Nonfunctioning islet cell carcinoma of the pancreas: survival results in a contemporary series of 163 patients

Novel Surgical Initiatives in Gastroenteropancreatic Neuroendocrine Tumours

PURPOSE OF REVIEW

Neuroendocrine tumours (NET) are rare entities arising from hormone producing cells in the gastroentero-pancreatic (GEP) tract. Surgery is the most common treatment of GEP-NETs.

RECENT FINDINGS

Improvements in surgical techniques allow for more locally advanced and metastasised GEP-NETs to be resected. Laparoscopic and robotically--assisted approaches are increasingly being utilised in the resection of selected GEP-NETs and are facilitated by novel intraoperative tumour localisation tools and parenchyma-sparing methods. At the same time, some authors suggest that indications for formal resections of small well differentiated non-functioning pancreatic NETs and appendiceal NETs should be more restrictive. Advancements in surgery allows for tissue-sparing resections of GEP-NETs. Indications for surgical resection and the extent of the procedure are highly dependent on GEP-NET size, localisation and grading. Robotically assisted surgeries with intraoperative ultrasound and visualisation methods as well as vessel-sparing radical retrograde lymphadenectomies for small intestinal NETs seem to be the future of GEP-NET surgery.

Pathological complete response of initially unresectable multiple liver metastases achieved using combined peptide receptor radionuclide therapy and somatostatin analogs following pancreatic neuroendocrine tumor resection: a case report

BACKGROUND

Peptide receptor radionuclide therapy (PRRT) serves as a novel and effective treatment option for somatostatin receptor-positive unresectable liver metastases of pancreatic neuroendocrine tumors (PNETs). However, there are few reported cases of surgical resection for initially unresectable liver metastases of PNET that were converted to resectable after PRRT. Here we report a case where PRRT and somatostatin analogs (SSAs) led to a pathological complete response of initially unresectable multiple liver metastases following PNET resection.

CASE PRESENTATION

A 52-year-old man underwent pylorus-preserving pancreaticoduodenectomy for PNET at age 40 and subsequent hepatectomies for resectable liver metastases at 44 and 47 years of age. At age 48, a follow-up examination revealed unresectable multiple liver metastases, and PRRT with 177Lu-DOTATATE therapy was initiated. After four cycles of PRRT, most liver metastases diminished according to imaging studies, and the remaining two hepatic lesions continued to shrink with additional lanreotide. Conversion surgery for liver metastases was successfully performed, revealing no viable tumor cells in tissue specimens. Seventeen months after surgery, imaging showed no detectable residual tumor or recurrence. We present a review of the relevant literature that highlights the significance of our findings.

CONCLUSIONS

This rare case highlights the pathological complete response of initially unresectable multiple liver metastases achieved by PRRT and SSAs following PNET resection, suggesting their potential as a multimodality treatment option for unresectable PNET.

Chronological improvement of pancreatectomy for resectable but advanced pancreatic neuroendocrine neoplasms

BACKGROUND

Progress of non-surgical treatments in the last decade has improved the prognosis of pancreatic neuroendocrine neoplasms (PanNEN). However, the improvement of surgery for advanced PanNEN remains unknown. This study aimed to investigate the chronological changes of the clinical impact of pancreatectomy for PanNEN.

METHODS

Patients undergoing curative-intent pancreatectomy for PanNEN between 1991 and 2010 were categorized into the earlier period group, and those between 2011 and 2021 were into the later period group. Advanced PanNEN was defined as showing resectable synchronous liver metastases or invasion to portal venous systems or adjacent organs. The recurrence-free survival (RFS) and overall survival (OS) were analyzed among patients with non-advanced and advanced PanNENs. The independent prognostic risk factors were identified using a Cox proportional hazard model.

RESULTS

A total of 189 patients (n = 54 in the earlier period and n = 135 in the later period) were included. The proportion of advanced PanNEN increased from 15% to 30% (P = 0.027). The RFS and OS of non-advanced PanNEN were similar between the periods. Whereas, among patients with advanced PanNEN, the later period group showed improved prognosis; The 5-year RFS of the earlier period vs. the later period was 0% vs. 27%, and the 5-year OS was 38% vs. 82% (p = 0.013).

CONCLUSIONS

A radical surgical treatment for advanced PanNEN has shown prognostic improvement in this decade. However, more careful perioperative examinations and possibly, additional treatments are required for PanNEN with portal vein invasion.

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.

[Surgery of pancreatic neuroendocrine neoplasms: state of the art]

Pancreatic neuroendocrine neoplasms (pNEN) have a rising incidence and are increasingly diagnosed at early and thus potentially resectable stages. Due to the rarity of these neoplasms the recommendations of currently available guidelines are mainly based on retrospective data. Surgical and oncological treatment of these rare diseases should only be performed at specialized centers. In cases of resectability without indications of diffuse metastases, complete resection with curative intent should be the treatment of choice. For small nonfunctional pNENs < 2 cm watch and wait strategies are recommended as an alternative to surgical treatment. Recent data, however, also showed an increased survival even of small (1-2 cm) pNENs after resection. For benign insulinomas and small nonfunctional well-differentiated pNENs parenchyma-sparing procedures, such as enucleation and segmental resection are available. The question of the influence of lymph node metastases on long-term disease-free survival and overall survival and consequently the role of systematic lymphadenectomy is still a matter of debate. In pNENs > 2 cm formal resection with lymphadenectomy is considered the gold standard. Minimally invasive and robotic-assisted procedures are of increasing importance also for formal pancreatic resection.

Benefit of Primary Tumor Resection in Stage IV, Grade 1 and 2, Pancreatic Neuroendocrine Tumors: A Propensity-Score Matched Cohort Study

Objective

To determine the association of primary tumor resection in stage IV pancreatic neuroendocrine tumors (Pan-NET) and survival in a propensity-score matched study.

Background

Pan-NET are often diagnosed with stage IV disease. The oncologic benefit from primary tumor resection in this scenario is debated and previous studies show contradictory results.

Methods

Patients from 3 tertiary referral centers from January 1, 1985, through December 31, 2019: Uppsala University Hospital (Uppsala, Sweden), Sahlgrenska University Hospital (Gothenburg, Sweden), and Brigham and Women's Hospital/Dana-Farber Cancer Institute (Boston, USA) were assessed for eligibility. Patients with sporadic, grade 1 and 2, stage IV pan-NET, with baseline 2000-2019 were divided between those undergoing primary tumor resection combined with oncologic treatment (surgery group [SG]), and those who received oncologic treatment without primary tumor resection (non-SG). A propensity-score matching was performed to account for the variability in the extent of metastatic disease and comorbidity. Primary outcome was overall survival.

Results

Patients with stage IV Pan-NET (n = 733) were assessed for eligibility, 194 were included. Patients were divided into a SG (n = 65) and a non-SG (n = 129). Two isonumerical groups with 50 patients in each group remained after propensity-score matching. The 5-year survival was 65.4% (95% CI, 51.5-79.3) in the matched SG and 47.8% (95% CI, 30.6-65.0) in the matched non-SG (log-rank, P = 0.043).

Conclusions

Resection of the primary tumor in patients with stage IV Pan-NET and G1/G2 grade was associated with prolonged overall survival compared to nonoperative management. A surgically aggressive regime should be considered where resection is not contraindicated.

Multimodal Management of Grade 1 and 2 Pancreatic Neuroendocrine Tumors

Pancreatic neuroendocrine tumors (p-NETs) are rare tumors with a recent growing incidence. In the 2017 WHO classification, p-NETs are classified into well-differentiated (i.e., p-NETs grade 1 to 3) and poorly differentiated neuroendocrine carcinomas (i.e., p-NECs). P-NETs G1 and G2 are often non-functioning tumors, of which the prognosis depends on the metastatic status. In the localized setting, p-NETs should be surgically managed, as no benefit for adjuvant chemotherapy has been demonstrated. Parenchymal sparing resection, including both duodenum and pancreas, are safe procedures in selected patients with reduced endocrine and exocrine long-term dysfunction. When the p-NET is benign or borderline malignant, this surgical option is associated with low rates of severe postoperative morbidity and in-hospital mortality. This narrative review offers comments, tips, and tricks from reviewing the available literature on these different options in order to clarify their indications. We also sum up the overall current data on p-NETs G1 and G2 management.

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.

Portal vein resection during pancreaticoduodenectomy for pancreatic neuroendocrine tumors. An international multicenter comparative study

BACKGROUND

The role of portal vein resection for pancreatic cancer is well established but not for pancreatic neuroendocrine neoplasms. Evidence from studies providing information on long-term outcome after venous resection in pancreatic neuroendocrine neoplasms patients is lacking.

METHODS

This is a multicenter retrospective cohort study comparing pancreaticoduodenectomy with vein resection with standard pancreaticoduodenectomy in patients with pancreatic neuroendocrine neoplasms. The primary endpoint was to evaluate the long-term survival in both groups. Progression-free survival and overall survival were calculated using the method of Kaplan and Meier, but a propensity score-matched cohort analysis was subsequently performed to remove selection bias and improve homogeneity. The secondary outcome was Clavien-Dindo ≥3.

RESULTS

Sixty-one (11%) patients underwent pancreaticoduodenectomy with vein resection and 480 patients pancreaticoduodenectomy. Five (1%) perioperative deaths were recorded in the pancreaticoduodenectomy group, and postoperative clinically relevant morbidity rates were similar in the 2 groups (pancreaticoduodenectomy with vein resection 48% vs pancreaticoduodenectomy 33%). In the initial survival analysis, pancreaticoduodenectomy with vein resection was associated with worse 3-year progression-free survival (48% pancreaticoduodenectomy with vein resection vs 83% pancreaticoduodenectomy; P < .01) and 5-year overall survival (67% pancreaticoduodenectomy with vein resection vs 91% pancreaticoduodenectomy). After propensity score matching, no significant difference was found in both 3-year progression-free survival (49% pancreaticoduodenectomy with vein resection vs 59% pancreaticoduodenectomy; P = .14) and 5-year overall survival (71% pancreaticoduodenectomy with vein resection vs 69% pancreaticoduodenectomy; P = .98).

CONCLUSION

This study demonstrates no significant difference in perioperative risk with a similar overall survival between pancreaticoduodenectomy and pancreaticoduodenectomy with vein resection. Tumor involvement of the superior mesenteric/portal vein axis should not preclude surgical resection in patients with locally advanced pancreatic neuroendocrine neoplasms.

Tumour stem cell markers CD133 and CD44 are useful prognostic factors after surgical resection of pancreatic neuroendocrine tumours

The aim of the present study was to investigate the expression profiles and prognostic values of CD133 and CD44 in a cohort of patients with pancreatic neuroendocrine tumours (PNETs). PNET data from patients who underwent radical resection at the Guangdong Provincial People's Hospital were retrospectively analysed. Immunohistochemistry was performed on PNET samples, and CD133 and CD44 expression was examined. Survival analysis was performed using the Kaplan-Meier method and the log-rank test. A total of 71 cases were included in the study. The mean age of the patients was 45.2 years, and the mean tumour size was 3.3 cm. CD44 expression was positively associated with poor tumour differentiation (P=0.007), high Ki-67 index (P=0.001), added mitotic count (P=0.003), high histological grade (P=0.001) and advanced stage (P=0.025). Similarly, CD133 expression was positively associated with high Ki-67 index (P=0.014) and added mitotic count (P=0.012). However, CD133 expression was not associated with tumour differentiation (P=0.118), histological grade (P=0.126) and stage (P=0.203). Survival analysis revealed that both CD44 and CD133 were prognostic factors for overall survival (OS) and/or disease-free survival (DFS), and that increased co-expression of CD44 and CD133 indicated poor OS and DFS rates in patients with PNET. In patients with no expression or low expression of either CD44 or CD133, a DFS rate of 100% was observed, indicating a low recurrence risk. The present findings suggested that high CD44 and CD133 expression was associated with a poor prognosis in patients with PNET. CD44 and CD133 may be used as prognostic indicators of OS and/or DFS in patients with PNETs.

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

The role of primary tumor resection in patients with pancreatic neuroendocrine neoplasms (PanNENs) and unresectable distant metastases remains controversial. We aimed to evaluate the effect of palliative primary tumor resection (PPTR) on overall survival (OS) in this setting. We searched the MEDLINE, Embase, Cochrane Library, Web of Science and SCOPUS databases up to January 2020 and used the Newcastle–Ottawa scale (NOS) criteria to assess quality/risk of bias. A total of 5661 articles were screened. In 10 studies, 5551 unique patients with stage IV PanNEN and unresectable metastases were included. The five-year OS for PanNEN patients undergoing PPTR in stage IV was 56.6% vs. 23.9% in the non-surgically treated patients (random effects relative risk (RR): 1.70; 95% CI: 1.53–1.89). Adjusted analysis of pooled hazard ratios (HR) confirmed longer OS in PanNEN patients undergoing PPTR (random effects HR: 2.67; 95% CI: 2.24–3.18). Cumulative OS analysis confirmed an attenuated survival benefit over time. The complication rate of PPTR was as high as 27%. In conclusion, PPTR may exert a survival benefit in stage IV PanNEN. However, the included studies were subject to selection bias, and special consideration should be given to PPTR anchored to a multimodal treatment strategy. Further longitudinal studies are warranted, with long-term follow-up addressing the survival outcomes associated with surgery in stage IV disease.

Predicting Aggressive Behavior in Nonfunctional Pancreatic Neuroendocrine Tumors With Emphasis on Tumor Size Significance and Survival Trends: A Population-Based Analysis of 1787 Patients

BACKGROUND

Nonfunctional pancreatic neuroendocrine tumors (NF-PNETs) are rare tumors with continued controversies in management. This study aims to identify demographic and clinicopathologic characteristics associated with aggressive behavior and survival.

METHODS

The Surveillance, Epidemiology, and End Results database was used to identify patients with NF-PNETs from 1988 to 2012. Multivariate regression analysis and Cox proportional hazards modeling were used to assess the impact of patient, tumor, and treatment characteristics on tumor behavior and overall survival.

RESULTS

In 1787 patients identified, size was a major determinant of aggressive behavior. The probability of aggressiveness increased 100% for tumor size ≥2 cm. For tumors ≥2 cm, every 1-cm increase in size was associated with an increase in probability of aggressive behavior by 11.3%. Patient age, tumor grade, and surgical resection were independent predictors of survival. Surgical resection was associated with improved survival but not grade I or II tumors with size <2 cm.

DISCUSSION

Patient age, tumor size, and grade should be in the decision-making process around the surgical management of NF-PNETs. For tumors ≤2 cm with histologic grades of I or II, the probability of aggressive behavior is low, and surgical resection does not appear to afford survival benefit. Therefore, close observation could be justified.

Management of Ileal Neuroendocrine Tumors with Liver Metastases

PURPOSE

Assessment of treating metastatic ileal neuroendocrine tumors (NETs) with complete resection of primary tumor, nodal and liver metastases, plus administration of long-acting somatostatin analogues (SSAs).

METHODS

A prospective database was queried for patients with ileal or pancreatic NETs with pathology-confirmed liver metastases and tumor somatostatin receptors. Patients did not have MEN-1 and had no previous treatment. The impacts of SSA treatment on the primary outcome of survival and secondary outcome of progression-free survival were assessed with Kaplan-Meier analysis. Log rank test was used to compare overall and progression-free survival among groups.

RESULTS

Seventeen ileal NET patients and 36 pancreatic NET patients who underwent surgical resection between 2001 and 2018, who had pathology-confirmed liver metastases and confirmed tumor somatostatin receptors, did not have MEN-1, and had no previous treatment were identified. Median follow-up for patients with ileal NETs was 80 months (range 0-197 months) and 32 months (range 1-182 months) for pancreatic NETs. Five-year survival was 93% and 72% for ileal and pancreatic NET, respectively. Progression-free 5-year survival was 70% and 36% for ileal and pancreatic NET, respectively. Overall 5-year survival for pNETs was greater in those patients treated with SSA (79%) compared to those who underwent surgery alone (34%, p < 0.01). The average ECOG score was low for surviving patients with ileal (0.15) and pancreatic NET (0.73) indicating a good quality of life.

CONCLUSIONS

Resection of primary lymph node and liver metastatic ileal or pancreatic NETs followed with continued SSAs is associated with an excellent progression-free and overall survival and minimal side effects.

Surgical management of primary pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (PanNETs) are the second most common malignancy of the pancreas, and their incidence is increasing. PanNETs are a diverse group of diseases which range from benign to malignant, can be sporadic or associated with genetic mutations, and be functional or nonfunctional. In as much, the treatment and management of PanNETs can vary from a "Wait and See" approach to orthotopic liver transplantation (OLT). Despite this, surgical resection is still the primary treatment modality to achieve cure. This review focuses on the surgical management of PanNETs.

Circulating Neuroendocrine Gene Transcripts (NETest): A Postoperative Strategy for Early Identification of the Efficacy of Radical Surgery for Pancreatic Neuroendocrine Tumors

BACKGROUND

Surgery remains the only treatment for the cure of pancreatic neuroendocrine tumors (PanNETs). Biomarkers to identify the completeness of resection and predict recurrence are lacking.

OBJECTIVE

The aims of this study were to evaluate if the blood measurement of neuroendocrine gene transcripts (NETest) was diagnostic of PanNETs, and whether NETest blood levels could identify complete resection. We compared transcript analysis with the biomarker chromogranin A (CgA).

METHODS

This was a prospective, longitudinal, single-center study including 30 patients with a postoperative histological confirmation of PanNET. Blood for NETest and CgA was collected preoperatively and on postoperative day (POD) 1, POD5, and POD30. Transcripts were measured by real-time quantitative reverse transcription polymerase chain reaction and multianalyte algorithmic analysis (NETest; normal < 20), and CgA was measured by enzyme-linked immunosorbent assay (ELISA; normal < 109 ng/mL). Data are expressed as mean ± standard deviation (SD).

RESULTS

Pancreatic surgical resections (n = 30) were R0, 26; R1, 2; and R2, 2. Preoperatively, NETest score was elevated in all 30 patients (44.7 ± 27), but postoperatively, NETest scores significantly decreased (p = 0.006) to POD30 (24.7 ± 24). The proportion of patients (15/30) with an elevated score significantly decreased by POD30 (p < 0.0001). CgA levels were elevated preoperatively (184 ± 360 ng/mL) in only 9/30 patients, but did not decrease significantly postoperatively at POD30 (260 ± 589 ng/mL, p = 0.398). The number of patients with elevated CgA levels remained unchanged (9/30).

CONCLUSIONS

The NETest is an accurate diagnostic biomarker for PanNETs (100%). A decrease in NETest levels after radical resection suggests this blood test provides early assessment of surgical efficacy. CgA had no clinical utility.

The Evolution of Surgical Strategies for Pancreatic Neuroendocrine Tumors (Pan-NENs): Time-trend and Outcome Analysis From 587 Consecutive Resections at a High-volume Institution

OBJECTIVE

The objective of the present analysis is 2-fold: first, to define the evolution of time trends on the surgical approach to pancreatic neuroendocrine neoplasms (Pan-NENs); second, to perform a complete analysis of the predictors of oncologic outcome.

BACKGROUND

Reflecting their rarity and heterogeneity, Pan-NENs represent a clinical dilemma. In particular, there is a scarcity of data regarding their long-term follow-up after surgical resection.

METHODS

From the Institutional Pan-NEN database, 587 resected cases from 1990 to 2015 were extracted. The time span was arbitrarily divided into 3 discrete clusters enabling a balanced comparison between patient groups. Analyses for predictors of recurrence and survival were performed, together with conditional survival analyses.

RESULTS

Among the 587 resected Pan-NENs, 75% were nonfunctioning tumors, and 5% were syndrome-associated tumors. The mean age was 54 years (±14 years), and 51% of the patients were female. The median tumor size was 20 mm (range 4 to 140), 62% were G1, 32% were G2, and 4% were G3 tumors. Time trends analysis revealed that the number of resected Pan-NENs constantly increased, while the size (from 25 to 20 mm) and G1 proportion (from 65% to 49%) decreased during the study period. After a mean follow-up of 75 months, recurrence analysis revealed that nonfunctioning tumors, tumor grade, N1 status, and vascular invasion were all independent predictors of recurrence. Regardless of size, G1 nonfunctioning tumors with no nodal involvement and vascular invasion had a negligible risk of recurrence at 5 years.

CONCLUSIONS

Pan-NENs have been increasingly diagnosed and resected during the last 3 decades, revealing reliable predictors of outcome. Functioning and nodal status, tumor grade, and vascular invasion accurately predict survival and recurrence with resulting implications for patient follow-up.

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.

Consideration of Age Is Necessary for Increasing the Accuracy of the AJCC TNM Staging System of Pancreatic Neuroendocrine Tumors

Purpose: Currently, of the two most common staging systems of pancreatic neuroendocrine tumors (pNETs) one is from the European Neuroendocrine Tumor Society (ENETS) and the other is from the American Joint Committee on Cancer (AJCC). However, there are imperfections in both these staging systems. Patients and methods: Patients were selected retrospectively from the Surveillance Epidemiology and End Results (SEER) database (2004 to 2013). The effect of age on the hazard ratio (HR) was evaluated using restricted cubic splines. The discriminatory power of the staging systems was determined using the concordance index (C-index). Results: A total of 3,034 patients with pNETs were included in the final analyses. The risk of death increased slowly along with age for patients under 60 years of age, but the risk of death rose sharply for those over 60 years of age, forming a mirrored L-shaped survival curve. In the current AJCC tumor-node-metastasis (TNM) staging system, no statistical significance was observed between stages IA and IB (p = 0.105). Patients with stage IIB even had longer OS than patients with IIA, although there was no statistical significance (p = 0.574). The proportion of stage III patients was small (2.7%). In the proposed aTNM staging system, significant survival differences could be observed among stage I, IIA, and IIB (p < 0.001) and the proportion of stage III rose from 2.7 to 25.7%. Conclusion: Our findings suggest that age has a critical influence on the survival of patients with pNETs. Age should be considered as a factor in future staging systems of pNETs.

A New Scoring System to Predict Recurrent Disease in Grade 1 and 2 Nonfunctional Pancreatic Neuroendocrine Tumors

OBJECTIVE

The aim of this study was to predict recurrence in patients with grade 1 or 2 nonfunctioning pancreatic neuroendocrine tumors (NF-pNET) after curative resection.

BACKGROUND

Surgical resection is the preferred treatment for NF-pNET; however, recurrence occurs frequently after curative surgery, worsening prognosis of patients.

METHODS

Retrospectively, patients with NF-pNET of 3 institutions were included. Patients with distant metastases, hereditary syndromes, or grade 3 tumors were excluded. Local or distant tumor recurrence was scored. Independent predictors for survival and recurrence were identified using Cox-regression analysis. The recurrence score was developed to predict recurrence within 5 years after curative resection of grade 1 to 2 NF-pNET.

RESULTS

With a median follow-up of 51 months, 211 patients with grade 1 to 2 NF-pNET were included. Thirty-five patients (17%) developed recurrence. The 5- and 10-year disease-specific/overall survival was 98%/91% and 84%/68%, respectively. Predictors for recurrence were tumor grade 2, lymph node metastasis, and perineural invasion. On the basis of these predictors, the recurrence score was made. Discrimination [c-statistic 0.81, 95% confidence interval (95% CI) 0.75-0.87] and calibration (Hosmer Lemeshow Chi-square 11.25, P = 0.258) indicated that the ability of the recurrence score to identify patients at risk for recurrence is good.

CONCLUSIONS

This new scoring system could predict recurrence after curative resection of grade 1 and 2 NF-pNET. With the use of the recurrence score, less extensive follow-up could be proposed for patients with low recurrence risk. For high-risk patients, clinical trials should be initiated to investigate whether adjuvant therapy might be beneficial. External validation is ongoing due to limited availability of adequate cohorts.

Gamma Emitters in Pancreatic Endocrine Tumors Imaging in the PET Era: Is there a Clinical Space for 99mTc-peptides?

Background:

Pancreatic Neuroendocrine Tumors (PNETs) are rare neoplasms, sporadic or familial, even being part of a syndrome. Their diagnosis is based on symptoms, hormonal disorders or may be fortuitous. The role of Nuclear Medicine is important, mainly because of the possibility of a theranostic strategy. This approach is allowed by the availability of biochemical agents, which may be labeled with radionuclides suitable for diagnostic or therapeutic purposes, showing almost identical pharmacokinetics. The major role for radiopharmaceuticals is connected with radiolabeled Somatostatin Analogues (SSA), since somatostatin receptors are highly expressed on some of the neoplastic cell types.

Discussion:

Nowadays, in the category of radiolabeled SSA, although 111In-pentetreotide, firstly commercially proposed, is still used, the best choice for diagnosis is related to the so called DOTAPET radiotracers labeled with 68-Gallium (Ga), such as 68Ga-DOTATATE, 68Ga-DOTANOC, and 68Ga-DOTATOC. More recently, labeling with 64-Copper (Cu) (64Cu-DOTATATE) has also been proposed. In this review, we discuss the clinical interest of a SAA (Tektrotyd©) radiolabeled with 99mTc, a gamma emitter with better characteristics, with respect to 111Indium, radiolabeling Octreoscan ©. By comparing both pharmacokinetics and pharmacodynamics of Octreoscan©, Tektrotyd© and PET DOTA-peptides, on the basis of literature data and of our own experience, we tried to highlight these topics to stimulate further studies, individuating actual clinical indications for all of these radiotracers.

Conclusion:

In our opinion, Tektrotyd© could already find its applicative dimension in the daily practice of NETs, either pancreatic or not, at least in centers without a PET/CT or a 68Ga generator. Because of wider availability, a lower cost, and a longer decay, compared with respect to peptides labeled with 68Ga, it could be also proposed, in a theranostic context, for a dosimetry evaluation of patients undergoing Peptide Receptor Radionuclide Therapy (PRRT), and for non-oncologic indications of radiolabelled SSA. In this direction, and for a more rigorous cost/effective evaluation, more precisely individuating its clinical role, further studies are needed.

Current Treatment Options in Gastroenteropancreatic Neuroendocrine Carcinoma

Poorly differentiated gastroenteropancreatic neuroendocrine carcinomas (GEPNECs) are a rare neoplasm with a bleak prognosis. Currently there are little prospective data available for optimal treatment. This review discusses the current available regimens and the future direction for the treatment of GEPNECs. Treatment plans for GEPNECs are often adapted from those devised for small cell lung cancer; however, differences in these malignancies exist, and GEPNECs require their own treatment paradigms. As such, current first-line treatment for GEPNECs is platinum-based chemotherapy with etoposide. Studies show that response rate and overall survival remain comparable between cisplatin and carboplatin versus etoposide and irinotecan; however, prognosis remains poor, and more efficacious therapy is needed to treat this malignancy. Additional first-line and second-line treatment options beyond platinum-based chemotherapy have also been investigated and may offer further treatment options, but again with suboptimal outcomes. Recent U.S. Food and Drug Administration approval of peptide receptor radionuclide therapy in low- and intermediate-grade neuroendocrine tumors may open the door for further research in its usefulness in GEPNECs. Additionally, the availability of checkpoint inhibitors lends promise to the treatment of GEPNECs. This review highlights the lack of large, prospective studies that focus on the treatment of GEPNECs. There is a need for randomized control trials to elucidate optimal treatment regimens specific to this malignancy. IMPLICATIONS FOR PRACTICE: There are limited data available for the treatment of poorly differentiated gastroenteropancreatic neuroendocrine carcinomas (GEPNECs) because of the rarity of this malignancy. Much of the treatment regimens used in practice today come from research in small cell lung cancer. Given the poor prognosis of GEPNECs, it is necessary to have treatment paradigms specific to this malignancy. The aim of this literature review is to summarize the available first- and second-line GEPNEC therapy, outline future treatments, and highlight the vast gap in the literature.

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.

Measurement of circulating transcript levels (NETest) to detect disease recurrence and improve follow-up after curative surgical resection of well-differentiated pancreatic neuroendocrine tumors

BACKGROUND

Recurrence of pancreatic neuroendocrine tumors (pNET) after surgery is common. Strategies to detect recurrence have limitations. We investigated the role of clinical criteria and the multigene polymerase chain reaction-based NETest during post-operative follow-up of pNET.

METHODS

We studied 3 groups of resections: R0 with no recurrence (n = 11), R0 with recurrence (n = 12), and R1 with no recurrence (n = 12). NETest levels (>40%) were compared with chromogranin A (CgA) and clinicopathological criteria (CC; grade, lymph node metastases, size). Nonparametric, receiver operating characteristics, logistic regression, and predictive feature importance analyses were performed.

RESULTS

NETest was higher in R0 with recurrence (56 ± 8%) compared with R1 with no recurrence (39 ± 6%) and R0 with no recurrence (28 ± 6%, P < .005). NETest positively correlated with recurrence (area under the curve: 0.82), CgA was not (area under the curve: 0.51 ± 0.09). Multiple regression analysis defined factor impact as highest for NETest (P < .005) versus CC (P < .03) and CgA (P = .23). NETest gave false positive or negative recurrence in 18% using a 40% cutoff. Logistic regression modeling of CC was 83% accurate; it was 91% when the NETest was included. Combining CC and NETest was approximately 2× more effective than individual CC alone (increase in R ² value from 43% to 80%).

CONCLUSIONS

A multigene blood test facilitates effective identification of pNET recurrence, prediction of disease relapse, and outperforms CgA.

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.

Decreased expression of LKB1 predicts poor prognosis in pancreatic neuroendocrine tumor patients undergoing curative resection

Background

Liver kinase B1 (LKB1) is a key regulatory protein of cellular metabolism, proliferation, and polarity. The present study aimed to characterize the expression pattern of LKB1 in pancreatic neuroendocrine tumors (pNETs) and evaluate the relationship between LKB1 expression and prognosis in pNETs.

Patients and methods

We retrospectively analyzed the pathologic and clinical data of 71 pNET patients who underwent curative surgical resection in Guangdong General Hospital. LKB1 mRNA and protein levels in tumor tissues and paired nontumor tissues were evaluated in 24 patients by quantitative real-time reverse-transcription polymerase chain reaction and Western blot, respectively. Immunohistochemical expression of LKB1 in tumor tissues was detected in all of the 71 patients, and the immunohistochemical expression level was re-coded in two classes (high versus low/negative) and correlated with clinicopathological parameters and survival outcomes. The association between LKB1 expression and clinicopathological characters was evaluated by chi-square test and Student’s t-test. Kaplan–Meier curves and log-rank test were used to analyze the survival outcomes, including overall survival (OS) and disease-free survival (DFS).

Results

Compared to adjacent normal tissues, LKB1 mRNA level and protein expression level in tumor tissues were both increased. The immunostaining of LKB1 was mainly found within the cytoplasm. Overall, 52 of 71 (73.2%) cases were positive for LKB1 protein, which showed either a diffuse staining pattern or a partial staining pattern. Decreased LKB1 expression was correlated with older age (P=0.042), increased Ki-67 index (P=0.004), increased mitotic count (P=0.001), and advanced histologic grade (P=0.001). Moreover, patients with low/negative LKB1 expression had shorter OS and DFS than those with high expression.

Conclusion

Our results suggested that LKB1 expression could be a useful prognostic marker for recurrence and survival in pNET patients who had received curative resection.

A Systematic review and meta-analysis on the role of palliative primary resection for pancreatic neuroendocrine neoplasm with liver metastases

BACKGROUND

Role of palliative pancreatic neuroendocrine neoplasm (PanNEN) resection (pPanNEN-R) is controversial. This study was designed as a meta-analysis of studies which allow a comparison of pPanNEN-R and non-surgical management (PanNEN-nR).

METHODS

All published studies until 2017 allowing for the comparison of pPanNEN-R and PanNEN-nR were reviewed. Primary outcome was overall survival (OS). Secondary outcomes measures included postoperative morbidity, reoperation, readmission, length of hospital stay (LOS), and quality of life (QoL). Risk of death was compared by computing the odds-ratio (OR), while 5- and 10-year OS using weighted mean differences.

RESULTS

Seven studies were included. A total of 885 patients were included, of whom 252 (28%) underwent pPanNEN-R and 633 (72%) underwent PanNEN-nR. Overall quality of included studies was fair. The risk of death was significantly reduced in patients who underwent pPanNEN-R compared to those who underwent PanNEN-nR (OR = 0.38, 95% CI 0.23-0.65). Data on postoperative morbidity, reoperation, readmission, LOS, and QoL were not adequately reported therefore a meta-analysis for the secondary outcomes was not performed.

DISCUSSION

pPanNEN-R in patients with unresectable LM seems to be associated with a better OS compared to non-surgical management but the limitations of included studies does not allow firm conclusions.

Role of palliative resection of the primary pancreatic neuroendocrine tumor in patients with unresectable metastatic liver disease: a systematic review and meta-analysis

BACKGROUND

Treatment for pancreatic neuroendocrine tumors (PNETs) in patients with unresectable metastatic liver disease has long been a controversial issue. This systematic review aims to summarize the existing evidence concerning the value of primary tumor resection in this group of patients.

METHODS

A systematic review of the literature and a meta-analysis were performed. The PubMed and Cochrane databases were searched to identify articles that compared palliative primary tumor resection and nonsurgical regimens in patients with PNETs and unresectable liver metastases. Relevant articles were identified in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The primary outcome was overall survival. The included studies were evaluated for heterogeneity and publication bias.

RESULTS

Overall, 10 studies were included in the analysis. No randomized controlled trials (RCTs) were identified. These studies included 1,226 patients who underwent a resection of the primary tumor and 1,623 patients who did not undergo surgery. The median overall survival was 36-137 and 13.2-65 months in the surgical and nonsurgical groups, respectively, and the 5-year overall survival rate was 35.7-83 and 5.4%-50%, respectively, in these two groups. The meta-analysis demonstrated that there was no significant difference in liver tumor burden (odds ratio [OR] =1.51, 95% CI: 0.59-3.89, P=0.39) or tumor grade (OR =2.88, 95% CI: 0.92-9.04, P=0.07) among patients who underwent surgery and nonsurgical therapy. Furthermore, patients who underwent an aggressive surgical approach appeared to have a higher tumor grade. However, the meta-analysis demonstrated that patients who underwent primary tumor resection had better overall survival (P<0.001), with a pooled hazard ratio of 0.36 (95% CI: 0.30-0.45). No publication bias was detected.

CONCLUSION

This meta-analysis demonstrates that the palliative resection of the primary tumor in patients with PNETs and unresectable liver metastases can increase survival, although a bias toward a more aggressive surgical approach in patients with better performance status, less advanced disease, or a tumor located in the body or tail of the pancreas appears likely. RCTs with longer follow-up periods are required to confirm the advantages of palliative primary tumor resection for PNETs.

[Surgical management of non-functioning pancreatic neuroendocrine tumors]

AIM

To analyze immediate and long-term results of surgical treatment of patients with non-functioning pancreatic neuroendocrine tumors (pNETs).

MATERIAL AND METHODS

Outcomes in 21 patients with non-functioning pNETs were retrospectively analyzed.

RESULTS

Long-term results were followed-up in 18 (85%) cases, median follow-up was 39 months. Postoperative mortality was 4.7%. The incidence of postoperative complications Clavien-Dindo degree IIIA and over was 20.8%, overall 5-year survival - 89%, desease-free 5-year survival - 78%.

CONCLUSION

At present time surgical intervention remains the only radical method of non-functioning pNETs management. Threshold tumor dimension should be 15 mm that determines surgical intervention or active surveillance. From an oncological point of view tumor enucleation is permissible only in case of small dimensions (up to 2 cm) and full confidence in low degree of malignancy. Lymphadenectomy should be performed in all cases in standard fashion because lymph node involvement is reliably poor prognostic sign.

The Role of Cytoreductive Hepatic Surgery as an Adjunct to the Management of Metastatic Neuroendocrine Carcinomas

BACKGROUND

Patients with metastatic neuroendocrine cancers to the liver often present with disabling endocrinopathies and pain associated with bulky disease. Quality of life for these patients is poor and can require long-term therapy with somatostatin analogs for control of their symptoms. Alternative therapies to decrease tumor burden and subsequent hormone release have been investigated. Of these, cytoreductive surgery was found to have the most consistent and profound impact on symptom regression and overall survival.

METHODS

Several cases are reported that illustrate an aggressive multimodality approach in the treatment of metastatic neuroendocrine cancers to the liver. The literature is reviewed and the role of cytoreductive surgery in the management of hepatic neuroendocrine metastases is discussed.

RESULTS

Cytoreductive surgery can be performed safely with minimal morbidity and mortality. Regression of symptoms occurs in the majority of patients and survival is prolonged.

CONCLUSIONS

Surgical intervention as part of an aggressive multimodality treatment plan results in improved outcomes for patients with advanced hepatic metastases of neuroendocrine origin. Future directions may include earlier surgical intervention with adjuvant therapies reserved for aggressive recurrent disease.

Effect of hormone secretory syndromes on neuroendocrine tumor prognosis

The treatment of hormone hypersecretory syndromes caused by neuroendocrine tumors (NETs) can be a major challenge. NETs originating from the small intestine often secrete serotonin causing flushing, diarrhea and valve fibrosis, leading to dehydration or heart failure in severe cases. NETs from the pancreas can secrete a wider variety of hormones, like insulin, glucagon and gastrin leading to distinct clinical syndromes. Historically mortality in patients with functioning NETs was high due to the complications caused by the hypersecretion of hormones. This has been reduced with several drugs: proton-pump inhibitors decrease acid secretion caused by gastrinomas. Somatostatin analogs can inhibit the secretion of multiple hormones and these are now the cornerstone for treating patients with a gastroenteropancreatic NET. However, peptide receptor radionuclide therapy (PRRT) with radiolabeled somatostatin analogs and everolimus can also decrease symptoms of hypersecretion and increase progression-free survival. Several factors affect the survival in patients with a functioning NET. Complications of hypersecretion negatively impact survival; however, secretion of hormones is also often a sign of a well-differentiated NET and due to the symptoms, functioning NETs can be detected in an earlier stage suggesting a positive effect on prognosis. The effect on survival is also dependent on the type of hormone being secreted. This review aims to study the effect of hormone secretion on the prognosis of NETs with the contemporary treatments options available today.

Characterization of single lesion nonfunctioning pancreatic neuroendocrine carcinoma via computed tomography

Nonfunctioning pancreatic neuroendocrine carcinoma (NPNEC) is a poorly differentiated neuroendocrine carcinoma and a rare type of pancreatic cancer. Computed tomography (CT)-based imaging is currently the most effective method for diagnosing and classifying NPNEC. The present study investigated the clinical features and CT manifestations of this disease. The CT manifestations and clinical data of 13 patients with NPNEC, confirmed by surgery or needle biopsy, were retrospectively analyzed. None of the 13 patients exhibited endocrine-related symptoms and a single lesion with a variable position in the pancreatic was observed in all patients. The tumors were generally round or irregular, with inhomogeneous density and an average diameter of 7.45±3.92 cm (range, 4.0–16.0 cm). Cystic necrosis zones were observed in 5 patients and calcification was observed in 2. A total of 4 patients exhibited intrahepatic metastases, and 2 patients demonstrated spleen and colon invasion. Enhanced scanning indicated that tumors were markedly enhanced. There were 11 cases of middle or high-grade enhancement (84.6%) and 2 cases of mild enhancement (15.4%). Marked envelope enhancement was observed in 3/11 patients with high-grade enhancement. In conclusion, the majority of patients with NPNEC lacked characteristic manifestations. While the CT examination revealed certain characteristics, histological analysis was necessary to confirm diagnoses.

A Clinicopathological Study of Malignant Insulinoma in a Contemporary Series

OBJECTIVE

The aim of the study was to address the origin and natural history of malignant insulinoma.

METHODS

Retrospective review of medical records of patients diagnosed with insulinoma at Cedars-Sinai Medical Center between 2000 and 2015 was conducted. Hormonal expression in tumor specimens was examined by immunostaining.

RESULTS

All the 9 patients with malignant insulinoma (35% of 26 patients with insulinoma) already had liver metastasis at hypoglycemia presentation with bulky cumulative tumor burden. Six patients had de novo diagnosis, 2 had known metastatic nonfunctioning pancreatic neuroendocrine tumor, and 1 had a known pancreatic mass. Tumor grade at presentation was G1 in 4 patients, G2 in 4, and unknown in 1. Four patients died 2 to 32 months after presentation, all with extensive liver tumor involvement. Tumor expression of proinsulin and insulin was heterogeneous and overall infrequent. The proinsulin levels and proinsulin/insulin molar ratio in patients with malignant versus benign insulinoma were 334 versus 44 pmol/L and 2.1 versus 0.9, respectively.

CONCLUSIONS

Malignant insulinoma seems to arise from and behave like nonfunctioning pancreatic neuroendocrine tumor oncologically but with metachronous hyperinsulinemic hypoglycemia. High proinsulin levels and proinsulin/insulin molar ratio may suggest malignant insulinoma.

Surgical treatment of non-functioning pancreatic neuroendocrine tumours based on three clinical scenarios

INTRODUCTION

The treatment of patients with non-functioning pancreatic neuroendocrine tumours (NFPNET) is resection in locally pancreatic disease, or with resectable liver metastases. There is controversy about unresectable liver disease.

METHODS

We analysed the perioperative data and survival outcome of 63 patients who underwent resection of NFPNET between 1993 and 2012. They were divided into 3 scenarios: A, pancreatic resection (44patients); B, pancreatic and liver resection in synchronous resectable liver metastases (12patients); and C, pancreatic resection in synchronous unresectable liver metastases (6patients). The prognostic factors for survival and recurrence were studied.

RESULTS

Distal pancreatectomy (51%) and pancreaticoduodenectomy (38%) were more frequently performed. Associated surgery was required in 44% of patients, including synchronous liver resections in 9patients. Two patients received a liver transplant during follow-up. According to the WHO classification they were distributed into G1: 10 (16%), G2: 45 (71%), and G3: 8 (13%). The median hospital stay was 11days. Postoperative morbidity and mortality were 49% and 1.6%, respectively. At the closure of the study, 43 (68%) patients were still alive, with a mean actuarial survival of 9.6years. The WHO classification and tumour recurrence were risk factors of mortality in the multivariate analysis. The median actuarial survival by scenarios was 131months (A), 102months (B), and 75months (C) without statistically significant differences.

CONCLUSIONS

Surgical resection is the treatment for NFPNET without distant disease. Resectable liver metastases in well-differentiated tumours must be resected. The resection of the pancreatic tumour with unresectable synchronous liver metastasis must be considered in well-differentiated NFPNET. The WHO classification grade and recurrence are risk factors of long-term mortality.

Resection of primary gastroenteropancreatic neuroendocrine tumors in the presence of irresectable liver metastases

Gastroenteropancreatic neuroendocrine tumors often present at an advanced stage and carry a variable prognosis, with many patients living long periods even with metastatic disease. Resection of the primary tumor when liver metastases are unresectable is a contentious subject with no consensus between existing guidelines. A number of recent studies have suggested a potential survival benefit as well as improved symptom control with resection. With variable results from nonoperative management strategies, the risk:benefit ratio of resection of the primary tumor may be favorable for carefully selected patients.

Systematic review of active surveillance versus surgical management of asymptomatic small non-functioning pancreatic neuroendocrine neoplasms

BACKGROUND

The incidence of asymptomatic, sporadic, small non-functioning pancreatic neuroendocrine neoplasms (NF-PNENs) has increased in recent decades. Conservative treatment has been advocated for these tumours. The aim of this study was systematically to evaluate the literature on active surveillance and to compare this with surgical management for asymptomatic sporadic small NF-PNENs.

METHODS

PubMed, Embase and the Cochrane Library were searched systematically for studies that compared the active surveillance of asymptomatic, sporadic, small NF-PNENs with surgical management. PRISMA guidelines for systematic reviews were followed.

RESULTS

After screening 3915 records, five retrospective studies with a total of 540 patients were included. Of these, 327 patients (60·6 per cent) underwent active surveillance and 213 (39·4 per cent) had surgery. There was wide variation in the tumour diameter threshold considered as inclusion criterion (2 cm to any size). The median length of follow-up ranged from 28 to 45 months. Measurable tumour growth was observed in 0-51·0 per cent of patients. Overall, 46 patients (14·1 per cent) underwent pancreatic resection after initial conservative treatment. In most patients the reason was an increase in tumour size (19 of 46). There were no disease-related deaths in the active surveillance group in any of the studies.

CONCLUSION

This systematic review suggests that active surveillance of patients affected by sporadic, small, asymptomatic NF-PNENs may be a good alternative to surgical treatment.

The First Case Report of Robotic Multivisceral Resection for Synchronous Liver Metastasis from Pancreatic Neuroendocrine Tumor: A Case Report and Literature Review

INTRODUCTION

Surgery for liver metastases in pancreatic neuroendocrine tumor (PNET) improves overall survival rate. We present the first case report for robotic multivisceral resection of distal pancreas, spleen, and left liver for metastatic PNET.

MATERIALS AND METHODS

We present a case of 52-year-old female diagnosed with PNET in the pancreatic neck metastatic to the liver, responding to somatostatin and bland embolization, who underwent surgical debulking using da Vinci robotic platform. Intraoperative Doppler ultrasound was used to define the vascular distribution and tumor extension. The parenchymal liver transection was performed with vessel sealer. The distal pancreas and the spleen were approached medial to lateral and resected in an en-bloc fashion. The left liver inflow, outflow, and splenic artery and vein were transected with vascular stapler device.

RESULTS

Da Vinci robot-assisted multivisceral resection has been performed with good postoperative outcome. Operative time was 369 minutes and the estimated blood loss was 100 mL. The patient had a short hospital stay with quick recovery and good outcome at 5 months follow-up after the surgery.

DISCUSSION

Liver metastases in PNETs are considered an adverse factor. Aggressive surgical management is a mainstay. The laparoscopic approach to pancreatic or hepatic surgery is difficult in inexperienced hands with steep learning curve. The recent robotic system seems to overcome many limitations. This is the first case of robotic multivisceral resection for synchronous liver metastasis from PNET. Concurrent primary tumor resection with hepatectomy offers potential curative intention.

Applications of a novel tumor-grading-metastasis staging system for pancreatic neuroendocrine tumors: An analysis of surgical patients from a Chinese institution

The ability to stratify patients with pancreatic neuroendocrine tumors (p-NETs) into prognostic groups has been hindered by the absence of a commonly accepted staging system. Both the 7th tumor-node-metastasis (TNM) staging guidelines by the American Joint Committee on Cancer (AJCC) and the 2010 grading classifications by the World Health Organization (WHO) were validated to be unsatisfactory.We aim to evaluate the feasibility of combining the latest AJCC and WHO criteria to devise a novel tumor-grading-metastasis (TGM) staging system. We also sought to examine the stage-specific survival rates and the prognostic value of this new TGM system for p-NETs.Data of 120 patients with surgical resection and histopathological diagnosis of p-NETs from January 2004 to February 2014 in our institution were retrospectively collected and analyzed. Based on the AJCC and WHO criteria, we replaced the stage N0 and N1 with stage Ga (NET G1 and NET G2) and Gb (NET G3 and MANEC) respectively, without changes of the definition of T or M stage. The present novel TGM staging system was grouped as follows: stage I was defined as T1-2, Ga, M0; stage II as T3, Ga, M0 or as T1-3, Gb, M0; stage III as T4, Ga-b, M0 and stage IV as any T, M1.The new TGM staging system successfully distributed 55, 42, 12, and 11 eligible patients in stage I to IV, respectively. Differences of survival compared stage I with III and IV for patients with p-NETs were both statistically significant (P < 0.001), as well as those of stage II with III and IV (P < 0.001). Patients in stage I showed better a survival than those in stage II, whereas difference between stages III and IV was not notable (P = 0.001, P = 0.286, respectively). In multivariate models, when the TGM staging system was evaluated in place of the individual T, G, and M variables, this new criteria were proven to be an independent predictor of survival for surgically resected p-NETs (P < 0.05).Stratifying patients well, the current proposed TGM staging system was predictive for overall survival of p-NETs and could be more widely applied in clinical practice.

Outcomes of Pancreaticoduodenectomy for Pancreatic Neuroendocrine Tumors: Are Combined Procedures Justified?

Efficacy and outcomes of resection for pancreatic neuroendocrine tumors (pNET) are well established; specific data on outcomes for pancreaticoduodenectomy (PD), either alone or with combined procedures, are limited. A retrospective review of PDs for pNET (1998-2014) at our institution was conducted. Patients were categorized into standard PD (SPD) alone or combined PD (CPD) defined as patients undergoing concurrent vascular reconstruction or additional organ resection for curative intent. Kaplan-Meier survival analyses were performed. PD for pNET was performed for 95 patients. Tumors were functional in 11 patients (9 %). Twenty-six patients (28 %) underwent CPD. The 30/90-day mortality was 1.1/5.3 % respectively and similar between SPD and CPD (p = 0.61/p = 0.24). Five-year overall survival after PD for pNET was 85.1/71.9 % and similar between SPD/CPD groups (p = 0.17). Recurrence-free and overall survival for low-grade tumors was 74.7/93.9 % at 5 years compared to only 14.8/49.7 % for high-grade tumors (p < 0.001) and not predicted by extent of resection (SPD/CPD, respectively). PD with or without concurrent resection provides an acceptable, perioperative and long-term oncologic, outcome for pNET. CPD is justified treatment modality, particularly for patients with low-grade tumors. The need for combinatorial procedures during PD is not contraindication alone for otherwise resectable patients with pNET.

Multidisciplinary management of nonfunctional neuroendocrine tumor of the pancreas

Pancreatic neuroendocrine tumors (PNETs) are a rare and diverse group of tumors; nonfunctional (NF) PNETs account for the majority of cases. Most patients with NF-PNETs have metastatic disease at the time of presentation. A variety of treatment modalities exist, including medical, liver directed, and surgical treatments. Aggressive surgical management is associated with prolonged survival, however available data are limited by selection bias and the frequent combination of PNETs with carcinoid tumors. Although few patients with metastatic disease will be cured, application of currently available therapies in a multidisciplinary setting can lead to excellent outcomes with prolonged patient survival.

Postoperative Complications, In-Hospital Mortality and 5-Year Survival After Surgical Resection for Patients with a Pancreatic Neuroendocrine Tumor: A Systematic Review

Studies on postoperative complications and survival in patients with pancreatic neuroendocrine tumors (pNET) are sparse and randomized controlled trials are not available. We reviewed all studies on postoperative complications and survival after resection of pNET. A systematic search was performed in the Cochrane Central Register of Controlled Trials, MEDLINE and EMBASE from 2000-2013. Inclusion criteria were studies of resected pNET, which described postoperative complications separately for each surgical procedure and/or 5-year survival after resection. Prospective and retrospective studies were pooled separately and overall pooled if heterogeneity was below 75%. The random-effect model was used. Overall, 2643 studies were identified and after full-text analysis 62 studies were included. Pancreatic fistula (PF) rate of the prospective studies after tumor enucleation was 45%; PF-rates after distal pancreatectomy, pancreatoduodenectomy, or central pancreatectomy were, respectively, 14-14-58%. Delayed gastric emptying rates were, respectively, 5-5-18-16%. Postoperative hemorrhage rates were, respectively, 6-1-7-4%. In-hospital mortality rates were, respectively, 3-4-6-4%. The 5-year overall survival (OS) and disease-specific survival (DSS) of resected pNET without synchronous resected liver metastases were, respectively, 85-93%. Heterogeneity between included studies on 5-year OS in patients with synchronous resected liver metastases was too high to pool all studies. The 5-year DSS in patients with liver metastases was 80%. Morbidity after pancreatic resection for pNET was mainly caused by PF. Liver resection in patients with liver metastases seems to have a positive effect on DSS. To reduce heterogeneity, ISGPS criteria and uniform patient groups should be used in the analysis of postoperative outcome and survival.

Malignant-functioning neuroendocrine tumors of the pancreas: A survival analysis

BACKGROUND

Malignant-functioning pancreatic neuroendocrine tumors (mFpNETs) are rare. Research analyzing the presentation, biological behavior, and patient outcomes of these tumors is limited.

METHODS

We used the Surveillance, Epidemiology, and End Results database to identify patients with malignant insulinomas, gastrinomas, glucagonomas, vasoactive intestinal peptide secreting tumors (VIPomas), somastatinomas, and mixed islet cell tumors (MICTs). The primary endpoint of this study was to identify factors affecting survival.

RESULTS

We identified 401 patients with mFpNETs. Between histologic subtypes, there were significant differences in sex and age, and in tumor size, grade, location, and stage. Median survival time for insulinomas was 12.7 years; gastrinomas, 10.2 years; glucagonomas, 7.7 years; VIPomas, 7.9 years; and MICTs, 3.4 years. Multivariable analysis showed that histology (insulinoma, gastrinoma, and VIPoma; P = .009), absence of distant metastases (P = .002), age < 50 years (P = .001), surgical intervention (P = .001), and stage I/II disease (P = .011) were independently associated with prolonged survival. Subgroup analysis demonstrated that removal of the primary tumor in stage IV mFpNETs was associated with significantly prolonged survival (P = .01).

CONCLUSION

mFpNETs are rare tumors that commonly present at an advanced stage despite hormonal secretion. Primary tumor resection is associated with longer survival in stages I-III as well as stage IV tumors.

Survival Analyses for Patients With Surgically Resected Pancreatic Neuroendocrine Tumors by World Health Organization 2010 Grading Classifications and American Joint Committee on Cancer 2010 Staging Systems

In 2010, World Health Organization (WHO) reclassified pancreatic neuroendocrine tumors (p-NETs) into 4 main groups: neuroendocrine tumor G1 (NET G1), neuroendocrine tumor G2 (NET G2), neuroendocrine carcinoma G3 (NEC G3), mixed adeno and neuroendocrine carcinoma (MANEC). Clinical value of these newly updated WHO grading criteria has not been rigorously validated. The authors aimed to evaluate the clinical consistency of the new 2010 grading classifications by WHO and the 2010 tumor-node metastasis staging systems by American Joint Committee on Cancer (AJCC) on survivals for patients with surgically resected p-NETs. Moreover, the authors would validate the prognostic value of both criteria for p-NETs.The authors retrospectively collected the clinicopathologic data of 120 eligible patients who were all surgically treated and histopathologically diagnosed as p-NETs from January 2004 to February 2014 in our single institution. The new WHO criteria were assigned to 4 stratified groups with a respective distribution of 62, 35, 17, and 6 patients. Patients with NET G1 or NET G2 obtained a statistically better survival compared with those with NEC G3 or MANEC (P < 0.001). Survivals of NET G1 was also better than those of NET G2 (P = 0.023), whereas difference of survivals between NEC G3 and MANEC present no obvious significance (P = 0.071). The AJCC 2010 staging systems were respectively defined in 61, 36, 12, and 11 patients for each stage. Differences of survivals of stage I with stage III and IV were significant (P < 0.001), as well as those of stage II with III and IV (P < 0.001); whereas comparisons of stage I with stage II and stage III with IV were not statistically significant (P = 0.129, P = 0.286; respectively). Together with radical resection, these 2 systems were both significant in univariate and multivariate analysis (P < 0.05).The newly updated WHO 2010 grading classifications and the AJCC 2010 staging systems could consistently reflect the clinical outcome of patients with surgically resected p-NETs. Meanwhile, both criteria could be independent predictors for survival analysis of p-NETs.

Resection of primary tumor site is associated with prolonged survival in metastatic nonfunctioning pancreatic neuroendocrine tumors

BACKGROUND

Nonfunctioning pancreatic neuroendocrine tumors (NFpNET) present with distant metastases in up to 50% of patients. It is unknown whether removal of the primary tumor in patients with NFpNET and metastases is beneficial.

METHODS

We used the Surveillance, Epidemiology, and End Results database to identify patients with NFpNET and distant metastases. The primary outcome measure in this study was overall survival.

RESULTS

We identified 882 patients with metastatic NFpNET who had survival data; 303 (34%) patients had operative removal of their primary tumor of which 243 (80%) were grade I or II. Median survival of patients undergoing resection of the primary site was 65 (95% confidence interval 60-86) versus 10 (8-12) months for those without resection (P < .0001). Patients diagnosed after 2003 (n = 625, 71%) were more likely to undergo an operation than those diagnosed earlier (P = .001). Multivariable analysis showed that a lesser tumor grade (P < .0001), younger age (P < .0001), diagnosis during or after 2003 (P = .0003), tumor site in the body/tail (P = .009), and operative resection of the primary tumor site (P < .0001) were associated with prolonged survival of patients with NFpNET and distant metastases.

CONCLUSION

This study suggests that resection of the site of the primary NFpNET is associated with greater survival in patients with distant metastases and could therefore be considered as a additional treatment option in this patient population.