Treatment of metastatic pancreatic neuroendocrine tumors: relevance of ENETS 2016 guidelines

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.

Assessment of the Role of Leptin and Adiponectinas Biomarkers in Pancreatic Neuroendocrine Neoplasms

Data on the possible connection between circulating adipokines and PanNENs are limited. This novel study aimed to assess the serum levels of leptin and adiponectin and their ratio in patients with PanNENs and to evaluate the possible relationship between them and PanNEN's grade or stage, including the presence of metastases. The study group consisted of PanNENs (n = 83), and healthy controls (n = 39). Leptin and adiponectin measurement by an ELISA assay was undertaken in the entire cohort. The serum concentration of adiponectin was significantly higher in the control group compared to the study group (p < 0.001). The concentration of leptin and adiponectin was significantly higher in females than in males (p < 0.01). Anincreased leptin-adiponectin ratio was observed in well-differentiated PanNENs (G1) vs. moderatelydifferentiated PanNENs (G2) (p < 0.05). An increased leptin-adiponectin ratio was found in PanNENs with Ki-67 < 3% vs. Ki-67 ≥ 3% (p < 0.05). PanNENs with distal disease presented lower leptin levels (p < 0.001) and a decreased leptin-adiponectin ratio (p < 0.01) compared with the localized disease group. Leptin, adiponectin, and the leptin-adiponectin ratio may serve as potential diagnostic, prognostic, and predictive biomarkers for PanNENs. Leptin levels and the leptin-adiponectin ratio may play an important role as predictors of malignancy and metastasis in PanNENs.

Discrimination of Liver Metastases of Digestive System Neuroendocrine Tumors From Neuroendocrine Carcinoma by Computed Tomography-Based Radiomics Analysis

OBJECTIVE

The aim of the study is to investigate the value of computed tomography (CT) radiomics features to discriminate the liver metastases (LMs) of digestive system neuroendocrine tumors (NETs) from neuroendocrine carcinoma (NECs).

METHODS

Ninety-nine patients with LMs of digestive system neuroendocrine neoplasms from 2 institutions were included. Radiomics features were extracted from the portal venous phase CT images by the Pyradiomics and then selected by using the t test, Pearson correlation analysis, and least absolute shrinkage and selection operator method. The radiomics score (Rad score) for each patient was constructed by linear combination of the selected radiomics features. The radiological model was constructed by radiological features using the multivariable logistic regression. Then, the combined model was constructed by combining Rad score and the radiological model into logistic regression. The performance of all models was evaluated by the receiver operating characteristic curves with the area under curve (AUC).

RESULTS

In the radiological model, only the enhancement degree (odds ratio, 8.299; 95% confidence interval, 2.070-32.703; P = 0.003) was an independent predictor for discriminating the LMs of digestive system NETs from those of NECs. The combined model constructed by the Rad score in combination with the enhancement degree showed good discrimination performance, with AUCs of 0.893, 0.841, and 0.740 in the training, testing, and external validation groups, respectively. In addition, it performed better than radiological model in the training and testing groups (AUC, 0.893 vs 0.726; AUC, 0.841 vs 0.621).

CONCLUSIONS

The CT radiomics might be useful for discrimination LMs of digestive system NECs from NETs.

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.

Pancreatic serous cystoadenoma (CSA) showing increased tracer uptake at 68-GaDOTA-peptide Positron Emission Tomography (68Ga-DOTA-peptide PET-CT): a case report

BACKGROUND

Serous cysto-adenoma (SCA) is a rare benign neoplasm of the pancreas. SCA can mimic other pancreatic lesions, such as neuroendocrine tumours. 68Gallium-DOTA-peptide Positron Emission Tomography (PET) is able to image in vivo the over-expression of the somatostatin receptors, playing an important role for the identification of neuroendocrine neoplasms.

CASE PRESENTATION

We reported a case of 63-year-old man, with a solid lesion of 7 cm of diameter of the body-tail of the pancreas. Two fine-needle-aspirations (FNA) were inconclusive. A 68Ga-DOTA-peptide PET-CT revealed a pathological uptake of the pancreatic lesion. The diagnosis of a pancreatic neuroendocrine neoplasm was established and a laparoscopic distal splenopancreatectomy and cholecystectomy was performed. Final histopathological report revealed the presence of a micro-cystic SCA.

CONCLUSIONS

The current case firstly reports a pancreatic SCA showing increased radiopharmaceutical uptake at 68Ga-DOTA-peptide PET-CT images. This unexpected finding should be taken into account during the diagnostic algorithm of a pancreatic lesion, in order to minimize the risk of misdiagnosis and overtreatment of SCA.

Impact of liver tumour burden, alkaline phosphatase elevation, and target lesion size on treatment outcomes with 177Lu-Dotatate: an analysis of the NETTER-1 study

PURPOSE

To assess the impact of baseline liver tumour burden, alkaline phosphatase (ALP) elevation, and target lesion size on treatment outcomes with ¹⁷⁷Lu-Dotatate.

METHODS

In the phase 3 NETTER-1 trial, patients with advanced, progressive midgut neuroendocrine tumours (NET) were randomised to 177Lu-Dotatate (every 8 weeks, four cycles) plus octreotide long-acting release (LAR) or to octreotide LAR 60 mg. Primary endpoint was progression-free survival (PFS). Analyses of PFS by baseline factors, including liver tumour burden, ALP elevation, and target lesion size, were performed using Kaplan-Meier estimates; hazard ratios (HRs) with corresponding 95% CIs were estimated using Cox regression.

RESULTS

Significantly prolonged median PFS occurred with ¹⁷⁷Lu-Dotatate versus octreotide LAR 60 mg in patients with low (< 25%), moderate (25-50%), and high (> 50%) liver tumour burden (HR 0.187, 0.216, 0.145), and normal or elevated ALP (HR 0.153, 0.177), and in the presence or absence of a large target lesion (diameter > 30 mm; HR, 0.213, 0.063). Within the ¹⁷⁷Lu-Dotatate arm, no significant difference in PFS was observed amongst patients with low/moderate/high liver tumour burden (P = 0.7225) or with normal/elevated baseline ALP (P = 0.3532), but absence of a large target lesion was associated with improved PFS (P = 0.0222). Grade 3 and 4 liver function abnormalities were rare and did not appear to be associated with high baseline liver tumour burden.

CONCLUSIONS

¹⁷⁷Lu-Dotatate demonstrated significant prolongation in PFS versus high-dose octreotide LAR in patients with advanced, progressive midgut NET, regardless of baseline liver tumour burden, elevated ALP, or the presence of a large target lesion. Clinicaltrials.gov : NCT01578239, EudraCT: 2011-005049-11.

The prognostic analysis of different metastatic patterns in pancreatic neuroendocrine tumors patients: A population based analysis

OBJECTIVE

To evaluate the prognostic value of pancreatic neuroendocrine tumors (pNETs) with different metastatic patterns.

METHODS

Data of pNETs cases were extracted from the Surveillance, Epidemiology, and End Result (SEER) database. They were classified according to the different metastatic patterns. We utilized chi-square test to compare the clinical and metastasis characteristics among different groups. We used Kaplan-Meier analysis and log-rank testing for survival comparisons. Adjusted HRs with 95% CIs was calculated using Cox regression model to estimate prognostic factors. P < .05 was considered statistically significant.

RESULTS

Among the 3909 patients, liver is the most metastatic organ, and isolated brain metastasis is the least common. At the same time, many patients have had multiple metastases. We studied the overall survival (OS) and cancer-specific survival (CCS) of the groups. OS: Non-organ metastasis: 5-year OS = 77.1%; Bone metastasis: median survival time (MST) = 56 m, 5-year OS = 42.7%; Liver metastasis: MST = 24 m, 5-year OS = 25.5%; Lung metastasis: MST = 14 m, 5-year OS = 33.7%; multiple metastases: MST = 7m, 5-year OS = 12.0%. CCS: Non-organ metastasis: 5-year OS = 84.2%; Bone metastasis: 5-year OS = 52.5%; Liver metastasis: MST = 27 m, 5-year OS = 28.6%; Lung metastasis: MST = 49 m, 5-year OS = 40.1%; multiple metastases: MST = 8 m, 5-year OS = 14.5%. In addition, the results showed that there were all statistical significances between the surgery and the no surgery group (all, P < .001). Multivariate analysis revealed that brain metastasis, multiple metastases, age over 60 years, unmarried, grade III/IV, regional/distant and no surgery were independently associated with decreased OS and CCS.

CONCLUSIONS

pNETs patients without organ metastasis had the best survival outcomes, while multiple had the worst outcomes. There were no significant differences in bone metastasis, liver metastasis and lung metastasis. Surgery was still an option for patients with metastasis.

Characterization, Prognosis, and Treatment of Patients With Metastatic Lung Carcinoid Tumors

INTRODUCTION

Metastatic lung carcinoids (MLCs) remain poorly characterized and no prognostic stratification exists.

METHODS

We conducted a retrospective study including patients with MLCs in two European expert centers. The aims were to characterize these cases and to identify prognostic factors of survival and effectiveness of their treatments.

RESULTS

A total of 162 patients with MLC were included: 50% were women, and the median age was 61 years. Half of the patients had synchronous metastases, mainly located in the liver (75%), bone (42%), and lung (25%). According to WHO classification, MLCs were typical (28%), atypical (60%), or unspecified (12%). A functioning syndrome was observed in 43% of cases and an uptake at somatostatin receptor scintigraphy in 76% of cases. The 5-year overall survival rate was 60% and at 10 years this was 25%. In multivariate analysis, Eastern Cooperative Oncology Group performance status of 0-1 (hazard ratio [HR]: 5.81, 95% confidence interval [CI]: 2.10-16.11), uptake on SRS (HR: 0.38, 95% CI: 0.22-0.66), low serum chromogranin A (HR: 2.27, 95% CI: 1.36-3.81), and typical carcinoid (HR: 1.87, 95% CI: 1.26-2.78) were associated with better survival. According to Response Evaluation Criteria in Solid Tumors version 1.0, the highest objective response rates were obtained after radiofrequency ablation of metastases (86%), liver embolization (56%), peptide receptor radionuclide therapy (27%), and oxaliplatin-based chemotherapy (18%).

CONCLUSIONS

MLCs are characterized by a high frequency of atypical carcinoids, functioning syndrome, and liver/bone metastases. WHO classification, performance status, somatostatin receptor scintigraphy, and chromogranin A were associated with longer survival. Partial response was more frequent with locoregional therapies, peptide receptor radionuclide therapy, or oxaliplatin-based chemotherapy.

Solid pseudopapillary and malignant pancreatic tumors in childhood: A systematic review and evidence quality assessment

A systematic review of 32 studies reporting on 489 children with pancreatic tumors was performed. The most prevalent histologic subtype was solid pseudopapillary tumor (SPT) (61.3%). Pancreaticoduodenectomy was the most commonly performed operation (48%). Neoadjuvant chemo/radiotherapy was utilized in 3.9, 36.2, 25, and 27.8% of patients with SPTs, pancreatoblastomas (PBLs), neuroendocrine tumors, and exocrine carcinomas, respectively. Adjuvant chemotherapy (75.6%) and radiation (34%) were most commonly utilized in PBLs. All-cause mortality was highest in exocrine carcinomas (50%). Overall, 98.8% of patients with SPTs survived. PBL exhibited the highest recurrence rate (14.7%) within a mean of 23.5 months.

A population-based analysis of a rare oncologic entity: Malignant pancreatic tumors in children

PURPOSE

To examine the clinicopathological characteristics and prognosis of pediatric patients with malignant pancreatic tumors in a population-based cohort.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was utilized to identify all pediatric patients with malignant pancreatic tumors, diagnosed between 1973 and 2013. Kaplan-Meier analysis was performed to determine median and five-year overall survival (OS) rates. Univariate survival analysis was executed using the log-rank test. Cox proportional hazards model was used to identify variables independently associated with mortality.

RESULTS

A total of 114 patients with pancreatic malignancies were identified. Median patient age was 16years and the majority of patients were white (64%) females (61.4%). The most prevalent histologic subtype was neuroendocrine tumors (35.1%), whereas pancreatoblastoma was more common during the first decade of life (P<0.001). Distant metastases were noted in 41.7% of the patients, while 33.3% and 25% had localized and regional disease respectively. Five-year OS rates were 77%, 66.4% and 64.8% for patients with pancreatoblastoma, neuroendocrine and epithelial tumors respectively. No death was observed in the solid pseudopapillary tumor group. Only history of having cancer-directed surgery (CDS) was significantly associated with lower overall mortality (HR: 5.1, 95% CI: 2.1, 12.4).

CONCLUSION

Pancreatic malignancies are rare in children. Their prognosis is variable and only CDS was independently associated with superior survival.

EVIDENCE RATING/CLASSIFICATION

Prognosis study, Level II.

Chemotherapy in NETs: When and how

The majority of neuroendocrine tumours (NETs) are well-differentiated tumours that follow an indolent course, in contrast to a minority of poorly differentiated neuroendocrine carcinomas (NECs) which exhibit an aggressive course and assocaited with an overall short survival. Although surgery is the only curative treatment for NETs it is not always feasible,necessitating the application of other therapies including chemotherapy. Streptozotocin (STZ)-based regimens have long been used for advanced or metastatic well-to-moderately differentiated (G1-G2) NETs, especially those originating from the pancreas (pNETs). In poorly differentiated grade 3 (G3) tumours, platinum-based chemotherapy is recommended as first-line therapy, albeit without durable responses. Although data for temozolomide (TMZ)-based chemotherapy are still evolving, this treatment may replace STZ-based regimens in pNETs due to its better tolerability and side effect profile. In addition, there is evidence that TMZ could also be used in the subgroup of well-differentiated G3 NETs. There is less clear-cut evidence of a benefit for chemotherapy in intestinal NETs, but still evolving data suggest that TMZ may be efficacious in particular patients. In lung and thymic carcinoids, chemotherapy is reserved for patients with progressive metastatic disease in whom other treatment options are unavailable. Overall, chemotherapy is indicated in patients who have progressed on first-line treatment with somatostatin analogues, have extensive tumour load or exhibit rapid growth following a period of follow-up, and/or have a high proliferative rate; it may occasionally can be used in a neo-adjuvant setting. Prospective randomised studies are awaited to substantiate the role of chemotherapy in the therapeutic algorithm of NETs along with other evolving treatments.