Surgery for primary pancreatic neuroendocrine tumors

[Enucleation of pancreatic tumors: a multiple-center study]

OBJECTIVE

To evaluate the immediate results of enucleation of pancreatic neuroendocrine tumors (pNETs).

MATERIAL AND METHODS

The results of enucleation of pancreatic neuroendocrine tumors (pNETs) were analyzed in 95 patients between 2016 and 2021. Functioning tumors (mean size 16.8 mm) were found in 70 patients, non-functioning (mean size 25 mm) - in 25 patients. Intraparenchymal tumors were found in 48 people, extraorganic lesion - in 47 patients.

RESULTS

There were 262 patients with pNETs who underwent various surgeries between 2016 and 2021. Various resections were performed in 167 (63.8%) cases, enucleations - in 95 (36.2%) patients. Traditional surgical approach was used in 65 patients. Pancreatic fistula occurred in 21 patients (type B - 17, type C - 4), while arrosive bleeding occurred in 6 patients with unfavorable outcomes in 2 cases. Minimally invasive surgeries were performed in 30 patients. Eight patients with intraparenchymal tumors required conversion to open surgery. Type B pancreatic fistula occurred in 5 patients that led to arrosive bleeding in 2 cases (hemostasis was provided by endovascular method). Comparison of intraparenchymal and extraorgan tumors regarding the incidence of pancreatic fistula revealed odds ratio 5.26 (95% CI 1.5355; 18.0323, p=0.0041). Postoperative mortality was 2.1%.

CONCLUSION

Enucleation is advisable for highly differentiated pancreatic neuroendocrine tumors up to 2 cm. Minimally invasive enucleation is indicated for extraorgan tumors. Intraparenchymal tumors significantly increase the risk of postoperative complications.

PROGNOSTIC FACTORS IN PATIENTS WITH SURGICAL RESECTION OF PANCREATIC NEUROENDOCRINE TUMOURS

CONTEXT

Pancreatic neuroendocrine tumours (PanNETs) are rare pancreatic neoplasms. PanNETs can be treated by multimodal approach including surgery, locoregional and systemic therapy.

OBJECTIVE

The aim of the present study is to evaluate predictive factors of overall survival in patients with PanNETs surgically treated at a single center.

SUBJECTS AND METHODS

The study group consisted of 120 patients with PanNETs who had undergone surgery at the Center of Digestive Diseases and Liver Transplantation of Fundeni Clinical Institute, Bucharest, Romania. Surgical resection of the primary tumor was performed in 110 patients.

RESULTS

Tumor size > 2 cm (p=0.048) (90% CI) lymph node involvement (p=0.048), ENET grade (p<0.001), distant metastases (p<0.001), Ki 67 index (<2%, 2-5%, 5-10%, 10-20%, >20%) (p<0.001) were identified as significant prognostic factors for OS on univariate analysis. Using multivariate Cox proportional regression model we found that distant metastases and Ki 67 index were independent risk factors for the survival outcome.

CONCLUSIONS

Surgery with curative intent should be considered in all cases if clinically appropriate and technically feasible. High grade (Ki67 index ≥10%) tumours were associated with a 2- fold increase in risk of death as compared to those with a Ki67 <10%.

Enucleation of non-invasive tumors in the proximal pancreas: indications and outcomes compared with standard resections

OBJECTIVE

The aim of this study was to evaluate the safety and efficiency of enucleation (EU) for proximal pancreatic non-invasive neoplasms.

METHODS

Patients with solitary non-invasive neoplasms in the proximal pancreas from January 1998 to April 2014 at the Second Affiliated Hospital of Zhejiang University, Hangzhou, China were included. Different operations and outcomes were analyzed.

RESULTS

A total of 123 patients were enrolled. Forty patients (32.5%) underwent EU including 18 patients who had tumors close to the main pancreatic duct (MPD). Sixty-one patients (49.6%) had pancreaticoduodenectomy (PD) performed and 22 (17.9%) underwent central pancreatectomy (CP). Pathological outcomes included neuroendocrine tumors, cystic lesions, and solid pseudopapillary tumors. Operation time, intra-operative blood loss, and duration of hospital stay were significantly reduced in the EU group. PD was associated with the greatest complication rate (55.7%), followed by EU (50%) and CP (40.9%), though the pancreatic fistula rate after EU was the highest (50%), especially in patients with tumors larger than 3 cm and tumors close to the MPD. EU had advantages in the preservation of pancreatic parenchyma and endocrine and exocrine function.

CONCLUSIONS

EU can be carried out safely and effectively for tumors in the proximal pancreas with improved outcomes compared with standard resections, even if the tumor is larger than 3 cm and close to the MPD.

Carcinoid Syndrome Complicating a Pancreatic Neuroendocrine Tumor: A Case Report

Neuroendocrine tumors (NETs) comprise a heterogeneous group of neoplasms. These tumors can produce a wide variety of hormones that can lead to syndromes of hormone excess, such as carcinoid syndrome. We present the case of a 47-year-old man who presented with right upper quadrant abdominal pain and emesis. He was found to have metastatic pancreatic NET and was treated with systemic chemotherapy. He subsequently developed dyspnea on exertion and was found to have severe right-sided heart disease secondary to elevated levels of serum serotonin. He was successfully treated with surgical tricuspid and pulmonic valve replacement. True carcinoid syndrome with pancreatic NETs is rare, but, as a treatable complication of the disease, is an important entity for which oncologists should be familiar.

Alternative Lengthening of Telomeres in Primary Pancreatic Neuroendocrine Tumors Is Associated with Aggressive Clinical Behavior and Poor Survival

Purpose: Alternative lengthening of telomeres (ALT), a telomerase-independent telomere maintenance mechanism, is strongly associated with ATRX and DAXX alterations and occurs frequently in pancreatic neuroendocrine tumors (PanNET).Experimental Design: In a Korean cohort of 269 surgically resected primary PanNETs and 19 sporadic microadenomas, ALT status and nuclear ATRX and DAXX protein expression were assessed and compared with clinicopathologic factors.Results: In PanNETs, ALT or loss of ATRX/DAXX nuclear expression was observed in 20.8% and 19.3%, respectively, whereas microadenomas were not altered. ALT-positive PanNETs displayed a significantly higher grade, size, and pT classification (all, P < 0.001). ALT also strongly correlated with lymphovascular (P < 0.001) and perineural invasion (P = 0.001) and the presence of lymph node (P < 0.001) and distant metastases (P = 0.002). Furthermore, patients with ALT-positive primary PanNETs had a shorter recurrence-free survival [HR = 3.38; 95% confidence interval (CI), 1.83-6.27; P < 0.001]. Interestingly, when limiting to patients with distant metastases, those with ALT-positive primary tumors had significantly better overall survival (HR = 0.23; 95% CI, 0.08-0.68; P = 0.008). Similarly, tumors with loss of ATRX/DAXX expression were significantly associated with ALT (P < 0.001), aggressive clinical behavior, and reduced recurrence-free survival (P < 0.001). However, similar to ALT, when limiting to patients with distant metastases, loss of ATRX/DAXX expression was associated with better overall survival (P = 0.003).Conclusions: Both primary ALT-positive and ATRX/DAXX-negative PanNETs are independently associated with aggressive clinicopathologic behavior and displayed reduced recurrence-free survival. In contrast, ALT activation and loss of ATRX/DAXX are both associated with better overall survival in patients with metastases. Therefore, these biomarkers may be used as prognostic markers depending on the context of the disease. Clin Cancer Res; 23(6); 1598-606. ©2016 AACR.

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.

Surgical management of neuroendocrine tumors

During the last decades an increase in the incidence of neuroendocrine tumors (NETs) was observed. Gastroenteropancreatic NETs represent the majority of NETs. Compared with their epithelial counterpart they usually have a more indolent behaviour and surgical resection improves survival. Tumor diameter is one of the main parameter in the decision making process for nonfunctioning forms. Generally, small lesions can be treated conservatively whereas larger tumors should be treated with standard surgical resection and lymphadenectomy. Functioning tumors should be resected regardless the dimension of the lesion. Locally advanced and metastatic disease should be also treated with extended resections, keeping in consideration the grading, size, Ki67, and presence of extra-abdominal disease. In the case of metastases the panel of operative treatment includes resection, ablation, up to liver transplantation.

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.

Application of AJCC/UICC and WHO-2010 classifications for GEP-NEN in Chinese patients

OBJECTIVE

To assess the prognostic value in Chinese patients of two new systems, the World Health Organization (WHO)-2010 and the American Joint Committee on Cancer and the Union for International Cancer Control (AJCC/UICC) systems, for the classification of gastroenteropancreatic neuroendocrine neoplasms (GEP-NEN).

METHODS

One hundred and three patients with GEP-NEN treated at the First Affiliated Hospital of Nanjing Medical University from January 2003 to December 2011 were included in the study. All patients were diagnosed pathologically and had complete follow-up data. Univariate and multivariate analyses of their clinicopathological characteristics were performed.

RESULTS

The 5-year survival rates were 95%, 74%, 24% and 15% based on the AJCC/UICC stages I to IV, and 92%, 62% and 29% according to WHO-2010 grades 1 to 3, respectively, in patients with GEP-NEN. A higher mortality was observed in patients with AJCC/UICC stage III and IV tumors compared with those at stage I-II, and patients with stage II compared with those with stage I, whereas there was no difference in survival between stage IV and III patients. Based on the WHO-2010 grading classification, patients with grade 3 tumors had the lowest survival rate than those with grade 1 and 2 tumors, followed by patients with grade 2 tumors.

CONCLUSION

The WHO-2010 and AJCC/UICC staging systems can effectively evaluate the prognosis of patients with GEP-NEN, although the latter might not accurately discriminate the prognosis of patients with local metastasis from those having distant metastasis.

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.

Insulinoma imaging with glucagon-like peptide-1 receptor targeting probe (18)F-FBEM-Cys (39)-exendin-4

PURPOSE

Glucagon-like peptide-1 receptor (GLP-1R) is a specific target for insulinomas imaging since it is overexpressed in the tumor. Exendin-4 exhibits high affinity for the GLP-1R. In this study, a novel (18)F-labeled exendin-4 analog, (18)F-FBEM-Cys(39)-exendin-4, was synthesized and its potentials for GLP-1R imaging were also evaluated.

METHODS

(18)F-FBEM was synthesized by coupling (18)F-fluorobenzoic acid ((18)F-FBA) with N-(2-aminoethyl) maleimide, and the reaction conditions were optimized. Cys(39)-exendin-4 was then conjugated with (18)F-FBEM to obtain (18)F-FBEM-Cys(39)-exendin-4. The GLP-1R targeting potential and pharmacokinetic profile of the tracer were analyzed in INS-1 insulinoma and MDA-MB-435 breast tumor model, respectively.

RESULTS

Under the optimal conditions, the yield of radiolabeled (18)F-FBEM was 49.1 ± 2.0 % (based on (18)F-FBA, non-decay corrected). The yield of (18)F-FBEM-Cys(39)-exendin-4 was 35.1 ± 2.6 % (based on the starting (18)F-FBEM, non-decay corrected). The radiochemical purity of (18)F-FBEM-Cys(39)-exendin-4 is >95 %, and the specific activity was at least 35 GBq/μmol. The GLP-1R-positive INS-1 insulinoma xenograft was clearly visible with good contrast to background, whereas GLP-1R-negative MDA-MB435 breast tumor was barely visible. Low levels of radioactivity were also detected at pancreas and lungs due to few GLP-1R expressions. GLP-1R binding specificity was demonstrated by reduced INS-1 tumor uptake of the tracer after coinjection with an excess of unlabeled Cys(39)-exendin-4 at 1 h postinjection.

CONCLUSION

The thiol-reactive reagent, (18)F-FBEM, was prepared with high yield and successfully conjugated to Cys(39)-exendin-4. Favorable preclinical data showing specific and effective tumor targeting by (18)F-FBEM-Cys(39)-exendin-4 suggest that the tracer may be a potential probe for insulinomas imaging.

Laparoscopic versus open pancreas resection for pancreatic neuroendocrine tumours: a systematic review and meta-analysis

BACKGROUND

Over the last decade laparoscopic pancreatic surgery (LPS) has emerged as an alternative to open pancreatic surgery (OPS) in selected patients with neuroendocrine tumours (NET) of the pancreas (PNET). Evidence on the safety and efficacy of LPS is available from non-comparative studies.

OBJECTIVES

This study was designed as a meta-analysis of studies which allow a comparison of LPS and OPS for resection of PNET.

METHODS

Studies conducted from 1994 to 2012 and reporting on LPS and OPS were reviewed. Studies considered were required to report on outcomes in more than 10 patients on at least one of the following: operative time; hospital length of stay (LoS); intraoperative blood loss; postoperative morbidity; pancreatic fistula rates, and mortality. Outcomes were compared using weighted mean differences and odds ratios.

RESULTS

Eleven studies were included. These referred to 906 patients with PNET, of whom 22% underwent LPS and 78% underwent OPS. Laparoscopic pancreatic surgery was associated with a lower overall complication rate (38% in LPS versus 46% in OPS; P < 0.001). Blood loss and LoS were lower in LPS by 67 ml (P < 0.001) and 5 days (P < 0.001), respectively. There were no differences in rates of pancreatic fistula, operative time or mortality.

CONCLUSIONS

The nature of this meta-analysis is limited; nevertheless LPS for PNET appears to be safe and is associated with a reduced complication rate and shorter LoS than OPS.

Pancreatic neuroendocrine tumours: hypoenhancement on arterial phase computed tomography predicts biological aggressiveness

BACKGROUND

Contrary to pancreatic adenocarcinoma, pancreatic neuroendocrine tumours (PNET) are commonly hyperenhancing on arterial phase computed tomography (APCT). However, a subset of these tumours can be hypoenhancing. The prognostic significance of the CT appearance of these tumors remains unclear.

METHODS

From 2001 to 2012, 146 patients with well-differentiated PNET underwent surgical resection. The degree of tumour enhancement on APCT was recorded and correlated with clinicopathological variables and overall survival.

RESULTS

APCT images were available for re-review in 118 patients (81%). The majority had hyperenhancing tumours (n = 80, 68%), 12 (10%) were isoenhancing (including cases where no mass was visualized) and 26 (22%) were hypoenhancing. Hypoenhancing PNET were larger, more commonly intermediate grade, and had higher rates of lymph node and synchronous liver metastases. Hypoenhancing PNET were also associated with significantly worse overall survival after a resection as opposed to isoenhancing and hyperenhancing tumours (5-year, 54% versus 89% versus 93%). On multivariate analysis of factors available pre-operatively, only hypoenhancement (HR 2.32, P = 0.02) was independently associated with survival.

DISCUSSION

Hypoenhancement on APCT was noted in 22% of well-differentiated PNET and was an independent predictor of poor outcome. This information can inform pre-operative decisions in the multidisciplinary treatment of these neoplasms.

Analysis of lymph node metastasis in pancreatic neuroendocrine tumors (PNETs) based on the tumor size and hormonal production

BACKGROUND

Because of the rarity and variety of pancreatic neuroendocrine tumors (PNETs), there have been few reports regarding the indication for lymph node dissection in patients with these tumors. This study aimed to evaluate the risk of lymph node metastasis of PNETs based on the tumor size and hormonal production.

METHODS

Data for a total of 66 patients who had PNETs resected at our department between 1987 and 2010 were retrospectively studied. The clinicopathological features, including the disease-specific survival rate, were assessed based on the status of lymph node metastasis at the time of initial surgical resection. Then the cut-off point of tumor size to predict lymph node metastasis was estimated.

RESULTS

There were 12 patients (18%) with lymph node metastasis. The frequency of lymph node metastasis tended to be higher in gastrinomas than that in other tumors (43 vs. 15%; P = 0.08). The size of PNETs with lymph node metastasis was significantly larger than that of the PNETs without metastasis (P = 0.04). The postoperative survival rate in the PNET patients with lymph node metastasis was significantly lower than that in the patients without metastasis (P < 0.0001). Only 2 (8%) of 26 PNETs with a tumor size of <15 mm had lymph node metastasis, and both of these were gastrinomas. On the other hand, 10 (25%) of the remaining 40 PNETs with a tumor size of ≥15 mm had lymph node metastasis. Notably, there were no PNETs with lymph node metastasis in 22 non-gastrinomas with a tumor size of <15 mm.

CONCLUSIONS

Non-gastrinomas with a tumor size of ≥15 mm and all gastrinomas would be an indication for pancreatectomy with lymph node dissection.

Pancreatic neuroendocrine tumors: radiographic calcifications correlate with grade and metastasis

BACKGROUND

Studies to identify preoperative prognostic variables for pancreatic neuroendocrine tumor (PNET) have been inconclusive. Specifically, the prevalence and prognostic significance of radiographic calcifications in these tumors remains unclear.

METHODS

From 1998 to 2009, a total of 110 patients with well-differentiated PNET underwent surgical resection at our institution. Synchronous liver metastases present in 31 patients (28%) were addressed surgically with curative intent. Patients with high-grade PNET were excluded. The presence of calcifications in the primary tumor on preoperative computed tomography was recorded and correlated with clinicopathologic variables and overall survival.

RESULTS

Calcifications were present in 16% of patients and were more common in gastrinomas and glucagonomas (50%), but never encountered in insulinomas. Calcified tumors were larger (median size 4.5 vs. 2.3 cm, P=0.04) and more commonly associated with lymph node metastasis (75 vs. 35%, P=0.01), synchronous liver metastasis (62 vs. 21%, P<0.01), and intermediate tumor grade (80 vs. 31%, P<0.01). On multivariate analysis of factors available preoperatively, calcifications (P=0.01) and size (P<0.01) remained independent predictors of lymph node metastasis. Overall survival after resection was significantly worse in the presence of synchronous liver metastasis (5-year, 64 vs. 86%, P=0.04), but not in the presence of radiographic calcifications.

CONCLUSIONS

Calcifications on preoperative computed tomography correlate with intermediate grade and lymph node metastasis in well-differentiated PNET. This information is available preoperatively and supports the routine dissection of regional lymph nodes through formal pancreatectomy rather than enucleation in calcified PNET.

Comparison of clinicopathologic factors in 122 patients with resected pancreatic and ileal neuroendocrine tumors from a single institution

BACKGROUND

Recent population-based studies have demonstrated significant differences in outcome between patients with pancreatic and ileal neuroendocrine tumors. The objective of this study was to examine the clinicopathologic differences between ileal and pancreatic neuroendocrine tumors following resection.

METHODS

A retrospective chart review was performed and data on clinicopathologic variables, biochemical markers, and follow-up of patients with resected ileal (INETs) and pancreatic (PNETs) neuroendocrine tumors were collected. The t test or analysis of variance (ANOVA) was used to compare means. Survival analysis was performed using the Kaplan-Meier method.

RESULTS

Between 1998 and 2010, 122 patients with PNETs and INETs were explored (70 PNETs and 52 INETs). Several variables were found to be significantly different between patients in both groups. INETs were more often associated with flushing (44 vs. 14%; P < 0.001) and diarrhea (63 vs. 16%; P < 0.001) and were more often associated with elevation in preoperative serum levels of pancreastatin (88 vs. 42%; P < 0.001), chromogranin A (78 vs. 54%; P = 0.036), and serotonin (90 vs. 43%; P < 0.001). INETs more frequently had vascular invasion on pathology (96 vs. 60%; P < 0.001), and presented more often with nodal and/or distant metastases (77 vs. 37%; P < 0.001). There was no significant difference in overall survival between patients in both groups.

CONCLUSION

In this series, patients with INETs presented with a more advanced stage of disease compared with PNETs, had higher preoperative levels of 3 markers, and were more often symptomatic. Despite these factors, there was no significant difference in overall survival between patients with these 2 tumor types.

Glucagon-like peptide-1 versus somatostatin receptor targeting reveals 2 distinct forms of malignant insulinomas

Glucagon-like peptide-1 (GLP-1) receptor imaging is superior to somatostatin receptor subtype 2 (sst(2)) imaging in localizing benign insulinomas. Here, the role of GLP-1 and sst(2) receptor imaging in the management of malignant insulinoma patients was investigated.

METHODS

Eleven patients with malignant insulinoma were prospectively included. (111)In-[Lys(40)(Ahx-diethylenetriaminepentaacetic acid [DTPA])NH(2)]-exendin-4 SPECT/CT, (68)Ga- DOTATATE PET/CT, and in vitro receptor autoradiography were performed to assess the receptor status and to evaluate the detection rate.

RESULTS

GLP-1 receptor targeting was positive in 4 of 11 patients, and sst(2) receptor expression was positive in 8 of 11. In only 1 patient were both receptors expressed. In 1 patient, GLP-1 receptor imaging was the only method that successfully localized the primary tumor in the pancreas. In 3 patients with sst(2)-expressing tumors, DOTATATE radiotherapy was effectively applied.

CONCLUSION

As opposed to benign insulinomas, malignant insulinomas often lack GLP-1 receptors. Conversely, malignant insulinomas often express sst(2), which can be targeted therapeutically.

TNM stage and grade in predicting the prognosis of operated, non-functioning neuroendocrine carcinoma of the pancreas--a single-institution experience

OBJECTIVE

To evaluate the prognostic significance of TNM and grading categories in curatively resected non-functioning neuroendocrine pancreatic carcinoma (nfnepC).

METHOD

Eighteen nfnepC were retrospectively analyzed for differences in survival.

RESULTS

(1) There was a correlation between pT (P = 0.026), respectively pM categories (P = 0.016) and survival. (2) G categories and length of survival were closely correlated (P = 0.0036). (3) Disease stages I-IV had a significant effect on survival (P = 0.051). (4) The WHO classification in well and poorly differentiated carcinomas proved to be the most conclusive predictive factor (P = 0.0009). (5) Subgroups with significantly different prognoses determined by histological grade were present within disease stage II.

CONCLUSIONS

The retrospective analysis showed a good correlation between survival and pT, pM, tumor stage, G categories, and WHO classification in well and poorly differentiated carcinomas. Including histological differentiation in the staging system or carrying it out separately in well and poorly differentiated carcinomas, could enhance the predictive potential of TNM-based disease stages.

Surgical treatment of pancreatic endocrine tumours in Italy: results of a prospective multicentre study of 262 cases

BACKGROUND

Information on the treatment of pancreatic endocrine tumours (PETs) comes mostly from small, retrospective, uncontrolled studies.

METHODS

Newly diagnosed, histologically proven PETs, observed from June 2004 to March 2007 in 24 Italian centres, were included in a specific dataset.

RESULTS

Three-hundred and ten patients (mean age 57.6 years, females 46.6%) were analysed. At the time of recruitment, 262 (84.5%) underwent surgery. The percentage of operated patients was 91.9% and 62.0% in surgical and non-surgical centres, respectively. A curative resection was carried out in 83.6% (n = 219) of cases, a palliative resection (debulking) in 10.7% (n = 28), an exploratory laparotomy in 4.6% (n = 12), and a bypass procedure in 1.1% (n = 3). Laparoscopy was performed in 8.0% (n = 21) of cases. Resection consisted of a pancreatoduodenectomy in 46 cases (21.0%), a distal pancreatectomy in 95 (43.4%), an enucleation in 50 (22.8%), a middle pancreatectomy in 16 (7.3%) and a total pancreatectomy in 12 (5.5%). Liver resection was associated with pancreatic resection in 26 cases (9.9%). Post-operative mortality was 1.5% and morbidity 39.7%, respectively. A curative resection was performed more frequently in asymptomatic, small, non-metastatic, benign and at uncertain behaviour tumours, with low Ki67 values.

CONCLUSIONS

This study strongly indicates the fact that surgical resection represents the cornerstone treatment of PETs.

Laparoscopic enucleation of pancreatic neoplasm

BACKGROUND

Enucleation is an alternative procedure for treating benign and borderline neoplasms of the pancreas, which preserves healthy parenchyma and pancreatic function. This study aimed to evaluate the postoperative and long-term results after laparoscopic enucleation.

METHODS

Data collected prospectively from 23 consecutive patients who underwent laparoscopic pancreatic enucleation were analyzed.

RESULTS

Laparoscopic enucleation was achieved successfully for 21 patients (91.3%). One death (4%) occurred. A postoperative pancreatic fistula was observed in three cases (13%), and was clinically significant in one case (4%). Enucleation was performed for endocrine neoplasm in 15 patients (65%) and for cystic neoplasm in eight patients (35%). All the patients had benign tumors at the final histopathologic diagnosis. During a median follow-up period of 53 months, no patient experienced tumor recurrence or new-onset exocrine or endocrine insufficiency.

CONCLUSION

Laparoscopic enucleation is a safe and effective procedure for the radical treatment of benign and borderline pancreatic tumors. The laparoscopic approach seems to be associated with a decrease in operative time, hospital stay, and pancreatic fistula after enucleation. Laparoscopy should become the standard approach in the future for enucleation of presumed benign lesions.

Parenchyma-preserving resections for small nonfunctioning pancreatic endocrine tumors

BACKGROUND

Parenchyma-preserving resections (PPRs), including enucleation and middle pancreatectomy (MP), are accepted procedures for insulinomas, but their role in the treatment of nonfunctioning pancreatic endocrine tumors (NF-PETs) is debated. The aim of this study was to evaluate perioperative and long-term outcomes after PPRs for NF-PETs.

METHODS

All patients who underwent PPRs for NF-PETs between 1990 and 2005 were included. Patients with multiple endocrine neoplasia type 1 were excluded.

RESULTS

Overall, 50 patients (23 men, 27 women, median age 59 years) underwent 26 enucleations and 24 MP. A total of 58% of NF-PETs were incidentally discovered. Median size of the tumors was 13.5 mm with no preoperative suspicion of malignancy in all patients. Overall morbidity and pancreatic fistula rates were 58 and 50%, respectively. Reoperation rate was 4%, with no mortality. Postoperative complications were higher in the MP group. At pathology, there were 34 (68%) benign lesions, 13 (26%) neoplasms of uncertain behavior, and 3 (6%) well-differentiated carcinomas. Forty-one patients (82%) had tumors < or =2 cm in size. Only eight patients (16%) had at least one lymph node removed. After a median follow-up of 58 months, no patient died of disease. Overall, four patients (8%) experienced tumor recurrence after a mean of 68 months. The incidence of exocrine/endocrine insufficiency was 8%.

CONCLUSIONS

PPRs are generally safe and effective procedures for treating small NF-PETs. However, better selection criteria must be identified, and lymph node sampling should be performed routinely to avoid understaging. Long-term follow-up evaluation (>5 years) is of paramount importance given the possible risk of late recurrence.

Enucleation of pancreatic cystadenomas

BACKGROUND

Optimal surgical treatment of pancreatic cystadenomas is controversial due to the rarity of the tumors and paucity of studies regarding long-term outcomes. This is especially true for large pancreatic cystadenomas. The objective of this study was to determine the safety and effectiveness of treating pancreatic cystadenomas by enucleation.

METHODS

Eleven cases of pancreatic mucinous or serous cystadenomas were selected for enucleation according to the following criteria: (1) the benign nature of the tumors was ascertained preoperatively and intraoperatively, (2) small tumors or larger tumors no more than 6 cm in diameter growing outwardly with small tumor beds, and (3) the main pancreatic duct was not in jeopardy of damage by enucleation. The patients' demographics, tumor features, morbidity, and follow-up results were retrospectively reviewed and analyzed.

RESULTS

Among 11 cases, three were serous cystadenomas and eight were mucinous cystadenomas; the average size of the neoplasms was 4.8 cm (ranging from 3 to 6 cm). Two cases were complicated by the development of fistulas postoperatively and one had an incision infection. All cases were followed up from 23 to 67 months, which revealed no neoplasm recurrence or new onset of diabetes mellitus; one patient developed a pseudocyst in the body 30 months after enucleation.

CONCLUSIONS

It is safe and effective to perform enucleation for well-selected benign pancreatic cystadenomas even if the tumor size is as large as 6 cm, and the endocrine or exocrine function of the pancreas is maintained as much as possible.

Parenchyma-sparing resections for pancreatic neoplasms

BACKGROUND/PURPOSE

In recent years there has been an increase in the indications for pancreatic resection of benign or low-grade malignant lesions, especially in young patients with long life expectancy. In this setting, patients may benefit from parenchyma-sparing resections in order to decrease the risk of development of exocrine/endocrine insufficiency.

METHODS

A review of the literature and authors experience was undertaken.

RESULTS

Parenchyma-sparing resections of the pancreas including enucleation, middle pancreatectomy (MP) and middle-preserving pancreatectomy are described. Short and long-term outcomes after surgery are analyzed with special regard to postoperative morbidity/mortality, and oncological and functional long-term results.

CONCLUSIONS

Parenchyma-sparing resections are safe and effective procedures for treatment of benign and low-grade malignant neoplasms. Despite a significant postoperative morbidity they are associated with good long-term functional and oncological results. Enucleation should preferentially be performed laparoscopically whenever possible.

Changing the clinical picture of challenging tumors: tales becoming reality?

The treatment of neoplastic diseases has become increasingly dependent on tumor biology and is focused on targeted therapy. Understanding complex networks of intracellular signaling pathways, blockades of specific targets and a myriad of other approaches has brought new fuel to the battle against many types of cancer. Unfortunately, the degree of benefit achieved in this new era of cancer treatment has not been distributed homogeneously among the different disease types. Neoplasms with lower incidence rates, but that are also highly challenging, are not consistently given due attention by research leaders. This article aims to evaluate new insights and potential gains obtained with new therapies in a particular group of tumors: those rarely debated in clinical practice, but which still pose a considerable challenge to clinical oncology.

Inherited pancreatic endocrine tumor syndromes: advances in molecular pathogenesis, diagnosis, management, and controversies

Pancreatic endocrine tumors (PETs) can occur as part of 4 inherited disorders, including Multiple Endocrine Neoplasia type 1 (MEN1), von Hippel-Lindau disease (VHL), neurofibromatosis 1 (NF-1) (von Recklinghausen disease), and the tuberous sclerosis complex (TSC). The relative frequency with which patients who have these disorders develop PETs is MEN1>VHL>NF-1>TSC. Over the last few years, there have been major advances in the understanding of the genetics and molecular pathogenesis of these disorders as well in the localization and the medical and surgical treatment of PETs in such patients. The study of PETs in these disorders not only has provided insights into the possible pathogenesis of sporadic PETs but also has presented several unique management and treatment issues, some of which are applicable to patients with sporadic PETs. Therefore, the study of PETs in these uncommon disorders has provided valuable insights that, in many cases, are applicable to the general group of patients with sporadic PETs. In this article, these areas are reviewed briefly along with the current state of knowledge of the PETs in these disorders, and the controversies that exist in their management are summarized briefly and discussed.

Gastroenteropancreatic neuroendocrine tumours

Gastroenteropancreatic (GEP) neuroendocrine tumours (NETs) are fairly rare neoplasms that present many clinical challenges. They secrete peptides and neuroamines that cause distinct clinical syndromes, including carcinoid syndrome. However, many are clinically silent until late presentation with mass effects. Investigation and management should be highly individualised for a patient, taking into consideration the likely natural history of the tumour and general health of the patient. Management strategies include surgery for cure (which is achieved rarely) or for cytoreduction, radiological intervention (by chemoembolisation and radiofrequency ablation), chemotherapy, and somatostatin analogues to control symptoms that result from release of peptides and neuroamines. New biological agents and somatostatin-tagged radionuclides are under investigation. The complexity, heterogeneity, and rarity of GEP NETs have contributed to a paucity of relevant randomised trials and little or no survival increase over the past 30 years. To improve outcome from GEP NETs, a better understanding of their biology is needed, with emphasis on molecular genetics and disease modeling. More-reliable serum markers, better tumour localisation and identification of small lesions, and histological grading systems and classifications with prognostic application are needed. Comparison between treatments is currently very difficult. Progress is unlikely to occur without development of centers of excellence, with dedicated combined clinical teams to coordinate multicentre studies, maintain clinical and tissue databases, and refine molecularly targeted therapeutics.

Enucleation of pancreatic neoplasms

BACKGROUND

Standard resections for benign and borderline neoplasms of the pancreas are associated with a significant risk of long-term functional impairment, whereas enucleation preserves healthy parenchyma and pancreatic function. The aim of this study was to evaluate postoperative and long-term oncological and functional results after pancreatic enucleation.

METHODS

Data collected prospectively from 61 consecutive patients who underwent pancreatic enucleation were analysed.

RESULTS

There were no deaths. A clinically significant pancreatic fistula was reported in 14 patients (23 per cent), and five patients (8 per cent) had a further operation for fistula-related complications. The most common indication for surgery was endocrine neoplasm (38 patients; 62 per cent) and two patients (3 per cent) had a final histopathological diagnosis of malignant neoplasm. At a median follow-up of 61 months no patient had developed tumour recurrence or exocrine insufficiency. Two elderly patients developed non-insulin-dependent diabetes.

CONCLUSION

Enucleation is an effective procedure for the radical treatment of benign and borderline neoplasms of the pancreas, with good long-term outcomes.

Clinicopathologic features and treatment trends of pancreatic neuroendocrine tumors: analysis of 9,821 patients

The natural history of pancreatic neuroendocrine tumors (PNET) remains poorly defined. Our objectives were to examine the clinicopathologic features of PNETs, to assess treatment trends over time, and to identify factors associated with undergoing resection. From the National Cancer Data Base (1985-2004), 9,821 patients were identified with PNETs. Clinicopathologic features and treatment trends were examined. Multivariable logistic regression was used to assess factors associated with undergoing resection. Of 9,821 patients with PNETs, 85% were nonfunctional, 7.1% were functional, and 7.9% were carcinoid tumors. Of the 3,851 (39.0%) patients who underwent pancreatectomy, 449 (11.7%) received adjuvant chemotherapy, and 254 (6.6%) received adjuvant radiation. From 1985 to 2004, utilization of pancreatectomy increased from 39.4 to 44.3% (P < 0.0001). Patients were less likely to undergo resection if they were > 55 years old, had tumors in the head of the pancreas, tumors > or = 4 cm, or had distant metastases (P < 0.0001). Patients treated at NCCN/NCI, academic, or high-volume hospitals were more likely to undergo resection. There are disparities in the utilization of pancreatectomy for PNETs. As PNETs have a better prognosis than adenocarcinoma, concerns regarding the morbidity and mortality of pancreatic surgery and neoplasms should not preclude resection.

Application of the pancreatic adenocarcinoma staging system to pancreatic neuroendocrine tumors

BACKGROUND

The American Joint Committee on Cancer (AJCC) 6(th) edition staging system for pancreatic adenocarcinoma specifically excludes pancreatic neuroendocrine tumors (PNETs), and a widely accepted staging classification does not exist. Our objective was to evaluate the feasibility of applying the AJCC pancreatic adenocarcinoma staging system to PNETs.

STUDY DESIGN

Patients with PNETs were identified from the National Cancer Data Base (1985 to 2004). Overall survival was estimated using the Kaplan-Meier method and compared using the log-rank test. Cox proportional hazards modeling was used to evaluate the effect of tumor size, nodal status, and distant metastases on survival.

RESULTS

Of 4,793 patients with PNETs, 93.6% were of islet cell origin, and 6.4% were carcinoid tumors; 1,815 (37.9%) underwent resection. Overall 5-year survival rates were 29.2% for all patients, 55.4% for resected patients, and 15.6% for unresected patients. The AJCC staging system provided good prognostic survival discrimination between stage groups for resected patients (p < 0.0001). When comparing outcomes to those of patients with pancreatic adenocarcinoma, the estimated median survival was significantly better for resected patients with PNETs (60 versus 13 months, p < 0.0001). Distant metastasis was the only independent predictor of survival (p < 0.0001).

CONCLUSIONS

When applied to PNETs, the AJCC staging system for pancreatic adenocarcinoma provides survival discrimination by stage for surgical and nonsurgical patients. Survival rates are better for PNETs than for pancreatic adenocarcinoma, but the staging system can effectively stratify patients with PNETs.

Incidentally discovered tumors of the endocrine glands

Clinically inapparent masses, or ‘incidentalomas’ of the endocrine glands are increasingly common owing to continued advancements in medical imaging. Incidentalomas of the adrenal glandS have received substantial attention in the literature, whereas lesions of the thyroid and endocrine pancreas, though frequently encountered in the clinic, have received relatively little attention. We review the detection and subsequent management of incidentalomas of the thyroid, adrenal and pancreas, with specific attention paid to the mode of detection and risk stratification of lesions.