Differences in survival for patients with resectable versus unresectable metastases from pancreatic islet cell cancer

Controversy Over Liver Transplantation or Resection for Neuroendocrine Liver Metastasis: Tumor Biology Cuts the Deal

BACKGROUND

In patients with neuroendocrine liver metastasis (NELM), liver transplantation (LT) is an alternative to liver resection (LR), although the choice of therapy remains controversial. In this multicenter study, we aim to provide novel insight in this dispute.

METHODS

Following a systematic literature search, 15 large international centers were contacted to provide comprehensive data on their patients after LR or LT for NELM. Survival analyses were performed with the Kaplan-Meier method, while multivariable Cox regression served to identify factors influencing survival after either transplantation or resection. Inverse probability weighting and propensity score matching was used for analyses with balanced and equalized baseline characteristics.

RESULTS

Overall, 455 patients were analyzed, including 230 after LR and 225 after LT, with a median follow-up of 97 months [95% confidence interval (CI): 85-110 months]. Multivariable analysis revealed G3 grading as a negative prognostic factor for LR [hazard ratio (HR)=2.22, 95% CI: 1.04-4.77, P =0.040], while G2 grading (HR=2.52, 95% CI: 1.15-5.52, P =0.021) and LT outside Milan criteria (HR=2.40, 95% CI: 1.16-4.92, P =0.018) were negative prognostic factors in transplanted patients. Inverse probability-weighted multivariate analyses revealed a distinct survival benefit after LT. Matched patients presented a median overall survival (OS) of 197 months (95% CI: 143-not reached) and a 73% 5-year OS after LT, and 119 months (95% CI: 74-133 months) and a 52.8% 5-year OS after LR (HR=0.59, 95% CI: 0.3-0.9, P =0.022). However, the survival benefit after LT was lost if patients were transplanted outside Milan criteria.

CONCLUSIONS

This multicentric study in patients with NELM demonstrates a survival benefit of LT over LR. This benefit depends on adherence to selection criteria, in particular low-grade tumor biology and Milan criteria, and must be balanced against potential risks of LT.

Effectiveness and Prognostic Factors of Everolimus in Patients with Pancreatic Neuroendocrine Neoplasms

Objective The effectiveness of everolimus for the management of pancreatic neuroendocrine neoplasms (PNENs), including the G3/NEC types, remains unclear. We therefore investigated the effectiveness of the drug for the management of PNENs. Methods We analyzed the progression-free survival (PFS) and overall survival (OS) associated with everolimus and factors influencing the PFS and OS. Results One hundred patients were evaluated. The PFS associated with the G1/G2 types tended to be significantly longer than that associated with the G3/NEC types [hazard ratio (HR), 0.45; p=0.005]. A multivariate analysis showed that the significant factors influencing the PFS were age (<65 years old; HR, 0.44; p=0.002), grade (G1/G2; HR, 0.42; p=0.006), everolimus treatment line (≤2nd; HR, 0.55; p=0.031), and presence of treatment with metformin (yes; HR, 0.29; p=0.044). The median OS was 63.8 months. In the multivariate analysis, the significant factors influencing the OS were grade (G1/G2; HR, 0.21; p<0.001), volume of liver metastasis (≤25%; HR, 0.27; p<0.001), everolimus treatment line (≤2nd; HR, 0.27; p<0.001), and presence of primary tumor resection (yes; HR, 0.33; p=0.005). Conclusion The effectiveness of everolimus in the management of G3/NEC types and prognoses tended to be poorer than those associated with the G1/G2 types. Everolimus combined with metformin and early-line treatment with everolimus may be effective for managing advanced PNENs.

Orchestrating Treatment Modalities in Metastatic Pancreatic Neuroendocrine Tumors-Need for a Conductor

Simple Summary

Pancreatic neuroendocrine tumors (pNET) are a heterogeneous and challenging entity, and today’s guidelines offer a variety of treatment modalities, while surgery has a clear role for patients with resectable tumors and early stages, advanced, or metastatic pNET may benefit from treatments that were evaluated in randomized controlled studies during the last year. With this review, we aim to provide an updated view on treatment options for metastatic pNET.

Abstract

Pancreatic neuroendocrine tumors (pNETs) are a vast growing disease. Over 50% of these tumors are recognized at advanced stages with lymph node, liver, or distant metastasis. An ongoing controversy is the role of surgery in the metastatic setting as dedicated systemic treatments have emerged recently and shown benefits in randomized trials. Today, liver surgery is an option for advanced pNETs if the tumor has a favorable prognosis, reflected by a low to moderate proliferation index (G1 and G2). Surgery in this well-selected population may prolong progression-free and overall survival. Optimal selection of a treatment plan for an individual patient should be considered in a multidisciplinary tumor board. However, while current guidelines offer a variety of modalities, there is so far only a limited focus on the right timing. Available data is based on small case series or retrospective analyses. The focus of this review is to highlight the right time-point for surgery in the setting of the multimodal treatment of an advanced pancreatic neuroendocrine tumor.

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.

Younger Age Is Associated with Improved Survival in Patients Undergoing Liver Transplantation Alone for Metastatic Neuroendocrine Tumors

BACKGROUND

Neuroendocrine tumor (NET) metastases are a major cause of morbidity and mortality. The role of liver transplantation to treat unresectable metastases from NET is controversial.

METHODS

We evaluated outcomes of all patients undergoing "isolated" liver transplantation (LT) for metastatic NETs in the USA, from October 1988 through June 2018 using the UNOS dataset.

RESULTS

During the study period, 160,360 LTs were performed. Two hundred six adult patients underwent "isolated" LT for metastatic NETs. The mean (SD) age was 48.2 (11.7) years, ranging from 19 to 75 years; 117 (56.8%) patients were male. Overall 1-, 3-, 5-, and 10-year patient survival rates were 89.1%, 75.3%, 64.9%, and 46.1%, respectively. Tumor recurrence was seen in 70 of 206 patients who underwent LT (34%). The median time to recurrence was 28 months (range, 1 to 192 months) and median wait time for LT was 112 days. Tumor recurrence was significantly higher in transplanted patients waiting less than 6 months compared with those waiting more than 6 months (74.3% vs. 25.7%). Patients' age ≤ 45 years had significantly better survival compared with those > 45 years (p = 0.03). Younger patients with carcinoid tumors had better survival but this trend was not observed in the non-carcinoid group. On multivariable analysis, recipient age, donor age, cold ischemic time MELD score, and tumor recurrence were significant predictors of poor patient survival.

CONCLUSIONS

Waiting time longer than 6 months is associated to lower rates of tumor recurrence. Younger patients ≤ 45 years had significantly improved survival after LT for NET metastases.

Recurrence Patterns After Surgical Resection of Gastroenteropancreatic Neuroendocrine Tumors: Analysis From the National Comprehensive Cancer Network Oncology Outcomes Database

OBJECTIVE

Current National Comprehensive Cancer Network guidelines for gastroenteropancreatic neuroendocrine tumors (GEPNETs) recommend complete (R0) surgical resection of the primary tumor and metastases, if feasible. However, large multicenter studies of recurrence patterns of GEPNETs after resection have not been performed.

METHODS

Patients 18 years or older who presented to 7 participating National Comprehensive Cancer Network institutions between 2004 and 2008 with a new diagnosis of a small bowel, pancreas, or colon/rectum neuroendocrine tumor (NET) and underwent R0 resection of the primary tumor, and synchronous metastases, if present, were included in this analysis. Descriptive statistics and Kaplan-Meier estimates were used to calculate recurrence rates and time-associated end points, respectively.

RESULTS

Of 294 patients with GEPNETs, 50% were male, 88% were White, and 99% had Eastern Cooperative Oncology Group performance status 0 to 1. The median age was 55 years (range, 20-90). The median follow-up time from R0 resection was 62.1 months. Recurrence rates were 18% in small bowel NETs (n = 110), 26% in pancreatic NETs (n = 141), and 10% in colon/rectum NETs (n = 50). The frequency of surveillance imaging was highly variable.

CONCLUSIONS

R0 resection was associated with variable risk of recurrence across subtypes. Further research to inform refinement of guidelines for the appropriate duration of surveillance after R0 resection is needed.

Pancreatic neuroendocrine tumors

PURPOSE OF REVIEW

Pancreatic neuroendocrine tumors (pNETs) are a rare, heterogeneous group of pancreatic neoplasms with a wide range of malignant potential. They may manifest as noninfiltrative, slow-growing tumors, locally invasive masses, or even swiftly metastasizing cancers.

RECENT FINDINGS

In recent years, because of the increasing amount of scientific literature available for pNETs, the classification, prognostic stratification criteria, and available consensus guidelines for diagnosis and therapy have been revised and updated.

SUMMARY

The vast majority of new pNET diagnoses consist of incidentally discovered lesions on cross-sectional imaging. The biologic behavior of pNETs is defined by the grade and stage of the tumor. Surgery is the only curative treatment and it, therefore, represents the first therapeutic choice for any localized pNET; however, recent evidence suggests that patients with small (<2 cm), nonfunctioning G1 tumors can be safely observed.An aggressive surgical approach towards liver metastases is recommended in selected cases, as well as liver-directed therapies for disease control. In the presence of unresectable progressive disease, somatostatin analogs, targeted therapies such as everolimus, peptide receptor radionuclide therapy, and systemic chemotherapy are all useful tools for prolonging survival.

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.

Role of surgery in pancreatic neuroendocrine tumor

Pancreatic neuroendocrine tumours (PNETs) are rare. They are generally accepted to be slow-growing and have an indolent course. These tumours can be non-functioning or functioning, consisting of a biochemically heterogeneous group of tumours including insulinomas, gastrinomas, carcinoids and glucagonomas. Although surgery remains the mainstay of treatment, controversy still exists especially for non-functioning tumours <2 cm in size. Whether these should be resected or undergo intensive surveillance remains unclear. The surgical approach depends on local expertise. Many studies have shown comparable short-term surgical outcome with laparoscopic pancreatic resection compared to open techniques, however data on long-term oncological outcome are still lacking. On the other hand, liver metastasis occurs in as high as 80% of PNET patients. Five-year survival rate is only 30% if left untreated compared to 60-80% if complete resection is achieved. Current evidence supports liver resection with an aim for symptomatic control and to improve survival in those with respectable disease and no extra-hepatic metastasis. Palliative debunking can be considered in those with intractable symptoms. This article reviews the current evidence on pancreatic resection for PNETs, in particular the role of laparoscopic resection and the management of liver metastasis.

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.

Rectal neuroendocrine neoplasms: a case report

The gastrointestinal neuroendocrine neoplasms (GI-NENs) are very rare, among which second most common type is the rectal NENs in China. Patients with rectal NENs may experience non-specific symptoms such as pain, perianal bulge, anemia, and bloody stools, and surgery is considered as the first treatment for rectal NENs. We report a case of rectal NENs in a 68-year-old male patient with bloody stools, who received surgery and postoperative pathology revealed an elevated well-differentiated neuroendocrine carcinoma.

Report of one case: surgical treatment for neuroendocrine tumors

A 68-year-old female patient was admitted to our center due to anorexia and epigastric pain for 2 months. Plain abdominal CT revealed a splenic space-occupying lesion; it had invaded the greater curvature of stomach and had blurred margin with the tail of pancreas. The longest diameter was about 10.7 cm. The lesion was considered to be malignant, accompanied with peritoneal nodules; the possibility of lymph node metastasis could not be ruled out. MRI revealed that the mass was located in front of the spleen, with irregular shape and unclear margin. Part of the mass invaded the greater curvature of stomach and part of it had blurred margin with the tail of pancreas. The largest cross section sized 9.4 cm × 6.9 cm. It showed intermediate and high signals on T2WI/FS, which corresponded to restricted diffusion on DWI sequences. The levels of tumor markers including CA19-9, CA242, and CEA were normal. Exploratory laparotomy + resection of the body and tail of pancreas + resection of part of stomach wall + removal of nodules on liver surface were performed. Postoperative pathology confirmed that the lesion was a neuroendocrine tumor (G1).

Palliative resection of the primary tumor in 442 metastasized neuroendocrine tumors of the pancreas: a population-based, propensity score-matched survival analysis

PURPOSE

There is an ongoing debate on whether palliative removal of the primary tumor may result in a survival benefit for patients with incurable stage IV pancreatic neuroendocrine tumors (P-NET). The objective of this study was to assess whether palliative resection of the primary tumor in patients with incurable stage IV P-NET has an impact on survival.

METHODS

Patients with stage IV P-NET registered in the Surveillance, Epidemiology, and End Results database between 2004 and 2011 were identified. Those undergoing resection of metastases were excluded. Overall and cancer-specific survival of patients who did and did not undergo resection of their primary tumor were compared by means of risk-adjusted Cox proportional hazard regression analysis and propensity score-matched analysis.

RESULTS

A total of 442 stage IV P-NET patients were identified, of whom 75 (17.0 %) underwent palliative primary tumor resection. The latter showed a significant benefit in both overall survival (hazard ratio [HR] of death = 0.41, 95 % confidence interval [CI] 0.25-0.66, p < 0.001) and cancer-specific survival (HR of death = 0.41, 95 % CI 0.25-0.67, p < 0.001) in unadjusted multivariate Cox regression analysis; the benefit persisted after propensity score adjustment.

CONCLUSIONS

This population-based analysis of stage IV P-NET patients provides compelling evidence that palliative resection of the primary tumor is associated with significant survival benefit. Thus, the recent recommendations judging resection of the primary as inadvisable and the accompanying trend towards fewer palliative resections of the primary tumor have to be contested.

A Single Centre Analysis of Clinical Characteristics and Treatment of Endocrine Pancreatic Tumours

Background. Endocrine Pancreatic Tumours (PENs) are rare and can be nonfunctioning or functioning. They carry a good prognosis overall though high grade lesions show a relatively shorter survival. The aim of the current study is to describe a single centre analysis of the clinical characteristics and surgical treatment of PENs. Patients and Methods. This is a cohort analysis of 40 patients of PENs who underwent surgery at Sir Ganga Ram Hospital, New Delhi, India, from 1995 to 2013. Patient particulars, clinical features, surgical interventions, postoperative outcome, and followup were done and reviewed. The study group was divided based on grade (G1, G2, and G3) and functionality (nonfunctioning versus functioning) for comparison. Results. PENs comprised 6.3% of all pancreatic neoplasms (40 of 634). Twenty-eight patients (70%) had nonfunctioning tumours. Eighteen PENs (45%) were carcinomas (G3), all of which were nonfunctioning. 14 (78%) of these were located in the pancreatic head and uncinate process (P = 0.09). The high grade (G3) lesions were significantly larger in size than the lower grade (G1 + G2) tumours (7.0 ± 3.5 cms versus 3.1 ± 1.6 cms, P = 0.007). Pancreatoduodenectomy was performed in 18 (45%), distal pancreatectomy in 10 (25%), and local resection in 8 (20%) and nonresective procedures were performed in 4 patients (10%). Fourteen patients (35%) had postoperative complications. All G3 grade tumours which were resected had positive lymph nodes (100%) and 10 had angioinvasion (71%). Eight neoplasms (20%) were cystic, all being grade G3 carcinomas, while the rest were solid. The overall disease related mortality attributable to PEN was 14.3% (4 of 28) and for malignant PENs was 33.3% (4 of 12) after a mean follow-up period of 49.6 months (range: 2–137 months). Conclusion. Majority of PENs are nonfunctioning. They are more likely malignant if they are nonfunctioning and large in size, show cystic appearance, and are situated in the pancreatic head. Early surgery leads to good long term survival with acceptable postoperative morbidity.

Distal pancreatic resection for neuroendocrine tumors: is laparoscopic really better than open?

BACKGROUND

The latest studies on surgical and cost-analysis outcomes after laparoscopic distal pancreatectomy (LDP) highlight mixed and insufficient results. Whereas several investigators have compared surgical outcomes of LDP vs. open distal pancreatectomy (ODP) for adenocarcinomas, few similar studies have focused on pancreatic neuroendocrine tumors (PNETs).

METHODS

We reviewed the medical records of PNET patients undergoing distal pancreatectomy between 2004 and 2014. Patients were divided into LDP vs. ODP groups. Demographics, relevant comorbidities, oncologic variables, and cost-analysis data were assessed. Survival and Cox proportional hazards analyses were used to evaluate outcomes.

RESULTS

Of the 171 distal pancreatectomies for PNETs, 73 were laparoscopic, whereas 98 were open. Patients undergoing LDP demonstrated significantly lower rates of postoperative complications (P=0.028) and had significantly shorter hospital stays (P=0.008). On multivariable analysis, positive resection margins (P=0.046), G3 grade (P=0.036), advanced WHO classification (P=0.016), TNM stage (P=0.018), and readmission (P=0.019) were significantly associated with poor survival; however, method of resection (LDP vs. ODP) was not (P=0.254). The median total direct costs of LDP vs. ODP did not differ significantly.

CONCLUSIONS

In response to the recent considerable controversy surrounding the costs and surgical outcomes of LDP vs. ODP, our results show that LDP for PNETs is cost-neutral and significantly reduces postoperative morbidity without compromising oncologic outcomes and survival.

Tumor-associated macrophages are a useful biomarker to predict recurrence after surgical resection of nonfunctional pancreatic neuroendocrine tumors

OBJECTIVE

Patients with nonfunctional pancreatic neuroendocrine tumors (NF-PNETs) have poorer survival than those with functional PNETs. Our objective was to identify risk factors for recurrence after resection to better define surveillance parameters to improve long-term outcomes.

METHODS

A retrospective analysis was performed for NF-PNET patients who underwent resection at the University of Michigan from 1995 to 2012. Immunohistochemical staining of tissues from patients with and without disease recurrence was performed for Ki-67 and the macrophage marker CD68, as tumor-associated macrophages are important for PNET development and progression. Clinicopathological factors and patient outcomes were measured.

RESULTS

Ninety-seven NF-PNET patients underwent surgical resection. There was a recurrence rate of 14.4% (14/97). The median time to recurrence was 0.61 years, with 10 (71%) patients recurring within the first 2 years. Six of 7 patients (86%) monitored at 6-month surveillance intervals were diagnosed with recurrence on their first computed tomographic scan or during the intervening intervals. By Cox proportional hazards analysis, the most significant independent risk factors for recurrence were higher grade, stage, and intraoperative blood loss. High CD68 score and Ki-67 index correlated with recurrence risk, and Ki-67 index inversely correlated with time to recurrence. In patients who otherwise had few risk factors, a high CD68 score was a significant prognostic factor for recurrence.

CONCLUSIONS

In patients with NF-PNETs, risk factors associated with recurrence were high EBL, grade, stage, CD68 score, and Ki-67 index. The CD68 score was an important prognostic factor in patients who otherwise had few clinicopathological risk factors; therefore, the CD68 score should be considered when planning surveillance strategies. We recommend that NF-PNET patients at high risk of recurrence undergo initial surveillance every 3 months for 2 years after surgery.

Surgical resection improves the outcome of the patients with neuroendocrine tumor liver metastases: large data from Asia

How to properly manage neuroendocrine liver metastasis (NELM) remains debatable, and only limited clinical data have been published from Asian population. The objective of this study is to identify possible prognostic factors affecting overall survival time and to provide a guideline for future clinical practice. A retrospective study was performed on 1286 patients who had neuroendocrine tumors in our specialized center, and data from 130 patients who had NELM were summarized. Demographic and clinicopathologic data, tumor grade, treatment method, and prognosis were statistically analyzed. Most of the NELMs originated from pancreas (65.4%). Important prognostic factors that included tumor location and size were identified with multivariate analysis. Patients with either primary tumor resection or liver metastasis resection showed a 5-year survival of 35.7% or 33.3%, respectively, whereas resection of both resulted in a 50% 5-year survival. More importantly, resection was performed on 7 patients with grade 3 (G3) tumors, and resulted in 1-year, 3-year, and 5-year survival of 100%, 42.8%, and 28.6%, respectively, whereas the other 9 G3 patients without resection died within 3 years. P = 0.49 comparing the resected group with nonresected group in G3 patients. Besides, the overall 5-year survival rates for resected and nonresected patients were 40.5% and 5.4%, respectively. Multiple prognostic factors influenced the overall outcome of NELM including patient age, tumor location, and size, etc. Aggressive surgical approaches could be considered for maximum survival time disregarding the pathological grade of the tumor. Study with larger sample size should be considered to reevaluate the recommendation of the WHO guidelines for G3 neuroendocrine tumors.

When should a liver resection be performed in patients with liver metastases from neuroendocrine tumours? A systematic review with practice recommendations

AIM

To determine the benefits and risks of hepatic resection versus non-resectional liver-directed treatments in patients with potentially resectable neuroendocrine liver metastases.

METHODS

A systematic review identified 1594 reports which alluded to a possible liver resection for neuroendocrine tumour metastases, of which 38 reports (all retrospective), comprising 3425 patients, were relevant.

RESULTS

Thirty studies reported resection alone, and 16 studies reported overall survival (OS). Only two studies addressed quality-of-life (QoL) issues. Five-year overall survival was reported at 41-100%, whereas 5-year progression-free survival (PFS) was 5-54%. We identified no robust evidence that a liver resection was superior to any other liver-directed therapies in improving OS or PFS. There was no evidence to support the use of a R2 resection (debulking), with or without tumour ablation, to improve either OS or QoL. There was little evidence to guide sequencing of surgery for patients presenting in Stage IV with resectable disease, and none to support a resection of asymptomatic primary tumours in the presence of non-resectable liver metastases.

CONCLUSION

Low-level recommendations are offered to assist in the management of patients with neuroendocrine liver metastases, along with recommendations for future studies.

Distal pancreatic resection for neuroendocrine tumors: is laparoscopic really better than open?

BACKGROUND

The latest studies on surgical and cost-analysis outcomes after laparoscopic distal pancreatectomy (LDP) highlight mixed and insufficient results. Whereas several investigators have compared surgical outcomes of LDP vs. open distal pancreatectomy (ODP) for adenocarcinomas, few similar studies have focused on pancreatic neuroendocrine tumors (PNETs).

METHODS

We reviewed the medical records of PNET patients undergoing distal pancreatectomy between 2004 and 2014. Patients were divided into LDP vs. ODP groups. Demographics, relevant comorbidities, oncologic variables, and cost-analysis data were assessed. Survival and Cox proportional hazards analyses were used to evaluate outcomes.

RESULTS

Of the 171 distal pancreatectomies for PNETs, 73 were laparoscopic, whereas 98 were open. Patients undergoing LDP demonstrated significantly lower rates of postoperative complications (P=0.028) and had significantly shorter hospital stays (P=0.008). On multivariable analysis, positive resection margins (P=0.046), G3 grade (P=0.036), advanced WHO classification (P=0.016), TNM stage (P=0.018), and readmission (P=0.019) were significantly associated with poor survival; however, method of resection (LDP vs. ODP) was not (P=0.254). The median total direct costs of LDP vs. ODP did not differ significantly.

CONCLUSIONS

In response to the recent considerable controversy surrounding the costs and surgical outcomes of LDP vs. ODP, our results show that LDP for PNETs is cost-neutral and significantly reduces postoperative morbidity without compromising oncologic outcomes and survival.

Laparoscopic resection of pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (PNETs) are a rare heterogeneous group of endocrine neoplasms. Surgery remains the best curative option for this type of tumor. Over the past two decades, with the development of laparoscopic pancreatic surgery, an increasingly larger number of PNET resections are being performed by these minimally-invasive techniques. In this review article, the various laparoscopic surgical options for the excision of PNETs are discussed. In addition, a summary of the literature describing the outcome of these treatment modalities is presented.

Clinical pathways for pancreatic neuroendocrine tumors

BACKGROUND

Pancreatic neuroendocrine tumors (PNETs) represent a group of diseases that pose diagnostic and therapeutic challenges due to their clinical and pathological heterogeneity as well as the limited number of patients available for clinical trials. Over the last couple of decades, a major progress in understanding tumor biology led to the discovery of new potential targets for the medical treatment of these tumors.

DISCUSSION

There are numerous novel targeted agents in various stages of preclinical and clinical development that offer considerable promise as monotherapy or combination therapy for PNETs. The question of whether traditional clinical research methods are appropriate for the development of novel, targeted anticancer agents has been the subject of many discussions. Major challenges include identifying a valid target, the most effective agent within a target class, the right subset of population to benefit from the drug, and the most appropriate setting to use the drug. As new agents emerge, oncologists are faced with making clinical decisions sometimes before having a high level of evidence. In this review, we attempt to address some of the management steps involved in treating patients with pancreatic neuroendocrine tumors, particularly well to moderately differentiated tumors. The purpose of this review is to offer a therapeutic sequence including surgery, liver-directed therapy, chemotherapy, and targeted therapy for this disease.

Surgery for GEP-NETs

Surgery is the only treatment that may cure the patient with gastroentero-pancreatic (GEP) neuroendocrine tumours (NET) and neuroendocrine carcinomas (NEC) and should always be considered as first line treatment if R0/R1 resection can be achieved. The surgical and interventional procedures for GEP-NET are accordingly described below. Life-long follow-up should be performed in almost all patients at a specialized NET center.

[Surgery for neuroendocrine tumors of the gastroenteropancreatic system (GEP-NET)]

Surgical treatment is still the only curative treatment proven for patients with neuroendocrine tumors (NET) of the gastroenteropancreatic system. In addition to the therapy of incidental findings, the treatment of NET with variable aggressiveness and often good long-term prognosis requires a thorough preoperative assessment and a surgical procedure that is based on each individual case. Treatment can be surgery alone (if the disease is locally confined) or can be combined with other therapies. Early NET of the stomach and rectum can be cured endoscopically without further diagnostics, while early findings of the appendix can be treated by an appendectomy. Functionally active pancreatic NET and NET of the small intestine are often preoperatively diagnosed based on symptoms. Thus, it is possible to refer the patient to a NET center, if necessary. Stratification of the necessary treatment combination can be made early. An alternative to radical surgical treatment is the operative reduction of the tumor size and hormone production in metastasized NET, which can lead to improved life expectancy and quality of life. Combination with other treatment forms is absolutely necessary in these patients. It has been proven useful to divide the large group of NET based on the different tumor locations, hormone activity, and the degree of differentiation of the tumor. Early forms, locoregionally limited tumor stages, and tumor stages with distant metastases are considered separately.

Pancreatic endocrine tumors in multiple endocrine neoplasia type 1 syndrome: review of literature

OBJECTIVE

To analyze the surgical approach to multiple endocrine neoplasia type 1 (MEN 1)-related pancreatic endocrine tumors (PETs).

METHODS

We reviewed selected publications and our personal experience with MEN 1-associated PETs to delineate their general characteristics, current practice and controversies, preoperative imaging and intraoperative assessment, and appropriate therapeutic strategies including radical surgical procedures.

RESULTS

The penetrance of PETs in the setting of MEN 1 is similar to that of parathyroid tumors, even though hyperparathyroidism is usually the first manifestation of MEN 1 syndrome. In contrast with the sporadic counterparts, MEN 1-related PETs are characterized by an early onset, multiplicity of lesions, variable expression of the tumors, and propensity for malignant degeneration. Both the histologic type and the size of these tumors correlate with malignant potential.

CONCLUSION

The rationale for surgical considerations for these tumors is to curtail the malignant progression of the disease and to cure or aid in management of the associated biochemical syndromes. A surgical procedure is often the treatment of choice for PETs in patients with MEN 1. Monitoring of pancreatic peptides and use of diagnostic imaging allow an early pancreatic resection, in conjunction with prevention of metastatic PETs and improvement of long-term survival. Hepatic metastatic lesions can be successfully treated by surgical resection.

Surgical treatment of liver metastases in neuroendocrine neoplasms

Neuroendocrine neoplasms (NENs) are a distinctive entity, and nearly 10% of patients already have liver metastases at presentation. The management of neuroendocrine liver metastases (NEN-LM) is complex with differing patterns of metastatic presentation. An aggressive approach should be used to resect the primary tumor, to remove regional lymph nodes, and to resect or treat appropriate distant metastases (including liver tumors). Despite having an indolent course, NENs have a significantly reduced survival when liver metastases are untreated. Though a wide range of therapies are now available with a multimodal approach to the treatment, surgical treatment offers the only chance for a significant survival prolongation and/or improvement of symptoms and quality of life. A review of the existing surgical modalities for NEN-LM is discussed in this paper.

Surgical treatment of neuroendocrine liver metastases

Management of Neuroendocrine liver metastases (NELM) is challenging. The presence of NELM worsens survival outcome and almost 10% of all liver metastases are neuroendocrine in origin. There is no firm consensus on the optimal treatment strategy for NELM. A systematic search of the PubMed database was performed from 1995-2010, to collate the current evidence and formulate a sound management algorithm. There are 22 case series with a total of 793 patients who had undergone surgery for NELM. The overall survival ranges from 46-86% at 5 years, 35-79% at 10 years, and the median survival ranges from 52-123 months. After successful cytoreductive surgery, the mean duration of symptom reduction is between 16-26 months, and the 5-year recurrence/progression rate ranges from 59-76%. Five studies evaluated the efficacy of a combination cytoreductive strategy reporting survival rate of ranging from 83% at 3 years to 50% at 10 years. To date, there is no level 1 evidence comparing surgery versus other liver-directed treatment options for NELM. An aggressive surgical approach, including combination with additional liver-directed procedures is recommended as it leads to long-term survival, significant long-term palliation, and a good quality of life. A multidisciplinary approach should be established as the platform for decision making.

Survival impact of malignant pancreatic neuroendocrine and islet cell neoplasm phenotypes

BACKGROUND

The low incidence of malignant "functional" (F) or "nonfunctional" (NF) neuroendocrine islet cell tumors (ICTs) of the pancreas represents a challenge to precise post-therapeutic survival prediction. This study examined the survival impact of malignant pancreatic ICT morphologic subtypes.

METHODS

A pancreatic ICT data set was created from a US-based population database from 1980-2004. Prognostic factors with survival impact and relationships between surgical therapy and overall survival (OS) were analyzed.

RESULTS

There were 2,350 individuals with malignant ICTs. Histologic subtypes included carcinoid tumors, islet cell carcinomas, neuroendocrine carcinomas, and malignant gastrinomas, insulinomas, glucagonomas, or VIPomas. There was no difference in resection rates between FICTs and NFICTs (23% vs. 20%, P = ns). Median OS was 30 months, with group differences ranging from NE carcinomas (21) to VIPomas (96; P < 0.0001). Median OS of resected versus unresected FICTs was 172 versus 37 months, while that of NFICTs was 113 versus 18 months (P < 0.0001). Compared to neuroendocrine carcinomas, hazard ratios were: VIPomas 0.48, gastrinomas 0.65, carcinoid tumors 0.76, insulinomas 0.84, glucagonomas 0.93, and islet cell carcinomas 1.0.

CONCLUSIONS

When controlled for other established prognostic parameters, histopathologic subtype assignment of pancreatic ICTs affects survival prediction. Resection is associated with superior survival for all tumor types.

Surgical resection and multidisciplinary care for primary and metastatic pancreatic islet cell carcinomas

INTRODUCTION

The role of multidisciplinary management of islet cell cancers (ICC) has not been fully investigated in a population-based setting.

METHODS

The Los Angeles County Cancer Surveillance Program was assessed for patients with ICC between the years 1982 to 2006. Patients were stratified by treatment received and clinicopathologic characteristics and survival were compared.

RESULTS

We identified 236 patients with ICC; 86 patients underwent curative-intent surgery with median survival for local, regional, and distant disease of 17.3, 12.2, and 4.0 years, respectively. In comparison, 102 patients underwent medical management alone; survival was significantly shorter when compared to the surgical cohort for local, regional, and distant disease (p < 0.05). To determine whether adjuvant chemotherapy was associated with improved survival, we compared patients who underwent surgery alone compared to patients who underwent surgery followed by adjuvant chemotherapy. Although patients with metastatic disease had 3-year longer survival with adjuvant chemotherapy, these improvements in survival were not statistically significant.

CONCLUSION

Surgical resection was associated with improved survival compared to medical management for any extent of disease in patients with ICC. Furthermore, adjuvant chemotherapy was not associated with survival but does warrant further examination in patients with metastatic disease.

Multimodal management of neuroendocrine liver metastases

BACKGROUND

The incidence of neuroendocrine tumours (NET) has increased over the past three decades. Hepatic metastases which occur in up to 75% of NET patients significantly worsen their prognosis. New imaging techniques with increasing sensitivity enabling tumour detection at an early stage have been developed. The treatment encompasses a panel of surgical and non-surgical modalities.

METHODS

This article reviews the published literature related to management of hepatic neuroendocrine metastases.

RESULTS

Abdominal computer tomography, magnetic resonance tomography and somatostatin receptor scintigraphy are widely accepted imaging modalities. Hepatic resection is the only potentially curative treatment. Liver transplantation is justified in highly selected patients. Liver-directed interventional techniques and locally ablative measures offer effective palliation. Promising novel therapeutic options offering targeted approaches are under evaluation.

CONCLUSIONS

The treatment of neuroendocrine liver metastases still needs to be standardized. Management in centres of expertise should be strongly encouraged in order to enable a multidisciplinary approach and personalized treatment. Development of molecular prognostic factors to select treatment according to patient risk should be attempted.

Non-functional neuroendocrine carcinoma of the pancreas: incidence, tumor biology, and outcomes in 2,158 patients

OBJECTIVE

Pancreatic neuroendocrine cancer is a rare, indolent malignancy with no effective systemic therapy currently available. This population-based analysis evaluated the hypothesis that long-term survival benefit is greater with aggressive, rather than limited, surgical therapy.

METHODS

Non-functional pancreatic neuroendocrine carcinoma (NF-pNEC) cases diagnosed from 1973 to 2004 were retrieved from the SEER database.

RESULTS

A total of 2,158 patients with NF-pNEC were identified, representing 2% of all pancreatic malignancies. The annual incidence increased from 1.4 to 3.0 per million during the study period. On average, tumors measured 59 +/- 35 mm (median 50), and age at diagnosis was 59 +/- 15 years; 29% of patients were younger than 50. Nodal (44%) and systemic metastases (60%) were common. Overall the 5-, 10-, and 20-year survival rates were 33%, 17%, and 10%, respectively. Removal of the primary tumor significantly prolonged survival in the entire cohort (median 1.2 vs. 8.4 years; p < 0.001) and among those with metastases (median 1.0 vs. 4.8 years; p < 0.001). No survival difference was seen between enucleation and resection of the primary tumor (median 10.2 versus 9.2 years, p = 0.456).

CONCLUSION

This study suggests that surgical therapy improves survival among patients with localized, as well as metastatic, NF-pNEC. Enucleation may be oncologically equivalent to resection.

Neuroendocrine tumors of the pancreas

Pancreatic endocrine tumors are rare neoplasms accounting for less than 5% of pancreatic malignancies. They are broadly classified into either functioning tumors (insulinomas, gastrinomas, glucagonomas, VIPomas, and somatostatinomas) or nonfunctioning tumors. The diagnosis of these tumors is difficult and requires a careful history and examination combined with laboratory tests and radiologic imaging. Signs and symptoms are usually related to hormone hypersecretion in the case of functioning tumors and to tumor size or metastases with nonfunctioning tumors. Surgical resection remains the treatment of choice even in the face of metastatic disease. Further development of novel diagnostic and treatment modalities offers potential to greatly improve quality of life and prolong disease-free survival for patients with pancreatic endocrine tumors.

Survival and prognostic factor analysis in patients with metastatic pancreatic endocrine carcinomas

OBJECTIVES

Pancreatic endocrine carcinomas (PECAs) are uncommon, with an incidence of 1 per 100,000. Past studies of chemotherapy and hepatic arterial embolization have described median survival durations of approximately 2 to 3 years. Overall survival from time of diagnosis of metastases has never been reported in a large cohort of patients. Our objective was to evaluate the stage-specific prognosis of patients with metastatic PECAs and to assess the impact of clinical and pathologic prognostic factors.

METHODS

We evaluated all cases of differentiated, metastatic PECAs seen at the H. Lee Moffitt Cancer Center between the years 1999 and 2003, measuring survival from time of diagnosis of metastases.

RESULTS

Ninety cases of metastatic PECAs were identified. Median overall survival was 70 months, and the 5-year survival rate was 56%. Age, sex, and tumor type (functional vs nonfunctional) did not impact prognosis. Tumor grade, however, was highly prognostic for survival.

CONCLUSIONS

Median overall survival is 70 months (5.8 years) among patients with metastatic PECAs. This prolonged survival duration may reflect the impact of multimodality treatments. Tumor grade (low vs intermediate grade) represents a highly significant prognostic factor.

A rare surgical case of multiple liver resections for recurrent liver metastases from pancreatic gastrinoma: liver and vena cava resection

Pancreatic gastrinoma is a rare non-beta islet cell tumor. Approximately 60% of gastrinomas are malignant; despite the fact that they are usually slow growing, liver metastases have a major impact on prognosis. Most authors have advocated aggressive surgical management as being the only potentially curative therapy to improve survival as well as to provide outstanding relief from symptoms. We present a case of a 57-year-old man referred to our hospital with a diagnosis of liver metastases from pancreatic gastrinoma, with suspected involvement of the inferior vena cava (IVC). At the age of 37 years, he was diagnosed in his local hospital as having a pancreatic gastrinoma, with liver metastases, and he underwent distal pancreatectomy, splenectomy and enucleation of liver metastases. A liver tumor recurred twice, 7 and 9 years after the first surgery, for which double liver resections were performed: the first time he underwent enucleation of multiple liver metastases in segments II, III, IV, V, VI, VII and VIII, with resection of the right hepatic vein and partially resection of the diaphragm; the second time he underwent enucleation of multiple liver metastases in segments II, III, IV, and V. In our hospital, 8 years after the last surgery, the patient underwent right extended trisectionectomy, resection of segment I, combined resection of the IVC, and partial removal of the diaphragm. To the best of our knowledge, from a review of the literature, this is the first case to achieve successful long-term survival through aggressive surgical management of this type of metastatic endocrine tumor. The patient described here is still alive, free of disease and leading a normal life, 20 years after the initial diagnosis and 3 years after the last surgery.

Treatment of liver metastases from neuroendocrine tumours in relation to the extent of hepatic disease

BACKGROUND

Hepatic surgery is presumed to improve survival of patients with liver metastases (LM) from neuroendocrine tumours (NET). This study identified LM-specific variables that could be used as additional selection criteria for aggressive treatment.

METHODS

A novel classification of LM from NET was established based on their localization and presentation.

RESULTS

From 1992 to 2006, 119 patients underwent staging and treatment of LM. Three growth types of LM were identified radiologically: single metastasis (type I), isolated metastatic bulk accompanied by smaller deposits (type II) and disseminated metastatic spread (type III). The three groups differed significantly in terms of chronological presentation of LM, hormonal symptoms, Ki-67 index, 5-hydroxyindoleacetic acid and chromogranin A levels, lymph node involvement, presence of bone metastases and treatment options. The 3-, 5- and 10-year disease-specific survival rates for the entire cohort were 76.4, 63.9 and 46.5 per cent respectively. There were significant differences in survival between the three groups: 5- and 10-year rates were both 100 per cent for type I, 84 and 75 per cent respectively for type II, and 51 and 29 per cent for type III.

CONCLUSION

The localization and biological features of LM from NET defines therapeutic management and is predictive of outcome.

Gastrointestinal neuroendocrine tumors: pancreatic endocrine tumors

Pancreatic endocrine tumors (PETs) have long fascinated clinicians and investigators despite their relative rarity. Their clinical presentation varies depending on whether the tumor is functional or not, and also according to the specific hormonal syndrome produced. Tumors may be sporadic or inherited, but little is known about their molecular pathology, especially the sporadic forms. Chromogranin A appears to be the most useful serum marker for diagnosis, staging, and monitoring. Initially, therapy should be directed at the hormonal syndrome because this has the major initial impact on the patient's health. Most PETs are relatively indolent but ultimately malignant, except for insulinomas, which predominantly are benign. Surgery is the only modality that offers the possibility of cure, although it generally is noncurative in patients with Zollinger-Ellison syndrome or nonfunctional PETs with multiple endocrine neoplasia-type 1. Preoperative staging of disease extent is necessary to determine the likelihood of complete resection although debulking surgery often is believed to be useful in patients with unresectable tumors. Once metastatic, biotherapy is usually the first modality used because it generally is well tolerated. Systemic or regional therapies generally are reserved until symptoms occur or tumor growth is rapid. Recently, a number of newer agents, as well as receptor-directed radiotherapy, are being evaluated for patients with advanced disease. This review addresses a number of recent advances regarding the molecular pathology, diagnosis, localization, and management of PETs including discussion of peptide-receptor radionuclide therapy and other novel antitumor approaches. We conclude with a discussion of future directions and unsettled problems in the field.

Is laparoscopic resection adequate in patients with neuroendocrine pancreatic tumors?

Since the first reports with laparoscopic resection of islet cell tumors in 1996, the experience worldwide is still limited, with only short-term outcomes available. Some have suggested that a malignant tumor is a contraindication to laparoscopic resection. Aim The aim of this study was to evaluate the feasibility, safety, and long-term outcome of the laparoscopic approach in patients with functioning, nonfunctioning, or overt malignant pancreatic neuroendocrine tumor (PNT). To our knowledge this is the largest single-institution series on this subject to date. Patients and methods A total of 49 consecutive patients (43 women, 6 men; mean age 58 years, range 22-83 years) underwent laparoscopic pancreatic surgery (LPS) from April 1998 to June 2007. Preoperative localization was done by computed tomography, magnetic resonance imaging, endoscopic ultrasonography, and Octreoscan imaging. Other than 9 PNTs localized in the head of the pancreas, all tumors were located in the left pancreas. Malignancy was diagnosed based on the presence of lymph nodes or liver metastasis. There were 33 patients with functioning tumors: 4 with gastrinomas (mean size 1.2 cm), 1 with a glucagonoma (4 cm), 3 with vipomas (3.2 cm), 2 with carcinoids (5.2 cm), 20 with sporadic insulinomas (1.4 cm), 2 with insulinoma/multiple endocrine neoplasia type 1 (MEN-1) (4.4 cm), and 1 with a malignant insulinoma (13 cm). Sixteen patients had a nonfunctioning tumor (mean size 5 cm). The following techniques were performed: laparoscopic spleen-preserving distal pancreatectomy (Lap SPDP), laparoscopic distal pancreatectomy with splenectomy (Lap SxDP) and laparoscopic enucleation (Lap En)/laparoscopic excision (Lap E). Lymph node dissection was performed when malignancy was suspected (Strasberg s technique). Evaluation criteria included operative and postoperative factors, pathologic data including R0 or R1 resection (the pancreatic transection margin and all transection margins on the specimen were inked). Long-term outcomes were analyzed by tumor recurrence and patient survival. Results Four cases (8.2%) were converted to open surgery. Overall, Lap SPDP, Lap SxDP, and Lap En/Lap E were performed in 15 (33.3%), 8 (17.8%), and 22 (48.9%) patients, respectively. The operative time and blood loss was significantly lower in the Lap En group compared with the other laparoscopic techniques. The group of patients with malignant tumors undergoing Lap SxDP had a longer operating time and greater blood loss compared with the other distal pancreatectomy (Lap DP) techniques. Overall, the postoperative complications were significantly higher in the Lap En group (42.8%) than in the Lap DP (Lap SPDP+Lap SxDP) group (22%). These complications were mainly pancreatic fistula: 8.7% after Lap DP and 38% after Lap En. The overall morbidity was significantly higher after Lap SPDP (26.7%) than after Lap SxDP (12.5%) owing to the occurrence of splenic complications in the Lap SPDP group without splenic vessel preservation two of seven (28.5%). The means and ranges of hospital stay after Lap SPDP, Lap SxDP, and Lap En/Lap E were 5.9 (5-14), 7.5 (5-12), and 5.5 (5-7) days, respectively (NS). Pathology examination of the specimen showed R0 resection in all patients with malignant PNT. The mean time to resumption of previous activities for patients undergoing Lap DP or Lap En was 3 weeks. There were no postoperative (30 days) or hospital deaths. Conclusions This series demonstrates that LPS is feasible and safe in benign-appearing and malignant neuroendocrine pancreatic tumors (NEPTs). The benefits of minimally invasive surgery were manifest in the short hospital stay and acceptable pancreas-related complications in high-risk patients. LPS can achieve negative tangential margins in a high percentage of patients with malignant tumors. Although surgical cure is rare in malignant NEPTs, significant long-term palliation can be achieved in a large proportion of patients with an aggressive surgical approach.

Pancreatic endocrine neoplasms: epidemiology and prognosis of pancreatic endocrine tumors

Pancreatic endocrine tumors (PETs) are uncommon tumors with an annual incidence <1 per 100 000 person-years in the general population. The PETs that produce hormones resulting in symptoms are designated as functional. The majority of PETs are non-functional. Of the functional tumors, insulinomas are the most common, followed by gastrinomas. The clinical course of patients with PETs is variable and depends on the extent of the disease and the treatment rendered. Patients with completely resected tumors generally have a good prognosis, and aggressive surgical therapy in patients with advanced disease may also prolong survival. The epidemiology, prognosis, and established and novel prognostic markers of PETs are reviewed.

Is surgery indicated for patients with symptomatic nonfunctioning pancreatic neuroendocrine tumor and unresectable hepatic metastases?

BACKGROUND

Patients with advanced pancreatic neuroendocrine tumor, even in the presence of unresectable hepatic metastases, have survival usually measured in years than in months. Theoretically, we would have reason to resect symptomatic primary pancreatic neuroendocrine tumors from these patients palliatively. However, the effect and feasibility of removing symptomatic primary pancreatic neuroendocrine tumor in patients with unresectable hepatic metastases has never been addressed.

METHODS

In 2000, we instituted a prospective study to resect symptomatic primary tumors and treat unresectable hepatic metastases by lanreotide and hepatic artery embolization in patients with definite tissue proof of pancreatic neuroendocrine tumor.

RESULTS

Thirteen patients were included in this study; seven patients underwent pancreaticoduodenectomy, and six underwent distal pancreatectomy and splenectomy. There were no operative deaths. Eight of thirteen patients had no radiologic evidence of disease progression. The other five patients had disease progression by their 6-month follow-up; they underwent hepatic artery chemoembolization or chemotherapy. One patient died of multiple lung and bone metastases 80 months after operation, and one patient died of continuous progression of liver metastases 18 months after operation. Telephone interviews of 11 patients who survived revealed that 10 reported improved quality of life after resection of symptomatic primary pancreatic neuroendocrine tumor and one patient reported no change.

CONCLUSIONS

We suggest that symptomatic primary pancreatic neuroendocrine tumors should be resected even when unresectable hepatic metastases are found at diagnosis because of the relatively low risk of pancreatic surgery, effective elimination of symptoms caused by primary tumors, and slow progression of hepatic metastases under lanreotide and hepatic artery embolization.

Benign pancreatic tumors

The goal of this article is to describe the different types of benign pancreatic neoplasms, methods to distinguish between them, and treatment options. Pancreatic adenocarcinoma is associated with specific neoplastic lesions that are similar in radiographic appearance to some benign lesions. The correct differentiation of these malignant and premalignant lesions from their benign counterpart is paramount to their proper management.

Pancreatic neuroendocrine tumours

Pancreatic neuroendocrine tumours are rare tumours ( approximately 1/100,00 population/year) of which 60% are non-functioning. Except for insulinoma all types are malignant in >50% of cases. In multiple endocrine neoplasia (MEN)1, pancreatic neuroendocrine tumours occur in 40-80% of patients and are mostly non-functioning tumours or gastrinomas. Insulinomas are benign in approximately 90%, solitary in 95% of sporadic cases whilst multiple in 90% of MEN1 patients. In contrast approximately 50% gastrinomas and the majority of non-functioning pancreatic neuroendocrine tumours are malignant. Pancreatic neuroendocrine tumours occur in 10-15% of patients with Von Hippel-Lindau (VHL) and are frequently multiple (>30%). Surgical excision is a key aspect of treatment for all cases of sporadic gastrinoma and if >2.5 cm in MEN1. Insulinomas are enucleated if solitary and may require pancreatectomy if multiple. Non-functioning tumours should also be resected if sporadic and if >2 cm in MEN1 or if >2-3 cm in VHL. Tumours <1cm require yearly follow-up by CT or MRI from an early age in VHL. The local treatment for liver metastases is now well established and options include liver resection, chemoembolisation and radiofrequency ablation. Systemic therapies have also been better defined and include radionuclide therapy against somatostatin receptors or MIBG and chemotherapy especially for poorly differentiated tumours. A number of novel agents are currently in clinical development.

Current medical treatment of pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (NETs) consist of a wide group of neoplasms, with different biological behaviors in terms of aggressiveness and hormone production. In the last two decades, significant progress has been observed in our understanding of their biology, diagnosis and treatment. Surgery remains to be the only curative approach, but unfortunately the diagnosis is often delayed due to the slow growth of these tumors and the difficulty in identifying the symptoms related to the tumor-released hormones. In addition to surgery, other approaches to control the disease are biological therapy consisting of somatostatin analogs and interferon (IFN), systemic chemotherapy, radioligand therapy and local therapy with chemoembolization. Several newer cytotoxic agents, including irinotecan, gemcitabine, taxanes, oxaliplatin, capecitabine and PS-341 have been studied in metastatic patients. Considering the high vascularity of these tumors, antiangiogenic agents like endostatin and thalidomide have also been evaluated in advanced NETs. Although these agents seem to have potential activity in NETs and may increase progression free survival, none of these currently available medical therapeutic options are curative. While more efficient novel strategies are to be developed, the rationale use of the current therapeutic options may improve quality of life, control the symptoms related to the hypersecretion of hormones and/or peptides, control tumor proliferation and prolong survival in patients suffering from NETs.