sirolimus therapy in treating chylous pleural and peritoneal collections in newborns and infants. Methods: We conducted a retrospective analysis of 10 children with either chylothorax or chyloperitoneum, treated in our department between 2018 and 2023. The study was approved by the Local Independent Ethics Committee of The National Medical Research Center of Children's Health, under Protocol №7, dated 11 May 2023. The parents voluntarily signed an informed consent form for the off-label use of the drug. We reviewed the medical records for demographic information, clinical presentation, management, and outcome. Results: Our study looked at patients aged between 0 and 5.5 months, with seven cases of chyloperitoneum and three cases of chylothorax. We initially used octreotide, which was then switched to sirolimus if there was no improvement. Octreotide was effective in five children after 10-18 days of treatment, while the effect of sirolimus was observed 8-14 days after starting treatment. One patient, who had a history of a giant omphalocele with primary closure, experienced complications after 8 weeks of sirolimus therapy, including bilateral knee arthritis, leukopenia, and lymphopenia. Fortunately, there were no fatal outcomes. Conclusion: Sirolimus therapy is effective in treating newborns with chylothorax or chyloperitoneum, with a low risk of complications even in those cases not responding to octreotide therapy. It is recommended that octreotide therapy should not exceed 10 days, after which sirolimus can be prescribed.

Use of perioperative telotristat in a patient with carcinoid heart disease.

Carcinoid heart disease is a rare complication of carcinoid syndrome, resulting in right-sided valvular heart disease and subsequent heart failure due to long-term exposure to vasoactive substances. The management of this condition is complex, often requiring surgical intervention. Current perioperative regimens entail the use of prophylactic somatostatin analogs to prevent carcinoid crisis; however, regimens vary widely among practitioners and evidence supporting their efficacy in this clinical setting is mixed. This case report describes the perioperative management of a 65-year-old man with carcinoid heart disease requiring tricuspid and pulmonary valve replacement surgery. As an adjunct to somatostatin analog therapy, the novel tyrosine hydroxylase inhibitor, telotristat, was initiated preoperatively. This combination resulted in normalization of preoperative urinary 5-HIAA levels. The patient successfully underwent tricuspid and pulmonic valve replacement without evidence of carcinoid crisis. This clinical case is the first published documenting the use of telotristat in the perioperative period in a patient with carcinoid syndrome and carcinoid heart disease and was associated with a good long-term outcome despite the high-risk nature of the case. Carcinoid crisis is a life-threatening complication of carcinoid syndrome, resulting in hemodynamic instability, bronchospasm, and arrhythmia. Cardiac surgical patients with carcinoid syndrome present a unique challenge as they are subject to physiologic conditions and medications which can potentiate intraoperative carcinoid crisis. Perioperative management of patients with carcinoid syndrome currently entails the use of prophylactic somatostatin analogs; however, these agents do not prevent carcinoid crisis in all cases. Telotristat, a tryptophan hydroxylase inhibitor, shows promise as an adjunctive therapy to somatostatin analogs to reduce the risk of intraoperative carcinoid crisis.

Treatment Patterns of Long-Acting Somatostatin Analogs for Neuroendocrine Tumors

Background: Long-acting somatostatin analog therapy (LA-SSA) is recommended as first-line therapy for treatment of unresectable or metastatic neuroendocrine tumors (NETs). Understanding treatment sequencing and dosing patterns of LA-SSA is essential for clinical decision-making to provide value-based management of NETs. Objective: To describe treatment patterns of LA-SSA among patients with NETs and subgroups with carcinoid syndrome (CS) in the United States. Methods: This retrospective study utilized claims data from MarketScan® databases to identify patients with NETs and newly treated with LA-SSA between January 1, 2015, and October 31, 2020. Patients were stratified by index LA-SSA (lanreotide and octreotide long-acting release [LAR]). Reported 28-day doses were based on claim fields for days’ supply/drug quantity or units of service. Dose escalation was defined as increases in quantity or frequency. Continuous variables, categorical variables, and Kaplan-Meier estimated treatment durations were compared using t-tests, chi-square/Fisher’s tests, and log-rank tests, respectively. Results: The study included 241 lanreotide and 521 octreotide LAR patients. Compared with octreotide LAR patients, treatment duration was longer for lanreotide patients (median, 41.3 vs 26.8 months; log-rank p=.004). Fewer lanreotide patients received rescue treatment with short-acting octreotide (7.9% vs 14.4%; p=.011), and a first (6.2% vs 27.3%) and second dose escalation (0.8% vs 5.2%; both p&lt;.05). Among patients with doses reported, fewer lanreotide patients received above-label doses (2.5% [5/202] vs 14.4% [60/416]; p&lt;.001). Among patients who ended treatment during follow-up, fewer lanreotide patients transitioned to another LA-SSA (18.9% [17/90] vs 33.6% [92/274]; p=.008). Similar treatment patterns were observed in CS subgroups. Results for switched treatment patterns were limited due to insufficient sample sizes. Discussion: Real-world treatment patterns of LA-SSA were assessed using more recent administrative claims data. Compared with octreotide LAR patients, lanreotide patients were more likely to remain longer on initial treatment and starting dose without dose escalations and less likely to use rescue treatment and transition to another LA-SSA after discontinuation of the index treatment. Conclusions: Findings from this claims study suggest a potential clinical benefit of lanreotide in NET management.

Treatment Patterns of Long-Acting Somatostatin Analogs for Neuroendocrine Tumors

Background: Long-acting somatostatin analog therapy (LA-SSA) is recommended as first-line therapy for treatment of unresectable or metastatic neuroendocrine tumors (NETs). Understanding treatment sequencing and dosing patterns of LA-SSA is essential for clinical decision-making to provide value-based management of NETs. Objective: To describe treatment patterns of LA-SSA among patients with NETs and subgroups with carcinoid syndrome (CS) in the United States. Methods: This retrospective study utilized claims data from MarketScan® databases to identify patients with NETs and newly treated with LA-SSA between January 1, 2015, and October 31, 2020. Patients were stratified by index LA-SSA (lanreotide and octreotide long-acting release [LAR]). Reported 28-day doses were based on claim fields for days’ supply/drug quantity or units of service. Dose escalation was defined as increases in quantity or frequency. Continuous variables, categorical variables, and Kaplan-Meier estimated treatment durations were compared using t-tests, chi-square/Fisher’s tests, and log-rank tests, respectively. Results: The study included 241 lanreotide and 521 octreotide LAR patients. Compared with octreotide LAR patients, treatment duration was longer for lanreotide patients (median, 41.3 vs 26.8 months; log-rank p=.004). Fewer lanreotide patients received rescue treatment with short-acting octreotide (7.9% vs 14.4%; p=.011), and a first (6.2% vs 27.3%) and second dose escalation (0.8% vs 5.2%; both p&lt;.05). Among patients with doses reported, fewer lanreotide patients received above-label doses (2.5% [5/202] vs 14.4% [60/416]; p&lt;.001). Among patients who ended treatment during follow-up, fewer lanreotide patients transitioned to another LA-SSA (18.9% [17/90] vs 33.6% [92/274]; p=.008). Similar treatment patterns were observed in CS subgroups. Results for switched treatment patterns were limited due to insufficient sample sizes. Discussion: Real-world treatment patterns of LA-SSA were assessed using more recent administrative claims data. Compared with octreotide LAR patients, lanreotide patients were more likely to remain longer on initial treatment and starting dose without dose escalations and less likely to use rescue treatment and transition to another LA-SSA after discontinuation of the index treatment. Conclusions: Findings from this claims study suggest a potential clinical benefit of lanreotide in NET management.

Optimal first-line treatment strategies of systemic therapy for unresectable gastrointestinal neuroendocrine tumors based on the opinions of Japanese experts.

There are several options for systemic therapy of gastroenteropancreatic neuroendocrine neoplasms (GEP-NEN), including somatostatin analogues (SSA), molecular-targeted agents, cytotoxic agents, and peptide receptor radionuclide therapy. However, the effectiveness of each agent varies according to the primary site. Although SSA and everolimus are key drugs used for systemic therapy of neuroendocrine tumors arising from the gastrointestinal tract (GI-NET), the optimal strategy for selecting among these modalities remains unexplored. Japanese experts on GI-NET discussed and determined optimal first-line treatment strategies based on the results of previously reported pivotal trials. The consensus was reached that tumor aggressiveness and prognosis can be predicted using hepatic tumor load and Ki-67 labeling index, which are thought to be clinically important factors when selecting systemic therapy for unresectable GI-NET. SSA therapy is considered appropriate for patients with a low hepatic tumor load and low Ki-67 value and everolimus for those with contraindications to SSA therapy. There was also agreement that the treatment strategy should be determined according to whether the origin is in the midgut, considering the biological differences. Based on this strategy, the experts have tentatively created treatment maps and applied them in representative cases of unresectable GI-NET. Japanese experts proposed tentative maps for optimal first-line treatment in patients with unresectable GI-NET. Further investigation is warranted to validate the usefulness of these maps.

THU063 Somatostatin Analog Neoadjuvant Treatment Before Endoscopic Surgery For Growth-Hormone Producing Pituitary Adenomas Invading The Cavernous Sinus: Case Series, Systematic Literature Review And Meta-analysis

Abstract Disclosure: B. Rapoport: None. A. Halstrom: None. A. Kelly: None. M. Roytman: None. J. Lantos: None. D. Phillips: None. R. Ramakrishna: None. T. Schwartz: None. G.A. Dobri: None. Background: Pituitary surgery remains the first line of treatment for acromegaly, yet 35-50% of patients with macroadenomas do not achieve biochemical remission postoperatively. Macroadenomas invading the cavernous sinus (Knosp grades 3 and 4) are particularly refractory to surgical management. Adjuvant therapy with somatostatin analogs in refractory cases is well established, but neoadjuvant use of these agents to consolidate invasive tumors prior to surgery remains controversial. Methods: We retrospectively analyzed our series of 84 consecutive cases of acromegaly treated with endoscopic transsphenoidal pituitary surgery between 2004 and 2020. We have used neoadjuvant pretreatment with somatostatin analogs for adenomas invading the cavernous sinus since 2017. We compared radiographic and long-term biochemical outcomes in the first 10 of these patients with a cohort of historical control patients who underwent resection only. We also performed a systematic review and meta-analysis of studies investigating neoadjuvant use of somatostatin analog therapy prior to transsphenoidal surgery for acromegaly. Results: Neoadjuvant therapy significantly reduced total tumor volume and volume of tumor in the cavernous sinus prior to surgery (mean reductions 30% and 48%, respectively, p&amp;lt;0.01), and was associated with trends toward increased rates of gross total resection and biochemical cure. Of those pretreated with neoadjuvant therapy, 60% were found to be in biochemical remission postoperatively compared to 50% in the control group, P 1. In addition, 70% of those pretreated had a gross total resection compared to 50% of controls, P 0.65. Gross total resection was achieved in all patients with Knosp grade 3 tumors, regardless of pretreatment status, and all of these patients entered biochemical remission. In patients with Knosp grade 4 tumors, gross total resection was achieved in 29% of surgery-only patients and 57% of pretreated patients; biochemical remission was achieved in 14% of surgery-only patients, and 29% of pretreated patients. The differences were not statistically significant. Conclusions: In this series of acromegalic patients with macroadenomas invading the cavernous sinus, neoadjuvant somatostatin analog therapy was associated with a trend toward increased rates of gross total resection and biochemical remission. Of note, those who were not in remission in the pretreatment group had a milder biochemical elevation and required lower-intensity medical therapy postoperatively. The systematic literature review and meta-analysis that we have performed confirm a statistically significant increase in remission rate in patients receiving neoadjuvant therapy. Presentation: Thursday, June 15, 2023

THU023 Sparse Granulation In Growth Hormone Secreting Adenomas: Clinical Implications Of A Rare Histological Finding

Abstract Disclosure: A. Merrill: None. R. Varughese: None. G. Campbell: None. L. Belalcazar: None. Introduction: Acromegaly is an uncommon disease. Endocrinologists may be unfamiliar with the clinical implications of granularity findings on the histology of growth hormone (GH)-secreting adenomas. We present the case of a patient with acromegaly in whom a sparsely granulated (SG) histological subtype was identified post-operatively. We discuss the clinical presentation and therapeutic implications of this finding. Case Presentation: A 36-year-old man was admitted to the hospital with rectal bleeding and incidentally found to have features consistent with acromegaly. Patient reported that over 1 year he had noticed changes in his facial features, enlargement of his hands and had developed hand and knee arthralgias. During the 6 months prior to admission, he experienced worsening fatigue, but denied severe headaches or vision changes. Past medical history was significant for osteosarcoma as a young child treated with an above the knee amputation. Family history was negative for pituitary tumors or colon cancer. Physical exam revealed a blood pressure of 104/53 mmHg and an amputation-adjusted body mass index of 27.4 _kg/ m2 . He had mild frontal bossing, enlarged nose, macroglossia, swollen hands and foot. Rectal examination revealed hemorrhoids but no masses. Gross visual field deficits were identified at bedside. Laboratory findings were significant for an elevated IGF-1 at 975 ng/mL (83-240 ng/mL) and GH 45.2 ng/mL (0.3-9 ng/mL). Patient was also found to have panhypopituitarism: TSH 1.54 mIU/L (0.45-4.70 mIU/L), Free T4 0.62 ng/dl (0.78 - 2.20 ng/dL); ACTH 13.3 pg/ml (7.2 - 63.3 pg/mL), cortisol AM 3.6 ug/dL (4.5-23.0 ug/dL), peak cortisol after ACTH stimulation 16.0 ug/dL; testosterone 31.6 ng/dl (132-813 ng/dL), LH 1.75 mIU/ml (1.2-8.6 mIU/mL). His hemoglobin A1c was 5.7%. MRI of the brain revealed a large enhancing lobulated sellar/suprasellar lesion of 5.0 x 2.4 x 2.8 cm, with extension to the third ventricle and mass effect on the optic chiasm. Patient underwent partial surgical resection of the large tumor. Pathology identified a SG somatotroph tumor with most cells being negative or weakly positive for GH on immunohistochemical staining. TSH, prolactin, and ACTH stains were negative. There was evidence of residual tumor, which was located superiorly, not accessible through the transsphenoidal route.A colonoscopy and formal visual field testing are pending currently. Patient is waiting for a second surgery via craniotomy and, given the SG finding on histology, pasireotide therapy will be offered. Discussion: The sparsely granulated (SG) subtype is an uncommon variant of GH-producing. Our patient illustrates the aggressive nature of SG GH-producing adenomas. These tumors express more invasive growth and resistance to standard somatostatin analogue therapy. There is a growing recognition that adenoma granulation is an important consideration in the management of acromegaly. Presentation: Thursday, June 15, 2023

THU511 Somatostatin Analogs Or Active Surveillance In Sporadic And MEN1 Associated Non-functioning Pancreatic Neuroendocrine Tumors

Abstract Disclosure: S. Raia: None. S. Chiloiro: None. M. Maratta: None. B. Maiorano: None. E. Rossi: None. M. Brizi: None. V. Rufini: None. L. De Marinis: None. G. Rindi: None. G. Schinzari: None. A. Pontecorvi: None. G. Tortora: None. A. Bianchi: None. Introduction: Non-functioning (NF), sporadic and MEN1 associated, G1-G2 pancreatic neuroendocrine tumors (PanNETs) usually display an indolent course. Surgery is the first-choice treatment for localized tumors &amp;gt;2 cm. Unresectable or metastatic PanNETs expressing somatostatin receptors (SSTRs) are treated with somatostatin analogs (SSAs). The standard treatment for patients with PanNETs ≤2cm is active surveillance (AS). Yet no evidence of the value of SSA treatment exist in such patient population. Aim(s): To assess the clinical value of SSAs in patients with PanNETs ≤2cm. Material and methods: Data from patients (pts) NF, G1-G2 PanNETs≤2cm were retrospectively collected. Median progression-free survival (mPFS) and response rate (RR) were analyzed in SSA group and AS group. Results: From June 2007 to June 2022, data from 46 pts were considered: 29 pts, who declined an AS program but had not indication for surgery, entered in the SSA group (21 sporadic and 8 MEN1 associatd PanNET) and 17 in the AS group. At a median follow-up of 64.8 months for sporadic and of 63.9 for MEN1 associated PanNET, no disease progression (PD) was reported in the SSA group, without differences between sporadic and MEN1 associated PanNET. While the PD rate was 23.5 % in the AS group, with a mPFS of 36.2 months. Conclusion: SSAs therapy showed significant antiproliferative activity in patients with both sporadic and MEN1 associated NF, G1-G2 PanNETs ≤2cm. SSAs treatment delay tumor progression and distant spread in small lesions that sometimes may reveal an unpredictable aggressiveness. Presentation: Thursday, June 15, 2023

Effects of somatostatin analogs on uptake of radiolabeled somatostatin analogs on imaging: a systematic review and meta-analysis.

The imaging of somatostatin receptors (SSTRs) plays a significant role in imaging neuroendocrine tumors (NETs). However, there has been no clear definition on whether it is necessary to withdraw somatostatin analogs (SSAs) before SSTRs imaging. We aimed to assess whether nonradioactive SSAs affect the uptake of radiolabeled SSAs on imaging for NETs patients. The databases of PubMed, Embase, and Web of Science (WoS) were searched until March 12, 2022 to identify eligible studies. Maximum standardized uptake values (SUVmax) in tumor and normal tissues were extracted, pooled, and compared before and after SSAs treatment. The change of tumor-to-background/liver ratio was also described. The quality of each study was assessed using the revised Quality Assessment of Diagnostic Accuracy Studies-2 tool. A total of 9 articles involving 285 patients were included and 5 studies using Gallium-68-labeled [1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid]-D-Phe1-Tyr3-Thr8-octreotide (68Ga-DOTATATE) were used for pooled evaluation. We found a significantly decreased SUVmax in the liver (9.56±2.47 vs. 7.62±2.12, P=0.001) and spleen (25.74±7.14 vs. 20.39±6.07, P=0.006) after SSAs treatment whereas no significant differences were observed in the uptake of thyroid, adrenal, and pituitary gland. For either primary tumor sites or metastases, the SUVmax did not change significantly before and after SSAs treatment. The tumor-to-liver/background ratio increased following SSAs therapy. High heterogeneity was observed across the studies, mainly due to inherent diversity of study design, sample size, and scanning technique. Based on current evidence, long-acting SSAs therapy before imaging has no effect on the uptake of radiolabeled SSAs at tumor primary sites and metastatic lesions, but results in a significant reduction of uptake in the liver and spleen. These findings may implicate the unnecessary discontinuation of SSAs before radiolabeled SSAs imaging.

1198P Phase Ib portion of the ACTION-1 phase Ib/3 trial of RYZ101 in gastroenteropancreatic neuroendocrine tumors (GEP-NET) progressing after 177Lu somatostatin analogue (SSA) therapy: Safety and efficacy findings

1198P Phase Ib portion of the ACTION-1 phase Ib/3 trial of RYZ101 in gastroenteropancreatic neuroendocrine tumors (GEP-NET) progressing after 177Lu somatostatin analogue (SSA) therapy: Safety and efficacy findings

Quantitative uptake in 99m Tc-EDDA/HYNIC-TOC somatostatin receptor imaging - the effect of long-acting release somatostatin analogue therapy.

Withdrawal of long-acting release somatostatin analogue (LAR-SSA) treatment before somatostatin receptor imaging is based on empirical reasoning that it may block uptake at receptor sites. This study aims to quantify differences in uptake of 99m Tc-EDDA/HYNIC-TOC between patients receiving LAR-SSA and those who were not. Quantification of 177 patients (55 on LAR-SSA) imaged with 99m Tc-EDDA/HYNIC-TOC was performed, with analysis of pathological tissue and organs with physiological uptake using thresholded volumes of interest. Standardised uptake values (SUVs) and tumour/background (T/B) ratios were calculated and compared between the two patient groups. SUVs were significantly lower for physiological organ uptake for patients on LAR-SSA (e.g. spleen: SUV max 13.3 ± 5.9 versus 33.9 ± 9.0, P < 0.001); there was no significant difference for sites of pathological uptake (e.g. nodal metastases: SUV max 19.2 ± 13.0 versus 17.4 ± 11.5, P = 0.552) apart from bone metastases (SUV max 14.1 ± 13.5 versus 7.7 ± 8.0, P = 0.017) where it was significantly higher. LAR-SSA has an effect only on physiological organ uptake of 99m Tc-EDDA/HYNIC-TOC, reducing uptake. It has no significant effect on pathological uptake for most sites of primary and metastatic disease. This should be taken into account if making quantitative measurements, calculating T/B ratios or assigning Krenning Scores. There is the potential for improved dosimetric results in Peptide Receptor Radionuclide Therapy by maintaining patients on LAR-SSA.

Small Bowel Neuroendocrine Tumors-10-Year Experience of the Ottawa Hospital (TOH).

(1) Aim: The prevalence and incidence of small bowel NETs have increased significantly over the past two decades. This study aims to report the 10-year experience of SB-NET management at a regional cancer center in Canada. (2) Materials and methods: We conducted a retrospective study of the clinical and pathological data of patients diagnosed with biopsy-proven SB-NET at The Ottawa Hospital (TOH), Ottawa, Canada between 2011 and 2021. We report the clinicopathological characteristics of these patients, as well as their outcomes data, including survival rates. (3) Results: Between 2011 and 2021, a total of 177 SB-NET cases were identified with 51% (n = 91) of cases being males. The most common sites of the tumors were the ileum 53% (n = 94), followed by the duodenum 9% (n = 16) and jejunum 7% (n = 12). Approximately 24% (n = 42) of the patients had symptoms for over six months prior to diagnosis and 18% (n = 32) had functioning SB-NET during the course of the disease. The majority of patients had locally advanced or metastatic disease at the time of presentation with stage III, and stage IV representing 42% (n = 75), and 41% (n = 73) respectively. The majority of patients 84% (n = 148) had well-differentiated histology. One hundred twenty patients underwent surgical resection of the primary tumor including 28 patients (16%) with limited metastatic disease. A total of 21 patients (18%) had recurrence after curative surgery. A total of 62 patients (35%) received first-line somatostatin analog (SSA) therapy for unresectable disease and seven patients had PRRT after progression on SSA. Five years OS was 100%, 91%, 97%, and 73% for stages I, II, III, and IV respectively. In univariate analysis, carcinoid symptoms, T stage, and differentiation were significant predictors for worse overall survival, but not RFS. (4) Conclusions: Compared to published historical controls, our study suggests improvement in the 5-year survival rate of SB-NETs over the last 10 years.

A somatostatin analogue and immunosuppressive therapy in the treatment of complex forms of chyloperitoneum and chylothorax in newborns and infants

Chyloperitoneum and chylothorax are rare conditions with high mortality rates whose optimal treatment strategy remains unclear. The aim of the study was to evaluate the results of chyloperitoneum and chylothorax treatment with a synthetic somatostatin analogue (octreotide) and immunosuppressive therapy with sirolimus. The study was approved by the Independent Ethics Committee and the Scientific Council of the National Medical Research Center for Children’s Health of Ministry of Healthсare of Russia. The patients' parents gave their consent to the use of their children's data, including photographs, for research purposes and in publications. We conducted a retrospective study of nine children diagnosed with congenital chyloperitoneum and chylothorax who had been treated from 2018 to 2022. All the children received either abdominal or pleural drainage, parenteral nutrition, and conservative therapy with drugs. The first line of therapy was octreotide for 14–20 days that was then switched to sirolimus if there had been no effect. The effectiveness of conservative therapy with octreotide at a dose of 5–10 µg/kg/hour was observed in 5 cases. If there had been no effect by day 14, the patients were started on sirolimus at a dose of 0.05–0.2 mg/day which proved to be effective in all the patients (n = 4). Our study showed that sirolimus is effective in complex cases of chyloperitoneum and chylothorax in newborns and infants. Because of the rarity of these disorders, our conclusions were based on the analysis of a small cohort. To confirm our results and develop uniform diagnostic and treatment guidelines, further, more targeted multicenter research is needed. Until such guidelines are adopted, decisions on the treatment of chyloperitoneum and chylothorax should be made on an individual basis and approved by the medical committee of a treatment center.

Outcome analysis in patients with metastatic gastroenteropancreatic neuroendocrine tumors receiving peptide receptor radionuclide therapy with Lu-177-DOTATATE.

Patients with neuroendocrine tumors (NET) of the gastroenteropancreatic tract (GEP-NET) were effectively treated with peptide receptor radionuclide therapy (PRRT) with Lu-177-DOTATATE in the NETTER-1 trial. The aim of this study was to assess the outcome of metastatic GEP-NET patients within a European Neuroendocrine Tumor Society (ENETS) certified center of excellence after this treatment. A total of 41 GEP-NET patients who received PRRT with Lu-177-DOTATATE between 2012 and 2017 at a single center were included in this analysis. Data on pre- and post-PRRT treatments [selective internal radiation therapy (SIRT), somatostatin analogue therapy (SSA), blood parameters, patient symptomatic burden and overall survival] was extracted from patient records. Overall, PRRT was well tolerated and did not increase patient symptomatic burden. Blood parameters were not significantly affected by PRRT (means before and after therapy: hemoglobin: 125.4 vs. 122.3 mg/L, P=0.201; creatinine: 73.8 vs. 77.7 µmol/L, P=0.146), while leukocytes (6.6 vs. 5.6 G/L, P<0.01) and platelets (269.9 vs. 216.7 G/L, P<0.001) were significantly decreased yet without clinical significance in our study. Seven of 9 patients with SIRT treatment prior to PRRT were deceased (mortality odds ratio =4.083). The mortality odds ratio of patients with a pancreatic tumor and SIRT was 1.33 compared to patients with a different tumor origin. 6 of 15 patients (40%) with post-PRRT SSA were deceased (mortality odds ratio =0.429 without SSA after PRRT). Patients with advanced GEP-NET might benefit from PRRT with Lu-177-DOTATATE as it can provide a valuable treatment modality in advanced disease stages. Safety profiles of PRRT were manageable without increasing the symptomatic burden. SIRT before PRRT or lack of SSA after PRRT seem to impair the response and reduce survival.

Long-term use of somatostatin analogs for chronic gastrointestinal bleeding in hereditary hemorrhagic telangiectasia.

Chronic bleeding due to gastrointestinal (GI) involvement in patients with hemorrhagic hereditary telangiectasia (HHT) can provoke severe anemia with high red blood cells (RBC) transfusion requirements. However, the evidence about how to deal with these patients is scarce. We aimed to assess the long-term efficacy and safety of somatostatin analogs (SA) for anemia management in HHT patients with GI involvement. This is a prospective observational study including patients with HHT and GI involvement attended at a referral center. SA were considered for those patients with chronic anemia. Anemia-related variables were compared in patients receiving SA before and during treatment. Patients receiving SA were divided into responders (patients with minimal hemoglobin levels improvement >10 g/L and maintaining hemoglobin levels ≥80 g/L during treatment), and non-responders. Adverse effects during follow-up were collected. Among 119 HHT patients with GI involvement, 67 (56.3%) received SA. These patients showed lower minimal hemoglobin levels (73 [60-87] vs. 99 [70.2-122.5], p < 0.001), and more RBC transfusion requirements (61.2% vs. 38.5%, p = 0.014) than patients without SA therapy. Median treatment period was 20.9 ± 15.2 months. During treatment, there was a statistically significant improvement in minimum hemoglobin levels (94.7 ± 29.8 g/L vs. 74.7 ± 19.7, p < 0.001) and a reduction of patients with minimal hemoglobin levels <80 g/L (39 vs. 61%, p = 0.007) and RBC transfusions requirement (33.9% vs. 59.3%, p < 0.001). Sixteen (23.9%) patients showed mild adverse effects, mostly diarrhea or abdominal pain, leading to treatment discontinuation in 12 (17.9%) patients. Fifty-nine patients were eligible for efficacy assessment and 32 (54.2%) of them were considered responders. Age was associated with non-responder patients, OR 95% CI; 1.070 (1.014-1.130), p = 0.015. SA can be considered a long-term effective and safe option for anemia management in HHT patients with GI bleeding. Older age is associated with poorer response.

Progress in the Treatment of Small Intestine Cancer.

Small intestine cancer is rare, accounting for approximately 3% of all gastrointestinal malignancies. The most common histological subtypes include adenocarcinoma, neuroendocrine tumours (NETs) and gastrointestinal stromal tumours (GISTs). In localised disease, surgery remains the mainstay of treatment and the best approach to improve survival. Current treatment for small intestine adenocarcinoma (SIA) is extrapolated from small studies and data from colorectal cancer (CRC). There is limited evidence to guide therapy in the adjuvant setting. However, there are small phase II studies in the advanced setting providing evidence for the role of chemotherapy and immunotherapy. There is also limited evidence assessing the efficacy of targeted therapies. Small intestine NETs are rare, with evidence for somatostatin analogue therapy, particularly in the low to intermediate-grade well-differentiated tumours. Poorly differentiated NETs are generally managed with chemotherapy but have worse outcomes compared with well-differentiated NETs. The management of small intestine GISTs is largely targeting KIT mutations with imatinib. Recent trials have provided evidence for effective therapies in imatinib-resistant tumours and the potential role of immunotherapy. The aim of this article was to review the evidence for the current management and recent advances in the management of small intestine adenocarcinoma, NETs and GISTs.

Survival outcomes for patients (pts) with gastroenteropancreatic neuroendocrine tumors (GEP-NETs) treated with lutetium-177-dotatate (Lu-177) in a Brazilian reference center: A six-year follow-up experience.

642 Background: GEP-NETs are the most common NETs primary site. Lu-177 is the standard treatment for patients with grade 1 (G1) or grade 2 (G2) midgut NETs who had disease progression during first-line somatostatin analog therapy. Methods: We performed a retrospective chart review including advanced GEP-NETs treated with at least one Lu-177 dose from our institution. Overall survival (OS) and progression-free survival (PFS) were calculated from the first Lu-177 dose using the Kaplan–Meier method. Cox regression analysis was performed for PFS adjusted by grade, primary tumor site, metastasis sites (1 vs.≥ 2), presence of liver metastasis, and previous local or other systemic treatments. Krenning Score (KS) and the maximum standardized uptake value (SUVmax) were calculated from the pre-treatment Ga-68 PET/CT. Maximally Selected Rank Statistics (MSRS) test was used for SUVmax simple cutpoint estimate and PFS was calculated using the Kaplan–Meier method. Results: 36 pts were included; the median age was 51 (range: 33-80). 19 (52.8%) pts had primary pancreatic NET and 17 (47.2%) had non-pancreatic primary NETs. Tumor grading was classified based on Ki67%. 10 pts were G1 (28.6%), 18 pts were G2 (51.4%), 7 pts were G3 (20%). 7 pts (19.4%) and 28 pts (77.7%) had KS 3 and 4, respectively. 125 cycles of Lu-177 were applied with 3.5 cycles per pts (mean; range: 1-6). 12 (33.3%) pts experienced grade 1 and 2 toxicity, mainly fatigue (n=4). No grade 3 or 4 toxicities were reported. 4 (11.1%) patients died (n=3 G3; n=1 G2) with median follow-up of 90.5 months (range: 16-122). 11 pts (30.6%) lost follow-up after Lu-177 treatment. 29 pts (80.5%) were eligible for OS. 24-month and 36-month survival rates were 92,7% (95% CI 73.7 - 98.1) and 86,9% (95% CI 63.5 - 95.7) respectively. The median OS was not reached for G1 and G2 tumors, and it was 30 months for G3 tumors (p=0.001). 34 (94%) pts were eligible for PFS. The median PFS was 23 months (95% CI 30.5-64.9) for the entire cohort. The median PFS was 30 months for G1, 27 months for G2 pts, and 7 months for G3 pts. G1/G2 vs. G3 median PFS was statistically different in the uni- and multivariate analysis [HR 8.41 (95%CI 2.2-31.0; p=0.001)]. The primary site, metastasis sites, number of previous systemic treatments, previous local treatment, and presence of liver metastasis did not correlate with PFS in the multivariate analyses. Pts with SUVmax &gt; 34.53 exhibited a statistical trend toward a longer PFS (median 52.0 vs 18.7 months; p=0.06). Conclusions: This real-life study supports that Lu-177 provides long-term PFS in pts KS 3/4 with G1/G2 GEP-NETs independent of clinical characteristics and primary site. Although G3 pts have worse survival, selected G3 GEP-NETs may experience long OS after Lu-177 treatment. SUVmax values from the pre-treatment Ga-68 PET/CT study may select ideal pts for Lu-177.

Parathyroid related peptide (PTHrP) secreting pancreatic neuroendocrine tumour (PNET): a case of PTHrP, hypercalcaemia and osteoarthrosis (OA) controlled by somatostatin analogue therapy (SSA)

Parathyroid related peptide (PTHrP) secreting pancreatic neuroendocrine tumour (PNET): a case of PTHrP, hypercalcaemia and osteoarthrosis (OA) controlled by somatostatin analogue therapy (SSA)