Long-Term Outcomes of Surgical Management of Pancreatic Neuroendocrine Tumors with Synchronous Liver Metastases

Gender impact on pancreatic neuroendocrine neoplasm (PanNEN) prognosis according to survival nomograms

PURPOSE

Personalizing care and outcome evaluation are important aims in the field of NEN and nomograms may represent useful tools for clinicians. Of note, gender difference is being progressively more considered in NEN care, as it may also impact on survival. This systematic review aims to describe and analyze the available nomograms on pancreatic NENs (PanNENs) to identify if gender differences are evaluated and if they could impact on patients' management and prognosis.

METHODS

We performed an electronic-based search using PubMed updated until June 2024, summarizing the available evidence of gender impact on PanNEN survival outcomes as emerges from published nomograms.

RESULTS

34 articles were identified regarding prognostic nomograms in PanNEN fields. The most included variables were age, tumor grade, tumor stage, while only 5 papers (14.7%) included sex as one of the key model variables with a significant impact on patients' prognosis. These 5 studies analyzed a total of 18,920 PanNENs. 3 studies found a significant impact of sex on overall survival (OS), whereas the remaining 2 studies showed no significant impact of sex on OS.

CONCLUSIONS

Gender difference is being progressively more considered in PanNEN diagnosis, care and survival. Nomograms represent a potentially useful tool in patients' management and in outcomes prediction in the field of PanNENs. A key role of sex in the prognosis of PanNENs has been found in few models, while definitive conclusions couldn't be drawn. Future studies are needed to finally establish gender impact on PanNEN prognosis.

Disease-free survival after pancreatectomy for pancreatic neuroendocrine tumors: A 17-year single-center experience of 223 patients

BACKGROUND

Metastasis or recurrence of pancreatic neuroendocrine tumors (pNETs) after pancreatectomy is an important source of postsurgical morbidity. This study aimed to define disease-free survival (DFS) in this population.

METHODS

Patients who underwent pancreatectomy for pNETs between January 2005 and January 2022 were included. Clinicopathologic and survival data were collected, and the primary endpoint was DFS. Kaplan-Meier survival analysis and Cox proportional hazards regression modeling were performed.

RESULTS

Of the 223 patients, 144 (65%) distal/subtotal/partial pancreatectomies, 71 (32%) pancreaticoduodenectomies, 6 (3%) total pancreatectomies, and 2 (1%) enucleations were performed. Of the 223 patients, 45 (20%) experienced disease recurrence or metastasis after index pancreatectomy during the 17 years of the study. Nonfunctional pNETs (162 [73%]) were more common than hormonally functional subtypes. The 2- and 5-year DFSs were 82% and 76%, respectively. Kaplan-Meier analysis demonstrated that N1 node positive disease, size of ≥ 4 cm, lymphovascular invasion, perineural invasion, Ki-67 of ≥ 20%, and nonfunctional pNETs are significantly associated with a lower DFS (P < .05). Univariate Cox analysis identified the following predictors to be significantly associated with poorer DFS: larger tumor size (hazard ratio [HR], 1.16; 95% CI, 1.04-1.28), Ki-67 index of ≥ 20% (HR, 4.93; 95% CI, 2.00-11.44), perineural invasion (HR, 3.23; 95% CI, 1.40-7.89), open surgery (HR, 3.34; 95% CI, 1.03-1.33), node-positive disease (HR, 5.27; 95% CI, 2.28-13.26), and increased body mass index (HR, 1.10; 95% CI, 1.03-1.17) (P < .05).

CONCLUSION

Of note, 1 in 5 patients who underwent resection developed recurrence or metastasis after pancreatectomy. Prognostic predictors of DFS in pNETs could help optimize treatment and enhance follow-up protocols to improve quality and reduce morbidity.

Primary hepatic neuroendocrine neoplasms: imaging characteristics and misdiagnosis analysis

Objective

To analyze the CT and MR features of Primary hepatic neuroendocrine neoplasms (PHNENs) in order to enhance the diagnostic accuracy of this disease.

Methods

A retrospective analysis was conducted on patients diagnosed with hepatic neuroendocrine neoplasms, excluding other sites of origin through general examination and postoperative follow-up. The CT and MR signs were analyzed according to the 2018 version of Liver Imaging Reporting and Data System (LI-RADS), along with causes of misdiagnosis.

Results

Twelve patients, including 6 males and 6 females, were enrolled in this study. There was no significant increase in liver tumor markers among all cases. Most masses were multiple (9/12), exhibiting low attenuation on pre-contrast CT scans, T1-hypointense signal, T2-hyperintense signal, and restricted diffusion. The majority of these masses (7/10) demonstrated similar rim arterial phase hyper-enhancement as well as peripheral "washout" during venous portal phase and delayed phase imaging. Three cases had incomplete capsules while one case had a complete capsule. Cyst/necrosis was observed in 7 out of all cases following administration of contrast agent, with 5 mainly distributed in the periphery. All masses lacked fat, calcification, vascular or bile duct tumor thrombus formation.

Conclusion

The imaging findings associated with PHNENs possess certain specificity, often presenting as multiple masses within the liver accompanied by peripheral cyst/necrosis, similar rim arterial phase hyper-enhancement during venous portal phase and delayed phase imaging.

Liver transplantation as an alternative for the treatment of neuroendocrine liver metastasis: Appraisal of the current evidence

BACKGROUND

Liver transplantation (LT) for neuroendocrine liver metastases (NELM) is still in debate. Studies comparing LT with liver resection (LR) for NELM are scarce, as patient selection is heterogeneous and experience is limited. The goal of this review was to provide a critical analysis of the evidence on LT versus LR in the treatment of NELM.

DATA SOURCES

A scoping literature search on LT and LR for NELM was performed with PubMed, including English articles up to March 2023.

RESULTS

International guidelines recommend LR for NELM in resectable, well-differentiated tumors in the absence of extrahepatic metastatic disease with superior results of LR compared to systemic or liver-directed therapies. Advanced liver surgery has extended resectability criteria whilst entailing increased perioperative risk and short disease-free survival. In highly selected patients (based on the Milan criteria) with unresectable NELM, oncologic results of LT are promising. Prognostic factors include tumor biology (G1/G2) and burden, waiting time for LT, patient age and extrahepatic spread. Based on low-level evidence, LT for low-grade NELM within the Milan criteria resulted in improved disease-free survival and overall survival compared to LR. The benefits of LT were lost in patients beyond the Milan NELM-criteria.

CONCLUSIONS

With adherence to strict selection criteria especially tumor biology, LT for NELM is becoming a valuable option providing oncologic benefits compared to LR. Recent evidence suggests even stricter selection criteria with regard to tumor biology.

Evolution of Liver Transplantation Indications: Expanding Horizons

Liver transplantation (LT) has significantly transformed the prognosis of patients with end-stage liver disease and hepatocellular carcinoma (HCC). The traditional epidemiology of liver diseases has undergone a remarkable shift in indications for LT, marked by a decline in viral hepatitis and an increase in metabolic dysfunction-associated steatotic liver disease (MASLD), along with expanded indications for HCC. Recent advancements in surgical techniques, organ preservation and post-transplant patients' management have opened new possibilities for LT. Conditions that were historically considered absolute contraindications have emerged as potential new indications, demonstrating promising results in terms of patient survival. While these expanding indications provide newfound hope, the ethical dilemma of organ scarcity persists. Addressing this requires careful consideration and international collaboration to ensure equitable access to LT. Multidisciplinary approaches and ongoing research efforts are crucial to navigate the evolving landscape of LT. This review aims to offer a current overview of the primary emerging indications for LT, focusing on acute-on-chronic liver failure (ACLF), acute alcoholic hepatitis (AH), intrahepatic and perihilar cholangiocarcinoma (i- and p-CCA), colorectal liver metastasis (CRLM), and neuroendocrine tumor (NET) liver metastases.

Chinese expert consensus on multidisciplinary diagnosis and treatment of pancreatic neuroendocrine liver metastases

Many management strategies are available for pancreatic neuroendocrine neoplasms with liver metastases. However, a lack of biological, molecular, and genomic information and an absence of data from rigorous trials limit the validity of these strategies. This review presents the viewpoints from an international conference consisting of several expert working groups. The working groups reviewed a series of questions of particular interest to clinicians taking care of patients with pancreatic neuroendocrine neoplasms with liver metastases by reviewing the existing management strategies and literature, evaluating the evidence on which management decisions were based, developing internationally acceptable recommendations for clinical practice, and making recommendations for clinical and research endeavors. The review for each question will be followed by recommendations from the panel.

Review of Merkel cell carcinoma with solitary pancreatic metastases mimicking primary neuroendocrine tumor of the pancreas

OBJECTIVE/BACKGROUND

Merkel cell carcinoma (MCC) but metastases to the pancreas are very rare. There are only a few cases of isolated metastases of MCC to the pancreas. Because of this rarity, it can be wrongly diagnosed as a neuroendocrine tumor of the pancreas(pNET), especially the poorly differentiated neuroendocrine carcinoma (PNEC) subtype, in which the treatment is vastly different than that of MCC with isolated metastases of the pancreas.

METHODS

An electronic search of the PubMed and google scholar databases was performed to obtain the literature on MCC with pancreatic metastases, using the following search terms: Merkel cell carcinoma, pancreas, and metastases. Results are limited to the following available article types: case reports and case series. We identified 45 cases of MCC with pancreatic metastases from the PubMed and Google Scholar database search and examined their potential relevance. Only 22 cases with isolated pancreatic metastases were taken for review including one case that we encountered.

RESULTS

The results from our review of cases of isolated pancreatic metastases of MCC were compared to the characteristics of the poorly differentiated pancreatic neuroendocrine tumor (PNEC). We found the following: (a) MCC with isolated pancreatic metastases occurred at an older age than PNEC and with male gender predominance (b) Most of the metastases occurred within 2 years of initial diagnosis of MCC (c) Resection of pancreatic mass was the first line treatment in case of resectable PNECs whereas resection of metastases was infrequently performed in MCC with pancreatic metastases.

Sporadic pancreatic neuroendocrine neoplasms: A retrospective clinicopathological and outcome analysis from a Latvian study group

Background

Although pancreatic neuroendocrine neoplasms (PNEN) are rare, there has been a constant increase in incidence. Furthermore, PNEN present unique clinical behaviors and long-term survival can be expected even in the presence of metastases as compared with ductal adenocarcinoma of the pancreas. Determining the best therapeutic approach and proper timing of therapy requires knowledge of reliable prognostic factors. Therefore, the aim of this study was to explore clinicopathological features, treatment, and survival outcomes of patients with PNEN based on Latvian gastroenteropancreatic neuroendocrine neoplasm (GEP-NEN) registry data.

Method

Patients with confirmed PNEN at Riga East Clinical University Hospital and Pauls Stradins Clinical University Hospital, between 2008 and 2020, were retrospectively analyzed. Data were collected and included in EUROCRINE, an open-label international endocrine surgical registry.

Results

In total, 105 patients were included. The median age at diagnosis was 64 years (IQR 53.0-70.0) for males and 61 years (IQR 52.5-69.0) for females. In 77.1% of patients, tumors were hormonally nonfunctional. Among those with functioning PNEN, 10.5% of patients presented with hypoglycemia and were diagnosed with insulinoma, 6.7% of patients presented with symptoms related to carcinoid syndrome; 30.5% of patients showed distant metastases at the time of diagnosis, and surgery was performed in 67.6% of patients. Notably, for five patients with nonfunctional PNEN <2 cm, a "watch and wait" approach was used; none of the patients developed metastatic disease. The median length of hospital stay was 8 days (IQR 5-13). Major postoperative complications were found in 7.0% of patients, and reoperation was conducted for 4.2% of patients, due to postpancreatectomy bleeding (2/71) and abdominal collection (1/71). The median follow-up period was 34 months (IQR 15.0-68.8). The OS at the last follow-up was 75.2% (79/105). The observed 1-, 5- and 10-year survival rates were 87.0, 71.2 and 58.0, respectively. Seven of the surgically treated patients had tumor recurrence. The median time of recurrence was 39 months (IQR 19.0-95.0). A univariable Cox proportional hazard analysis provided evidence that a nonfunctional tumor, a larger tumor size, the presence of distant metastases, a higher tumor grade, and the tumor stage were strong, negative predictors of OS.

Conclusion

Our study represents the general trends of clinicopathological features and treatment of PNEN in Latvia. For PNEN patients, tumor functionality, size, distant metastases, grade, and stage may be useful to predict OS and must be confirmed in further studies. Furthermore, a "surveillance" strategy might be safe for selected patients with small asymptomatic PNEN.

Risk Stratification of Pancreatic Neuroendocrine Neoplasms Based on Clinical, Pathological, and Molecular Characteristics

Pancreatic neuroendocrine neoplasms consist of heterogeneous diseases. Depending on the novel features detected by various modern technologies, their classification and related prognosis predictions continue to change and develop. The role of traditional clinicopathological prognostic factors, including classification systems, is also being refined, and several attempts have been made to predict a more accurate prognosis through novel serum biomarkers, genetic factors, and epigenetic factors that have been identified through various state-of-the-art molecular techniques with multiomics sequencing. In this review article, the latest research results including the traditional approach to prognostic factors and recent advanced strategies for risk stratification of pancreatic neuroendocrine neoplasms based on clinical, pathological, and molecular characteristics are summarized. Predicting prognosis through multi-factorial assessments seems to be more efficacious, and prognostic factors through noninvasive methods are expected to develop further advances in liquid biopsy in the future.

Treatment strategies for neuroendocrine liver metastases: a systematic review

BACKGROUND

Gastroenteropancreatic neuroendocrine tumors are often diagnosed when metastatic. The liver is the main site of metastases. Unfortunately, optimal management of neuroendocrine liver metastases remains a topic of debate. The aim of this study was to make a systematic review of the current literature about the results of the different treatments of neuroendocrine liver metastases.

METHODS

A systematic review was conducted for English language publications from 1995 to 2021. Outcomes were analyzed according to survival, disease-free survival, and in the case of systemic therapies, progression-free survival.

RESULTS

5509 patients were analyzed in the review. 67% of patients underwent surgery achieving 5 years overall survival despite only 30% percent without a recurrence. 60% of patients that had received a transplant reached 5 years survival with a low disease-free survival rate (20%). Five-year survival rate was 36.2% for patients undergoing loco-regional therapies.

CONCLUSION

Surgical resection is the best treatment when metastases are resectable, with the highest rate of survival, although liver transplantation shows good results for patients not eligible for surgery. Loco-regional therapies may be useful when surgical resection is contraindicated, or selectively used as a bridge to surgery or transplantation. Systemic therapies are indicated in patients for whom curative treatment cannot be obtained.

Surgery, Liver Directed Therapy and Peptide Receptor Radionuclide Therapy for Pancreatic Neuroendocrine Tumor Liver Metastases

Pancreatic neuroendocrine tumors (PNETs) are described by the World Health Organization (WHO) classification by grade (1–3) and degree of differentiation. Grade 1 and 2; well differentiated PNETs are often characterized as relatively “indolent” tumors for which locoregional therapies have been shown to be effective for palliation of symptom control and prolongation of survival even in the setting of advanced disease. The treatment of liver metastases includes surgical and non-surgical modalities with varying degrees of invasiveness; efficacy; and risk. Most of these modalities have not been prospectively compared. This paper reviews literature that has been published on treatment of pancreatic neuroendocrine liver metastases using surgery; liver directed embolization and peptide receptor radionuclide therapy (PRRT). Surgery is associated with the longest survival in patients with resectable disease burden. Liver-directed (hepatic artery) therapies can sometimes convert patients with borderline disease into candidates for surgery. Among the three embolization modalities; the preponderance of data suggests chemoembolization offers superior radiographic response compared to bland embolization and radioembolization; but all have similar survival. PRRT was initially approved as salvage therapy in patients with advanced disease that was not amenable to resection or embolization; though the role of PRRT is evolving rapidly

A real-life treatment cohort of pancreatic neuroendocrine tumors: High-grade increase in metastases confers poor survival

Background

Tumor grade determined by the Ki67 index is the best prognostic factor for pancreatic neuroendocrine tumors (PanNETs). However, we often observe that the grade of metastases differs from that of their primary tumors. This study aimed to investigate the frequency of grade changes between primary tumors and metastases, explore its association with clinical characteristics, and correlate the findings with the prognosis.

Methods

Six hundred forty-eight patients with pancreatic neuroendocrine neoplasms treated at Fudan University Shanghai Cancer Center were screened for inclusion, and 103 patients with PanNETs who had paired primary tumors and metastases with an available Ki67 index were included. Re-evaluation of Ki67 was performed on 98 available samples from 69 patients.

Results

Fifty cases (48.5%) had a Ki67 index variation, and 18 cases (17.5%) displayed a grade increase. Metachronous metastases showed significantly higher Ki67 index variation than synchronous metastases (P=0.028). Kaplan-Meier analyses showed that high-grade metastases compared to low-grade primary tumors were significantly associated with decreased progression-free survival (PFS, P=0.012) and overall survival (OS, P=0.027). Multivariable Cox regression analyses demonstrated that a low-grade increase to high-grade was an unfavorable and independent prognostic factor for PFS and OS (P=0.010, and P=0.041, respectively).

Conclusions

A high-grade increase in metastases was an unfavorable predictor of PanNETs, which emphasized the importance of accurate pathological grading and could provide a reference for clinical decision-making.

Resection of the Primary Tumor Improves the Survival of Patients With Stage IV Gastric Neuroendocrine Carcinoma

Background

The prognostic prolongation effect of surgical resection in the management of gastric neuroendocrine carcinoma (GNEC) with distant metastases was still uncertain. The purpose of this study was to investigate the association of primary tumor resection (PTR) with outcomes in patients with stage IV GNEC.

Methods

This retrospective study analyzed patients with distant metastatic GNEC diagnosed between 2000 and 2018 and identified using the Surveillance, Epidemiology, and End Results (SEER) database. Patients were divided into PTR and non-PTR groups. The stabilized inverse probability of treatment weighting (IPTW) method was used to reduce the selection bias. Overall survival (OS) and cancer-specific survival (CSS) were estimated using the Kaplan-Meier method and log-rank test. Cox-regression analyses (uni- and multivariate) were performed to evaluate factors potentially influencing survival.

Results

A total of 126 patients with a median follow-up of 79 months were identified. Forty-four patients underwent PTR and 82 patients did not undergo surgery. After the IPTW approach, PTR improved the OS in patients with stage IV GNEC (median OS 12 vs. 6 months, P = 0.010). The 1- and 3-year OS for patients with or without PTR were 43.8% and 34.5%, and 27.9% and 6.5%, respectively. The median CSS was 12 months for patients undergoing PTR and 6 months for those who did not. The 1 and 3-year CSS for patients with or without PTR were 45.1% and 37.0%, and 27.9% and 6.5%, respectively. In IPTW-adjusted Cox proportional hazards regression analysis, PTR was recognized as an independent factor for improved survival after the occurrence of distant metastatic disease [OS: hazard ratio (HR) = 0.305; 95% confidence interval (CI): 0.196, 0.475; and CSS: HR = 0.278; 95% CI: 0.171, 0.452].

Conclusion

PTR for stage IV GNEC contributes to a better prognosis compared with non-surgery. This study supported the resection of the primary tumor in patients with distant metastatic GNEC.

Induction therapy with 177Lu-DOTATATE procures long-term survival in locally advanced or oligometastatic pancreatic neuroendocrine neoplasm patients

PURPOSE

Peptide receptor radionuclide therapy (PRRT) with 177Lu-DOTATATE induces objective response in up to 57% of pancreatic neuroendocrine neoplasms (panNENs). Therefore, PRRT may comprise a downstaging option for panNEN patients who are not eligible for upfront curative surgery or are at high risk for recurrence. The aim of this study was to assess the potency of induction PRRT for locally advanced panNENs and to evaluate the effect of surgery after PRRT on overall survival (OS).

METHODS

Retrospective cohort study of panNEN patients treated with induction 177Lu-DOTATATE.

RESULTS

After PRRT, 26 out of 49 patients underwent pancreatic surgery with curative intent (PRRT + surgery). Partial objective response was obtained in 62% of the PRRT + surgery group versus 26% of the patients not undergoing panNEN surgery (PRRT-only group, p = 0.02). Downstaging in tumour-vessel interface was observed in 38% of all patients with at least one involved vessel. Median OS was 14.7 years (95% CI 5.9-23.6) for the PRRT + surgery group compared to 5.5 years (95% CI 4.5-6.5) for the PRRT-only group (p = 0.003). In the Cox proportional hazards analysis, surgery was not significantly associated with OS after propensity score adjustment with cumulative activity, performance status, tumour size after PRRT, and tumour grade. Median progression-free survival was 5.3 years (95% CI 2.4-8.1) for the PRRT + surgery group and 3.0 years (95% CI 1.6-4.4) for the PRRT-only group (p = 0.02).

CONCLUSION

Early administration of PRRT followed by surgery is associated with favourable long-term outcomes in patients with locally advanced or oligometastatic panNEN and can be considered for selected patients with vascular involvement and/or increased risk of recurrence.

The diagnostic value of intravoxel incoherent motion diffusion-weighted imaging for distinguishing nonhypervascular pancreatic neuroendocrine tumors from pancreatic ductal adenocarcinomas

PURPOSE

To primarily evaluate the diagnostic performance of the monoexponential and intravoxel incoherent motion (IVIM) diffusion weighted imaging (DWI) models for differentiating between nonhypervascular pancreatic neuroendocrine tumors (PNETs) and pancreatic ductal adenocarcinomas (PDACs).

METHODS

63 patients with PNETs (35 nonhypervascular PNETs and 28 hypervascular PNETs) and 164 patients with PDACs were retrospectively enrolled in the study and underwent multiple b-value DWI. Intraobserver and interobserver reliabilities of DWI parameters were assessed by using the intraclass correlation coefficient (ICC). The parameters of apparent diffusion coefficient (ADC), true diffusion coefficient (D), pseudo-diffusion coefficient (D*), and perfusion fraction (f) of nonhypervascular PNETs were compared with PDACs and hypervascular PNETs using the independent sample t test or the Mann-Whitney U test. The diagnostic performance was evaluated using receiver operating characteristic (ROC) analysis.

RESULTS

All DWI parameters values showed good to excellent intra- and interobserver agreements (ICC = 0.743-0.873). Nonhypervascular PNETs had significantly lower ADC and D, but significantly higher f than PDACs (P = 0.005, P < 0.001 and P < 0.001, respectively). ADC, D and f of nonhypervascular PNETs were lower than hypervascular PNETs (P = 0.001, <0.001 and 0.093, respectively). D* of nonhypervascular PNETs showed no statistically significant differences with PDACs and hypervascular PNETs (P = 0.809 and 0.420). D showed a higher area under the curve (AUC), followed by ADC and f (AUC = 0.885, 0.665 and 0.740, respectively) in differentiating nonhypervascular PNETs from PDACs.

CONCLUSION

Monoexponential and IVIM diffusion models are valuable to differentiate nonhypervascular PNETs from PDACs. D showed better performance than f and ADC.

Surgery in Patients with Gastro-Entero-Pancreatic Neuroendocrine Carcinomas, Neuroendocrine Tumors G3 and High Grade Mixed Neuroendocrine-Non-Neuroendocrine Neoplasms

OPINION STATEMENT

In the 2019 WHO guidelines, the classification of gastro-entero-pancreatic neuroendocrine neoplasms (GEP NEN) has changed from one being based on Ki-67 proliferation index alone to one that also includes tumor differentiation. Consequently, GEP NENs are now classified as well-differentiated neuroendocrine tumor (NET), NET G1 (Ki-67 <3%), NET G2 (Ki-67 3-20%) and NET G3 (Ki-67 >20%), and poorly differentiated neuroendocrine carcinoma (NEC) (Ki-67 >20%). It has been suggested that NET G3 should be treated as NET G2 with respect to surgery, while surgical management of NEC should be expanded from local disease to also include patients with advanced disease where curative surgery is possible. High grade mixed neuroendocrine-non-neuroendocrine neoplasms (MiNEN) have a neuroendocrine and a non-neuroendocrine component mostly with a poor prognosis. All studies evaluating the effect of surgery in NEC and MiNEN are observational and hold a risk of selection bias, which may overestimate the beneficial effect of surgery. Further, only a few studies on the effect of surgery in MiNEN exist. This review aims to summarize the data on the outcome of surgery in patients with GEP NET G3, GEP NEC and high grade MiNEN. The current evidence suggests that patients with NEN G3 and localized disease and NEN G3 patients with metastatic disease where curative surgery can be achieved may benefit from surgery. In patients with MiNEN, it is currently not possible to evaluate on the potential beneficial effect of surgery due to the low number of studies.

Therapeutic strategies for gastroenteropancreatic neuroendocrine neoplasms: State-of-the-art and future perspectives

Although gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) have always been considered rare tumors, their incidence has risen over the past few decades. They represent a highly heterogeneous group of neoplasms with several prognostic factors, including disease stage, proliferative index (Ki67), and tumor differentiation. Most of these neoplasms express somatostatin receptors on the cell surface, a feature that has important implications in terms of prognosis, diagnosis, and therapy. Although International Guidelines propose algorithms aimed at guiding therapeutic strategies, GEP-NEN patients are still very different from one another, and the need for personalized treatment continues to increase. Radical surgery is always the best option when feasible; however, up to 80% of cases are metastatic upon diagnosis. Regarding medical treatments, as GEP-NENs are characterized by relatively long overall survival, multiple therapy lines are adopted during the lifetime of these patients, but the optimum sequence to be followed has never been clearly defined. Furthermore, although new molecular markers aimed at predicting the response to therapy, as well as prognostic scores, are currently being studied, their application is still far from being part of daily clinical practice. As they represent a complex disease, with therapeutic protocols that are not completely standardized, GEP-NENs require a multidisciplinary approach. This review will provide an overview of the available therapeutic options for GEP-NENs and attempts to clarify the possible approaches for the management of these patients and to discuss future perspectives in this field.

What Are the Place and Modalities of Surgical Management for Pancreatic Neuroendocrine Neoplasms? A Narrative Review

Pancreatic neuroendocrine neoplasms (panNENs) are a heterogeneous group of tumors derived from cells with neuroendocrine differentiation. They are considered malignant by default. However, their outcomes are variable depending on their presentation in the onset of hereditary syndromes, hormonal secretion, grading, and extension. Therefore, although surgical treatment has long been suggested as the only treatment of pancreatic neuroendocrine neoplasms, its modalities are an evolving landscape. For selected patients (small, localized, non-functional panNENs), a "wait and see" strategy is suggested, as it is in the setting of multiple neuroendocrine neoplasia type 1, but the accurate size cut-off remains to be established. Parenchyma-sparring pancreatectomy, aiming to limit pancreatic insufficiency, are also emerging procedures, which place beyond the treatment of insulinomas and small non-functional panNENs (in association with lymph node picking) remains to be clarified. Furthermore, giving the fact that the liver is generally the only metastatic site, surgery keeps a place of choice alongside medical therapies in the treatment of metastatic disease, but its modalities and extensions are still a matter of debate. This narrative review aims to describe the current recommended surgical management for pancreatic NENs and controversies in light of the actual recommendations and recent literature.

Patterns and predictors of pancreatic neuroendocrine tumor prognosis: Are no two leaves alike?

Pancreatic neuroendocrine tumors (PanNETs) are heterogeneous; thus, individual prognostic prediction is important. Clinicopathological features, like TNM stage, grade, and differentiation, are independent clinical predictors. However, single predictors are insufficient, as patients sharing similar clinicopathological features usually show distinct prognoses. Accordingly, novel nomograms and risk stratifications have been developed for more accurate PanNET prognostic prediction. Moreover, the exploration of molecular mechanisms has identified novel prognostic predictors for PanNET. Multi-analyte assays of molecular biomarkers provide a deeper understanding of PanNET features; however, the priority, and the optimal combination of classic and novel predictors for PanNET prognosis prediction remain unclear. In this review, we summarized the patterns and predictors of PanNET prognosis and discussed their clinical utility; we emphasized that PanNET at different stages have different superior predictor, and that multi-analyte assays are more sensitive than mono-analyte biomarkers. Therefore, combined biomarkers improve the accuracy of surveillance and optimize decision-making in clinical practice.

Long-term outcome after resection and thermal hepatic ablation of pancreatic neuroendocrine tumour liver metastases

BACKGROUND

Pancreatic neuroendocrine tumours (Pan-NETs) are rare tumours that often present with or develop liver metastases. The aim of this retrospective study was to evaluate liver surgery and thermal hepatic ablation (THA) of Pan-NET liver metastases and to compare the outcomes with those of a control group.

METHOD

Patients with Pan-NET treated in Uppsala University Hospital and Sahlgrenska University Hospital from 1995-2018 were included. Patient records were scrutinized for baseline parameters, survival, treatment and complications.

RESULTS

Some 108 patients met the criteria for inclusion; 57 patients underwent treatment with liver surgery or THA and 51 constitute the control group. Median follow-up was 3.93 years. Five-year survival in the liver surgery/THA group was 70.6 (95 per cent c.i. 0.57 to 0.84) per cent versus 42.4 (95 per cent c.i. 40.7 to 59.1) per cent in the control group (P = 0.016) and median survival was 9.1 (95 per cent c.i. 6.5 to 11.7) versus 4.3  (95 per cent c.i. 3.4-5.2) years. In a multivariable analysis, surgery or THA was associated with a decreased death-years rate (hazard ratio 0.403 (95 per cent c.i. 0.208 to 0.782, P = 0.007).

CONCLUSION

Liver surgery and/or THA was associated with longer overall survival in Pan-NET with acceptable mortality and morbidity rates. These treatments should thus be considered in Pan-NET patients with reasonable tumour burden in an intent to alleviate symptoms and to improve survival.

Long-Term Results after Surgical Resection of Peritoneal Metastasis from Neuroendocrine Tumors

INTRODUCTION

Peritoneal metastases from neuroendocrine tumors are associated with a bad prognosis. The objective of our study was to evaluate whether surgical resection could lead to prolonged survival in selected patients. This survival was compared to that of patients operated for liver metastasis.

METHODS

From our prospectively maintained database we included 88 patients who underwent the complete resection of peritoneal and/or liver metastasis between January 1995 and December 2016 in Gustave-Roussy. Three resection groups were compared: peritoneal metastasis alone, liver metastasis alone, and the combined resection of liver and peritoneal metastases.

RESULTS

The median peritoneal cancer index was 10 in the peritoneal group and 11 in the peritoneal + liver group. The 5-year overall survival was 81% (60-100) in the peritoneal group compared to 78% (65.2-92.8) in the liver group, and 72% (58.7-89.7) in the peritoneal + liver group (p = 0.71). The 3-year disease-free survival reached 26.9% (16.1-45.1) in the liver group, 12.5% (2.3-68.2) in the peritoneal group, and 32.4% (19.9-52.6) in the combined liver + peritoneal group (p = 0.45). In the univariate analysis, the prognosis factors for a longer survival were: small bowel primary tumor origin, low preoperative chromogranin A level, and tumor grade ≤1.

CONCLUSION

Despite a high recurrence rate, long-term overall survival can be achieved after the resection of peritoneal metastasis in selected patients. This survival is comparable to that of patients operated for liver metastasis only. Surgery should stand as a standard treatment for peritoneal metastases in patients with resectable disease.

Clinical practice guidelines for the management of liver metastases from extrahepatic primary cancers 2021

BACKGROUND

Hepatectomy is standard treatment for colorectal liver metastases; however, it is unclear whether liver metastases from other primary cancers should be resected or not. The Japanese Society of Hepato-Biliary-Pancreatic Surgery therefore created clinical practice guidelines for the management of metastatic liver tumors.

METHODS

Eight primary diseases were selected based on the number of hepatectomies performed for each malignancy per year. Clinical questions were structured in the population, intervention, comparison, and outcomes (PICO) format. Systematic reviews were performed, and the strength of recommendations and the level of quality of evidence for each clinical question were discussed and determined. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess evidence and make recommendations.

RESULTS

The eight primary sites were grouped into five categories based on suggested indications for hepatectomy and consensus of the guidelines committee. Fourteen clinical questions were devised, covering five topics: (1) diagnosis, (2) operative treatment, (3) ablation therapy, (4) the eight primary diseases, and (5) systemic therapies. The grade of recommendation was strong for one clinical question and weak for the other 13 clinical questions. The quality of the evidence was moderate for two questions, low for 10, and very low for two. A flowchart was made to summarize the outcomes of the guidelines for the indications of hepatectomy and systemic therapy.

CONCLUSIONS

These guidelines were developed to provide useful information based on evidence in the published literature for the clinical management of liver metastases, and they could be helpful for conducting future clinical trials to provide higher-quality evidence.

Examining Perioperative Risk Associated with Simultaneous Resection of Primary Neuroendocrine Tumors and Synchronous Hepatic Metastases

BACKGROUND

Surgical debulking of primary neuroendocrine tumors (NETs) and hepatic resection of metastatic NET disease may each independently improve overall survival. However, evidence for combined primary site debulking and metastasectomy on survival and impact on short-term perioperative outcomes is limited.

METHODS

The 2014-2016 ACS-NSQIP targeted hepatectomy database was queried for all patients undergoing liver resection for metastatic NET. Secondary procedure codes were evaluated for major concurrent operations. Multivariable analysis was performed to determine risk factors for 30-day morbidity and mortality.

RESULTS

A total of 472 patients were identified, of whom 153 (32.4%) underwent ≥1 additional concurrent major operation. The most common concurrent procedures were small bowel resection (14.6%), partial colectomy (8.9%), and radical lymphadenectomy (7.4%). Among all patients, overall 30-day mortality and morbidity were 1.5% and 25.6%, respectively. Modifiable and treatment-related factors associated with increased major postoperative morbidity risk included >10% weight loss within six months of surgery (p = 0.05), increasing number of hepatic lesions treated (p = 0.05), and biliary reconstruction (p = 0.001). No major concurrent procedure was associated with increased 30-day morbidity (all p > 0.05).

CONCLUSIONS

Approximately one-third of patients with stage IV NET underwent combined hepatic and multi-organ resection. Although modifiable and treatment-related factors predictive of perioperative morbidity were identified, performance of concurrent major procedures did not increase perioperative morbidity. These results support consideration of multi-organ resection in carefully selected patients with metastatic NET.

Curative Surgery and Ki-67 Value Rather than Tumor Differentiation Predict the Survival of Patients with High-grade Neuroendocrine Neoplasms

OBJECTIVE

To elucidate the role of surgery in patients with high-grade neuroendocrine neoplasms (hg-NENs) and Ki-67 > 20%.

BACKGROUND

Although surgery is the first treatment choice in patients with low-grade NENs, whether it increases the survival of patients with hg-NENs is debatable.

METHODS

Between 2005 and 2018, 63 patients pathologically diagnosed with hg-NENs treated at our institution were retrospectively analyzed. The risk factors for overall survival (OS) and recurrence-free survival (RFS) were analyzed, and OS was compared between each treatment group.

RESULTS

The median observation time was 21.2 months, and the median Ki-67 value was 52%. Patients with hg-NENs were classified into low Ki-67 (Ki-67 < 52%) and high Ki-67 (Ki-67 ≥ 52%) groups. Multivariate analysis for OS identified surgery (P = 0.013) and low Ki-67 value (P = 0.007) as independent risk factors, while morphological differentiation defined by the WHO 2017 criteria showed no association with OS. Patients with low Ki-67 value subjected to R0/1, R2, and chemotherapy had a median survival time (MST) of 83.8, 16.6, and 28.1 months, respectively. The MST for R0/1 group was significantly longer than that for chemotherapy group (P = 0.001). However, no difference in survival was reported between patients from R0/1 and chemotherapy groups with high Ki-67. Ki-67 value could determine RFS (P = 0.006) in patients that underwent R0/1 surgery for pancreatic hg-NENs.

CONCLUSION

R0/1 surgery predicted prognoses in the low Ki-67 group. The indication of surgery for patients with hg-NENs did not depend on tumor differentiation.

Pattern of disease recurrence and treatment after surgery for nonfunctioning well-differentiated pancreatic neuroendocrine tumors

BACKGROUND

The risk of recurrence after curative surgery for pancreatic neuroendocrine tumors is reported to be between 10% and 30%. Among the available locoregional and systemic treatments, there are no specific recommendations regarding the best option for treating recurrent disease. The aims of this study were to evaluate the pattern of recurrence after surgery performed with curative intent for nonfunctioning pancreatic neuroendocrine tumors and to analyze the impact of treatment on disease progression.

METHODS

All patients submitted to curative surgery for sporadic, well-differentiated, nonfunctioning pancreatic neuroendocrine tumors at 2 Italian centers between 2001 and 2018, with evidence of disease recurrence during follow-up, were included (n = 46).

RESULTS

The most frequent type of recurrence was distant metastases (n = 38, 83%), located in the liver in 100% of cases, whereas 8 patients (17%) had an isolated local recurrence. Therapy for first disease recurrence included both locoregional (n = 14) and systemic treatments (n = 32). A second disease recurrence/progression occurred in 28 patients (61%). Patients who underwent systemic treatment after the first disease recurrence had better progression-free survival (1-year progression-free survival 78%) compared with those submitted to a locoregional procedure (1-year progression-free survival 50%; P = .007). Independent predictors of shortened progression-free survival after the first disease recurrence were the type of treatment (locoregional, hazard ratio 4.452, P = .001), the presence of necrosis (hazard ratio 2.732, P = .022) and age (>60 year, hazard ratio 2.494, P = .040).

CONCLUSION

Upfront locoregional treatment of the first recurrence of nonfunctioning pancreatic neuroendocrine tumors after curative surgery should be avoided in favor of systemic therapy.

Sequence of therapy and survival in patients with advanced pancreatic neuroendocrine tumours

Background

Pancreatic neuroendocrine tumours (pnets) often present as advanced disease. The optimal sequence of therapy is unknown.

Methods

Sequential patients with advanced pnets referred to BC Cancer between 2000 and 2013 who received 1 or more treatment modalities were reviewed, and treatment patterns, progression-free survival (pfs), and overall survival (os) were characterized. Systemic treatments included chemotherapy, small-molecule therapy, and peptide receptor radionuclide therapy.

Results

In 66 cases of advanced pnets, median patient age was 61.2 years (25%-75% interquartile range: 50.8-66.2 years), and men constituted 47% of the group. First-line therapies were surgery (36%), chemotherapy (33%), and somatostatin analogues (32%). Compared with first-line systemic therapy, surgery in the first line was associated with increased pfs and os (20.6 months vs. 6.3 months and 100.3 months vs. 30.5 months respectively, p < 0.05). In 42 patients (64%) who received more than 1 line of therapy, no difference in os or pfs between second-line therapies was observed.

Conclusions

Our results confirm the primary role of surgery for advanced pnets. New systemic treatments will further increase options.

Natural history and clinical outcomes of pancreatic neuroendocrine neoplasms based on the WHO 2017 classification; a single-center experience of 30 years

BACKGROUND/OBJECTIVES

This single-center study aimed to evaluate treatment outcomes and long-term prognosis of patients with pancreatic neuroendocrine neoplasms (PanNENs) based on the World Health Organization (WHO) 2017 classification.

METHODS

We enrolled 245 patients with PanNENs treated at Kyushu University Hospital between January 1987 and March 2018. PanNENs were categorized according to the WHO 2017 classification or further subdivisions of Ki-67 index. Clinicopathological features, median survival time (MST), and prognostic factors were retrospectively analyzed.

RESULTS

The number of PanNENs, especially non-functioning PanNENs, has increased over the last decade. The mean MST of all patients was 202 months; which was longest in patients with NET G1 (n = 145, MST = 261 months) relative to NET G2 (n = 72, 132 months), NET G3 (n = 3, 34 months) and NEC G3 (n = 17, 9 months). Prognosis in patients with surgery as the first-line treatment was significantly better than in those with drug therapy. However, 26% of patients who underwent curative resection developed recurrence after a median time of 28.7 months. In unresectable PanNENs (n = 97), the MST and 5-year survival rate were 78 months and 55.8%, respectively. Poor differentiation, Ki-67 index of >10% and presence of liver metastasis were significant unfavorable predictors. Response to first-line therapy (stable disease/partial response) and three or more treatment regimens were significant favorable predictors for unresectable PanNENs according to multivariate analyses (p < 0.01).

CONCLUSIONS

We demonstrated the utility of the WHO 2017 classification for PanNENs in the real clinical setting. For better prognosis in PanNENs, the use of three or more regimens should be considered.

Long-term outcome of surgical resection in patients with gastroenteropancreatic neuroendocrine neoplasia: results from a German nation-wide multi-centric registry

BACKGROUND

Neuroendocrine neoplasia (NEN) are rare and heterogenous tumours. Few data exist on the impact of surgical therapy.

MATERIALS AND METHODS

This is a retrospective analysis of prospectively collected data of gastroenteropancreatic NEN in the German NET-Registry (1999-2012). It focuses on patients without distant metastases (limited disease, LD, stage I-IIIB).

RESULTS

Data of 2239 patients with NEN were recorded. Median age was 59 years, the gender ratio was 1:1.3 (f:m). A total of 986 patients (44%) had LD, and the 5-year survival rate (5 years) was 77% for all and 90% for patients with LD. A total of 1635 patients (73%) received a surgical therapy (1st to 6th line); the 5 and 10 ysr were 83/65% after and 59/35% without surgery for all patients (p < .001). The resection margins in the LD patients were 76%, 16%, and 3% for R0, R1 and R2, respectively. The 10 ysr was 84%, 59% and 42% for R0, R1 and R2 resections, respectively (p = .021 R0/R1, p < .001 R0/R2). The R0 resection rate was 75% for G1/G2 NET and 67% for G3 NEC.

CONCLUSION

The rate of complete tumour resection (R0) in LD is independent of tumour grading, and R0 resection is the key determinant of long-term survival, as demonstrated by the 10 ysr. of 84%. All NEN patients with limited disease should be considered for operation, if possible, as the best 10-year survival is shown after an R0 resection.

Surgical Principles in the Management of Pancreatic Neuroendocrine Neoplasms

OPINION STATEMENT

Pancreatic neuroendocrine neoplasms (PanNENs) are increasingly recognized entities, whose incidence has dramatically grown during the last two decades. Surgery plays a pivotal role in their management as it represents the only chance of cure. Since PanNENs display a wide range of aggressiveness, their surgical management needs to be tailored on tumor's and patient's characteristics. Currently, there are several open questions and burning issues in the field of PanNEN, such as the management of asymptomatic nonfunctioning pancreatic neuroendocrine tumors (NF-PanNET) ≤ 2 cm. An active surveillance of these small lesions has been demonstrated to be safe although the available evidences are only based on retrospective studies. On the other hand, formal pancreatic resection associated with lymphadenectomy represents the gold standard for patients with localized NF-PanNEN > 2 cm or NF-PanNEN ≤ 2 cm in the presence of symptoms, dilation of the main pancreatic duct or suspicion of nodal metastases. Surgery plays also an important role in the setting of metastatic disease. In particular, surgery is generally recommended in the presence of low-grade, resectable, metastatic disease, but several series have reported also a survival benefit of palliative primary tumor resection in patients with unresectable liver metastases. The role of surgery in PanNEN G3 is still controversial. Indeed, surgery is associated with an improved survival in patients with well-differentiated PanNET G3, whereas there is almost no survival benefit in case of poorly differentiated lesions.

Neoadjuvant Capecitabine/Temozolomide for Locally Advanced or Metastatic Pancreatic Neuroendocrine Tumors

OBJECTIVES

The combination chemotherapy regimen capecitabine/temozolomide (CAPTEM) is efficacious for metastatic well-differentiated pancreatic neuroendocrine tumors (PNETs), but its role in the neoadjuvant setting has not been established.

METHODS

The outcomes of all patients with locally advanced or resectable metastatic PNETs who were treated with neoadjuvant CAPTEM between 2009 and 2017 at 2 high-volume institutions were retrospectively reviewed.

RESULTS

Thirty patients with locally advanced PNET (n = 10) or pancreatic neuroendocrine hepatic metastases (n = 20) received neoadjuvant CAPTEM. Thirteen patients (43%) exhibited partial radiographic response (PR), 16 (54%) had stable disease, and 1 (3%) developed progressive disease. Twenty-six (87%) patients underwent resection (pancreatectomy [n = 12], combined pancreatectomy and liver resection [n = 8], or major hepatectomy alone [n = 6]); 3 (18%) declined surgery despite radiographic PR, and 1 (3%) underwent aborted pancreatoduodenectomy. Median primary tumor size was 5.5 cm, and median Ki-67 index was 3.5%. Rates of PR were similar across tumor grades (P = 0.24). At median follow-up of 49 months, median progression-free survival was 28.2 months and 5-year overall survival was 63%.

CONCLUSIONS

Neoadjuvant CAPTEM is associated with favorable radiographic objective response rates for locally advanced or metastatic PNET and may facilitate selection of patients appropriate for surgical resection.

The impact of surgery for metastatic pancreatic neuroendocrine tumor: a contemporary evaluation matching for chromogranin a level

BACKGROUND

Studies supporting surgical management of metastatic pancreatic neuroendocrine tumor (PNET) are limited by selection bias. Chromogranin A (CgA) has been used as a biomarker for PNET and may reflect disease burden or biology. This study aimed to correlate CgA level with overall survival and to use it to match patients selected for different treatment approaches in an analysis of the impact of surgical management.

METHODS

1478 patients diagnosed with PNET in the National Cancer Database (2004-2014) were retrospectively identified, and logistic regression analyses were used to evaluate associations between the presence of metastatic disease and CgA level. After matching patients by CgA level and other factors predictive of surgical management, Kaplan-Meier survival analysis was performed.

RESULTS

Median CgA level was significantly higher in metastatic versus localized PNET(169 ng/mL versus 66 ng/mL, p < 0.001). On multivariate logistic regression, CgA level was predictive of metastatic disease(OR 1.002, p < 0.001) and survival in metastatic and non-metastatic patients. After matching for CgA level, surgery was associated with improved overall survival.

DISCUSSION

CgA level is predictive of the presence of distant metastatic disease and overall survival in PNET. When matched by CgA and other predictors of treatment approach, patients with metastatic PNET undergoing surgery have improved survival.

The North American Neuroendocrine Tumor Society Consensus Paper on the Surgical Management of Pancreatic Neuroendocrine Tumors

This manuscript is the result of the North American Neuroendocrine Tumor Society consensus conference on the surgical management of pancreatic neuroendocrine tumors from July 19 to 20, 2018. The group reviewed a series of questions of specific interest to surgeons taking care of patients with pancreatic neuroendocrine tumors, and for each, the available literature was reviewed. What follows are these reviews for each question followed by recommendations of the panel.

Prognostic and predictive factors on overall survival and surgical outcomes in pancreatic neuroendocrine tumors: recent advances and controversies

Introduction: Recent advances in diagnostic modalities and therapeutic agents have raised the importance of prognostic factors in predicting overall survival, as well as predictive factors for surgical outcomes, in tailoring therapeutic strategies of patients with pancreatic neuroendocrine neoplasms (panNENs).Areas covered: Numerous recent studies of panNEN patients report the prognostic values of a number of clinically related factors (clinical, laboratory, imaging, treatment-related factors), pathological factors (histological, classification, grading) and molecular factors on long-term survival. In addition, an increasing number of studies showed the usefulness of various factors, specifically biomarkers and molecular makers, in predicting recurrence and mortality related to surgical treatment. Recent findings (from the last 3 years) in each of these areas, as well as recent controversies, are reviewed.Expert commentary: The clinical importance of prognostic and predictive factors for panNENs is markedly increased for both overall outcome and post resection, as a result of recent advances in all aspects of the diagnosis, management and treatment of panNENs. Despite the proven prognostic utility of routinely used tumor grading/classification and staging systems, further studies are required to establish these novel prognostic factors to support their routine clinical use.

Surgery with Radical Intent: Is There an Indication for G3 Neuroendocrine Neoplasms?

BACKGROUND

While platinum-based chemotherapy represents the standard treatment for advanced grade 3 (G3) neuroendocrine neoplasms (NENs) according to the European Neuroendocrine Tumor Society guidelines, the role of radical-intended surgery in these patients, as well as the use of adjuvant chemotherapy, are still controversial. The aim of the present work is to describe, in a retrospective series of gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) G3, the overall survival (OS) rate and risk factors for death after radical surgery. Secondary aims are the description of median recurrence-free survival (RFS) and of the role of adjuvant chemotherapy.

PATIENTS AND METHODS

Multicenter analysis of a series of stage I-III GEP-NEN G3 patients receiving radical surgery (R0/R1) with/without adjuvant chemotherapy was performed.

RESULTS

Sixty patients from eight neuroendocrine tumor (NET) referral centers, with median follow-up of 23 months (5-187 months) were evaluated. While 28.6% of cases had NET G3, 71.4% had neuroendocrine carcinoma G3 (NEC G3). The 2-year OS rate after radical surgery was 64.5%, with a statistically significant difference in terms of Ki67 threshold (cut-off 55%, P = 0.03) and tumor differentiation (NEC G3 vs. NET G3, P = 0.03). Median RFS after radical surgery was 14 months, and 2-year RFS rate was 44.9%. Use of adjuvant chemotherapy provided no benefit in terms of either OS or RFS in this series.

CONCLUSIONS

Surgery with radical intent might represent a valid option for GEP-NEN G3 patients with locoregional disease, especially with Ki67 value ≤ 55%.

Differentiation of atypical non-functional pancreatic neuroendocrine tumor and pancreatic ductal adenocarcinoma using CT based radiomics

PURPOSE

To develop and validate an effective model to differentiate NF-pNET from PDAC.

MATERIALS AND METHODS

Between July 2014 and December 2017, 147 patients (80 patients with PDAC and 67 patients with atypical NF-pNET) with pathology results and enhanced CT were consecutively enrolled and chronologically divided into primary and validation cohorts. Three models were built to differentiate atypical NF-pNET from PDAC, including a model based on radiomic signature alone, one based on clinicoradiological features alone and one that integrated the two. The diagnostic performance of the three models was estimated and compared with the area under the receiver operating characteristic curve (AUC) in the validation cohort. A nomogram was used to represent the model with the best performance, and the associated calibration was also assessed.

RESULTS

In the validation cohort, the AUC for differential diagnosis was 0.884 with the integrated model, which was significantly improved over that of the model based on clinicoradiological features (AUC = 0.775, p value = 0.004) and was comparable to that of the model based on the radiomic signature (AUC = 0.873, p value = 0.512). The nomogram representing the integrated model achieved good discrimination performances in both the primary and validation cohorts, with C-indices of 0.960 and 0.884, respectively.

CONCLUSION

The integrated model outperformed the model based on clinicoradiological features alone and was comparable to the model based on the radiomic signature alone with respect to the differential diagnosis of atypical NF-pNET and PDAC. The nomogram achieved an optimal preoperative, noninvasive differential diagnosis between atypical pNET and PDAC, which can better inform therapeutic choice in clinical practice.

Treatment of Liver Metastases from Midgut Neuroendocrine Tumours: A Systematic Review and Meta-Analysis

Strong evidence comparing different treatment options for liver metastases (LM) arising from gastroenteropancreatic neuroendocrine tumours (GEP-NET) is lacking. The aim of this study was to determine which intervention for LMs from GEP-NETs shows the longest overall survival (OS). A systematic search was performed in MEDLINE, Embase and the Cochrane Library in February 2018. Studies reporting on patients with LMs of any grade of sporadic GEP-NET comparing two intervention groups were included for analysis. Meta-analyses were performed where possible. Eleven studies, with a total of 1108, patients were included; 662 patients had LM from pancreatic NETs (pNET), 164 patients from small-bowel NETs (SB-NET) and 282 patients of unknown origin. Improved 5-year OS was observed for surgery vs. chemotherapy (OR .05 95% CI [0.01, 0.21] p < 0.0001), for surgery vs. embolization (OR 0.18 95% CI [0.05, 0.61] p = 0.006) and for LM resection vs. no LM resection (OR 0.15 95% CI [0.05, 0.42] p = 0.0003). This is the largest meta-analysis performed comparing different interventions for LMs from GEP-NETs. Despite the high risk of bias and heterogeneity of data, surgical resection for all tumour grades results in the longest overall survival. Chemotherapy and embolization should be considered as an alternative in case surgery is not feasible.

Surgery for Pancreatic Neuroendocrine Tumor G3 and Carcinoma G3 Should be Considered Separately

BACKGROUND

The role of surgery in pancreatic neuroendocrine neoplasm grade 3 (pNEN-G3) treatment remains unclear. We aimed to clarify the role of surgery for pNEN-G3, which has recently been reclassified as pancreatic neuroendocrine tumor-G3 (pNET-G3) and pancreatic neuroendocrine carcinoma-G3 (pNEC-G3), with and without metastases, respectively.

METHODS

We analyzed a subgroup of patients from the Japanese pancreatic NEC study, a Japanese multicenter case-series study of pNEN-G3. Pathologists subclassified 67 patients as having pNET-G3 or pNEC-G3 based on morphological features. We compared the overall survival (OS) rates among patients who were grouped according to whether they had undergone tumor-targeted surgery for tumors without (SwoM) or with (SwM) metastases, or non-surgical procedures (NS).

RESULTS

Data from 21 patients with pNET-G3 (SwoM, n = 6; SwM, n = 5; NS, n = 10) and 46 patients with pNEC-G3 (SwoM, n = 8; SwM, n = 5; NS, n = 33) were analyzed. OS of patients with pNET-G3 was significantly longer after SwoM and SwM than with NS (p = 0.018 and p = 0.022). In contrast, OS did not significantly differ between either SwoM or SwM and NS (p = 0.093 and p = 0.489) among patients with pNEC-G3.

CONCLUSION

The role of surgery should be considered separately for pNET-G3 and pNEC-G3. Although SwoM and SwM can be considered for pNET-G3, caution is advised before considering SwM and SwoM for pNEC-G3.

Systematic review of current prognostication systems for pancreatic neuroendocrine neoplasms

BACKGROUND

Pancreatic neuroendocrine neoplasms are a heterogenous group of rare tumors whose natural history remains poorly defined. Accurate prognostication of pancreatic neuroendocrine neoplasms is essential for guiding clinical decisions. This paper aims to summarize all the commonly utilized and recently proposed prognostication systems for pancreatic neuroendocrine neoplasms published in the literature to date.

METHODS

A systematic review of Pubmed, Scopus, and Embase databases, of the period from January 1, 2000-November 29, 2016, was conducted to identify all published articles reporting on prognostication systems of pancreatic neuroendocrine neoplasms.

RESULTS

A total of 23 articles were included in our review, and a total of 25 classification systems were identified. There were 2 modifications of the World Health Organization 2004 criteria, 4 modifications of the World Health Organization 2010 criteria, 2 modifications of the American Joint Committee on Cancer 2010 staging system, 3 modifications of the European Neuroendocrine Tumor Society 2006 tumor, node, metastasis staging system, 7 novel categorial classification systems, and 2 novel proposed continuous classifications. The most commonly included variables included age, size of tumor, presence of distant and lymph node metastases, Ki-67 index, and mitotic count.

CONCLUSION

Numerous prognostication systems have been proposed for pancreatic neuroendocrine neoplasms, of which the most commonly used systems presently include the World Health Organization 2010 criteria and the two tumor, node, metastasis staging systems by the European Neuroendocrine Tumor Society and the American Joint Commission on Cancer. However, prognostication systems for pancreatic neuroendocrine neoplasms continue to evolve with time as more prognostication factors are identified. More validation and comparative studies are needed to identify the most effective prognostication system.

Resection of Liver Metastases: A Treatment Provides a Long-Term Survival Benefit for Patients with Advanced Pancreatic Neuroendocrine Tumors: A Systematic Review and Meta-Analysis

Purpose

Nonsurgical therapies, including biotherapy, chemotherapy, and liver-directed therapy, provided a limit survival benefit for PNET patients with hepatic metastases. With the development of liver resection technique, there was a controversy on whether to perform a liver resection for these patients.

Methods

A computerized search was made of the Medline/PubMed, EMbase, Cochrane Library, and SinoMed (CBM) before March 2018. A meta-analysis was performed to investigate the differences in the efficacy of liver resection and nonliver resection treatments based on the evaluation of morbidity, 30-day mortality, symptom relief rate, and 1-, 3-, and 5-year survival. Two investigators reviewed all included articles and extracted the data of them. The meta-analysis was performed via Review Manager 5.3 software.

Results

A total of 13 cohort studies with 1524 patients were included in this meta-analysis. Compared with the nonliver resection group, liver resection group had a longer 1-, 3-, and 5-year survival time and a higher symptom relief with an acceptable mortality and morbidity.

Conclusions

Liver resection is a safe treatment and could significantly prolong the long-term prognosis for highly selected patients with resectable liver metastases from PNET. Further randomized, controlled trials are needed.

Exploring the surgical landscape of pancreatic neuroendocrine neoplasia in Austria: Results from the ASSO pNEN study group

INTRODUCTION

Pancreatic neuroendocrine neoplasia (pNEN) show increasing incidence and management is complex due to biological heterogeneity. Most publications report isolated high-volume single-centre data. This Austrian multi-centre study on surgical management of pNENs provides a comprehensive real-life picture of quality indicators, recurrence-patterns, survival factors and systemic treatments.

METHODS

Retrospective, national cohort-study from 7 medium-/high-volume centres in Austria, coordinated under the auspices of the Austrian Society of Surgical Oncology (ASSO).

RESULTS

Two-hundred patients underwent resection for pNEN, 177 had non-functioning tumours and 31 showed stage 4 disease. Participating centres were responsible for 2/3 of pNEN resections in Austria within the last years. The mean rate of completeness of variables was 98.6%. Ninety-days mortality was 3.5%, overall rate of complications was 42.5%. Morbidity did not influence long-term survival. The 5-year overall-survival (OS) was 81.3%, 10-year-OS 52.5% and 5-year recurrence-free-survival (RFS) 69.8%. Recurrence was most common in the liver (68.1%). Four out of five patients with recurrence underwent further treatment, most commonly with medical therapy or chemotherapy. Multivariable analysis revealed grading (HR:2.7) and metastasis (HR:2.5) as significant factors for relapse. Tumours-size ≥2 cm (HR:5.9), age ≥60 years (HR:3.1), metastasis (HR:2.3) and grading (HR:2.0) were associated with OS. Tumours <2 cm showed 93.9% 10-year-OS, but 33% had G2/G3 grading, 12.5% positive lymph-nodes and 4.7% metastasis at diagnosis, each associated with significant worse survival.

CONCLUSION

Resection of pNENs in Austria is performed with internationally comparable safety. Analysed factors allow for risk-stratification in clinical treatment and future prospective trials. A watch-and-wait strategy purely based on tumour-size cannot be recommended.

A Nationwide Population-Based Study on the Survival of Patients with Pancreatic Neuroendocrine Tumors in The Netherlands

Background

Large population-based studies give insight into the prognosis and treatment outcomes of patients with pancreatic neuroendocrine tumors (pNETs). Therefore, we provide an overview of the treatment and related survival of pNET in the Netherlands.

Methods

Patients diagnosed with pNET between 2008 and 2013 from the Netherlands Cancer Registry were included. Patient, tumors and treatment characteristics were reported. Survival analyses with log-rank testing were performed to compare survival.

Results

In total, 611 patients were included. Median follow-up was 25.7 months, and all-cause mortality was 42%. Higher tumor grade and TNM stage were significantly associated with worse survival in both the overall and metastasized population. The effect of distant metastases on survival was more significant in lower tumor stages (T1–3 p < 0.05, T4 p = 0.074). Resection of the primary tumor was performed in 255 (42%) patients. Patients who underwent surgery had the highest 5-year survival (86%) compared to PRRT (33%), chemotherapy (21%), targeted therapy and somatostatin analogs (24%) (all p < 0.001). Patients with T1M0 tumors (n = 115) showed favorable survival after surgical resection (N = 95) compared to no therapy (N = 20, p = 0.008). Resection also improved survival significantly in patients with metastases compared to other treatments (all p > 0.05). Without surgery, PRRT showed the best survival curves in patients with distant metastases. Grade 3 tumors and surgical resection were independently associated with survival (HR 7.23 and 0.12, respectively).

Conclusion

Surgical resection shows favorable outcome for all pNET tumors, including indolent tumors and tumors with distant metastases. Prospective trials should be initiated to confirm these results.

The prognostic impact of primary tumor resection in pancreatic neuroendocrine tumors with synchronous multifocal liver metastases

BACKGROUND

Whether primary tumor resection benefits patients with synchronous multifocal liver metastases from pancreatic neuroendocrine tumors remains controversial. We investigated whether primary tumor resection significantly affects survival in this study.

METHODS

A retrospective study of patients with synchronous multifocal liver metastases from pancreatic neuroendocrine tumors between 1998 and 2016 was performed. Patient demographics, operation details, adjuvant treatment, and pathological and survival information were collected, and relevant clinical-pathological parameters were assessed in univariate and multivariate survival analyses.

RESULTS

Sixty-three patients were included in this study, including 35 who underwent primary tumor resection. The median survival time and 5-year survival rate of this cohort were 50 months and 44.5%, respectively. Median survival time in the resected group was significantly longer at 72 months than that of 32 months in the nonresected group (p = 0.010). Multivariate analysis showed that primary tumor surgery was a significant independent prognostic factor (HR 0.312, 95% CI: 0.128-0.762, p = 0.011).

CONCLUSIONS

Primary tumor resection significantly benefits patients with synchronous multifocal liver metastases from pancreatic neuroendocrine tumors.

The Role of Cytotoxic Chemotherapy in Advanced Pancreatic Neuroendocrine Tumors

BACKGROUND

Pancreatic neuroendocrine tumors (PNETs) are rare neoplasms accounting for less than 5% of all pancreatic malignancies. These tumors are characterized by clinical and prognostical heterogeneity and are predominantly diagnosed in a metastatic stage. Cytotoxic chemotherapy, along with alkylating agents and antimetabolites as well as molecular targeted agents (everolimus, sunitinib), is used in the treatment of advanced PNETs. After the approval of lanreotide for unresectable PNETs, an additional therapeutic option has become available; however, the best sequence of therapies and patient stratification to different treatments remains challenging. Furthermore, no randomized phase-3 trials or head-to-head comparisons are available to support treatment decisions.

SUMMARY

The publication of 3 large single-center retrospective studies on streptozocin-(STZ)-based chemotherapy in advanced PNETs in 2015 confirmed the effectiveness of this treatment as described in previously reported trials. All studies investigated markers for progression-free and overall survival and strongly supported the value of the Ki-67 index as a robust prognostic marker. Interestingly, chemotherapy consistently displayed antitumor efficacy in different therapeutic lines. Moreover, a recent study of dacarbazine (DTIC) in a cohort of patients predominantly with PNETs demonstrated that a once monthly infusional DTIC schedule was well tolerated and yielded similar response rates (RR) as STZ-based schedules. Given the overall good tolerability of a monthly infusion and RR similar to STZ schedules, DTIC thus represents a feasible alternative or additional treatment option for PNETs. In this article, we review the current standard and summarize the most recent advances in the field of cytotoxic chemotherapy for PNET patients. Key Messages: (1) Despite the lack of phase3 trials, cytotoxic chemotherapy offers efficacy for patients with advanced PNETs; (2) the best therapeutic option and sequence remain open since comparable randomized studies are lacking; (3) careful patient selection and treatment stratification may increase overall outcome; and (4) currently, no biomarkers for clinical routine exist to predict response to chemotherapy.

Proactive multi-modality treatment of Pancreatic Neuroendocrine Tumours (PNETs): Potential survival benefits

BACKGROUND/OBJECTIVES

Primary and metastatic pancreatic neuroendocrine tumours (PNET) can be treated with combination of surgery, locoregional and systemic therapy. Survival benefits from individual treatments have been well reported, however, the combined outcome from multimodal treatments are not well described in the literature. We report outcomes in a cohort of PNET patients treated with proactive, multimodality therapy.

METHODS

106 patients were identified from a single tertiary referral centre prospective database. Outcomes of treatment were studied, with the primary end point being death from any cause.

RESULTS

Median follow-up was 71 months and overall 5-year survival of 62%. In patients with stage I-III disease (51 patients) estimated 5-year survival was 90%. Median survival in patients with stage IV disease was 51 months with an estimated 5-year survival of 40% in this group. A total of 80 patients (75%) had surgery of which 16% suffered complications requiring intervention. There was no perioperative mortality.

CONCLUSIONS

This study demonstrates that proactive multimodal treatment is safe and may confer a survival benefit to patients in this cohort compared to historical data.