Circulating Regulatory T Cells: A Novel Marker Associated with Liver Metastasis and the Treatment Response of Transarterial Embolization in Gastroenteropancreatic Neuroendocrine Tumors.

INTRODUCTION: To investigate the role of circulating regulatory T cells (Tregs) as a novel marker associated with liver metastases and treatment response to transarterial embolization (TAE) in patients with gastroenteropancreatic neuroendocrine tumors (GEP-NETs). METHODS: Circulating Tregs, defined as the CD4+CD25+CD127low/- population, were examined by flow cytometry in peripheral blood mononuclear cells (PBMCs) from patients with GEP-NETs. Clinicopathological parameters, radiologic response, and hepatic progression-free survival (hPFS) data were collected. RESULTS: The association between circulating Tregs and clinicopathological parameters was analyzed in 139 GEP-NET patients. Higher Treg levels were significantly associated with more progressive clinical features, including a higher WHO grade, more advanced TNM stage, and the presence of liver metastases. A Treg level ≥ 8.015% distinguished between patients with and without liver metastases. Among a cohort of 51 GEP-NET patients who were subjected to TAE for reducing liver metastasis burden, patients with higher Treg levels depicted unfavorable responses and significantly reduced hPFS after TAE treatment. We also revealed that patients with Treghigh (≥8.975%) displayed significantly shorter median hPFS than patients with Treglow (< 8.975%). Additionally, after adjusting for other confounding clinical parameters, the association between Tregs and treatment response as well as hPFS remained significant, suggesting that Tregs may have a strong and independent prognostic impact in GEP-NETs. CONCLUSIONS: Our data suggest that circulating Tregs are a novel immunological marker associated with liver metastases and treatment response to TAE in patients with GEP-NETs.

Safety and Efficacy of 177 Lu-DOTATATE in Neuroendocrine Tumor Patients With Extensive Bone Disease.

AIM: The aim of this study was to assess the efficacy and safety of 177 Lu-DOTATATE in patients with neuroendocrine tumors (NETs) and extensive bone metastases, that is, more than 50% of the skeleton involved. METHOD: A single-center retrospective analysis was performed in 30 patients (13 women and 17 men, mean age, 60 years; range, 35-77 years) undergoing 177 Lu-DOTATATE therapy. Patients had progressive metastatic NETs with extensive skeletal metastases (>50% skeletal involvement seen on baseline 68 Ga-DOTATATE PET/CT). The average administered activity was 7.308 (SD, 0.02) GBq per cycle with average treatment interval of 15 weeks. Survival analyses (progression-free survival [PFS], overall survival), radiological response assessment, toxicity assessment, and health-related quality of life (QoL) was performed. RESULTS: Overall, 26 patients completed 4 cycles, and 4 patients had less than 4 cycles of 177 Lu-DOTATATE. One patient (3%) did not complete treatment because of hematological toxicity. The estimated median PFS and median overall survival were calculated at 27 and 35 months, respectively. End-of-treatment radiological assessment showed partial response in 5 patients (17%), stable disease in 20 patients (66%), and radiological progressive disease in 3 patients (10%). Clinical progression was seen in a further 2 patients (7%).The incidence of grade 3/4 bone marrow toxicity was 10%. No patient had grade 3/4 peptide receptor radionuclide therapy-related nephrotoxicity. There was overall improvement in global QoL score (European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Gastrointestinal NET-21) ( P = 0.019). CONCLUSION: 177 Lu-DOTATATE seems to have satisfactory therapeutic outcome in patients with advanced metastatic NET with extensive bone disease, with reasonable PFS and significant improvement in the global health-related QoL. The bone marrow toxicity was within the accepted range. Increasing the interval between cycles does not seem to reduce efficacy and may reduce toxicity, ensuring the bone marrow has sufficient time to recover between cycles.

The Mutational, Prognostic, and Therapeutic Landscape of Neuroendocrine Neoplasms.

BACKGROUND: Neuroendocrine neoplasms (NENs) represent clinically and genetically heterogeneous malignancies, thus a comprehensive understanding of underlying molecular characteristics, prognostic signatures, and potential therapeutic targets is urgently needed. METHODS: Next-generation sequencing (NGS) and immunohistochemistry were applied to acquire genomic and immune profiles of NENs from 47 patients. RESULTS: Difference was distinguished based on differentiation grade and primary localization. Poorly differentiated neuroendocrine carcinomas (NECs) and well-differentiated neuroendocrine tumors (NETs) harbored distinct molecular features; we observed that tumor mutational burden (TMB) and tumor neoantigen burden (TNB) were significantly higher in NECs versus NETs. Notably, we identified a 7-gene panel (MLH3, NACA, NOTCH1, NPAP1, RANBP17, TSC2, and ZFHX4) as a novel prognostic signature in NENs; patients who carried mutations in any of the 7 genes exhibited significantly poorer survival. Furthermore, loss of heterozygosity (LOH) and germline homogeneity in human leukocyte antigen (HLA) are common in NENs, accounting for 39% and 36%, respectively. Notably, HLA LOH was an important prognostic biomarker for a subgroup of NEN patients. Finally, we analyzed clinically actionable targets in NENs, revealing that TMB high (TMB-H) or gene mutations in TP53, KRAS, and HRAS were the most frequently observed therapeutic indicators, which granted eligibility to immune checkpoint blockade (ICB) and targeted therapy. CONCLUSION: Our study revealed heterogeneity of NENs, and identified novel prognostic signatures and potential therapeutic targets, which directing improvements of clinical management for NEN patients in the foreseeable future.

Novel staging for gastric neuroendocrine neoplasms by incorporating the WHO grading into the TNM staging system.

BACKGROUND: The 8th tumor-node-metastasis (TNM) classification of the American Joint Committee on Cancer (AJCC) can be used to estimate the prognosis of gastric neuroendocrine tumor (gNET) and gastric neuroendocrine carcinoma (gNEC) patients but not gastric neuroendocrine neoplasms (gNENs). METHODS: First, in the SEER (training) dataset, a TNMG system was built by combining the WHO G grade (G1-4; NEC grouped into G4) with the 8th AJCC T (T1-4), N (N0-1), and M (M0-1) stage, which was then validated in a Chinese (validation) cohort. RESULTS: In all, 2245 gNENs cases from the training dataset and 280 cases from the validation dataset were eligible. The T stage, M stage, and G grade were independent prognostic factors for OS in both datasets (all p < 0.05). The TNMG staging system demonstrated better C-index for predicting OS than the 8th AJCC TNM staging system in both the training (0.87, 95%CI: 0.86-0.88 vs. 0.79, 95%CI: 0.77-0.81) and validation (0.77, 95%CI: 0.73-0.80 vs. 0.75, 95%CI: 0.71-0.79) datasets. The AUC of the 3-year OS for the TNMG staging system was 0.936 and 0.817 in the SEER and validation dataset, respectively; higher than those of the 8th AJCC system (vs. 0.843 and 0.779, respectively). DCA revealed that compared with the 8th AJCC TNM staging system, the TNMG staging system demonstrated superior net prognostic benefit in both the training and validation datasets. CONCLUSIONS: The proposed TNMG staging system could more accurately predict the 3- and 5-year OS rate of gNENs patients than the 8th AJCC TNM staging system.

Special issue "The advance of solid tumor research in China": Prediction of Sunitinib efficacy using computed tomography in patients with pancreatic neuroendocrine tumors.

Clinically effective methods to predict the efficacy of sunitinib, for patients with metastatic or locally advanced pancreatic neuroendocrine tumors (panNET) are scarce, making precision treatment difficult. This study aimed to develop and validate a computed tomography (CT)-based method to predict the efficacy of sunitinib in patients with panNET. Pretreatment CT images of 171 lesions from 38 patients with panNET were included. CT value ratio (CT value of tumor/CT value of abdominal aorta from the same patient) and radiomics features were extracted for model development. Receiver operating curve (ROC) with area under the curve (AUC) and decision curve analysis (DCA) were used to evaluate the proposed model. Tumor shrinkage of >10% at first follow-up after sunitinib treatment was significantly associated with longer progression-free survival (PFS; P < .001) and was used as the major treatment outcome. The CT value ratio could predict tumor shrinkage with AUC of 0.759 (95% confidence interval [CI], 0.685-0.833). We then developed a radiomics signature, which showed significantly higher AUC in training (0.915; 95% CI, 0.866-0.964) and validation (0.770; 95% CI, 0.584-0.956) sets than CT value ratio. DCA also confirmed the clinical utility of the model. Subgroup analysis showed that this radiomics signature had a high accuracy in predicting tumor shrinkage both for primary and metastatic tumors, and for treatment-naive and pretreated tumors. Survival analysis showed that radiomics signature correlated with PFS (P = .020). The proposed radiomics-based model accurately predicted tumor shrinkage and PFS in patients with panNET receiving sunitinib and may help select patients suitable for sunitinib treatment.

The role of quantitative tumor burden based on [68 Ga]Ga-DOTA-NOC PET/CT in well-differentiated neuroendocrine tumors: beyond prognosis.

PURPOSE: We aimed to elucidate the role of quantitative tumor burden based on PET/CT of somatostatin receptors in well-differentiated neuroendocrine tumors (NETs). METHODS: This study enrolled patients with [68 Ga]Ga-DOTA-NOC PET/CT-positive advanced NETs who did not receive medical treatment prior to PET/CT. Tumor burden was calculated using methods based on the background threshold and relative fixed threshold values (30%, 40%, and 50%). The prognostic value of the measured tumor burden in reference to overall survival (OS) and progression-free survival (PFS) on treatment with octreotide long-acting repeatable (LAR) was assessed using Cox regression analysis, Harrell's C-index, and survival analysis. A classification and regression tree (CART) was used to determine the optimal threshold for tumor burden. RESULTS: A total of 204 patients were included. Somatostatin receptor-expressing tumor volume (SRETV) and liver SRETV derived from a relative fixed threshold of 30% (SRETV30 and liver SRETV30) were statistically significantly associated with OS (C-index: 0.802 [95% confidence interval (CI), 0.658-0.946] and 0.806 [95% CI, 0.664-0.948], respectively). Extrahepatic tumor burden was not correlated with OS (hazard ratio: 0.617, 95% CI: 0.241-1.574, P = 0.312). Among 155 patients with non-functional NETs with a ki-67 index of ≤ 10%, those with a high SRETV30 (P = 0.016) or high liver SRETV30 (P = 0.014) showed statistically significantly worse PFS on treatment with octreotide LAR. Patients receiving a higher dose of octreotide LAR normalized by SRETV30 or liver SRETV30 (a normalized dose or a liver normalized dose) showed prolonged PFS on treatment with octreotide LAR and a prolonged OS. CONCLUSION: Quantitative tumor burden based on [68 Ga]Ga-DOTA-NOC PET/CT was correlated with OS and PFS in patients with non-functional NETs with a ki-67 index of ≤ 10% who received octreotide LAR. Calculating normalized and liver normalized doses may help in selecting the starting dose of octreotide LAR.

Single centre retrospective review of outcome of 177 Lu-DOTATATE peptide receptor radionuclide therapy in the treatment of progressive metastatic neuroendocrine tumours: Survival, toxicity, and prognostic factors.

The aim of this study was to evaluate the efficacy and safety of 177 Lu-DOTATATE therapy in advanced metastatic disease. A retrospective analysis of 395 patients (180 female, 215 males, mean age 62) with progressive metastatic neuroendocrine tumours (NETs) who were treated with 177 Lu-DOTATATE was performed. Overall, 115 patients had less than four cycles and 280 completed four cycles of treatment. Progression-free survival (PFS) and overall survival (OS) was performed using Kaplan-Meier analysis. Analysis of survival predictors was performed using Cox regression model. Toxicity was defined using the Common Terminology Criteria for Adverse Events version 5 (CTCAE 5.0). The percentage of patients with liver and skeletal metastases were 91 and 57%, respectively. Median PFS and OS were calculated at 33 months (95% CI: 29-37 months) and 46 months (95% CI: 48-56 months), respectively. End of treatment response assessment was performed using cross sectional imaging demonstrated partial response in 22%, stable disease in 64% and progressive disease in 14% of patients. Overall, grade 3 and 4 bone marrow toxicity was seen in 8%. One patient (0.3%) developed irreversible grade 4 nephrotoxicity. Myelodysplastic disease was recorded in one patient (0.3%). Univariate analysis of PFS predictors showed that body mass index (BMI), baseline chromogranin A (CgA) >400 ng/l, baseline alkaline phosphatase (ALP) >130 mg/dl, liver tumour volume and overall tumour burden were significant. On multivariate analysis only Ki67, high CgA and low BMI retained significance. 177 Lu-DOTATATE is an effective treatment in advanced NETs with generally high-volume metastases. It is well-tolerated. Ki-67, CgA and BMI appear to be predictors for PFS.

Clinical implications of immune checkpoint markers and immune infiltrates in patients with thymic neuroendocrine neoplasms.

The potential response of immune checkpoint blockade (ICB) in thymic neuroendocrine neoplasms (T-NEN) is largely unknown and full of great expectations. The expression of immune checkpoint molecules and immune infiltrates greatly determine the response to ICB. However, studies regarding the immune landscape in T-NEN are scarce. This work was aimed to characterize the immune landscape and its association with clinical characteristics in T-NEN. The expression of programmed cell death protein 1 (PD-1) and its ligand, programmed death ligand-1 (PD-L1), and the density of tumor-infiltrating lymphocytes (TILs), monocytes, and granulocytes were determined by immunohistochemical (IHC) staining on tumor tissues from T-NEN. Immune landscapes were delineated and correlated with clinicopathological factors. We found that T-NEN with increased immune cell infiltration and enhanced expression of PD-1/PD-L1 tended to have restricted tumor size and less metastases. A higher density of CD8+ TILs was associated with a significantly lower rate of bone metastasis. In addition, we presented three cases of T-NEN who progressed after multiple lines of therapies and received ICB for alternative treatment. ICB elicited durable partial responses with satisfactory safety in two patients with atypical carcinoid, but showed resistance in 1 patient with large cell neuroendocrine carcinoma. This innovative study delineated for the first time the heterogeneous immune landscape in T-NEN and identified CD8+ TILs as a potential marker to predict bone metastasis. An "immune-inflamed" landscape with the presence of TILs predominated in T-NEN, making T-NEN a potentially favorable target for ICB treatment. Further judicious designs of "tailor-made" clinical trials of ICB in T-NEN are urgently needed.

Bcl-2 and Noxa are potential prognostic indicators for patients with gastroenteropancreatic neuroendocrine neoplasms.

PURPOSE: Bcl-2 family proteins are of great significance in the pathogenesis and development of tumors. In this study, the correlations between the expression of Bcl-2 family proteins and clinicopathological features and prognosis of neuroendocrine neoplasms (NENs) were further investigated. METHODS: 105 Patients diagnosed with gastroenteropancreatic NENs (GEP-NENs) with the paraffin specimen of the tumor available were retrospectively included. Immunohistochemistry (IHC) was performed to detect the expression of Bcl-2 family proteins in paraffin-embedded samples. Student's t-test and Chi-square test were applied to compare the difference of quantitative and categorical variables, respectively. Survival analysis was conducted according to Kaplan-Meier method. Univariate and multivariate cox regression analysis were used to identify the independent prognostic factors. RESULTS: The IHC score of Bcl-2 was significantly higher in neuroendocrine carcinoma (NEC) patients (65.6%), while a higher IHC score of Noxa was more common in neuroendocrine tumor (NET) patients (49.3%). Survival analysis indicated that patients with higher Bcl-2 expression and lower Noxa expression had worse 5-year survival (39.3% vs. 75.6%, p < 0.001; 40.6% vs. 84.9%, p < 0.001). Multivariate cox analysis indicated that high Bcl-2 expression was an independent factor associated with inferior DFS (hazard ratio [HR]: 2.092; 95% confidence interval [CI]: 1.106-3.955; p = 0.023) and OS (HR: 2.784; 95% CI: 1.326-5.846; p = 0.007), while higher Noxa expression was associated with superior DFS (HR:0.398; 95% CI: 0.175-0.907; p = 0.028) and OS (HR: 0.274; 95% CI: 0.110-0.686; p = 0.006). CONCLUSIONS: Higher expression of Bcl-2 and lower expression of Noxa were associated with unfavorable prognosis of GEP-NENs patients.

Safety of Peptide Receptor Radionuclide Therapy with 177Lu-DOTATATE in Neuroendocrine Tumor Patients with Chronic Kidney Disease.

Our purpose was to assess the efficacy and safety of 177Lu-DOTATATE in neuroendocrine tumor patients with reduced renal function. Methods: A single-center retrospective analysis was performed on 33 patients with an estimated glomerular filtration rate (eGFR) of less than 60 mL/min/1.73 m2 Of these, 26 had chronic kidney disease (CKD) stage 3a (eGFR, 45-60 mL/min/1.73 m2) and 7 had CKD 3b (eGFR, 30-45 mL/min/1.73 m2). Renal toxicity and temporal changes in eGFR were recorded. The association between potential risk factors and any kidney function deterioration (>10% reduction in eGFR) was evaluated. Data on survival, the radiologic response assessment, and quality of life were collected. Results: The incidence of permanent grade 3 or 4 nephrotoxicity was 3% (a single patient with grade 4 nephrotoxicity). The mean annual reduction in eGFR was estimated at 2.5%. A permanent decline of less than 10% in eGFR of any grade was recorded in 45% of patients (n = 15). Nine patients moved into higher CKD categories (8 patients who moved from CKD 3a to CKD 3b and 1 patient who moved from CKD 3b to CKD 5). No significant relationship was found between renal risk factors and a permanent reduction in renal function. Grade 3 or 4 bone marrow toxicity was observed in 9% of patients. The estimated median progression-free survival was 42 mo, and the median overall survival was 47 mo. At the end of treatment, the radiologic assessment showed a partial response in 33%, stable disease in 55%, and progressive disease in 12%. There was an improvement in global quality of life and endocrine score (European Organization for Research and Treatment of Cancer Quality-of-Life Questionnaire-Gastrointestinal NET-21) (P = 0.046 and 0.041, respectively). Conclusion: 177Lu-DOTATATE appears to be generally well tolerated in patients with preexisting CKD 3, with a low incidence of permanent major nephrotoxicity. 177Lu-DOTATATE appears to have a good therapeutic effect, with most patients reporting improvement in quality of life.

Prognostic stratification for patients with neuroendocrine tumours receiving 177Lu-Dotatate.

177Lu-Dotatate is increasingly used in patients with advanced neuroendocrine tumour (NET). However, few prognostic markers are available to stratify progression-free survival (PFS) of patients who received 177Lu-Dotatate. Clinicopathological data including baseline circulating biomarkers of patients with advanced NET who received 177Lu-Dotatate were routinely collected and were retrospectively analysed. Continuous variables were normalized by dividing them by their upper normal limits. The whole data set was randomly divided into a training set and a validation set. Univariate and multivariate logistic regression analyses were used to identify independent markers and to develop a scoring model to predict treatment failure at 1 year. In total, 195 patients were included. Elevated baseline chromogranin A (CgA), normal creatinine and previous chemotherapy were three risk factors independently associated with 1-year treatment failure. By combining these risk factors, a scoring model was developed which could accurately predict 1-year treatment failure both in the training set (area under curve, AUC, 0.813; 95% CI, 0.731-0.895; P< 0.001) and in the validation set (AUC, 0.816; 95% CI, 0.644-0.968; P< 0.001). After selecting a score of 29.7 as the cut-off value of the scoring model, patients could be stratified into two groups namely low-risk and high-risk with significantly different 1-year treatment failure rate, PFS and overall survival (OS; P< 0.001) both in the training set and validation set. In conclusion, baseline CgA, creatinine level and previous chemotherapy were independently associated with 1-year treatment failure of patients with advanced NET who received 177Lu-Dotatate and the scoring model and prognostic stratification based on these markers could accurately predict 1-year treatment failure, PFS and OS.

177Lu-DOTATATE in older patients with metastatic neuroendocrine tumours: safety, efficacy and health-related quality of life.

PURPOSE: The safety and efficacy of 177Lu-DOTATATE in older patients with advanced neuroendocrine tumours (NET) are not well understood. METHODS: Patients ≥70 years of age and treated with 177Lu-DOTATATE were included. Toxicity, health-related quality of life (HRQoL), objective response, progression-free survival (PFS) and overall survival (OS) were assessed. The relationship between baseline characteristics and PFS and OS was analysed using the Kaplan-Meier method. Univariate analyses were performed using the Cox proportional hazards model. RESULTS: In total, 71 patients were included (76.1% midgut primary). The median age at diagnosis and age at 177Lu-DOTATATE treatment were 70 and 74 years, respectively. The majority (78.9%) of patients completed 4 cycles of 177Lu-DOTATATE. Clinically significant myelosuppression was rare (2.8%). There was no deterioration in HRQoL and 'disease-specific worries' significantly improved (P = 0.029). Radiological response assessment was available in 66 patients. Partial response, stable disease and progression of disease were found in 10 (15.2%), 52 (78.8%) and 4 patients (6.1%), respectively. Median PFS and OS were 36.0 and 47.0 months, respectively. Increased baseline alkaline phosphatase was associated with poorer PFS (P = 0.002) and OS (P = 0.006). CONCLUSION: Patients ≥70 years of age with advanced NET treated with 177Lu-DOTATATE have efficacy and toxicity profiles similar to the wider NET population, without deterioration of HRQoL.

Genetic Characteristics of Colorectal Neuroendocrine Carcinoma: More Similar to Colorectal Adenocarcinoma.

BACKGROUND: Despite the increasing incidence rate of colorectal neuroendocrine carcinoma (CR-NEC), there are still few sequencing data to depict the genomic characteristics of CR-NEC. PATIENTS AND METHODS: Next-generation sequencing data of CR-NEC, colorectal adenocarcinoma (COREAD), lung neuroendocrine carcinoma (lung NEC), and gastrointestinal neuroendocrine tumor (GI-NET) were retrieved from the American Association of Cancer Research Project Genomics, Evidence, Neoplasia, Information, Exchange (GENIE) database platform. Overall survival data of patients were obtained from cBioPortal. RESULTS: The median tumor mutation burden (TMB) was 5.18 per megabase. TP53 (65.5%), APC (59.5%), KRAS (36.9%), BRAF (20.2%), and RB1 (16.7%) were the most common genes harboring somatic mutations. Nearly all of the BRAF mutations (88.2%) caused V600E. The most common copy number alterations were gain of MYC (12.3%), loss of RB1 (10.7%), and loss of PTEN (5.4%). Compared to lung NEC and GI-NET, the genetic characteristics of CR-NEC were more similar to that of COREAD. CR-NEC had a higher rate of potentially targetable gene alterations compared to lung NEC and GI-NET, and BRAFV600E might be a promising treatment target. Survival analysis indicated that patients with high TMB had significantly worse survival than patients with low TMB (P < .001). In addition, KRAS and RB1 alteration were found to be correlated with worse survival (both P = .023). CONCLUSION: CR-NEC has genetic alterations that are more similar to COREAD than other entities. A substantial group of CR-NEC harboring potentially targetable alterations (BRAFV600E) deserves to be tested in clinical practice.

Myeloid-derived suppressor cells in gastroenteropancreatic neuroendocrine neoplasms.

BACKGROUND: Expanded myeloid-derived suppressor cells (MDSCs) correlate with disseminated metastases and poor prognosis in various human cancers. However, the role of MDSCs in gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) is still unknown. We investigated the distribution of MDSCs and their clinical significance in patients with GEP-NENs. METHODS: Peripheral blood mononuclear cells (PBMCs) and paraffin-embedded tumor tissues were acquired from patients with GEP-NENs. Multicolor flow cytometry was performed to determine the frequency of MDSCs in peripheral blood, and immunohistochemistry was performed to determine the distribution of MDSCs in primary NEN tissues. RESULTS: Compared to healthy donors, patients with GEP-NENs had significantly higher levels of circulating monocytic (M)-MDSCs. Frequency of M-MDSCs in both peripheral blood and primary NEN tissues was significantly higher in GEP-NEN patients with metastases compared to patients without metastases. Tumor-infiltrating M-MDSCs can serve as a valuable prognostic marker of metastasis in patients with GEP-NENs, as indicated by the area under the curve (AUC) = 0.71; 95% confidence interval (CI) = 0.56-0.87, p < 0.01. CONCLUSIONS: High M-MDSC levels were associated with significantly increased metastases in patients with GEP-NENs. M-MDSCs appear to be a promising prognostic immunologic biomarker and therapeutic target in GEP-NEN management.

Development of a novel scoring system based on endoscopic appearance for management of rectal neuroendocrine tumors.

BACKGROUND: The clinical significance of the endoscopic appearance of rectal neuroendocrine tumors (NETs) is poorly understood. We aimed to develop a novel scoring system based on endoscopic appearances to predict endoscopically advanced disease in patients with rectal NETs when initially diagnosed. METHODS: Patients diagnosed with well-differentiated rectal NETs between January 2005 and December 2019 were retrospectively included. Logistic regression analyses were applied to study the relationship between endoscopic appearance and advanced disease. The whole dataset was randomly divided into training and validation sets, which were used to develop and validate a novel scoring system, respectively. RESULTS: 309 patients were included. The endoscopic appearance of rectal NETs was significantly associated with advanced disease (P < 0.001). A novel scoring system was developed based on endoscopic appearance, including tumor size, tumor shape, and mucosal surface, using the training set. The area under curve (AUC) of the scoring system to predict advanced disease was 0.953 (95 % confidence interval [CI] 0.915 - 0.991; P < 0.001) and 0.960 (95 %CI 0.905 - 1.000; P < 0.001) in the training and validation sets, respectively. Furthermore, the scoring system was significantly associated with tumor grade. Patients with high scores had significantly worse disease-free and overall survival than patients with low scores (P < 0.001). CONCLUSION: This novel scoring system based on the endoscopic appearance of the primary tumor can help to accurately identify patients with endoscopically advanced disease who are not suitable for endoscopic resection. In addition, it is of great value in monitoring tumor recurrence and overall survival in patients with rectal NETs.

Concordance Between the Ki-67 Index Cutoff Value of 55% and Differentiation in Neuroendocrine Tumor and Neuroendocrine Carcinoma in Grade 3 Pancreatic Neuroendocrine Neoplasms.

OBJECTIVE: In 2017 and 2019, the World Health Organization defined grade 3 neuroendocrine tumors (G3 NETs) and neuroendocrine carcinoma (G3 NEC) in the pancreas. The validity of this classification remains to be verified. METHODS: Clinical data were collected and analyzed for 39 G3 pancreatic neuroendocrine neoplasms (PanNENs) patients between 2009 and 2018. RESULTS: The tumor-node-metastasis stage (P = 0.0260), differentiation (P = 0.0115), and Ki-67 index (P = 0.0371) are prognostic factors for G3 PanNENs by Kaplan-Meier survival analysis. Among 39 patients, 18 had a Ki-67 index of less than 55% and well-differentiated morphology (G3 NET) and 16 had a Ki-67 index of 55% or greater and poorly differentiated morphology (G3 NEC). Grade 3 neuroendocrine tumor had a significant better prognosis than G3 NEC (median overall survival time, 25 months [95% confidence interval, 10.854-39.146 months] vs 12 months [95% confidence interval, 6.316-17.684 months], P = 0.0164). Based on Cox regression analyses, tumor-node-metastasis stage (P = 0.016) was identified as the independent prognostic factor for G3 PanNENs. CONCLUSIONS: The upper Ki-67 index cutoff of 55% might be the best cutoff value to define G3 NETs and G3 NECs for G3 PanNENs. The World Health Organization 2017 and 2019 classification system for G3 PanNENs can identify high-risk patients with G3 PanNENs.

Quantitative Pretreatment CT Parameters as Predictors of Tumor Response of Neuroendocrine Tumor Liver Metastasis to Transcatheter Arterial Bland Embolization.

PURPOSE: To assess whether parameters on preprocedural CT can be utilized to predict the response of NETLM to transcatheter arterial bland embolization (TAE). METHODS: We retrospectively reviewed 135 target lesions from 48 NETLM patients who underwent TAE and with complete preprocedural multiphasic CT. Parameters on preprocedural CT including the longest diameter, mean attenuation value in nonenhanced, arterial, and portal-venous phases were collected from each target lesion. Radiological responses were assessed according to RECIST 1.1. The parameters of responder lesions and nonresponder lesions were compared. Arterial enhancement index (AEI) and portal-venous enhancement index (PEI) were calculated. The predictive function of AEI and PEI on tumor response was analyzed by receiver operating characteristic (ROC) curve. RESULTS: A total of 72.6% target lesions had a partial response. For patients, the objective response rate was 72.9%. Mean attenuation values of responder lesions were significantly higher than nonresponder lesions in both arterial and portal-venous phases (105.36 ± 37.24 vs. 76.01 ± 19.19, p < 0.001; 96.61 ± 24.04 vs. 82.12 ± 21.37, p = 0.002). ROC curve showed that both AEI and PEI were effective in predicting tumor response (area under the curve [AUC] 0.757, p < 0.001; AUC 0.655, p = 0.005). CONCLUSION: AEI and PEI, parameters from evaluation of CT pretreatment attenuation of NETLMs, could predict response to TAE treatment.

Clinicopathological features and prognostic validity of the European Neuroendocrine Tumor Society (ENETS) and American Joint Committee on Cancer (AJCC) 8th staging systems in colonic neuroendocrine neoplasms.

PURPOSE: This study aimed to investigate the characteristics of colonic neuroendocrine neoplasms (NENs) and to validate the prognostic value of the European Neuroendocrine Tumor Society (ENETS) and American Joint Committee on Cancer (AJCC) 8th staging systems. METHODS: A total of 167 and 1248 patients with colonic NENs from 12 medical centers across China and from the Surveillance, Epidemiology, and End Results (SEER) cancer registry in the United States, respectively, were reviewed. Patients were staged according to the ENETS and AJCC 8th staging systems. RESULTS: Clinicopathological features of colonic NENs in the Chinese cohort and SEER cohort were significantly distinct. In both the Chinese cohort and the SEER cohort, colonic neuroendocrine carcinoma (NEC) and mixed adeno-neuroendocrine carcinoma (MANEC) were more frequent in the midgut than in the hindgut. Tumors originating from the midgut tended to be larger and at a more advanced stage than those from the hindgut. The AJCC 8th staging system and the ENETS system appeared to have similar prognostic ability for colonic NEC/MANEC. CONCLUSIONS: Our study revealed that tumors originating from the midgut and the hindgut shared different clinicopathological features. The AJCC 8th staging system and the ENETS system appeared to have similar prognostic ability for colonic NEC/MANEC.