Prevalence of metastases outside the liver and abdominal lymph nodes on 68Ga-DOTATOC-PET/CT in patients with small intestinal and pancreatic neuroendocrine tumours.

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 metastatic patterns in patients with Si-NET compared to Pan-NET. The impact of such metastases on overall survival and clinical decision-making needs further evaluation.

Modified Histopathological Grading Optimizes Prediction of Survival Outcomes in Small Intestinal Neuroendocrine Tumours.

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% could be superior to predict differences in SI-NET patient survival outcomes.

Impact of fine-needle aspiration cytology in thyroidectomy extent and associated surgical morbidity in thyroid cancer.

PURPOSE: To assess the impact of fine-needle aspiration cytology (FNAC) in the extent of surgery in patients with thyroid cancer (TC) and the associated surgical morbidity in primary and completion setting. METHODS: A Swedish nationwide cohort of patients having surgery for TC (n = 2519) from the Scandinavian Quality Register for Thyroid, Parathyroid and Adrenal surgery between 2004 and 2013 was obtained. Data was validated through scrutinizing FNAC and histology reports. RESULTS: Among the 2519 cases operated for TC, the diagnosis was substantiated and validated through the histology report in 2332 cases (92.6%). Among these, 1679 patients (72%) were female, and the median age at TC diagnosis was 52.3 years (range 18-94.6). Less than total thyroidectomy (LTT) was undertaken in 944 whereas total thyroidectomy (TT) in 1388 cases. The intermediate FNAC categories of atypia of undetermined significance/follicular lesion of undetermined significance (AUS/ FLUS), as well as suspicion for follicular neoplasm (SFN) lesions were more often encountered in LTT (n = 314, 33.3%) than TT (n = 63, 4.6%), whereas FNACs suspicion for malignancy and/or malignancy were overrepresented in TT (n = 963, 69.4%). Completion thyroidectomies were undertaken in 553 patients out of 944 that initially had LTT. In 201 cases with cancer lesions > 1 cm, other than FTC (Follicular TC)/ HTC (Hürthle cell TC) subjected to primary LTT, inadequate procedures were undertaken in 81 due to absent, Bethesda I or II FNAC categories, preoperatively. Complications at completion of surgery in this particular setting were 0.5% for RLN palsy (n = 1) and 1% (n = 2) for hypoparathyroidism 6 months postoperatively. The overall postoperative complication rate was higher in primary TT vs. LTT for RLN palsy (4.8% [n = 67] vs. 2.4% [n = 23]; p = 0.003) and permanent hypoparathyroidism (6.8% [n = 95] vs. 0.8% [n = 8]; p < 0.0001). CONCLUSIONS: FNAC results appear to affect surgical planning in TC as intermediate FNAC categories lead more often to LTT. Overall, inadequate procedures necessitating completion surgery are encountered in up to 15% of TC patients subjected to LTT due to absent, inconclusive, or misleading FNAC, preoperatively. However, completion of thyroidectomy in this setting did not yield significant surgical morbidity. Primary LTT is a safer primary approach compared to TT in respect of RLN palsy and permanent hypoparathyroidism complication rates; therefore, primary TT should probably be reserved for lesions > 1 cm or even larger with suspicion for malignancy or malignant FNAC.

Pancreatic metastases in patients with neuroendocrine neoplasms: A multi-centre cohort study.

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.

Meta-analysis of placebo-arm dropouts in osteoporosis randomized-controlled trials and implications for nocebo-associated discontinuation of anti-osteoporotic drugs in clinical practice.

Dropout from placebo arms in randomized-controlled trials is a surrogate for nocebo responses, resulting from patients' negative expectations to treatment. Among 16,460 placebo-treated patients in oral anti-osteoporotic drug trials, nocebo dropouts were 8% on average, being higher in older patients. This implies that nocebo may contribute to the osteoporosis treatment gap in clinical practice. PURPOSE: Osteoporosis is a common disease requiring long-term treatment. Despite the availability of effective anti-osteoporotic drugs, adherence to treatment is low. Nocebo, a behavior mostly related to the negative expectations to a certain treatment, decreases adherence and negatively affects treatment outcomes and health-related care costs in chronic diseases. Since in double-blind placebo-controlled randomized trials any unfavorable outcome leading to discontinuation in placebo arms is considered as nocebo, we aimed to investigate the size of nocebo response in patients participating in osteoporosis trials. METHODS: We searched MEDLINE, EMBASE, SCOPUS, and Cochrane databases for dropouts due to reported adverse events in the placebo arms (nocebo dropouts) in all double-blind trials investigating anti-osteoporotic drugs published between January 1993 and March 2022. Only data on bisphosphonates and selective estrogen receptor modulators (SERMs) were analyzed (Prospero registration number CRD42020212843). RESULTS: Data from 44 trials were extracted. In 16,460 placebo-treated patients, the pooled nocebo-dropout was 8% both for bisphosphonates (average: 0.08; range 0.01-0.27; 95%CI 0.06-0.10) and SERMs (average: 0.08; range 0.03-0.15; 95%CI 0.05-0.13). Nocebo-dropouts were higher in bisphosphonate trials enrolling individuals ≥ 65 years (11%) (n = 18) compared to trials enrolling younger individuals (6%) (n = 18) (average: 0.11; 95%CI 0.08-0.13 vs. average: 0.06; 95%CI 0.05-0.08, respectively, p = 0.001). Participants' sex, dosing-intervals, publication year, or severity of osteoporosis had no impact on the nocebo-dropouts. CONCLUSION: Almost 1 in 10 osteoporosis patients receiving placebo in trials of bisphosphonates and SERMs experiences AEs leading to dropout, implying that nocebo contributes to treatment-discontinuation in clinical practice. Efforts to identify and minimize nocebo, especially in older patients, are warranted.

Hemicolectomy versus appendectomy for patients with appendiceal neuroendocrine tumours 1-2 cm in size: a retrospective, Europe-wide, pooled cohort study.

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. FUNDING: Swiss Cancer Research foundation.

Association of lymph node metastases, grade and extent of mesenteric lymph node dissection in locoregional small intestinal neuroendocrine tumors with recurrence-free survival.

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 independent prognostic factors for RFS. In conclusion, LRS with a meticulous MLND and a minimum number of five harvested LNs appears to be critical in the surgical management of SI-NET patients with locoregional disease. In patients who underwent LRS and MLND, the Ki-67 proliferation index and the LN metastases count were independent predictors of RFS.

Efficacy, safety and unmet needs of evolving medical treatments for carcinoid syndrome.

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.

Heterogeneity of Small Intestinal Neuroendocrine Tumors Metastasis: Biologic Patterns of a Series with Virchow's Node Involvement.

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 and one pancreatic metastasis), whereas peritoneal carcinomatosis (PC) in two patients. We used a control group of 18 age- and sex-matched SI-NET patients from the same cohort with stage IV disease but no extra-abdominal metastases. There was no difference in best-recorded response to first line treatment according to RECIST 1.1 as well as progression-free survival (PFS) between patients with VM and those in the control group (Chi-square test p = 0.516; PFS 71.7 vs. 106.9 months [95% CI 38.1-175.8]; log-rank p = 0.855). In addition, median overall survival (OS) of SI-NET patients with VM did not differ from those in the control group (138.6 [95% CI 17.2-260] vs. 109.9 [95% CI 91.7-128] months; log-rank p = 0.533). In conclusion, VM, although relatively rare in patients with SI-NETs, is more often encountered in patients with G2 tumors and established distant para-aortic lymph node metastases. The presence of VM in SI-NET patients does not seem to impact patients' survival outcomes and treatment responses, when compared to age- and sex-matched SI-NET patients with stage IV disease confined in the abdomen.

A Critical Appraisal of Contemporary and Novel Biomarkers in Pheochromocytomas and Adrenocortical Tumors.

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.

Cardiovascular Toxicities Secondary to Biotherapy and Molecular Targeted Therapies in Neuroendocrine Neoplasms: A Systematic Review and Meta-Analysis of Randomized Placebo-Controlled Trials.

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 conclusion, SSAs and TPH inhibitors appear to be safer as compared to mTOR inhibitors and TKIs with regards to their overall toxicity profile, and cardiovascular toxicities in particular. Special consideration should be given to a patient-tailored approach with anticipated toxicities of targeted NEN treatments together with assessment of cardiovascular comorbidities, assisting clinicians in treatment selection and early recognition/management of cardiovascular toxicities. This approach could improve patient compliance and preserve cardiovascular health and overall quality of life.

Clinical Utility of 18F-FDG PET in Neuroendocrine Tumors Prior to Peptide Receptor Radionuclide Therapy: A Systematic Review and Meta-Analysis.

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.

Changing biological behaviour of NETs during the evolution of the disease: progress on progression.

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.

Currently available treatment options for neuroendocrine liver metastases.

Neuroendocrine neoplasms (NEN) are frequently characterized by a high propensity for metastasis to the liver, which appears to be a dominant site of distant-stage disease, affecting quality of life and overall survival. Liver surgery with the intention to cure is the treatment of choice for resectable neuroendocrine liver metastases (NELM), aiming to potentially prolong survival and ameliorate hormonal symptoms refractory to medical control. Surgical resection is indicated for patients with NELM from well-differentiated NEN, while its feasibility and complexity are largely dictated by the degree of liver involvement. As a result of advances in surgical techniques over the past decades, complex 1- and 2-stage, or repeat liver resections are performed safely and effectively by experienced surgeons. Furthermore, liver transplantation for the treatment of NELM should be anchored in a multimodal and multidisciplinary therapeutic strategy and restricted only to highly selected individual cases. A broad spectrum of interventional radiology treatments for NELM have recently been available, with expanding indications that are more applicable, as they are less limited by patient- and tumor-related parameters, being therefore important adjuncts or alternatives to surgery. Overall, liver-targeted treatment modalities may precede the administration of systemic molecular targeted agents and chemotherapy for patients with liver-dominant metastatic disease; these appear to be a crucial component of multimodal management of patients with NEN. In the present review, we discuss surgical and non-surgical liver-targeted treatment approaches for NELM, each complementing the other, with a view to assisting physicians in optimizing multimodal NEN patient care.

The Role of Serum 5-HIAA as a Predictor of Progression and an Alternative to 24-h Urine 5-HIAA in Well-Differentiated Neuroendocrine Neoplasms.

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.

Association of a Palliative Surgical Approach to Stage IV Pancreatic Neuroendocrine Neoplasms with Survival: A Systematic Review and Meta-Analysis.

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.

The effect of prophylactic surgery in survival and HRQoL in appendiceal NEN.

BACKGROUND/AIMS: Long-term outcomes are understudied in patients with well-differentiated appendiceal neuroendocrine neoplasms (WD-ANENs). We aimed to evaluate the validity of currently applied criteria for completion prophylactic right hemicolectomy (pRHC) and determine its association with patient outcomes, including health-related quality of life (HRQoL). METHODS: Eligible patients from five European referral centers were divided between those who underwent appendectomy alone and those who underwent completion pRHC. HRQoL EORTC-QLC-C30 questionnaires and cross-sectional imaging data were prospectively collected. Age- and sex-matched healthy controls were recruited for HRQoL analysis' validation. RESULTS: We included 166 patients (119 women [71.2%]: mean age at baseline: 31 ± 16 years). Mean follow-up was 50.9 ± 54 months. Most patients (152 [92%]) had tumors ≤20 mm in size. Fifty-eight patients (34.9%) underwent pRHC that in final analysis was regarded as an overtreatment in 38/58 (65.5%). In multivariable analysis, tumor size >20 mm was the only independent predictor for lymph node (LN) involvement (p = 0.002). No mortality was reported, whereas 2-, 5- and 10-year recurrence-free survival in patients subjected to postoperative cross-sectional imaging (n = 136) was 98.5%, 97.8%, and 97.8%, respectively. Global HRQoL was not significantly impaired in patients with WD-ANEN compared with age- and sex-matched healthy individuals (median scores 0.83[0.08-1] vs 0.83[0.4-1], respectively; p = 0.929). Among patients with WD-ANEN impaired social functioning (p = 0.016), diarrhea (p = 0.003) and financial difficulties (0.024) were more frequently reported in the pRHC group. CONCLUSIONS: WD-ANEN is a low-malignant neoplasm with unconfirmed associated mortality, low recurrence rate, and overall preserved HRQoL. pRHC comes at a price of excessive surgery, functional HRQoL issues, and diarrhea. The value per se of a prophylactic surgical approach to patients with WD-ANENs <20 mm is challenged.

Pathogenesis and Clinical Management of Mesenteric Fibrosis in Small Intestinal Neuroendocine Neoplasms: A Systematic Review.

Mesenteric fibrosis (MF) constitutes an underrecognized sequela in patients with small intestinal neuroendocrine neoplasms (SI-NENs), often complicating the disease clinical course. The aim of the present systematic review, carried out by Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology, is to provide an update in evolving aspects of MF pathogenesis and its clinical management in SI-NENs. Complex and dynamic interactions are present in the microenvironment of tumor deposits in the mesentery. Serotonin, as well as the signaling pathways of certain growth factors play a pivotal, yet not fully elucidated role in the pathogenesis of MF. Clinically, MF often results in significant morbidity by causing either acute complications, such as intestinal obstruction and/or acute ischemia or more chronic conditions involving abdominal pain, venous stasis, malabsorption and malnutrition. Surgical resection in patients with locoregional disease only or symptomatic distant stage disease, as well as palliative minimally invasive interventions in advanced inoperable cases seem clinically meaningful, whereas currently available systemic and/or targeted treatments do not unequivocally affect the development of MF in SI-NENs. Increased awareness and improved understanding of the molecular pathogenesis of MF in SI-NENs may provide better diagnostic and predictive tools for its timely recognition and intervention and also facilitates the development of agents targeting MF.

Increased autophagy/mitophagy levels in primary tumours of patients with pancreatic neuroendocrine neoplasms.

BACKGROUND/AIMS: We assessed the levels of autophagy and mitophagy, that are linked to cancer development and drug resistance, in well differentiated pancreatic neuroendocrine neoplasms (PanNENs) and correlated them with clinico-pathological parameters. METHODS: Fluorescent immunostaining for the autophagy markers LC3Β and 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 analysed 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 20 mm; 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 with 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. CONCLUSIONS: 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.