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CONTEXT: One of the major prognostic indices in neuroendocrine tumours (NETs) is Ki67 proliferation index. OBJECTIVE: To identify optimal grading Ki-67 cut-offs to delineate differences in prognosis of patients with small intestinal NETs (SI-NETs). DESIGN, SETTING, PARTICIPANTS: Multicentre retrospective cohort analysis of 551 SI-NET patients diagnosed from 1993 through 2021 at five European referral centres with a mean(±SD) follow-up time of 51.5(±52.9) months. MAIN OUTCOME MEASURES: Overall- and event-free survival (OS and EFS) rates. RESULTS: Median age at baseline was 62.3(range:17-90) years; 252(45.7%) patients were female. All SI-NETs were well-differentiated with 326 being grade 1(G1; 59.2%), 169G2(30.7%), and only 8G3(1.5), while 48 tumours were of unspecified grade (8.7%). The median Ki67 was 2%(range:1-70%). Two-hundred forty-seven patients (44.8%) had distant metastases at baseline (stage IV), 217 locoregional disease (41.1%; stage III), whereas 29(7.1%) and 25(4.5%) presented at stages II and I, respectively. The median OS was 214.7(95%CI:152.7-276.6) months and the median EFS was 79.8(95%CI:68.2-91.5) months, respectively. In multivariable Cox-regression OS analysis, the proposed modified histopathological Ki67 grading system (K67:5-10% group: HR=2.2, 95%CI:1.15-4.31; p=0.018 and K67≥10% group: HR=5.11, 95%CI:2.87-9.09; p<0.001), age (HR=1.07, 95%CI:1.04-1.09; p<0.001), Charlson Comorbidity Index (HR=1.08, 95%CI:1-1.16; p=0.028) and TNM stage (HR=1.79, 95%CI:1.05-3.06; p=0.034) were independent predictors for death. Pertinent EFS analysis, confirmed the proposed modified histopathological Ki67 grading system (K67≥10% group: HR=4.01, 95%CI:2.6-6.37; p<0.001) and age (HR=1.04, 95%CI:1.02-1.05; p<0.001) as independent predictors for recurrence, progression and/or death. CONCLUSIONS: Ki-67 proliferation index was a strong and independent predictor of OS and EFS. A modified histopathological grading system applying Ki-67 cut-offs of 5 and 10% cou

Metastases outside the liver and abdominal/retroperitoneal lymph nodes are nowadays detected frequently in patients with neuroendocrine tumours (NETs), owing to the high sensitivity of positron emission tomography (PET) with Gallium-68-DOTA-somatostatin analogues (68Ga-SSA) and concomitant diagnostic computed tomography (CT). Our aim was to determine the prevalence of extra-abdominal metastases on 68Ga-DOTATOC-PET/CT in a cohort of patients with small intestinal (Si-NET) and pancreatic NET (Pan-NET), as well as that of pancreatic metastasis in patients with Si-NET. Among 2090 patients examined by 68Ga-DOTATOC-PET/CT at two tertiary referral centres, a total of 1177 patients with a history of Si- or Pan-NET, were identified. The most recent 68Ga-DOTATOC-PET/CT report for each patient was reviewed, and the location and number of metastases of interest were recorded. Lesions outside the liver and abdominal nodes were found in 26% of patients (n = 310/1177), of whom 21.5% (255/1177) were diagnosed with Si-NET and 4.5% (55/1177) Pan-NET. Bone metastases were found in 18.4% (215/1177), metastases to Virchow's lymph node in 7.1% (83/1177), and lung/pleura in 4.8% (56/1177). In the subset of 255 Si-NET patients, 5.4% (41/255) manifested lesions in the pancreas, 1.5% in the breast (18/255), 1.3% in the heart (15/255) and 1% in the orbita (12/255). In Si-NET patients, the Ki-67 proliferation index was higher in those with ≥2 metastatic sites of interest, than with 1 metastatic site, (p <0.001). Overall, extra-abdominal or pancreatic metastases were more often found in patients with Si-NET (34%) than in those with Pan-NET (13%) (p <0.001). Bone metastases were 2.6 times more frequent in patients with Si-NET compared to Pan-NET patients (p <0.001). Lesions to the breast and orbita were encountered in almost only Si-NET patients. In conclusion, lesions outside the liver and abdominal nodes were detected in as many as 26% of the patients, with different prevalence and me

Introduction: Neuroendocrine metastases to the orbita, heart, breast, bone, Virchow's lymph node, and pancreas are rarely encountered in small intestinal (SI-NETs) and pancreatic NETs (P-NETs). Aim(s): We aimed to assessthe prevalence of rare metastatic locations in patients with well-differentiated SI-NETs and P-NETs, who had undergone 68Ga-DOTATOC-PET/CT at diagnosis and/or follow-up. Materials and methods: In this retrospective analysis of 753 SI-NET patients and 418 P-NET patients treated at two tertiary referral centers, rare metastases were evident in 26.5% (310/1171) of the patient cohort. Results: Among patients with rare metastases (n=310), 45 % were women and median age at metastases diagnosis was 70 years (43-90). Median Ki-67 was 7% (1-70); 106 were G1 tumors, 142 G2, 11 G3 and 51 of unknown grade. Rare metastatic sites were present in bone 18 % (215/1171), Virchow's lymph node 6 % (75/1171) and 4 % (42/1171) in the lung/pleura. Metastases to the pancreas, breast, heart and orbita were only encountered in SI-NET primaries with a frequency of 5 % (41/753), 2 % (17/753), 2 % (14/753) and 2 % (12/753) respectively. Concomitant liver metastases were present in 86 %. Uncommon metastases were more frequent in SI-NET as compared with P-NET primaries, 255/753 [34%] vs. 55/418 [13%], p ˂0.00001. Bone metastases were present in 23 % (175/753) of SI-NET and 10 % (40/418) of p-NET primaries. Conclusion: In conclusion, rare metastases are more frequent in SI-NET than p-NETs. The variety and pattern of rare metastases seems different between SI-NETs and P-NET primaries, as orbita, heart, breast and Virchow's lymph node deposits were only encountered in SI-NETs patients; and bone metastases were approximately twice more often inthis group.

Pancreatic metastases (PMs) from neuroendocrine neoplasms (NENs) are rare but the increased sensitivity of new diagnostic tools such as 68 Ga-DOTATATE PET/CT has resulted in their increased recognition at initial diagnosis or follow-up. A retrospective analysis of the data of patients from six tertiary referral centres was performed in order to identify the characteristics and the prognostic significance of PMs in patients with NENs. We used a control group of 69 age-, sex- and primary tumour - matched NEN patients from the same cohort with stage IV disease but no PMs. Overall survival (OS) was assessed using the Kaplan-Meier method log-rank analysis was used to assess the impact of various clinical and histopathological variables in OS. We identified 25 patients (11 females) with PMs with a median age at diagnosis of 60 years. The small intestine was the most common primary (80%) with a prevalence of 4.2% PMs (21/506). Fourteen patients presented with synchronous PMs whereas 11 developed metachronous PMs after a median time of 28 months (range: 7-168 months). Grading was available in 24 patients; 16 patients had G1 tumours, four G2, two atypical lung carcinoid, one typical and one atypical thymic carcinoid. Most patients had other concomitant metastases (12 hepatic, 4 lung and 6 bone) while five patients exhibited peritoneal carcinomatosis. Median OS in the PMs group was not reached compared with 212 months in the control group (95% CI: 26-398). The univariate analysis identified no prognostic factors statistically significantly associated with the OS. In conclusion, PMs are encountered with a low prevalence among NEN patients mostly developing in patients with advanced metastatic disease. The presence of PMs does not seem to be associated with a negative prognostic impact in OS.

[Background] Awareness of the potential global overtreatment of patients with appendiceal neuroendocrine tumours (NETs) of 1–2 cm in size by performing oncological resections is increasing, but the rarity of this tumour has impeded clear recommendations to date. We aimed to assess the malignant potential of appendiceal NETs of 1–2 cm in size in patients with or without right-sided hemicolectomy., [Methods] In this retrospective cohort study, we pooled data from 40 hospitals in 15 European countries for patients of any age and Eastern Cooperative Oncology Group performance status with a histopathologically confirmed appendiceal NET of 1–2 cm in size who had a complete resection of the primary tumour between Jan 1, 2000, and Dec 31, 2010. Patients either had an appendectomy only or an appendectomy with oncological right-sided hemicolectomy or ileocecal resection. Predefined primary outcomes were the frequency of distant metastases and tumour-related mortality. Secondary outcomes included the frequency of regional lymph node metastases, the association between regional lymph node metastases and histopathological risk factors, and overall survival with or without right-sided hemicolectomy. Cox proportional hazards regression was used to estimate the relative all-cause mortality hazard associated with right-sided hemicolectomy compared with appendectomy alone. This study is registered with ClinicalTrials.gov, NCT03852693., [Findings] 282 patients with suspected appendiceal tumours were identified, of whom 278 with an appendiceal NET of 1–2 cm in size were included. 163 (59%) had an appendectomy and 115 (41%) had a right-sided hemicolectomy, 110 (40%) were men, 168 (60%) were women, and mean age at initial surgery was 36·0 years (SD 18·2). Median follow-up was 13·0 years (IQR 11·0–15·6). After centralised histopathological review, appendiceal NETs were classified as a possible or probable primary tumour in two (1%) of 278 patients with distant peritoneal metastases and in two (1%) 278 patients with distant metastases in the liver. All metastases were diagnosed synchronously with no tumour-related deaths during follow-up. Regional lymph node metastases were found in 22 (20%) of 112 patients with right-sided hemicolectomy with available data. On the basis of histopathological risk factors, we estimated that 12·8% (95% CI 6·5 –21·1) of patients undergoing appendectomy probably had residual regional lymph node metastases. Overall survival was similar between patients with appendectomy and right-sided hemicolectomy (adjusted hazard ratio 0·88 [95% CI 0·36–2·17]; p=0·71)., [Interpretation] This study provides evidence that right-sided hemicolectomy is not indicated after complete resection of an appendiceal NET of 1–2 cm in size by appendectomy, that regional lymph node metastases of appendiceal NETs are clinically irrelevant, and that an additional postoperative exclusion of metastases and histopathological evaluation of risk factors is not supported by the presented results. These findings should inform consensus best practice guidelines for this patient cohort.

Simple Summary Virchow's node metastasis (VM) refers to the involvement of the left supraclavicular lymph nodes at the junction of the thoracic duct and the left subclavian vein. Generally, VM is considered by clinicians to be a strong indicator of metastatic abdominal malignancy, and its dismal prognostic significance has previously been described in patients with metastatic gastric and ovarian cancer. To date, comprehensive descriptions of patients with small intestinal neuroendocrine tumors (SI-NETs) and rare metastatic manifestations, including that of VM, are sparse. In the present study from two tertiary referral centers, the prevalence of the VM secondary to SI-NET primaries was found to be 3.9%. VM was more often encountered in patients with higher-grade tumors and established disseminated disease to distant para-aortic lymph nodes. However, the presence of VM did not yield any negative prognostic impact in patient outcomes when compared to age- and sex-matched patients of similar grade with distant metastases confined in the abdomen Small intestinal neuroendocrine tumors (SI-NETs) may rarely metastasize to the left supraclavicular lymph nodes, also known as Virchow's node metastasis (VM). Data on prevalence, prognostic significance, and clinical course of disease for SI-NET patients with VM is limited. In this retrospective analysis of 230 SI-NET patients treated at two tertiary referral centers, we found nine patients with VM (prevalence 3.9%). Among those, there were 5 females and median age at SI-NET and VM diagnosis was 61 and 65 years, respectively. Two patients had G1 tumors and five G2, while two tumors were of unspecified grade (median Ki67: 7%, range 2-15%). Four patients presented with synchronous VM, whereas five developed metachronous VM after a median of twenty-four months (range: 4.8-117.6 months). Hepatic metastases were present in seven patients, extrahepatic metastases (EM) in eight (six para-aortic distant lymph node metastases, one lung a

We aimed to assess the prognostic impact of tumor- and patient-related parameters in patients with stage I-III small intestinal neuroendocrine tumors (SI-NETs), who underwent locoregional resective surgery (LRS) with curative intent. We included 229 patients with stage I-III SI-NETs diagnosed from June 15, 1993, through March 8, 2021, identified using the SI-NET databases from five European referral centers. Mean ± SD age at baseline was 62.5 ± 13.6 years; 111/229 patients were women (49.3%). All tumors were well-differentiated; 160 were grade 1 (G1) tumors, 51 were G2, two were G3 and 18 tumors were of unspecified grade (median Ki-67: 2%, range 1%-50%). One-hundred and sixty-three patients (71.2%) had lymph node (LN) involvement. The median number of retrieved lymph nodes was 10 (0-63), whereas the median number of positive LNs was 2 (0-43). After a mean ± SD follow-up of 54.1 ± 64.1 months, 60 patients experienced disease recurrence at a median (range) of 36.2 (2.5-285.1) months. The 5- and 10-year recurrence-free survival (RFS) rates were 66.6% and 49.3% respectively. In univariable analysis, there was no difference in RFS and overall survival (OS) between LN-positive and LN-negative patients (log-rank, p = .380 and .198, respectively). However, in stage IIIb patients who underwent mesenteric lymph node dissection (MLND) with a minimum of five retrieved LN (n = 125), five or more LN metastases were associated with shorter RFS (median RFS [95% CI] = 107.4 [0-229.6] vs. 73.7 [35.3-112.1] months; log-rank, p = .048). In addition, patients with G2 tumors exhibited shorter RFS compared to patients with G1 tumors (median RFS [95% confidence interval (CI)] = 46.9 [36.4-57.3] vs. 120.7 [82.7-158.8] months; log-rank, p = .001). In multivariable Cox-regression RFS analysis in stage IIIb patients, the Ki-67 proliferation index (hazard ratio = 1.08, 95% CI = 1.035-1.131; p < .0001) and the number of LN metastases (hazard ratio = 1.06, 95% CI = 1.001-1.125; p = .047) were

This review reports on the currently available medical treatment options for the control of symptoms due to carcinoid syndrome in patients with neuroendocrine tumors. The efficacy and adverse events (AEs) of approved drugs such as somatostatin analogues (SSA), telotristat ethyl (TE) and interferon-alpha, are reviewed. Somatostatin analogues remain the standard treatment of carcinoid syndrome based on the high expression of somatostatin receptors and the resulting inhibition of secretion of bioactive compounds; their use is associated with relatively mild AEs, involving mainly the gastrointestinal system, and being usually transient. Although dose escalation of SSA remains an unapproved option, it is clinically implemented to alleviate symptoms in refractory carcinoid syndrome and supported by the most recent guidelines. The side effects associated with the increased dose are in general mild and consistent with standard dose of SSA. Telotristat ethyl, an oral inhibitor of tryptophan hydroxylase, the rate-limiting enzyme in serotonin biosynthesis, represents a rather novel innovative treatment option in patients with carcinoid syndrome suffering from diarrhea and complements the standard therapy of SSA. Given the low toxicity profile, TE may be considered an early add-on treatment to SSA in patients with uncontrolled carcinoid syndrome. However, further prolonged follow-up of patients treated with TE may be needed to exclude potential AEs, such as liver toxicity or depressed mood, in patients with long-term treatment. Interferon alpha is a cytokine with direct inhibitory effect on hormone secretion and tumor cell proliferation and an approved therapy in carcinoid syndrome but is associated with significant AEs in the majority of the patients requiring frequently dose reduction. The finding of a more favorable tolerability of pegylated interferon needs to be confirmed in a prospective study., Funding agency:ENETS CoE Training Fellowship 2020

Introduction: There is a continuity of changes from ECL-cell hyperplasia to type 1 gastric neuroendocrine neoplasms (GNEN1) development with important clinical implications. Aim(s): Although the effect of the circadian clock system on neuroendocrine tumorigenesis has been addressed, the role of the peripheral clock system in the transition from ECL-cell hyperplasia to GNEN1 remains to be explored. Materials and methods: Six GNEN1 patients and 10 patients with ECL-cell hyperplasia were included. Blood samples were collected at 8 am, 3pm and 10pm for peripheral blood mononuclear ells (PBMCs) isolation. The mRNA expression of clock-related genes (CLOCK, BMAL1, CRY-1, PER2, ROR-α and REV-ERBβ) were evaluated by real-time quantitative PCR from PBMCs. Results: In GNEN1 patients, BMAL genes where lower expressed at night than early in the morning (p=0.02), whereas patients with ECL-cell hyperplasia expressed lower levels of PER2 and REV-ERBβ (p=0.03 and p=0.05,respectively). In addition, GNEN1 patients expressed lower levels of CLOCK, PER2 and REV-ERBβ in the early evening than in the morning (p=0.04; p=0.03; p=0.05, respectively). When comparing the two groups (GNEN1 vs. ECL-cell hyperplasia) at the three different time points, a marginal increase in CLOCK, PER2 and REV-ERBβ expression early in the morning (p=0.06, 0.02 and 0.07, respectively) along with a marginal increase in REV-ERBβ and BMAL expression in the early evening (p=0.09 and p=0.08, respectively) and a marginal increase in BMAL at night (p=0.09) in GNEN1 patients was observed. Conclusion: Our findings point towards an upregulated expression of clock-related genes in patients with GNEN1 as compared to ECL-cell hyperplasia, suggesting a possible involvement in GNEN1 tumorigenesis that needs to be confirmed in a larger patients group.

Pheochromocytomas/Paragangliomas (PPGLs) and adrenocortical tumors are rare neoplasms with significant heterogeneity in their biologic and clinical behavior. Current diagnostic and predictive biomarkers include hormone secretion, as well as histopathological and genetic features. PPGL diagnosis is based on biochemical measurement of catecholamines/metanephrines, while histopathological scoring systems have been proposed to predict the risk of malignancy. Adrenocortical tumors are mostly benign, but some can be malignant. Currently, the stage of disease at diagnosis and tumor grade, appear to be the most powerful prognostic factors. However, recent genomic and proteomic studies have identified new genetic and circulating biomarkers, including genes, immunohistochemical markers and micro-RNAs that display high specificity and sensitivity as diagnostic or prognostic tools. In addition, new molecular classifications have been proposed that divide adrenal tumors in distinct subgroups with different clinical outcomes. Simple Summary Pheochromocytomas/paragangliomas (PPGLs) and adrenocortical tumors are neoplasms that originate from different regions of the adrenal gland and display significant heterogeneity with respect to their biological and clinical behavior. They may be sporadic or develop in the context of hereditary syndromes. Adrenocortical tumors are mostly benign but less than 2% are carcinomas associated with a poor outcome when diagnosed in advanced disease. The majority of PPGLS are benign, but a subset may develop metastatic disease. In particular, for PPGLs, it is mandatory to identify biomarkers of high sensitivity and specificity that lead to accurate diagnosis and predict patients with a malignant potential that would benefit from aggressive surveillance and administration of early treatment. Current biomarkers include mostly histopathological and genetic parameters but none of them can be considered independent predictive factors. Recent genomic studies

Our aim was to investigate the clinical utility of serum 5HIAA for disease surveillance and diagnostic purposes in a cohort of patients with well-differentiated neuroendocrine neoplasms (WD-NENs). Forty-eight patients with WD-NENs and concurrent serum and urinary 5HIAA testing, as well as CT/MRI imaging, were included. Analysis of matching-pairs did not reveal any association between RECIST 1.1 responses and changes in serum 5HIAA levels (p = 0.673). In addition, no correlation was evident between RECIST 1.1 responses and >10%, >25% or >50% changes in serum 5HIAA levels (Fisher's exact test p = 0.380, p > 0.999, and p > 0.999, respectively). The presence of liver metastases and extensive liver tumor involvement were associated with higher serum 5HIAA levels (p = 0.045 and p = 0.041, respectively). We also confirmed a strong linear correlation between the measurements of serum and urine 5HIAA (n = 24, r = 0.791, p < 0.0001). The concordance rate of serum and urinary 5HIAA positivity at standardized laboratory cut-offs was 75%. In patients with normal renal function tests, the concordance between the two methods was as high as 89%, and a sensitivity and specificity of 80% and 88.9%, respectively, was evident (Cohen's kappa coefficient = 0.685). In conclusion, serum 5HIAA performs well compared to urinary testing for diagnostic purposes, mainly in advanced disease stages, and corresponds well to liver tumor burden. However, it is not adequate to predict tumor progression.

A broad spectrum of novel targeted therapies with prime antitumor activity and/or ample control of hormonal symptoms together with an overall acceptable safety profile have emerged for patients with metastatic neuroendocrine neoplasms (NENs). In this systematic review and quantitative meta-analysis, the PubMed, EMBASE, Cochrane Central Register of Controlled Trials and clinicaltrials.gov databases were searched to assess and compare the safety profile of NEN treatments with special focus on the cardiovascular adverse effects of biotherapy and molecular targeted therapies (MTTs). Quality/risk of bias were assessed using GRADE criteria. Placebo-controlled randomized clinical trials (RCTs) in patients with metastatic NENs, including medullary thyroid cancer (MTC) were included. A total of 3695 articles and 122 clinical trials registered in clinicaltrials.gov were screened. We included sixteen relevant RCTs comprising 3408 unique patients assigned to different treatments compared with placebo. All the included studies had a low risk of bias. We identified four drug therapies for NENs with eligible placebo-controlled RCTs: somatostatin analogs (SSAs), tryptophan hydroxylase (TPH) inhibitors, mTOR inhibitors and tyrosine kinase inhibitors (TKI). Grade 3 and 4 adverse effects (AE) were more often encountered in patients treated with mTOR inhibitors and TKI (odds ratio [OR]: 2.42, 95% CI: 1.87-3.12 and OR: 3.41, 95% CI: 1.46-7.96, respectively) as compared to SSAs (OR:0.77, 95% CI: 0.47-1.27) and TPH inhibitors (OR:0.77, 95% CI: 0.35-1.69). MTOR inhibitors had the highest risk for serious cardiac AE (OR:3.28, 95% CI: 1.66-6.48) followed by TKIs (OR:1.51, 95% CI: 0.59-3.83). Serious vascular AE were more often encountered in NEN patients treated with mTOR inhibitors (OR: 1.72, 95% CI: 0.64-4.64) and TKIs (OR:1.64, 95% CI: 0.35-7.78). Finally, patients on TKIs were at higher risk for new-onset or exacerbation of pre-existing hypertension (OR:3.31, 95% CI: 1.87-5.86). In concl

The role of 18F-FDG PET in patients with variable grades of neuroendocrine tumors (NETs) prior to peptide receptor radionuclide therapy (PRRT) has not been adequately elucidated. We aimed to evaluate the impact of 18F-FDG PET status on disease control rate (DCR), progression-free survival (PFS), and overall survival (OS) in neuroendocrine tumor (NET) patients receiving PRRT. We searched the MEDLINE, Embase, Cochrane Library, and Web of Science databases up to July 2020 and used the Newcastle-Ottawa scale (NOS) criteria to assess quality/risk of bias. A total of 5091 articles were screened. In 12 studies, 1492 unique patients with NETs of different origins were included. The DCR for patients with negative 18F-FDG PET status prior to PRRT initiation was 91.9%, compared to 74.2% in patients with positive 18F-FDG PET status (random effects odds ratio (OR): 4.85; 95% CI: 2.27–10.36). Adjusted analysis of pooled hazard ratios (HRs) confirmed longer PFS and OS in NET patients receiving PRRT with negative 18F-FDG PET (random effects HR:2.45; 95%CIs: 1.48–4.04 and HR:2.25; 95% CIs:1.55–3.28, respectively). In conclusion, 18F-FDG PET imaging prior to PRRT administration appears to be a useful tool in NET patients to predict tumor response and survival outcomes and a negative FDG uptake of the tumor is associated with prolonged PFS and OS., Funding Agency:ENETS CoE Training Fellowship 2020

Following improvements in the management and outcome of neuroendocrine neoplasms (NENs) in recent years, we see a subset, particularly of pancreatic NENs, which become more aggressive during the course of the disease. This is reflected by an increase in the Ki-67 labelling index, as a marker of proliferation, which may lead to an occasion of increase in grading, but generally does not appear to be correlated with histologically confirmed dedifferentiation. A systematic review of the literature was performed in PubMed, Cochrane Library, and Embase until May 2020 to identify cases that have behaved in such a manner. We screened 244 articles: only seven studies included cases in their cohort, or in a subset of the cohort studied, with a proven increase in the Ki-67 during follow-up through additional biopsy. In addition to these studies, we have also tried to identify possible pathophysiological mechanisms implicated in advanced NENs, although currently no studies appear to have addressed the mechanisms implicated in the switch to a more aggressive biological phenotype over the course of the disease. Such progression of the disease course may demand a change in the management. Summarising the overall evidence, we suggest that future studies should concentrate on changes in the molecular pathways during disease progression with sequential biopsies in order to shed light on the mechanisms that render a neoplasm more aggressive than its initial phenotype or genotype.

Introduction: Above-label doses of long-acting somatostatin analogues (SSAs) are increasingly used for the control of secretory syndrome or as anti-proliferative treatment in patients with gastroenteropancreatic neuroendocrine tumors (GEP-NETs). Aim(s): The aim of this study was to evaluate the anti-proliferative effect of increased dose of SSAs in patients with GEP-NETs. Materials and methods: We collected retrospectively the data of patients with GEP-NETs that received SSAs every 3 or 2 weeks, after disease progression on standard 4-weekly doses. We analysed clinical, biochemical and radiographic response data and identified factors that may influence the outcome. Results: We analysed the data of 16 patients. 7 patients suffered from pancreatic NET (pNET) and 9 from small intestinal NET (si-NET). Indications for dose increase were radiographic progression (62,5%), increasing biomarkers (12,5%) or inadequate syndrome control (25%). Among patients with radiographic progression before the escalation of SSA dose, 3 had disease stabilization and 7 eventually progressed radiographically. Median PFSwas 36 months. PNETs were associated with a significantly lower PFS compared to si-NETs (P= 0.041). Patients with NET with a Ki-67 labelling index≤5 displayed a significantly higher PFS (P= 0.047). No significant difference was observed between patients who received above-label SSAs due to clinical/biochemical or radiographic response (P=0.1). In univariate analysis, the Ki-67≤5 was marginally associated with significantly longer PFS (P=0.05). Conclusion: The administration of above-label doses of SSAs maybe a valuable option in patients who progress on the standard 4-weekly regimen, especially in patients with si-NETs or a Ki-67 labelling index≤5.

Introduction: There are only few studies on the diagnostic value of serum 5HIAA as compared to the 24-hours urinary sampling method and a lack of evidence on the prognostic significance of its serum levels, as well as the markers' ability to predict changes in disease status. Aim(s): Our aim was to investigate the clinical utility of serum 5HIAA for diagnostic purposes and disease surveillance in a cohort of patients with well-differentiated neuroendocrine neoplasms (WD-NENs). Materials and methods: Forty-eight patients with WD-NENs and concurrent serum and urinary 5HIAA testing as well as CT/MRI imaging were included. Results: A positive correlation between disease stage and serum 5HIAA positivity (Pearson Chi-square p=0.017), and between liver tumor burden and serum 5HIAA levels (Spearman’s rank correlation coefficient: 0.46; p=0.013) was confirmed. Further analysis did not reveal any correlation between RECIST 1.1 responses and >25% changes in serum 5HIAA levels (Fisher ́s exact test p=0.735). The concordance rate of serum and urinary 5HIAA positivity at standardized laboratory cut-offs was 75%. In patients without any impairment of the renal function, the concordance between the two tests was as high as 89% and a sensitivity and specificity of 80% and 88.9%, respectively was evident (Cohen’s kappa coefficient=0.685). Conclusion: Serum 5HIAA performs well compared to urinary testing for diagnostic purposes and corresponds well to tumor stage and liver tumor burden. However, it is not adequate to predict tumor progression.

Many trials have demonstrated prime antitumor activity of novel, small molecule multikinase inhibitors (MKIs) in advanced and/or metastatic thyroid cancer (TC). In this work, the PubMed, EMBASE, Cochrane Central Register of Controlled Trials, Web of Science, SCOPUS, and clinicaltrials.gov databases were searched. Quality/risk of bias were assessed using GRADE criteria. Randomized clinical trials (RCTs) comparing two or more systemic therapies in patients with advanced and/or metastatic thyroid cancer were assessed. A total of 1347 articles and 548 clinical trials in clinicaltrials.gov were screened. We included seven relevant RCTs comprising 1934 unique patients assigned to different MKIs. Two separate network meta-analyses included four RCTs in radioiodine refractory well-differentiated thyroid cancer (RR-WDTC) and three RCTs in medullary thyroid cancer (MTC), respectively; all with a low risk of bias. We identified three therapies for RR-WDTC: sorafenib [disease control rate (DCR) odds ratio (OR): 0.11 (95% CI: 0.03–0.40); progression-free survival (PFS) hazard ratio (HR): 1.99 (95% CI: 1.62–2.46)], vandetanib [DCR_OR:0.26 (95% CI: 0.06–1.24); PFS_HR: 0.99 (95% CI: 0.82–1.20)] and lenvatinib [DCR_OR: 0.26 (95% CI: 0.05–1.33); PFS_HR: 0.99 (95% CI: 0.81–1.22)]; and the following therapies for MTC: vandetanib 300 mg [objective response rate (ORR)_OR: 3.31 (95% CI: 0.68–16.22); vandetanib 150 mg ORR_OR: 0.60 (95% CI: 0.16–2.33)]; and cabozantinib [ORR_OR: 85.32 (95% CI: 5.22–1395.15)]. Serious side effect (SE) analysis per organ/system demonstrated a varying MKI SE profile across both RR-WDTC and MTC diagnoses, more commonly involving metabolic/nutritional disorders [OR: 2.07 [95% CI: 0.82–5.18)] and gastrointestinal SE [OR: 1.63 (95% CI: 1.0–2.66)]. This network meta-analysis on advanced and/or metastatic TC points towards a higher efficacy of lenvatinib in RR-WDTC. The included MKIs exhibit a varying SE profile across different organs/systems favoring a patient-tai

The role of primary tumor resection in patients with pancreatic neuroendocrine neoplasms (PanNENs) and unresectable distant metastases remains controversial. We aimed to evaluate the effect of palliative primary tumor resection (PPTR) on overall survival (OS) in this setting. We searched the MEDLINE, Embase, Cochrane Library, Web of Science and SCOPUS databases up to January 2020 and used the Newcastle-Ottawa scale (NOS) criteria to assess quality/risk of bias. A total of 5661 articles were screened. In 10 studies, 5551 unique patients with stage IV PanNEN and unresectable metastases were included. The five-year OS for PanNEN patients undergoing PPTR in stage IV was 56.6% vs. 23.9% in the non-surgically treated patients (random effects relative risk (RR): 1.70; 95% CI: 1.53-1.89). Adjusted analysis of pooled hazard ratios (HR) confirmed longer OS in PanNEN patients undergoing PPTR (random effects HR: 2.67; 95% CI: 2.24-3.18). Cumulative OS analysis confirmed an attenuated survival benefit over time. The complication rate of PPTR was as high as 27%. In conclusion, PPTR may exert a survival benefit in stage IV PanNEN. However, the included studies were subject to selection bias, and special consideration should be given to PPTR anchored to a multimodal treatment strategy. Further longitudinal studies are warranted, with long-term follow-up addressing the survival outcomes associated with surgery in stage IV disease.

Introduction: Autophagy and mitophagy are key homeostatic machineries linked to cancer development and drug resistance. Aim(s): To assess the levels of autophagy and mitophagy in well differentiated pancreatic neuroendocrine neoplasms (PanNENs) and correlate them with clinico-pathological parameters. Materials and methods: Fluorescent immunostaining for the autophagy markers LC3 Βand p62/or LAMP1 was performed on 22 PanNENs and 11 controls of normal pancreatic tissues and validated through Western blotting. Autophagy quantitative scoring was generated for LC3B-positive puncta and analyzed in relation to clinico-pathological parameters. TOMM20/LC3B qualitative assessment of mitophagy levels was undertaken by fluorescent immunostaining. The presence of autophagy/mitophagy was validated by transmission electron microscopy. Results: Autophagy levels (LC3B-positive puncta/cell) were discriminative for normal vs. NEN pancreatic tissue (p=0.007). A significant association was observed between autophagy levels and tumour grade (Ki67<3% vs. Ki67≥3%; p=0.021), but not functionality (p=0.266) size (cut-off of 20mm; p=0.808), local invasion (p=0.481), lymph node- (p=0.849) and distant metastases (p=0.699). Qualitative assessment of TOMM20/LC3B demonstrated strong mitophagy levels in PanNENs by fluorescent immunostaining as compared to normal tissue. Transmission electron microscopy revealed enhanced autophagy and mitophagy in PanNEN tissue. Response to molecular targeted therapies in metastatic cases (n=4) did not reveal any patterns of association to autophagy levels. Conclusion: Increased autophagy levels are present in primary tumours of patients with PanNENs and are partially attributed to upregulated mitophagy. Grade was the only clinico-pathological parameter associated with autophagy scores.