A single institution's 21-year experience with surgically resected pancreatic neuroendocrine tumors: an analysis of survival and prognostic factors

Venous Invasion in Pancreatic Neuroendocrine Tumors Is Independently Associated With Disease-free Survival and Overall Survival

In this study, we evaluated venous invasion and its association with survival in patients with resected pancreatic neuroendocrine tumor (PanNET). Surgical Pathology Archives were searched for pancreatectomies performed for PanNET between October 1, 2005, and December 31, 2019. Hematoxylin and eosin (H&E)-stained slides were evaluated for venous invasion, and Movat's stain was performed in all cases with no venous invasion detected on H&E stains. Pathology reports and electronic medical records were also reviewed. Venous invasion was identified in 23 of 145 (15.9%) cases on H&E stains, and Movat's stain identified additional 34 cases with venous invasion (39.3% overall). Orphan arteries with adjacent well-defined tumor nodules or subtle hyalinizing nodules in hyalinizing tumors are highly specific for venous invasion. In stage I-III cases (n=122), venous invasion was associated with larger tumor size, higher World Health Organization (WHO) tumor grade, perineural invasion, extrapancreatic extension, lymph node metastasis, and liver metastasis ( P <0.05). In univariate analyses, tumor size, WHO grade, venous invasion, perineural invasion, T stage, and lymph node metastasis all correlated with disease-free survival; however, only venous invasion was associated with worse disease-free survival in multivariate analyses ( P <0.01). In all-stage cases, venous invasion was the only attributor associated with worse overall survival in multivariate analyses ( P =0.03). In summary, venous invasion in PanNET can be histologically subtle, and Movat's stain can greatly increase the detection rate. More importantly, enhanced venous invasion by Movat's stain correlates independently with disease-free survival in patients with stage I-III tumors and overall survival in all-stage patients.

Functionality is not an independent prognostic factor for pancreatic neuroendocrine tumors

BACKGROUND

Pancreatic neuroendocrine neoplasms (pNENs) that produce hormones leading to symptoms are classified as functional tumors, while others are classified as nonfunctional tumors. The traditional view is that functionality is a factor that affects the prognosis of pNEN patients. However, as the sample sizes of studies have increased, researches in recent years have proposed new viewpoints.

AIM

To assess whether functionality is an independent factor for predicting the prognosis of pNEN patients.

METHODS

From January 2004 to December 2016, data of patients who underwent surgery at the primary site for the treatment of pNENs from the Surveillance, Epidemiology, and End Results (SEER) database and West China Hospital database were retrospectively analyzed.

RESULTS

Contemporaneous data from the two databases were analyzed separately as two cohorts and then merged as the third cohort to create a large sample that was suitable for multivariate analysis. From the SEER database, age (P = 0.006) and T stage (P < 0.001) were independent risk factors affecting the survival. From the West China Hospital database, independent prognostic factors were age (P = 0.034), sex (P = 0.032), and grade (P = 0.039). The result of the cohort consisting of the combined populations from the two databases showed that race (P = 0.015), age (P = 0.002), sex (P = 0.032) and T stage (P < 0.001) were independent prognostic factors. In the West China Hospital database and in the total population, nonfunctional pNETs and other functional pNETs tended to have poorer prognoses than insulinoma. However, functionality was not associated with the survival time of patients with pNETs in the multivariate analysis.

CONCLUSION

Functionality is not associated with prognosis. Race, age, sex, and T stage are independent factors for predicting the survival of patients with pNETs.

Indications for resection and perioperative outcomes of surgery for pancreatic neuroendocrine neoplasms in Germany: an analysis of the prospective DGAV StuDoQ|Pancreas registry

PURPOSE

Pancreatic neuroendocrine neoplasms (pNENs) are rare, and their surgical management is complex. This study evaluated the current practice of pNEN surgery across Germany, including its adherence with guidelines and its perioperative outcomes.

METHODS

Patients who underwent surgery for pNENs (April 2013-June 2017) were retrieved from the prospective StuDoQ|Pancreas registry of the German Society of General and Visceral Surgery and retrospectively analyzed.

RESULTS

A total of 287 patients (53.7% male) with a mean age of 59.2 ± 14.2 years old underwent pancreatic resection for pNENs. Tumors were localized in the pancreatic head (40.4%), body (23%), or tail (36.6%). A total of 239 (83.3%) patients underwent formal resection with lymphadenectomy, 40 (14%) parenchyma-sparing resection, and 8 (2.8%) only exploration. Fifty (17.4%) patients underwent a minimally invasive approach. Among the 245 patients with complete pathological information, 42 (17.1%) had distant metastases, 78 (31.8%) had stage I tumors, 74 (30.2%) stage II, and 51 (20.8%) stage III. A total of 112 (45.7%) patients had G1 tumors, 101 (41.2%) G2, and 24 (9.8%) G3. Nodal involvement on imaging was an independent predictor of lymph node metastasis according to the multivariable analysis (odds ratio: 0.057; 95% confidence interval: 0.016-0.209; p < 0.01). R0 resection was reported in 240 (83.6%) patients. The 30- and 90-day mortality rates were 2.8% and 4.2%, respectively.

CONCLUSION

In Germany the rate of potential curative resection for pNEN is high. However, formal pancreatic resection seems to be overrepresented, while minimally invasive resection is underrepresented.

Systematic review of current prognostication systems for pancreatic neuroendocrine neoplasms

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Cystic pancreatic neuroendocrine tumors (cPNETs): a systematic review and meta-analysis of case series

Cystic pancreatic neuroendocrine tumors represent 13% of all neuroendocrine tumors. The aim of this study is to analyze the phenotype and biologic behavior of resected cystic neuroendocrine tumors. A systematic review and meta-analysis were conducted until September 2016 using a search in Medline, Scopus, and EMBASE with the terms "cystic pancreatic endocrine neoplasm", "cystic islets tumors" and "cystic islets neoplasms". From the 795 citations recovered 80 studies reporting on 431 patients were selected. 87.1% (n = 387) were sporadic tumors and 10.3% (n = 40) corresponded to multiple endocrine neoplasia endocrine type 1. Were diagnosed incidentally 44.6% (n = 135). Cytology was found to have a sensitivity of 78.5%. Were non-functional tumors 85% (n = 338), and among the functional tumors, insulinoma was the most frequent. According to the European Neuroendocrine Tumor Society staging, 87.8% were limited to the pancreas (I-IIb), and 12.2% were advanced (III-IV). Disease-free survival at 5 years in stages (I-IIIa) and (IIIb-IV) was 91.5% and 54.2%, respectively; and was significantly lower (p = 0.0001) in functional tumors. In patients with multiple endocrine neoplasia there was a higher incidence of functional (62.5%) and multifocal (28.1%) tumors. Disease-free survival at 5 and 10 years was 60%. Cystic pancreatic neuroendocrine tumors exhibit phenotypical characteristics which are different to those of solid neuroendocrine tumors.

Detection of pancreatic neuroendocrine tumors: 23 years of experience

INTRODUCTION AND AIMS

Neuroendocrine tumors are of great scientific interest, given that they are difficult to diagnose and treat. Despite being relatively rare (< 1/100,000 individuals, 1-2% of the gastrointestinal neoplasias) and indolent, their potential malignancy must not be forgotten. An increase in the number of diagnosed tumors has been observed in recent years. The aim of the present study was to update a published case series of 19 patients suspected of presenting with pancreatic neuroendocrine tumor with 51 current cases, to study and compare the new results with those of the previous case series, as well as with other recent publications from Spain, the United States, China, and India.

MATERIALS AND METHODS

A retrospective, multicenter case series was conducted on 70 patients (19 cases published in 2011), whose data has been collected over a period of 23 years. The variables analyzed were: age, sex, symptomatology, tumor size, location, metastasis, final diagnosis, and surgery, among others.

RESULTS

Mean patient age was 55 years and 60% of the patients were men. Disease location was the pancreatic head in 28.5% of the patients and the tail in 27.1%, mean tumor size was 3.9cm (0.2-10cm), 71.4% of the patients had non-functioning tumors, 32.8% had metastases (100% to the liver), 74.2% of the patients were operated on, and actuarial survival was 75%.

CONCLUSIONS

Differences were observed between the previously published case series and the current results. There was an increase in incidentalomas and non-functioning tumors, but no variation in the overall survival rate. The differences with other case series (age, sex, and tumor location) were dependent on the country where the cases were compiled. The increase in tumors could be related to a higher number of diagnoses made through imaging studies and to the greater sensitivity of the devices employed.

A meta-analysis of Prognostic factor of Pancreatic neuroendocrine neoplasms

Pancreatic neuroendocrine neoplasms (pNENs) are a group of clinically rare and heterogeneous diseases of the pancreas. However, the prognostic factors for this disease in patients still remain controversial. The purpose of our study is to evaluate the predictive roles of those prognostic factors for pNENs. All related articles published until Sep 17, 2017 were identified via PubMed, EMBASE, Web of Science, Ovid and the Cochrane Library. Studies that examined the prognostic factors of pNENs were enrolled. 17 articles (2822 patients) were finally included in this study. The pooled data suggested that patients with positive surgical resection margin and lymph node, advanced G stage and TMN stage, organ metastasis, vascular invasion and the necrosis of specimens had a decreased overall survival for pNENs. Similarly, patients with functional tumors might have a poor prognosis. However, age, gender, surgical type and size of tumor could not be regarded as prognostic factors for pNENs. Our analytic data demonstrated that surgical resection margin, G stage, TMN stage, lymph node, metastasis, vascular invasion and the necrosis could be prognostic factors for pNENs. Our study may assist doctors to screen patients with different prognosis more efficiently during follow-up and select appropriate treatment measures.

Author´s reply: Cystic pancreatic neuroendocrine tumors. A diagnostic challenge

We are grateful for the helpful comments of Varas et al. with regard to the phenotype of cystic pancreatic neuroendocrine tumors (CPNT) reported in a recent meta-analysis of 436 patients. Varas et al. highlight the lower incidence of CPNT diagnosed incidentally in 135 patients (44.6%) in comparison with a recent series of 49 patients with an incidental tumor diagnosis of 56.5%.

Neuroendocrine tumour in pancreatic dorsal agenesis: a rare association

Pancreatic dorsal agenesis (PDA) is a rare congenital anomaly, usually asymptomatic, that can present with abdominal pain, pancreatitis, diabetes mellitus and jaundice. Pancreatic tumours in PDA background are extremely rare, and when they occur are mainly pancreatic ductal adenocarcinoma. We present a case of a 48-year-old female patient with incidental detection of a 26×20 mm nodular lesion of the cephalic pancreas on ultrasound. Surgery was performed and gross examination revealed PDA with a tumour developed around the Wirsung duct. Histology showed a neuroendocrine tumour G1 with neural and vascular invasion. Two and half years later, the patient is alive and without tumour relapse. Awareness of the association of PDA and pancreatic tumours is fundamental in order to develop personalised follow-up programmes.

Pancreatic neuroendocrine tumors. Prognostic factors

We thank Modesto Varas et al. for their opportune comments with regard to the oncologic outcomes of our series of patients undergoing surgery for pancreatic neuroendocrine tumors (PNET). We agree with Varas et al. in relation to the increase in non-functional tumors (73%) and the incidental form of presentation (44%). These figures are in line with those presented in most series.

Neuroendocrine tumors of the pancreas: keys issues in dealing with heterogeneity

We thank Modesto Varas et al. for their opportune comments with regard to the oncologic outcomes of our series of patients undergoing surgery for a pancreatic neuroendocrine tumor. We agree Varas et al. with respect to the increase in nonfunctional tumors (73%) and the figures of the incidental form of presentation (44%), which are in line with those from most series.

Pancreas neuroendocrine tumors - not so rare or benign

Neuroendocrine tumors (NETs) are a heterogeneous group of neoplasms characterized by a common embryonic origin and highly variable clinical outcome.