Heterogeneous Uptake of 68Ga-DOTATATE and 18F-FDG in Initial Diagnosed Neuroendocrine Tumors Patients: Which Patients Are Suitable for Dual-Tracer PET Imaging?

PURPOSE: This study was designed to assess the uptake heterogeneity in neuroendocrine tumor (NET) patients at initial diagnosis with dual-tracer PET imaging and the staging changes and prognostic value it brings to explore the indication of the use of dual-tracer PET. METHODS: Fifty-one newly diagnosed patients with pathologically confirmed NET who underwent 18F-FDG and 68Ga-DOTATATE PET imaging between January 2020 and September 2022 were enrolled. Dual-tracer uptake patterns were classified into 3 groups: A. 68Ga-DOTATATE positive and 18F-FDG negative, B. 68Ga-DOTATATE positive and 18F-FDG positive, and C. 68Ga-DOTATATE negative and 18F-FDG positive. Descriptive statistics were used to evaluate the heterogeneity of dual-tracer uptake patterns among different grading (G) groups, between primary and metastatic lesions, and staging changes. Moreover, dual-tracer uptake patterns, grade, age, sex, and stage were compared with progression-free survival (PFS) by Cox regression. RESULTS: In the different G groups, none of the patients with dual-tracer uptake pattern A had grade 3 histology, but 57% of patients with grade 1 disease had FDG avidity (25% of them resulting in dual-tracer uptake pattern C). Patients with no metastasis were well differentiated, but one of them presented with dual-tracer uptake pattern C. Different uptake patterns were also observed between primary and metastatic lesions, particularly 44% of patients with dual-tracer uptake pattern A of primary with FDG avidity of metastases. Moreover, 9 (17.6%) had new lesions detected by additional 18F-FDG PET imaging, and 3 of them (5.9%) had clinical stage changed accordingly. The Cox regression test showed that the dual-tracer uptake patterns were significantly correlated with PFS by univariate and multivariate analyses (P = 0.026 and 0.039, respectively), whereas the grade and stage did not correlate with survival (all P>0.05). CONCLUSION: The current study has proven the uptake heterogeneity of the NET at initial diagnosis and demonstrated the staging and prognostic value of dual-tracer PET imaging. Our preliminary results have confirmed the importance of dual-tracer imaging modalities and concluded that dual-tracer PET imaging could be considered as prognostic tool for all patients with an initial diagnosis of NET.

Surufatinib combined with transarterial embolization versus surufatinib monotherapy in patients with liver metastatic neuroendocrine tumors: Study protocol for a prospective, randomized, controlled trial.

BACKGROUND: More than half of neuroendocrine tumor (NET) patients will experience liver metastasis, and interventional therapy represented by transarterial embolization (TAE) is the main local treatment method. Surufatinib is recommended as a standard systemic treatment for advanced NETs. The efficacy and safety of surufatinib combined with TAE in the treatment of liver metastasis are undetermined. This study was conducted to compare the clinical outcome of surufatinib combined with TAE versus surufatinib monotherapy in liver metastatic NETs. METHODS: This is a prospective, multicenter, open-label, and randomized controlled trial. Patients diagnosed with liver metastatic NETs will be enrolled. Participants are randomly assigned in a 1:1 ratio to either the experimental group or the control group. Patients will be treated with surufatinib plus TAE in the experimental group, while patients in the control group will receive surufatinib monotherapy. The primary endpoint is progression-free survival (PFS) assessed by a blinded independent image review committee (BIIRC). The secondary endpoints are investigator-assessed PFS, liver-specific objective response rate (ORR), objective response rate (ORR), disease control rate (DCR), overall survival (OS), and incidence of adverse events. DISCUSSION: This is the first prospective study to investigate the efficacy of surufatinib combined with TAE. We expect this trial to propose a new and effective treatment strategy for liver metastatic NETs.

A nomogram to preoperatively predict the aggressiveness of non-functional pancreatic neuroendocrine tumors based on CT features.

OBJECTIVES: To develop a nomogram to predict the aggressiveness of non-functional pancreatic neuroendocrine tumors (NF-pNETs) based on preoperative computed tomography (CT) features. METHODS: This study included 176 patients undergoing radical resection for NF-pNETs. These patients were randomly divided into the training (n = 123) and validation sets (n = 53). A nomogram was developed based on preoperative predictors of aggressiveness of the NF-pNETs which were identified by univariable and multivariable logistic regression analysis. The aggressiveness of NF-pNETs was defined as a composite measure including G3 grading, N+, distant metastases, and/ or disease recurrence. RESULTS: Altogether, the number of patients with highly aggressive NF-pNETs was 37 (30.08 %) and 15 (28.30 %) in the training and validation sets, respectively. Multivariable logistic regression analysis identified that tumor size, biliopancreatic duct dilatation, lymphadenopathy, and enhancement pattern were preoperative predictors of aggressiveness. Those variables were used to develop a nomogram with good concordance statistics of 0.89 and 0.86 for predicting aggressiveness in the training and validation sets, respectively. With a nomogram score of 59, patients with NF-pNETs were divided into low-aggressive and high-aggressive groups. The high-aggressive group had decreased overall survival (OS) and disease-free survival (DFS). Moreover, the nomogram showed good performance in predicting OS and DFS at 3, 5, and 10 years. CONCLUSION: The nomogram integrating CT features helped preoperatively predict the aggressiveness of NF-pNETs and could potentially facilitate clinical decision-making.

Prognostic role of radiological splenic vessel involvement in patients with resectable pancreatic ductal adenocarcinoma of the body and tail: A retrospective analysis based on a large population.

BACKGROUND: Tumors located in the pancreatic body or tail are more likely to invade splenic vessels; however, splenic artery (SpA) or vein (SpV) involvement is not included in the criteria for resectability. We aimed to analyze the prognostic role of radiological splenic vessel involvement in patients with resectable pancreatic ductal adenocarcinoma (PDAC) of the body and tail. METHODS: Patients with resetable PDAC were retrospectively reviewed and analyzed. SpA and SpV involvement were graded as clear, abutment and encasement. Multivariate Cox and logistic regression analyses were used to identify prognostic factors for overall survival (OS) and risk factors for early recurrence, respectively. RESULTS: Of the 234 patients, 94 patients had radiologic SpA invasion, including abutment in 47 patients and encasement in 47 patients, while 123 patients had radiological SpV invasion, including abutment in 69 patients and encasement in 54 patients. Patients with SpA or SpV encasement showed a significantly worse OS and recurrence-free survival than those with SpA or SpV clear (P < 0.001, respectively). In multivariate analysis, both SpA and SpV encasement were independently associated with poor OS (SpA: hazard ratio [HR] 1.89, P = 0.010; SpV: HR 2.01, P = 0.001) and early recurrence (SpA: odds ratio [OR] 4.98, P < 0.001; SpV: OR 3.71, P = 0.002). CONCLUSION: Radiological SpA or SpV encasement independently decreases OS, and is associated with early recurrence of resectable PDAC of the body/tail.

Copper deprivation enhances the chemosensitivity of pancreatic cancer to rapamycin by mTORC1/2 inhibition.

Cuproplasia, or copper-dependent cell proliferation, has been observed in varieties of solid tumors along with aberrant copper homeostasis. Several studies reported good response of patients to copper chelator assisted neoadjuvant chemotherapy, however, the internal target molecules are still undetermined. Unravel copper-associated tumor signaling would be valuable to forge new links to translate biology of copper into clinical cancer therapies. We evaluated the significance of high-affinity copper transporter-1 (CTR1) by bioinformatic analysis, and in 19 pairs of clinical specimens. Then, with the help of gene interference and chelating agent, enriched signaling pathways were identified by KEGG analysis and immunoblotting. Accompanying biological capability of pancreatic carcinoma-associated proliferation, cell cycle, apoptosis, and angiogenesis were investigated. Furthermore, a combination of mTOR inhibitor and CTR1 suppressor has been assessed in xenografted tumor mouse models. Hyperactive CTR1 was investigated in pancreatic cancer tissues and proven to as the key point of cancer copper homeostasis. Intracellular copper deprivation induced by CTR1 gene knock-down or systematic copper chelation by tetrathiomolybdate suppressed proliferation and angiogenesis of pancreatic cancer cell. PI3K/AKT/mTOR signaling pathway was suppressed by inhibiting the activation of p70(S6)K and p-AKT, and finally inhibited mTORC1 and mTORC2 after copper deprivation. Additionally, CTR1 gene silencing successfully improved the anti-cancer effect of mTOR inhibitor rapamycin. Our study reveals that CTR1 contributes to pancreatic tumorigenesis and progression, by up-regulating the phosphorylation of AKT/mTOR signaling molecules. Recovering copper balance by copper deprivation addresses as promising strategy for improved cancer chemotherapy.

The differential effects of sarcopenia and cachexia on overall survival for pancreatic ductal adenocarcinoma patients following pancreatectomy: A retrospective study based on a large population.

OBJECTIVES: Both cachexia and sarcopenia have been considered adverse predictors for prognosis in patients with pancreatic cancer; although sarcopenia and cachexia share some similarities, they are still defined as distinct nutritional conditions. We aimed to explore the differential impacts of sarcopenia and cachexia on prognosis for pancreatic ductal adenocarcinoma (PDAC) patients following radical excision. METHODS: From January 2015 to May 2022, 614 patients undergoing surgery for PDAC were retrospectively included. Sarcopenia was defined as the L3 total skeletal muscle index below 52.4 cm2 /m2 (men) and 38.5 cm2 /m2 (women). Cachexia was classified according to the following criteria: involuntary weight loss >5% over the past 6 months, or weight loss >2% and BMI <20 kg/m2 , or weight loss >2% and sarcopenia. RESULTS: Of the 614 patients included in the analysis, 62% and 48% were diagnosed with sarcopenia and cachexia, respectively. Kaplan-Meier analysis showed that sarcopenia and/or cachexia were significantly associated with worse overall survival (OS) rather than worse recurrence-free survival (RFS). Moreover, Cox regression analysis revealed that cachexia rather than sarcopenia was an adverse factor for OS in all PDAC patients. For poorly differentiated PDAC, both cachexia and sarcopenia were significantly associated with shorter OS. However, for moderately/well-differentiated PADC, cachexia was an independent factor for adverse OS, but not sarcopenia. CONCLUSIONS: Sarcopenia and cachexia have different effects on OS for PDAC patients undergoing radical excision. This difference may provide some important information for preoperative management.

Toward regulating biodegradation in stages of polyurethane copolymers with bicontinuous microphase separation.

For typical biodegradable polymers, their overall performance almost declines exponentially to the degradation degree, which inevitably leads to a dilemma between the requirements of service life and retention time in the environment (both in vitro and in vivo). It is a great challenge to develop a biodegradable polymeric device with relatively stable performance in service while rapidly degrading out of service. Herein, we demonstrate an effective strategy to control degradation of biodegradable polymers in stages by constructing separated bicontinuous microphases with very different microphase degradation rates. First, polyurethane copolymers (PCL-b-CrP-U) containing two blocks, i.e., semicrystalline poly(ε-caprolactone) (PCL) blocks and amorphous random copolymer blocks (CrP) based on ε-CL and p-dioxanone (PDO), were synthesized. The microscopic morphology of PCL-b-CrP-U is investigated by an alkali-accelerated degradation experiment, which also demonstrates that the chain cleavage-induced crystallization during degradation resulted in a self-reinforcement by forming degradation residues with a scaffold-like morphology. The tensile test shows that PCL-b-CrP-U has excellent mechanical properties (1500% of elongation at break, a tensile strength of about 7.5 MPa, and an elastic modulus of 40.0 MPa). The degradation experiments with artificial pancreatic juice as a working medium reveal that PCL-b-CrP-U samples containing relatively high PDO units exhibit a three-stage degradation, i.e. an induction stage, a steady degradation stage and an accelerated degradation stage. The CrP phase preferentially hydrolyzes to form some microchannels due to its amorphous nature and relatively high hydrophilicity, effectively accelerating the entry of water and enzymes into the inner parts of the sample. Meanwhile, at this stage, those originally amorphous PCL segments gradually crystalize owing to their enhanced chain mobility induced by the chain cleavage, forming a "scaffold"-like structure, which effectively reinforces the sample to resist the damage from external force and therefore guarantees a relatively stable mechanical performance of PCL-b-CrP-U during service. With the further depletion of the CrP phase, the intermediate "scaffold"-like structure is also very beneficial to accelerate the degradation of residues owing to its large specific surface area, which is expected to be beneficial for preventing long-term retention of the implantation devices.

Prognostic role and predictors of lymph node involvement in pancreatic neuroendocrine tumors.

PURPOSE: To define the prognostic role of lymph node involvement (LNI) in patients with pancreatic neuroendocrine tumors (PNETs) and identify predictors of LNI using a comprehensive multifactor analysis focusing on preoperative radiological features. METHODS: This study included 236 patients with preoperative computed tomography who underwent radical surgical resection of PNETs at our hospital between 2009 and 2019. Univariate and multivariable logistic regression analyses were performed to investigate the risk factors associated with LNI and tumor recurrence. The disease-free survival (DFS) rates with and without LNI were compared. RESULTS: Forty-four of the 236 patients (18.6%) had LNI. Biliopancreatic duct dilatation (odds ratio [OR], 2.295; 95% confidence interval [CI], 1.046-5.035; p = 0.038), tumor margin (OR, 2.189; 95% CI, 1.034-4.632; p = 0.041), and WHO grade (G2: OR, 2.923; 95% CI, 1.005-8.507; p = 0.049; G3: OR, 12.067; 95% CI, 3.057-47.629; p < 0.001) were independent risk factors of LNI in PNETs. Multivariable analysis showed that LNI (OR, 2.728; 95% CI, 1.070-6.954; p = 0.036), G3 (OR, 4.894; 95% CI, 1.047-22.866; p = 0.044), and biliopancreatic duct dilatation (OR, 2.895; 95% CI, 1.124-7.458; p = 0.028) were associated with PNET recurrence in patients after surgery. Patients with LNI had a significantly worse DFS than those without LNI (3-year DFS: 85.9 vs. 96.7%; p < 0.001; 5-year DFS: 65.1 vs. 93.9%; p < 0.001). CONCLUSION: LNI was associated with decreased DFS. Biliopancreatic duct dilatation, irregular tumor margins, and grades G2 and G3 were independent risk factors for LNI.

Laparoscopic versus open central pancreatectomy: a propensity score-matched analysis in a single centre.

PURPOSE: Laparoscopic central pancreatectomy (LCP) has been implemented in pancreatic surgery; however, open surgery is still the predominant approach for central pancreatectomy (CP). Our objective was to compare LCP with open CP (OCP). METHODS: Data were collected from patients with tumours located in the pancreatic neck and proximal body who underwent CP in the Department of Pancreatic Surgery West China Hospital from January 1, 2010, to June 30, 2019. A comparison between the LCP and OCP groups was performed. RESULTS: Fifteen patients underwent CP via the laparoscopic approach, and 96 patients underwent CP via the open approach. Using 1:2 propensity score matching (PSM), 12 patients in the LCP group were matched to 21 in the OCP group. Regarding safety, postoperative pancreatic fistula (POPF) was not significantly different between the two groups (13.3% vs. 12.5%, P = 1.000), even with PSM (16.7% vs. 14.3%, P = 1.000). However, regarding effectiveness, the operative time in the OCP group was significantly shorter than that in the LCP group before (307.0 ± 92.3 ml vs. 220.6 ± 63.6 ml, P < 0.000) and after (300.3 ± 90.2 ml vs. 212.7 ± 44.4 ml, P = 0.002) PSM. Regarding length of stay (LOS), there was no difference between the two groups before (13.1 ± 13.7 days vs. 12.7 ± 10.1 days, P = 0.376) and after PSM (14.4 ± 15.1 days vs. 14.5 ± 16.2 days, P = 0.985). The length of the resected pancreas was shorter in the OCP group than in the LCP group before PSM (50.0 ± 13.2 mm vs. 41.1 ± 11.1 mm, P = 0.043). However, there was no difference between the two groups after PSM (47.9 ± 12.5 mm vs. 37.9 ± 10.4 mm, P = 0.084). Moreover, the other variables showed no difference between the two groups before and after PSM. CONCLUSION: LCP can demonstrate similar safety and effectiveness to OCP, even in the early stages of the learning curve.

An Orthotopic Resection Surgical Technique Using an Inferior Infracolic Approach for Laparoscopic Pancreaticoduodenectomy.

The no-touch isolation technique has been widely used in cancer surgery as a strategy to prevent cancer cells from spreading; however, it is difficult to apply in laparoscopic pancreaticoduodenectomy (LPD). Here, we describe an orthotopic resection surgical technique that applies a no-touch principle for LPD and can help with the in situ resection of tumors. In implementing this surgical strategy, Kocher's maneuver was not performed first. Instead, after the exploration of the abdominal cavity, the distal stomach and the pancreatic neck were transected. Then, the dissection of the uncinate process of the pancreas, the duodenum, and the superior mesenteric vein and artery is carried out via an inferior infracolic approach. Finally, the pancreatic head and duodenum were removed in situ. Among the 41 patients who underwent this technique, two (4.9%) required conversion to open surgery due to uncontrolled bleeding. The average operative time was 335 min (248-1055 min). The mean estimated blood loss was 300 mL (50-1250 mL). Two patients (4.9%) underwent combined PV resection and reconstruction; six patients (14.6%) required a blood transfusion; two patients (4.9%) suffered from postoperative bleeding; two patients (4.9%) suffered from Grade B pancreatic fistulas; one patient (2.4%) suffered from bile leakage; and three patients (7.3%) suffered from abdominal fluid collection. No patients died during the perioperative period. Therefore, orthotopic LPD using an inferior infracolic approach is safe and feasible for patients with malignant pancreatic head and periampullary tumors. However, further investigations are required to elucidate its oncological benefits.

Long Term Outcomes of No-Touch Isolation Principles Applied in Pancreaticoduodenectomy for Treatment of Pancreatic Adenocarcinoma: A Multicenter Retrospective Study with Propensity Score Matching.

Background: The recurrence and liver metastasis rates are still high in pancreatic head cancer with curative surgical resection. A no-touch isolation principle in pancreaticoduodenectomy (PD) may improve this situation, however, the exact advantages and efficacy of these principles have not been confirmed. Materials and methods: Among 370 patients who underwent PD, three centers were selected and classified into two groups: the no-touch PD group (n = 70) and the conventional PD group (n = 300). Propensity score matching was used to control for selection bias at a ratio of 1:1. The confounding variables were age, sex, body mass index, adjuvant chemotherapy, carbohydrate antigen 19-9, tumor size and tumor differentiation. Results: Patients in the no-touch PD group had better overall survival (OS) and disease-free survival (DFS) than those in the conventional PD group (OS: 17 vs. 13 months, p = 0.0035, DFS: 15 vs. 12 months, p = 0.087), with lower 1- and 2-year disease-related mortality rates (1-year: 32.9% vs. 47%, p = 0.032; 2-year: 42.5% vs. 82% p = 0.000) and recurrence and liver metastasis rates (1-year: 30.0% vs. 43.3%, p = 0.041; 2-year: 34.3% vs. 48.7%, p = 0.030). Compared with the matched conventional PD group, the no-touch PD group also had a better OS (17 vs. 12 months, p = 0.032). Conclusions: Our study showed the no-touch isolation principle may be a better choice to improve long-term survival for pancreatic cancer patients.

Clinicopathological features and long-term prognosis of purely cystic pancreatic neuroendocrine tumors: A single-center experience.

BACKGROUND: Pancreatic neuroendocrine tumors (pNETs) are heterogenous neoplasms, of which the prognosis varies widely. Purely cystic pancreatic neuroendocrine tumors (C-pNETs) are a small subset of pNETs in which data are extremely rare. This study aimed to compare clinicopathological and long-term survival differences between C-pNETs and solid pNETs (S-pNETs). METHODS: A retrospective review of 242 patients with pNETs underwent resection in our institution from 2009 to 2019 was conducted. Demography characteristics, clinicopathological features and long-term outcomes of them were analyzed. RESULTS: Sixteen out of 242 patients (6.6%) were identified as C-pNETs. Compared with S-pNETs, C-pNETs were more frequently non-functional (75% vs 45%, P = 0.02), and the median tumor diameter of C-pNETs was smaller (36 mm vs. 47 mm, P = 0.001). And the accuracy of preoperative diagnosis of C-pNETs was significantly lower (31% vs 78%, P = 0.001). Of note, the majority of C-pNETs were well-differentiated with G1 (81% vs 35%, P = 0.001). And there were no G3 (0 vs 7%, P = 0.001) in C-pNETs. No T4 stage or R1/R2 surgical margin detected in C-pNETs. And only one C-pNETs (6%) had regional lymph node metastasis (N) or synchronous distant metastasis (M). Additionally, only one patient with C-pNETs (6%) suffered tumor recurrence, compared with 24 (13%) for S-pNETs. And survival analysis showed the patients with C-pNETs seemed to be with better disease-free survival (P = 0.26). CONCLUSION: C-pNETs are rare subtype with possibly less aggressive behavior comparing with their solid counterparts. Recurrence and tumor-related death still occurs in patients with resected C-pNETs, although they tend to be with more favorable prognosis.

Function and characteristics of TIM­4 in immune regulation and disease (Review).

T­cell/transmembrane immunoglobulin and mucin domain containing 4 (TIM­4) is a phosphatidylserine receptor that is mainly expressed on antigen­presenting cells and is involved in the recognition and efferocytosis of apoptotic cells. TIM­4 has been found to be expressed in immune cells such as natural killer T, B and mast cells and to participate in multiple aspects of immune regulation, suggesting that TIM­4 may be involved in a variety of immune­related diseases. Recent studies have confirmed that TIM­4 is also abnormally expressed in a variety of malignant tumor cells and is closely associated with the occurrence and development of tumors and the tumor immune microenvironment. The present study aimed to describe the expression and functional characteristics of TIM­4 in detail and to comprehensively discuss its role in pathophysiological processes such as infection, allergy, metabolism, autoimmunity and tumor immunity. The current review provided a comprehensive understanding of the functions and characteristics of TIM­4, as well as novel ideas for the diagnosis and treatment of diseases.

Prognostic Factors of Small Non-Functional Pancreatic Neuroendocrine Tumors and the Risk of Lymph Node Metastasis: A Population-Level Study.

Background: Small non-functional neuroendocrine tumors (NF-PNETs) are a heterogeneous subset of tumors with controversy regarding their optimal management. We aimed to analyze the prognostic factors of patients with small NF-PNETs and create a risk score for lymph node metastasis (LNM). Methods: Data of 751 patients with NF-PNETs ≤ 2 cm were obtained from the Surveillance, Epidemiology, and End Results (SEER) database. Multivariate survival analysis was performed to analyze the prognostic factors. Logistic regression was used to identify risk factors for LNM. Results: Of the 751 patients, 99 (13.2%) were confirmed to have LNM. In multivariate survival analysis, LNM (hazard ratio [HR], 2.12; 95% CI, 1.04-4.32, p = 0.040) was independently associated with disease-specific survival. Logistic regression identified that tumor location in the head of the pancreas (odds ratio [OR], 4.33; 95% CI, 2.75-6.81; p < 0.001), size ≥ 1.5-2 cm (OR, 1.84; 95% CI, 1.17-2.87; p = 0.009), and grade III-IV (OR, 7.90; 95% CI, 1.79-34.90; p = 0.006) were independent risk factors of LNM. According to the OR value, the risk of LNM was scored as follows: a score of 1 for tumors located in the body/tail of the pancreas and 4 for those located in the head; a score of 1 for tumors <1 cm and 2 for those ≥1.5-2 cm; and a score of 1 for tumors with grade I-II and 8 for those with grade III-IV. Finally, the median score for this cohort was 4, with an interquartile range of 3-6. Therefore, patients were classified as three groups based on the risk score system: a total score of 1-3 for low risk, 4-6 for intermediate risk (OR, 2.98; 95% CI, 1.59-5.60; p = 0.001), and 7-14 for high risk (OR, 8.94; 95% CI, 4.50-17.7; p < 0.001), with an incidence of LNM 5.0%, 13.5%, and 31.8%, respectively (p < 0.001). Conclusion: Surgical resection with regional lymphadenectomy is recommended for small NF-PNETs with malignant potential of LNM. A risk score for LNM based on tumor grade, location, and size may preoperatively predict LNM of small NF-PNETs and guide clinical practice.

Development and Validation of a Novel Radiomics-Based Nomogram With Machine Learning to Preoperatively Predict Histologic Grade in Pancreatic Neuroendocrine Tumors.

Backgroud: Tumor grade is the determinant of the biological aggressiveness of pancreatic neuroendocrine tumors (PNETs) and the best current tool to help establish individualized therapeutic strategies. A noninvasive way to accurately predict the histology grade of PNETs preoperatively is urgently needed and extremely limited. Methods: The models training and the construction of the radiomic signature were carried out separately in three-phase (plain, arterial, and venous) CT. Mann-Whitney U test and least absolute shrinkage and selection operator (LASSO) were applied for feature preselection and radiomic signature construction. SVM-linear models were trained by incorporating the radiomic signature with clinical characteristics. An optimal model was then chosen to build a nomogram. Results: A total of 139 PNETs (including 83 in the training set and 56 in the independent validation set) were included in the present study. We build a model based on an eight-feature radiomic signature (group 1) to stratify PNET patients into grades 1 and 2/3 groups with an AUC of 0.911 (95% confidence intervals (CI), 0.908-0.914) and 0.837 (95% CI, 0.827-0.847) in the training and validation cohorts, respectively. The nomogram combining the radiomic signature of plain-phase CT with T stage and dilated main pancreatic duct (MPD)/bile duct (BD) (group 2) showed the best performance (training set: AUC = 0.919, 95% CI = 0.916-0.922; validation set: AUC = 0.875, 95% CI = 0.867-0.883). Conclusions: Our developed nomogram that integrates radiomic signature with clinical characteristics could be useful in predicting grades 1 and 2/3 PNETs preoperatively with powerful capability.

The Role of Primary Tumor Resection in Patients With Pancreatic Neuroendocrine Tumors With Liver Metastases.

Background: Liver metastases (LMs) are common in advanced pancreatic neuroendocrine tumor (PNET) patients. Currently, the benefit of primary tumor resection (PTR) in the setting of PNET patients with liver metastases is still controversial in several guidelines. Methods: Data were extracted from the Surveillance, Epidemiology and End Results (SEER) database to evaluate this issue. The main index of interest in our study was overall survival time. Results: Information on 536 PNET patients with liver metastases from the SEER database was identified. A total of 214 patients (PTR group) received primary tumor resection, and more than half of them (132 patients) had synchronous LM resection. The other 322 PNET patients (non-PTR group) with liver metastases did not receive primary tumor resection. A significant survival benefit was gained from PTR when compared with non-PTR patients, both in OS (72.93 ± 2.7 vs. 36.80 ± 2.22 months) and 3- or 5-year survival rates (75.1% vs. 28.9% and 67.9% vs. 22.3%, respectively). No difference was found between PTR alone and PTR with synchronous LM resection. From univariate and multivariate analyses, younger age (<65 years) and good or moderate tumor differentiation may be more important when considering primary tumor resection. However, we found that all grades of tumor differentiation could result in a better overall survival time after primary tumor resection. Conclusion: Our study suggested that primary tumor resection in pancreatic neuroendocrine patients with liver metastases could result in a longer survival time. Primary tumor resection with synchronous liver metastasis resection was not related to a better survival benefit. This treatment strategy may routinely be taken into consideration in these patients.

The expression of m6A regulators correlated with the immune microenvironment plays an important role in the prognosis of pancreatic ductal adenocarcinoma.

BACKGROUND: The relationship between N6-methyladenosine (m6A) RNA methylation regulators and the tumor immune microenvironment has been extensively studied. Nevertheless, the potential function of m6A regulators in the tumor immune landscape of pancreatic ductal adenocarcinoma (PDAC) remains to be fully elucidated. METHODS: Here, we systematically evaluated the expression of 19 m6A regulators in PDAC patients from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) database. Utilizing consensus clustering, the PDAC patients were segmented into two subgroups according to the expression of 19 m6A regulators. A prognostic risk signature of 5 m6A methylation regulators (ALKBH5, IGF2BP2, IGF2BP3, LRPPRC, and KIAA1429) was then built, and the PDAC patients were divided into high-risk and low-risk groups. Subsequently, differences in independent prognostic parameters, risk score distribution, survival, and cluster analysis between high-risk and low-risk groups were analyzed. RESULTS: We found two subgroups with dramatically different immune landscapes and prognoses. Subsequently, differences in independent prognostic parameters, risk score distribution, survival, and cluster analysis between the high-risk and low-risk groups were found. Moreover, these gene signatures displayed good discriminative performances in the GEO datasets. We also found that the risk score was positively correlated with the tumor mutation burden (TMB), and the TMB value was higher in the high-risk scoring group. The low-risk scoring group was linked by a stronger response to anti-programmed cell death ligand 1 (anti-PD-L1) immunotherapy and clinical advantages in the immunotherapeutic advanced urothelial cancer (IMvigor210) cohort. Ultimately, we found that these 5 m6A regulators had a fatal regulatory role on the tumor immune microenvironment in PDAC patients. CONCLUSIONS: The construction signature based on the m6A regulators may be crucial regulators of the tumor immune microenvironment in PDAC, providing a new approach to improving the immunotherapy strategy for PDAC patients.

Successful Neoadjuvant Chemotherapy for Small-Cell Neuroendocrine Carcinoma of the Pancreas: A Case Report.

Neoadjuvant therapy for pancreatic neuroendocrine tumors may potentially aid downstaging, increase the possibility of radical surgery. We herein report a case of a 63-year-old man who had been diagnosed with locally advanced small-cell neuroendocrine carcinomas of the pancreas according to the diagnostic biopsy. The patient received 6 courses of etoposide and cisplatin as neoadjuvant therapy in an attempt to stop tumor progression, which promoted obvious tumor shrinkage without adverse effects and allowed subsequent Appleby procedure, the distal pancreatectomy with celiac artery resection. The patient showed no recurrence in the follow-up of a contrast-enhanced computed tomographic scan, which is 8 months after surgery. To the best of our knowledge, this is a rare case to report etoposide and cisplatin administration before surgery for unresectable pancreatic neuroendocrine carcinoma promoted a pathological partial response and finally achieved a radical surgery, providing a novel therapeutic option for patients with locally advanced pancreatic neuroendocrine carcinoma.