Is there a prognostic difference between functional and nonfunctional islet cell tumors?

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.

Consensus Recommendations for the Diagnosis and Management of Pancreatic Neuroendocrine Tumors: Guidelines from a Canadian National Expert Group

Pancreatic neuroendocrine tumors (pNETs) are rare heterogeneous tumors that have been steadily increasing in both incidence and prevalence during the past few decades. Pancreatic NETs are categorized as functional (F) or nonfunctional (NF) based on their ability to secrete hormones that elicit clinically relevant symptoms. Specialized diagnostic tests are required for diagnosis. Treatment options are diverse and include surgical resection, intraarterial hepatic therapy, and peptide receptor radionuclide therapy (PRRT). Systemic therapy options include targeted agents as well as chemotherapy when indicated. Diagnosis and management should occur through a collaborative team of health care practitioners well-experienced in managing pNETs. Recent advances in pNET treatment options have led to the development of the Canadian consensus document described in this report. The discussion includes the epidemiology, classification, pathology, clinical presentation and prognosis, imaging and laboratory testing, medical and surgical management, and recommended treatment algorithms for pancreatic neuroendocrine cancers.

Non-hyperfunctioning neuroendocrine tumours of the pancreas: MR imaging appearance and correlation with their biological behaviour

OBJECTIVE

To describe MR imaging features of non-hyperfunctioning neuroendocrine pancreatic tumours by comparing them to histopathology and to determine the accuracy of MR imaging in predicting biological behaviour.

MATERIALS AND METHODS

After institutional review board approval, we retrospectively reviewed 45 patients with pathologically proven NF-NET of the pancreas and ≥1 preoperative MR/MRCP examinations. Of the NF-NETS, 29/45 (64.4 %) were G1 and 16/45 (35.5 %) were G2. Image analysis included the lesion maximum diameter, vascular encasement, extrapancreatic spread, signal intensity on T1- and T2-weighted, contrast enhancement features, and presence of metastases. Tumour vessel density was calculated on the histological specimen using a grid.

RESULTS

The median maximum diameter of NF-NETs was 20 mm (range 5-200 mm). Eighty per cent of the NF-NETs were hypointense on T1-weighted images, 82.2 % were hyperintense on T2-weighted images, and 75.6 % were hypervascular. Overall MRI accuracy showed a mean AUC of 0.86 compared to pathology. Lesions with a maximum diameter of 30 mm irregular margins, absence of a cleavage plane with the main pancreatic duct, vascular encasement, extrapancreatic spread and abdominal metastases were significantly associated with malignant NF-NETs. No correlation was found between the tumour vessel density and contrast-enhanced MR imaging pattern.

CONCLUSIONS

Hyperintensity on T2-weighted images and iso-/hypervascularity occurred in 27/45 (60.0 %) of NF-NETs. MRI identifies malignant NF-NETs with a sensitivity of 93.3 % and a specificity of 76.9 % (AUC = 0.85).

KEY POINTS

• Non-hyperfunctioning neuroendocrine pancreatic tumours (NF-NET) pose a difficult diagnostic challenge. • On T2-weighted MRI, 82.2 % of neuroendocrine tumours appeared hyperintense. • MR imaging showed 0.94 sensitivity and 0.77 specificity in predicting biological behaviour. • The hyper-/isointensity during dynamic MRI did not correlate with vessel density at pathology.

Malignant pancreatic neuroendocrine tumour: lymph node ratio and Ki67 are predictors of recurrence after curative resections

INTRODUCTION

Malignant pancreatic neuroendocrine tumours (PNENs) are generally associated with a good prognosis after radical resection. In other pancreatic malignancies predictors of recurrence and the role of lymph node ratio (LNR) are well known, but both have been scarcely investigated for malignant PNETs.

METHODS

The prospective database from the surgical Department of Verona University was queried. Clinical and pathological data of all patients with resected malignant PNET between 1990 and 2008 were reviewed. Univariate and multivariate analysis were performed.

RESULTS

Fifty-seven patients (male/female ratio=1) with a median age of 58 years (33-78) entered in the study. Twenty-nine (51%) patients underwent pancreaticoduodenectomy and 28 (49%) distal pancreatectomy. Postoperative mortality was nil with a 37% morbidity rate. There were 36 (63%) patients with lymph node metastases (N1). Of these, 23 (64%) had a lymph node ratio (LNR) >0 and ≤0.20 and 13 (36%) had a LNR >0.20. The median overall survival and the median disease free survival (DFS) were 190 and 80 months, respectively. Recurrent disease was identified in 24 patients (42%) with a 2 and 5-year DFS rate of 82% and 49%, respectively. On multivariate analysis, LNR >0.20 (HR=2.75) and a value of Ki67 >5% (HR=3.39) were significant predictors of recurrence (P<0.02).

CONCLUSIONS

After resection for malignant PNETs, LNR and a Ki67 >5% are the most powerful predictors of recurrence. The presence of these factors should be considered for addressing patients to adjuvant treatment in future clinical trials.

Imaging of neuroendocrine tumors

Neuroendocrine tumors (NETs) constitute a large group of diverse neoplasms with a wide spectrum of clinical, imaging, and pathologic findings. Imaging diagnosis of NETs can be challenging, and several complementary imaging modalities may be needed during the diagnostic workup. Accurate interpretation of the imaging findings is important to facilitate diagnosis and contribute to patient management. This article discusses the gastrointestinal site-specific features and the tumor-specific features of several NETs and the role of several imaging modalities such as computed tomography, MR imaging, ultrasonography, and positron emission tomography in the evaluation of these NETs.

Comparison of functional and nonfunctional neuroendocrine tumors in the pancreas and peripancreatic region

OBJECTIVE

To present our experience of 93 neuroendocrine tumors (NETs) in the pancreas and peripancreatic region, with emphasis on how resectability affects long-term survival and the impact of functional status on the survival outcome.

METHODS

Ninety-three patients with NETs in the pancreas and peripancreatic region were included to compare the clinical features between functional and nonfunctional NETs. Prognostic factors were determined by univariate and multivariate analyses.

RESULTS

There were 39 functional (41.9%) and 54 nonfunctional NETs (58.1%). According to World Health Organization (WHO) tumor categories, there were 57 well-differentiated tumors (61.3%), 26 well-differentiated carcinomas (28%), and 10 poorly differentiated carcinomas (10.8%). Univariate analysis showed that functional status of the tumor, tumor stage, lymph node status, and pathological classification were prognostic factors for both disease-free survival and disease-specific survival. Resectability did not influence the survival outcome, with the resectable and unresectable groups demonstrating a 5-year disease-specific survival of 86.4% and 65.6%, respectively (P = 0.210). Only the WHO pathological classification was an independent prognostic factor after multivariate analysis.

CONCLUSIONS

Irresectability does not necessarily preclude long-term survival for both functional and nonfunctional NETs. It is the WHO pathological classification, instead of hormonal functional status, that is an independent prognostic factor and has impact on the survival outcome.

Clinicopathological features of pancreatic endocrine tumors: a prospective multicenter study in Italy of 297 sporadic cases

OBJECTIVES

Information on pancreatic endocrine tumors (PETs) comes mostly from small, retrospective, uncontrolled studies conducted on highly selected patients. The aim of the study was to describe the clinical and pathological features of PETs in a prospective, multicenter study.

METHODS

Newly diagnosed, histologically proven, sporadic PETs observed from June 2004 to March 2007 in 24 Italian centers were included in a specific data set.

RESULTS

Two hundred ninety-seven patients (mean age 58.6+/-14.7 years, females 51.2%, males 48.8%) were analyzed. In 73 cases (24.6%), the tumor was functioning (F) (53 insulinomas, 15 gastrinomas, 5 other syndromes) and in 232 (75.4%) it was non-functioning (NF); in 115 cases (38.7%), the diagnosis was incidental. The median tumor size was 20 mm (range 2-150). NF-PETs were significantly more represented among carcinomas (P<0.001). Nodal and liver metastases were detected in 84 (28.3%) and 85 (28.6%) cases, respectively. The presence of liver metastases was significantly higher in the NF-PETs than in the F-PETs (32.1% vs. 17.8%; P<0.05), and in the symptomatic than in the asymptomatic patients (34.6% vs. 19.1%; P<0.005). At the time of recruitment, the majority of patients (251, 84.5%) had undergone surgery, with complete resection in 209 cases (83.3%).

CONCLUSIONS

This study points out the high number of new cases of PETs observed in Italy, with a high prevalence of NF and incidentally discovered forms. The size of the tumor was smaller and the rate of metastasis was lower than usually reported, suggesting a trend toward an earlier diagnosis.

A simplified prognostic system for resected pancreatic neuroendocrine neoplasms

BACKGROUND

A number of prognostically relevant clinicopathological variables have been proposed for pancreatic neuroendocrine neoplasms. However, a standardized prognostication system has yet to be established for patients undergoing potentially curative tumour resection.

METHODS

We examined a prospectively maintained, single-institution database to identify patients who underwent potentially curative resection of non-metastatic primary pancreatic neuroendocrine neoplasms. Patient, operative and pathological characteristics were analysed to identify variables associated with disease-specific and disease-free survival.

RESULTS

Between 1991 and 2007, 43 patients met inclusion criteria. After a median follow-up of 68 months, 5-year disease-specific survival was 94% and 5-year disease-free survival was 72%. Tumours sized > or = 5 cm and vascular invasion were associated with worse disease-specific survival. Tumours sized > or = 5 cm, nodal metastases, positive resection margins and perineural invasion were associated with worse disease-free survival. A scoring system consisting of tumour size > or = 5 cm, histological grade, nodal metastases and resection margin positivity (SGNM) permitted stratification of disease-specific (P= 0.006) and disease-free (P= 0.0004) survival. This proposed scoring system demonstrated excellent discrimination of individual disease-specific and disease-free survival outcomes as reflected by concordance indices of 0.814 and 0.794, respectively.

CONCLUSIONS

A simple scoring system utilizing tumour size, histological grade, nodal metastases and resection margin status can be used to stratify outcomes in patients undergoing resection of primary pancreatic neuroendocrine neoplasms.

Management of the primary tumor in patients with metastatic pancreatic neuroendocrine tumor: a contemporary single-institution review

BACKGROUND

Pancreatic nonfunctioning neuroendocrine tumors (PNFNETs) are an uncommon malignancy and often present with metastatic disease. There is a lack of information on the management of the primary tumor in patients who present with unresectable synchronous hepatic metastases.

METHODS

A retrospective review (2001-2008) of PNFNETs was conducted. Patients were divided into 3 groups: PNFNET without evidence of hepatic metastasis (group A), PNFNET with metastatic disease involving less than 50% of the liver (group B), and PNFNET with metastatic disease involving more than 50% of the liver (group C). Clinical data and outcomes were analyzed.

RESULTS

Thirty-five patients with PNFNET were identified (group A = 15, group B = 11, group C = 9). Resection of the pancreatic tumor was performed in 26 patients. With a mean follow-up period of 30 months, death from disease progression occurred in 1 patient in group A, none in group B, and in 7 in group C.

CONCLUSIONS

In selected patients, resection of the primary pancreatic tumor even in the setting of unresectable but limited hepatic metastases may be indicated.

Pancreatic neuroendocrine tumours

INTRODUCTION

Pancreatic neuroendocrine tumours (PNT) are infrequent epithelial neoplasms associated with a better outcome than pancreatic adenocarcinoma.

MATERIALS AND METHODS

We analysed our 22 years of experience in managing PNT. Forty-nine patients (27 women and 22 men) with a mean age of 49 years were studied. There were 28 insulinomas, eight glucagonomas, three gastrinomas, one VIPoma and one carcinoid. Eight patients presented with nonfunctional tumours. Enucleation was performed in 20 patients, distal pancreatectomy in 16, middle pancreatic resection in four, cephalic pancreatoduodenectomy in two and total pancreatoduodenectomy in one. In six patients, the tumour was not resected.

RESULTS

Postoperative complication rate was 22%: six pancreatic fistulas, three intra-abdominal collections, one remnant pancreatitis and one pancreatic pseudocyst. There was no mortality. 39 cases showed benign histologic features and ten malignant ones. Symptomatic palliation was achieved in 94% of the cases. Five patients presented recurrences: three liver metastases and two pancreatic recurrences. Actuarial mean survival was 163 months and was longer in insulinomas, in those tumours completely resected and in tumours with benign histological features.

CONCLUSION

Conservative surgery of the pancreas is preferred, but aggressive surgery is indicated when the primary tumour can be controlled. Despite of minimising pancreatic resection, there is a high complication rate, mainly pancreatic fistulas, though they can often be conservatively managed. Insulinomas are the PNT with better outcome; those completely resected also associate a better prognosis.

Pancreatic neuroendocrine tumors (PNETs): incidence, prognosis and recent trend toward improved survival

BACKGROUND

Pancreatic neuroendocrine tumors (PNETs) are uncommon neoplasms that can present with symptoms of hormone overproduction. We evaluated the incidence, prognosis, and temporal trends of PNETs.

PATIENTS AND METHODS

We analyzed all cases of PNETs registered in the Surveillance, Epidemiology, and End Results database from 1973 to 2000. Age-adjusted incidence and survival rates were calculated and survival trends over time were evaluated.

RESULTS

We identified 1483 cases of PNETs. The crude annual incidence per 1,000,000 was 1.8 in females and 2.6 in males and increased with advancing age. The incidence increased over the study period. Most patients (90.8%) had nonfunctional tumors. Advanced stage, higher grade, and age were the strongest predictors of worse survival. Patients with functional tumors had better outcomes than patients with nonfunctional tumors in both univariate and multivariate analysis (P = 0.004). Survival time increased over the period from 1973 to 2000. No differences were seen in the distribution of stage or age at diagnosis among time periods.

CONCLUSION

PNETs are uncommon neoplasms but the incidence may be increasing. Age, grade, stage, and functional status predict survival in patients with PNETs. Survival has improved over time, but this is not explained by earlier diagnosis or stage migration.

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.

Predicting prognosis in gastroentero-pancreatic neuroendocrine tumors: an overview and the value of Ki-67 immunostaining

Gastroenteropancreatic neuroendocrine tumors (GEP-NETS) are unusual and rare neoplasms for which prognostic assessment and the diagnosis of malignancy, on the basis of histology alone, represent considerable challenges for the pathologist. To date, many molecular markers have been identified with a view to providing accurate and timely prediction of response to treatment and long-term survival. Proliferation remains a key feature of tumor progression, which has been widely estimated by the immunohistochemical use of the Ki-67 nuclear antigen. Given the continued difficulties inherent in prediction of malignancy in pancreatic neuroendocrine tumors (PETs) in particular, it has become unclear whether Ki-67 is truly a reliable prognostication marker. This review seeks to better establish what the consensus is on the role of the Ki-67 proliferation index as a prognostic indicator of long-term outcome in pancreatic neuroendocrine tumors. We conclude that most studies favor the utility of the Ki-67 proliferation index despite different critical percentages and in concert with other pathological parameters in the routine work-up of PETs.

Surgical treatment of pancreatic endocrine neoplasms

BACKGROUND

Pancreatic endocrine neoplasia (PEN) is an entity with an indolent course and prolonged survival. The aim of the current study was to review the prognostic factors and outcome of patients with PEN at 1 institution.

METHODS

Records of patients with the diagnosis of PEN in the period of 1980 to 2001 were reviewed. Descriptive statistics and log-rank test were used; significance was defined as P < .05.

RESULTS

Of 49 patients, 25 had functional and 24 nonfunctional tumors. Surgery was performed in 43 patients, 36 with curative intent. With a median follow-up of 31 months, there were 5 deaths. Symptoms were controlled with surgical resection in 86%. Median disease-free survival (DFS) was 46 months; actuarial 5-year disease-specific (DSS) was 72%. Factors associated with better DFS and DSS were absence of liver involvement (P = .02) and resection of the primary tumor (P = .04).

CONCLUSIONS

Surgical resection and absence of liver metastases are associated with better DFS and DSS in patients with PEN.

Alkaline phosphatase predicts survival in patients with metastatic neuroendocrine tumors

The clinical course of patients with metastatic neuroendocrine tumors is highly variable. While some patients experience an indolent clinical course over many years, other patients may rapidly succumb to their disease. Little is known about prognostic factors in these patients, making decisions regarding their management more difficult. We performed a retrospective analysis of 137 patients with metastatic neuroendocrine tumors referred to our institution for treatment. Potential prognostic factors were evaluated using multivariate survival analysis. The median overall survival of patients in our cohort was 6.0 years, although the range of survival times was broad (48 days to 23.4 years). Alkaline phosphatase levels above normal were predictive of shorter survival in both univariate and multivariate analysis. Elevated chromogranin A levels were also associated with shorter survival in univariate analysis; in a multivariate analysis, however, this correlation was no longer significant. There was no association between survival and gender, primary tumor site, or presence or absence of carcinoid syndrome. Elevated alkaline phosphatase is a robust adverse prognostic factor for survival in patients with metastatic neuroendocrine tumors and may be superior to chromogranin A in this setting. Close monitoring of alkaline phosphatase levels may be useful when considering initiation or changes of therapy in patients with metastatic neuroendocrine tumors.

Endocrine tumours of the gastrointestinal tract. Management of metastatic endocrine tumours

Gastroenteropancreatic tumours are rare. They compromise a heterogenous class of neoplasm. If there is no hypersecretion syndrome, symptoms may be uncharacteristic and thus diagnosis occurs rather late after the first manifestations of the disease. The most important prognostic parameters are histological classification, the localisation of the primary, the tumour size and stage at diagnosis, and the presence or absence of metachronous or synchronous neoplasia. The article will focus on the importance of each of these parameters for the various treatment options in patients with metastatic disease.

Surgery of resectable nonfunctioning neuroendocrine pancreatic tumors

Nonfunctioning neuroendocrine pancreatic tumors (NFNEPTs) comprise about one-third of pancreatic endocrine tumors. Based on immunohistochemistry, nonfunctioning tumors are difficult to distinguish from functioning ones; therefore the final diagnosis is basically the result of a synopsis of pathology and clinical data. Owing to their incapacity to produce hormone-dependent symptoms, NFNEPTs are detected incidentally or because of uncharacteristic symptoms resulting from local or distant growth. About two-thirds of NFNEPTs are located in the pancreatic head, so jaundice may be a late symptom of this tumor. Modern diagnostic procedures are best applied by a stepwise approach: first endoscopic ultrasonography and computed tomography/magnetic resonance imaging followed by somatostatin receptor scintigraphy or positron emission tomography (or both). Due to significant false-positive and false-negative findings, for decision-making the latter should be confirmed by a second imaging modality. Regarding indications for surgery and the surgical approach to the pancreas, three pancreatic manifestations of NFNEPTs can be distinguished: (1) solitary benign non-multiple endocrine neoplasia type 1 (non-MEN-1); (2) multiple benign MEN-1; and (3) malignant NFNEPTs. Reviewing the literature and including our experience with 18 NFNEPTs (8 benign, 10 malignant) reported here, the following conclusions can be drawn: (1) Solitary benign non-MEN-1 NFNEPTs can be removed by enucleation or by pancreas-, spleen-, and duodenum-preserving techniques in most cases. The choice of surgical technique depends on the location and site of the tumor and its anatomic relation to the pancreatic duct. (2) With multiple benign MEN-1 NFNEPTs, because of the characteristics of the underlying disease a preferred, more conservative concept (removal of only macrolesions) competes with a more radical procedure (left pancreatic resection with enucleation of head macrolesions). Further studies are necessary to clarify the best way to balance quality of life (by preserving organ function) with growth control of potentially malignant tumors in the pancreas. (3) Malignant NFNEPTs comprise more than half of all NFNEPTs. Few studies have analyzed treatment strategies for localized or metastatic tumors. Whereas radical (including multivisceral) resection of tumors without distant metastases is widely accepted, the indication for radical surgery on metastasizing tumors has been questioned, as radical removal of the primary tumor may fail to increase survival. Adjuvant regimens in these tumor stages are mandatory and should be further optimized.

Valosin-containing protein (p97) and Ki-67 expression is a useful marker in detecting malignant behavior of pancreatic endocrine neoplasms

OBJECTIVE

To determine the prognostic value of valosin-containing protein (VCP) expression and the Ki-67 labeling index (LI) in pancreatic endocrine neoplasms (PENs), the present analysis was employed.

METHODS

The Ki-67 LI and VCP expression at the mRNA and protein level were evaluated in 32 patients (12 male and 20 female) with PENs aged from 22 to 73 years (median 49 years). VCP staining intensity in tumor cells was categorized as weaker (level 1) or equal to stronger (level 2) compared to nontumorous islet cells. Ki-67 LI was divided into two categories: level 1, Ki-67 LI < 5%, and level 2, > or = 5%.

RESULTS

Five cases (15.6%) showed level 1 and 25 (84.4%) level 2 VCP expression by immunohistochemistry. A significant association was observed between VCP expression and the malignant behavior of PENs (p < 0.01). All level 1 VCP tumors were benign PENs. Quantitative reverse transcription polymerase chain reaction analysis showed higher VCP mRNA expression in malignant PENs (n = 5) than benign cases (n = 5) (p < 0.05). For Ki-67 LI, 28 cases (87.5%) showed level 1 and 4 (12.5%) level 2 expression. All patients with level 2 Ki-67 LI had metastasis.

CONCLUSION

VCP expression analysis and Ki-67 LI are useful prognosticators for PENs.

Management of nonfunctioning islet cell tumors

AIM: To more clearly define the clinical and pathological characteristics and appropriate diagnosis and treatment of nonfunctioning (NFICTs) islet cell tumors, and to review our institutional experience over the last 30 years.

METHODS: The records of 43 patients confirmed to have nonfunctioning islet cell tumors of pancreas were retrospectively reviewed. Survival was estimated by the Kaplan-Meier methods and potential risk factors for survival were compared with the log-rank tests.

RESULTS: The mean age was 31.63 years (range, 8 to 67 years). There were 7 men and 36 women. Twenty-eight patients had a confirmed diagnosis of nonfunctioning islet cell carcinoma (NFICC) and benign islet cell tumors were found in 15 patients. The most common symptoms in patients with NFICTs were abdominal pain (55.8%), nausea and/or vomiting (32.6%), fatigue (25.6%) and abdominal mass (23.3%). Preoperative ultrasonic and computed tomography localized the tumors in all patients. Forty-three NFICTs were distributed throughout the pancreas, with 21 located to the right of the superior mesenteric vessels, 10 in the body of the pancreas, 6 in the tail of the pancreas, and multiple tumors were found in one patient. Thirty-nine of 43 patients (91%) underwent surgical resection. Surgical treatment was curative in 30 patients (70%) and palliative in 9 (21%). The resectability and curative resection rate in patients with NFICC of pancreas were 89% and 61%, respectively. The overall cumulative 5-year and 10-year survival rates for patients with NFICC were 58.05% and 29.03%, respectively. Radical operation and diameter of cancer small than 10 cm were positive prognostic factors in females younger than 30 years old. Multivariate Cox regression analysis indicated that radical operation was the only independent prognostic factor, P = 0.007.

CONCLUSION: Nonfunctioning islet cell tumors of pancreas are found mainly in young women. The long-term results for patients undergone surgery, especially curative resection are good.

Diagnosis of non-functioning neuro-endocrine gastro-enteropancreatic tumours

Non-functioning neuro-endocrine gastro-enteropancreatic tumours are neoplasms of neuro-endocrine differentiation without symptoms of hormonal hypersecretion. In pancreatic tumours, symptoms are related to an expanding tumour mass, while most midgut tumours are small and symptoms of intermittent intestinal entrapment are due to mesenteric fibrosis. Positive somatostatin receptor imaging indicates the neuro-endocrine differentiation of the tumour. The high spatial resolution of MRI/CT improves preoperative planning. In localized pancreatic tumours, curative resection of the primary improves survival. In midgut tumours, resection of the primary should be performed, irrespective of the presence of liver metastases. Palliative surgery and cytoreductive therapy of liver metastases may prolong survival in both, pancreatic and midgut tumours. Combination chemotherapy is effective in pancreatic disease, while in midgut tumours the response rate is only 22%. As the antiproliferative effect of biotherapy is still uncertain, it cannot yet be recommended as a routine treatment in non-functioning neuro-endocrine gastro-enteropancreatic tumours.

[Non-functioning tumor of the islets of Langerhans]

About 15% of tumors of Langerhans, islets do not cause any hormone induced syndrome although they sintetise and secrete one or more regulatory peptides. These tumors are most frequently localised in the head and tail of the pancreas. They are usually greater then 5 cm. In diameter and present with pain, jaundice, palpable mass and malaise, rarely with variceal bleeding due to compression of the splenic vein. About 50% of the tumors present with symptoms caused by metastases. We present a 51 year old women in whom during the investigation for paraumbilical pain, predominantly on the left side a tumor of the tail of the pancreas was discovered and subsequently surgically removed. Standard histology showed a neuroendocrine tumor. Immunohistochemistry showed generalised immunoreactivity with antibodies against chromographin A, neuron specific enolasa and glucagon in more then 95% of cells. Somatostatatin was coexpressed in more then 5% of cells, PP in rare scattered cells. No reactivity was found for the other hormone markers. Ten years after surgery the patient has no signs of tumor recurrency.

Predictive factors associated with long-term survival in patients with neuroendocrine tumors of the pancreas

BACKGROUND

Neuroendocrine tumors of the pancreas are rare tumors. We identified predictive factors that are associated with long-term survival (> or=5 years).

METHODS

Fifty patients with a diagnosis of neuroendocrine tumors of the pancreas were retrospectively evaluated. The following factors were evaluated for disease-specific mortality: age, sex, primary tumor location, functional status, type of primary tumor treatment, presence or absence of liver metastases, timing of liver metastases occurrence, and type of liver metastases treatment. Aggressive treatment of the liver metastases included surgery, chemoembolization, or intrahepatic arterial infusion chemotherapy.

RESULTS

Twenty-three patients (47%) had tumor located in the head of the pancreas, and 29 patients (58%) had nonfunctioning tumor. Thirty-nine patients (78%) had liver metastases. The median follow-up for the entire group was 35 months (range,.76-206 months). The median survival for the entire group was 40 months, and the overall 1-, 2-, and 5-year survival rates were 84%, 69%, and 36%, respectively. Factors that had a significant favorable effect on survival included curative resection of the primary tumor, metachronous liver metastases, absence of liver metastases, and aggressive treatment of the liver metastases.

CONCLUSIONS

Definitive surgical resection of the primary tumor, absence of liver metastases, metachronous liver metastases, and aggressive treatment of the liver metastases were predictors of long-term survival in patients with neuroendocrine tumors of the pancreas.

Nonfunctioning Islet Cell Carcinoma of the Pancreas: Case Report

Islet cell carcinomas have an incidence of 5 per million per year; 50 per cent of these are nonfunctioning islet cell tumors. The presenting symptoms mimic pancreatic ductal adenocarcinoma. The CT finding of a pancreatic head mass that spares the main duct may distinguish between the two. The treatment of choice is resection. Most nonfunctioning islet cell tumors are not discovered until metastases are present. However, favorable survival rates have been reported in locally advanced tumors that have undergone resection. Liver metastases carry an unfavorable prognosis. Five-year survival over 60 per cent has been reported. Node-negative patients have a median survival of more than 10 years, and node-positive patients who have undergone resection have a median survival of 75 months. Streptozotocin and 5-fluorouracil are used postoperatively in patients with advanced disease. Considering the favorable survival with resection aggressive surgical treatment is mandated in cases of nonfunctioning islet cell tumors.

Prognostic factors in pancreatic endocrine neoplasms: an analysis of 136 cases with a proposal for low-grade and intermediate-grade groups

PURPOSE

In some organs (eg, the lung), endocrine tumors are classified on the basis of mitotic rate and necrosis. The purpose of this study was to evaluate prognostic factors in pancreatic endocrine neoplasms recently treated at a single institution.

PATIENTS AND METHODS

In 136 patients undergoing surgery from 1979 to 1998, the influence on disease-free survival (DFS) and disease-specific survival (DSS) of tumor size, mitotic rate, vascular invasion, necrosis, metastases, and nuclear grade was determined. Cases were further grouped according to an existing proposed classification system and then regrouped on the basis of mitotic rate (< 2 mitoses per 50 high-power fields v higher) and necrosis (present or absent) into low- and intermediate-grade groups.

RESULTS

Correlations with DFS and DSS in univariate analysis included < or = 2 mitoses per 50 high-power fields (P =.001, P =.002), vascular invasion (P =.02, P =.04), size < or = 2 cm (P =.01, P =.05), metastases (P =.0002, P =.07), necrosis (P =.002, P =.16), and nuclear grade (P =.04, P =.33), respectively. By multivariate analysis, for DFS, tumor necrosis and presence of metastases retained significance (P =.01, P =.04, respectively). For DSS, only mitotic rate was a prognostic factor (P =.02). Among the 18 macroadenomas, eight borderline tumors, and 48 low-grade carcinomas, there was no significant difference in DSS between any groups (P =.3). However, in evaluating our newly proposed groups, the differences in DFS and DSS between low- and intermediate-grade groups were highly significant (P =.0007, P =.006, respectively).

CONCLUSION

Pancreatic endocrine neoplasms exhibit a spectrum of biologic behavior, and the proposed benign (macroadenoma) and borderline groups contain potentially aggressive tumors. An alternative system based on mitotic rate and necrosis correlates strongly with survival without specifically designating any group as benign.

Protocol for the examination of specimens from patients with endocrine tumors of the pancreas, including those with mixed endocrine and acinar cell differentiation: a basis for checklists. Cancer Committee of the College of American Pathologists

No Abstract Available

Pancreatic endocrine tumours: evidence for a tumour suppressor pathogenesis and for a tumour suppressor gene on chromosome 17p

Two molecular pathways leading to cancer are known. Common-type cancers arise from the 'tumour suppressor' pathway, characterized by gross chromosomal changes and allelic losses (LOH) in an average of 25 per cent or more of randomly chosen chromosomal loci. The 'mutator pathway' has been recognized in a subset of cancers, characterized by widespread microsatellite DNA instability and rarity of chromosomal losses. The present study has investigated 20 pancreatic endocrine tumours (PETs) for loss of heterozygosity (LOH) at seven chromosomal loci (3p14, 7q31-32, 11q13, 13q14, 18q21, 17p13, and 17q21); microsatellite instability; and Ki-ras, N-ras, and p53 gene mutations. LOH was found in an average of 24 per cent of the chromosomal loci analysed. No tumour showed microsatellite instability. Ki-ras and p53 mutations were each found in one case. The frequency of losses was higher in malignant (40 per cent) than in benign (17 per cent) tumours (p = 0.009), and the specific chromosome 17p13 LOH was associated with extrapancreatic extension of disease (p = 0.007), high proliferative activity (p = 0.001), and absence of progesterone receptors (p = 0.01). A common deleted region on chromosome 17p13 and the rarity of p53 gene mutations suggest the existence of a novel tumour suppressor gene involved in the pathogenesis of PETs in this chromosomal area.

Huge non-functioning pancreatic cystic neuroendocrine tumour: a case report

A case of an 18-cm large cystic, non-functioning endocrine (islet cell) tumour located at the tail of the pancreas in a 29-year-old Caucasian female is reported here. Pre-operative radioimmunoassays for pancreatic peptides were negative, while immunohistochemistry confirmed the neuroendocrine nature of the tumour. This is the largest cystic non-functioning islet-cell tumour so far described.

Pancreatic endocrine tumour: a 22-year clinico-pathological experience with morphological, immunohistochemical observation and a review of the literature

The clinico-pathological features of 53 Chinese patients (27 males; 26 females) with pancreatic endocrine tumours were studied. The age range was from 14 to 78 years old (mean: 48 years) with the modal peak in the sixth decade for both sexes. Pancreatic endocrine tumours accounted for 14% of the primary pancreatic tumours operated on in Queen Mary Hospital. The autopsy incidence was 0.11%. Seventy-two per cent (38 cases) of the tumours were clinically functioning, comprising 33 insulinomas, three gastrinomas and two glucagonomas. A rare case of malignant gastrinoma associated with Cushing's syndrome was also documented. The functional tumours were seen in the younger patients. The calculated annual incidence of clinically significant tumours was approximately 0.2 per 100,000 population. There was no correlation between the site, functional status and histological patterns of the tumours. Seventy-two per cent of the tumours showed a trabecular pattern. Calcification was present in 5.7% (three cases); two such cases being gastrinomas. Amyloid was found in 25% of tumours, chiefly (92%) in the insulinomas. The main difficulty encountered in diagnosis was distinguishing between solid and cystic tumours of the pancreas. The incidence of malignancy was 15% and the histological features were poor predicative indicators of malignant potential. The metastatic pancreatic endocrine tumours were often detected in the liver and lymph nodes. Immunohistochemical stains showed evidence of multi-hormone production in 18% of cases and all tumours showed a positive reaction to at least one of the six markers, namely, neuron-specific enolase (NSE), chromogrannin (CG), synaptophysin (SYN), insulin (INS), glucagon (GLU) or somatostatin (SOM). The three panendocrine markers (NSE, SYN, CG) were satisfactory for initial screening of the endocrine nature of the tumours if used in combination, as 92% of tumours were positive for at least one of these three markers.

Proliferative Activity in Pancreatic Endocrine Tumors: Association with Function, Metastases, and Survival

Endocrine tumors of the pancreas are slow-growing lesions, yet one-third to one-half will metastasize. It is generally accepted that histopathologic features do not reliably predict metastatic potential or outcome. We investigated whether proliferative activity, as determined by MIB-l labeling, correlated with tumor type, metastasis, or patient survival. Formalin-fixed sections of pancreatic endocrine tumors were immunohistochemically stained for the MIB-l antibody against Ki-67 using the avidin-biotin complex technique. Labeling index (LI) was determined by counting 1000 consecutive tumor cells in an area of greatest staining intensity at x400 and expressed as a percentage. The study group included 37 patients, including 10 gastrinomas, 9 insulinomas, 4 glucagonomas, 2 VlPomas, and 12 nonfunctioning tumors. Twenty-one patients had metastases, primarily to regional lymph nodes and the liver. Five patients had MEN I. MIB-1 LI was significantly greater in the nonfunctioning tumors (mean 20S%) than in the functioning tumors (mean 51%) (p = 0.01). LI for functional tumors (insulinomas 64%, glucagonoma 44%, gastrinomas 32%, VlPomas 32%) were similar to each other, MIB-1 was significantly higher in those tumors that metastasized (mean 15.6%) compared to those that did not (mean 31%), (p = 0.04). All tumors with MIB-1 LI >10% developed metastases. Logistic regression showed that MIB-1 was a significant predictor of metastases (p = 0.003) after adjusting for functional status. MIB-1 LI also correlated with outcome in that those patients with MIB-1 LI >/=10% had a mean survival of 19 mo compared to 72 mo for those with levels <10% (p = 0.0001). Results of the proportional hazards model showed that MIR-1 remained a significant (p = 0.03) and independent predictor of survival times after adjustment for tumor size and functional status. Higher MIB-1 LI values were significantly associated with shorter survival times. In conclusion, MIB-1 LI appears to be a useful indicator of metastatic potential and is predictive of outcome in PET.