Method for dissection of mesenteric metastases in mid-gut carcinoid tumors

Flushing Disorders Associated with Gastrointestinal Symptoms: Part 1, Neuroendocrine Tumors, Mast Cell Disorders and Hyperbasophila

Flushing is the subjective sensation of warmth accompanied by visible cutaneous erythema occurring throughout the body with a predilection for the face, neck, pinnae, and upper trunk where the skin is thinnest and cutaneous vessels are superficially located and in greatest numbers. Flushing can be present in either a wet or dry form depending upon whether neural-mediated mechanisms are involved. Activation of the sympathetic nervous system results in wet flushing, accompanied by diaphoresis, due to concomitant stimulation of eccrine sweat glands. Wet flushing is caused by certain medications, panic disorder and paroxysmal extreme pain disorder (PEPD). Vasodilator mediated flushing due to the formation and release of a variety of biogenic amines, neuropeptides and phospholipid mediators such as histamine, serotonin and prostaglandins, respectively, typically presents as dry flushing where sweating is characteristically absent. Flushing occurring with neuroendocrine tumors accompanied by gastrointestinal symptoms is generally of the dry flushing variant, which may be an important clinical clue to the differential diagnosis. A number of primary diseases of the gastrointestinal tract cause flushing, and conversely extra-intestinal conditions are associated with flushing and gastrointestinal symptoms. Gastrointestinal findings vary and include one or more of the following non-specific symptoms such as abdominal pain, nausea, vomiting, diarrhea or constipation. The purpose of this review is to provide a focused comprehensive discussion on the presentation, pathophysiology, diagnostic evaluation and management of those diseases that arise from the gastrointestinal tract or other site that may cause gastrointestinal symptoms secondarily accompanied by flushing. This review is divided into two parts given the scope of conditions that cause flushing and affect the gastrointestinal tract: Part 1 covers neuroendocrine tumors (carcinoid, pheochromocytomas, vasoactive intestinal polypeptide, medullary carcinoma of the thyroid), polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, skin changes (POEMS), and conditions involving mast cells and basophils; while Part 2 covers dumping syndrome, mesenteric traction syndrome, rosacea, hyperthyroidism and thyroid storm, anaphylaxis, panic disorders, paroxysmal extreme pain disorder, and food, alcohol and medications.

Mesenteric fibrosis and palliative surgery in small intestinal neuroendocrine tumours

Mesenteric fibrosis (MF) surrounding a mesenteric mass is a hallmark feature of small intestinal neuroendocrine tumours (SI-NETs). Since this can induce intestinal obstruction, oedema and ischaemia, prophylactic resection of the primary tumour and mesenteric mass is often recommended. This study assessed the predictors for mesenteric metastasis and fibrosis and the effect of MF and palliative surgery on survival. A retrospective analysis of 559 patients with pathologically proven SI-NET and available CT-imaging data was performed. Clinical characteristics, presence of mesenteric mass and fibrosis on CT imaging and the effect of palliative abdominal surgery on overall survival were assessed. We found that MF was present in 41.4%. Older age, 5-HIAA excretion ≥67 μmol/24 h, serum CgA ≥121.5 μg/L and a mesenteric mass ≥27.5 mm were independent predictors of MF. In patients ≤52 years, mesenteric mass was less often found in women than in men (39% vs 64%, P = 0.002). Corrected for age, tumour grade, CgA and liver metastasis, MF was not a prognostic factor for overall survival. In patients undergoing palliative surgery, metastasectomy of mesenteric mass or prophylactic surgery did not result in survival benefit. In conclusion, we confirmed known predictors of MF and mesenteric mass and suggest a role for sex hormones as women ≤52 years have less often a mesenteric mass. Furthermore, the presence of MF has no effect on survival in a multivariate analysis, and we found no benefit of metastasectomy of mesenteric mass or prophylactic surgery on overall survival.

Small intestinal neuroendocrine tumours and fibrosis: an entangled conundrum

Small intestinal neuroendocrine tumours (SI-NETs) are neoplasms characterized by their ability to secrete biogenic amines and peptides. These cause distinct clinical pathology including carcinoid syndrome, marked by diarrhoea and flushing, as well as fibrosis, notably mesenteric fibrosis. Mesenteric fibrosis often results in significant morbidity by causing intestinal obstruction, oedema and ischaemia. Although advancements have been made to alleviate symptoms of carcinoid syndrome and prolong the survival of patients with SI-NETs, therapeutic options for patients with mesenteric fibrosis are still limited. As improved insight in the complex pathogenesis of mesenteric fibrosis is key to the development of new therapies, we evaluated the literature for known and putative mediators of fibrosis in SI-NETs. In this review, we discuss the tumour microenvironment, growth factors and signalling pathways involved in the complex process of fibrosis development and tumour progression in SI-NETs, in order to elucidate potential new avenues for scientific research and therapies to improve the management of patients suffering from the complications of mesenteric fibrosis.

Surgical Treatment of Small Intestinal Neuroendocrine Tumors G1/G2

Although the majority of neuroendocrine tumors of the small intestine (siNETs) classified as low-grade G1 or G2 show slow local growth, they are frequently diagnosed at an advanced stage of metastatic disease. The surgical treatment is curative in stages I-III or palliative in stage IV in an attempt to avoid local complications of bowel obstruction and ischemia of the small bowel by unremoved lymph node metastases. Individualized surgical procedures performed by experienced surgeons considering tumor multifocality and the primary extent of lymph node metastases along the mesenteric vessels are recommended to remove as much tumor volume as possible, while avoiding major complications intraoperatively and small bowel syndrome postoperatively.

Neoadjuvant peptide receptor radionuclide therapy and modified multivisceral transplantation for an advanced small intestinal neuroendocrine neoplasm: an updated case report

Small intestinal neuroendocrine neoplasms (SI-NEN) frequently metastasise to regional lymph nodes, and surgery is the mainstay of therapy for such patients. However, despite the possible use of advanced surgical techniques, the resection of both primary and locoregional diseases is not always attainable. Intestinal and multivisceral transplantation has been performed in a small number of patients with conventionally nonresectable, slow-growing tumours threatening the mesenteric root but has remained controversial. The use of donor skin in “sentinel flaps” in transplantation theoretically offers advantages in tailoring immunosuppression and monitoring for rejection. We represent (with extended follow-up) the first case of a patient with inoperable extensive mesenteric metastases from SI-NEN, who underwent neoadjuvant peptide receptor radionuclide therapy before a modified multivisceral transplant with a concomitant vascularised sentinel forearm flap. At 48 months after transplantation, our patient remained at full physical activity with no evidence of disease recurrence on either tumour biochemistry or radiological imaging.

The Surgical Management of Small Bowel Neuroendocrine Tumors: Consensus Guidelines of the North American Neuroendocrine Tumor Society

Small bowel neuroendocrine tumors (SBNETs) have been increasing in frequency over the past decades, and are now the most common type of small bowel tumor. Consequently, general surgeons and surgical oncologists are seeing more patients with SBNETs in their practices than ever before. The management of these patients is often complex, owing to their secretion of hormones, frequent presentation with advanced disease, and difficulties with making the diagnosis of SBNETs. Despite these issues, even patients with advanced disease can have long-term survival. There are a number of scenarios which commonly arise in SBNET patients where it is difficult to determine the optimal management from the published data. To address these challenges for clinicians, a consensus conference was held assembling experts in the field to review and discuss the available literature and patterns of practice pertaining to specific management issues. This paper summarizes the important elements from these studies and the recommendations of the group for these questions regarding the management of SBNET patients.

Aggressive Surgical Approach to the Management of Neuroendocrine Tumors: A Report of 1,000 Surgical Cytoreductions by a Single Institution

BACKGROUND

Neuroendocrine tumors (NETs) are rare neoplasms. Our group has treated more than 2,000 NET patients and has performed more than 1,000 surgical cytoreductive procedures.

STUDY DESIGN

Records of 834 NET patients who underwent surgical cytoreduction at our institution were reviewed. Demographic information, intraoperative findings, extent of disease, complications, and survival rates were calculated.

RESULTS

Eight hundred patients underwent 1,001 cytoreductive operations. Sixty-five percent had small bowel primaries. One hundred and thirty-eight patients presented with an unknown primary site, which was localized intraoperatively in 89% of these cases. The intraoperative complication rate was 9%. The incidence of intraoperative carcinoid crisis was 1%. Mean ± SD operative time was 368 ± 146 minutes. Mean ± SD hospital stay was 9 ± 10 days. Minor postoperative complications occurred after 43% of procedures and major postoperative complications were noted after 19% of procedures. The 30-day postoperative mortality rate was 2%. Median overall survival (OS) for patients with pancreatic NETs was 124 months. The 5-, 10-, and 20-year OS rates for patients with pancreatic NETs were 67%, 51%, and 36%, respectively. The life expectancy difference (between OS and actuarial survival) after surgical cytoreduction for patients with pancreatic NETs was 16.6 years. Median OS for patients with small bowel NETs was 161 months. The 5-, 10-, and 20-year OS rates for patients with small bowel NETs were 84%, 67% and 31%, respectively. The life expectancy difference after surgical cytoreduction for patients with small bowel NETs was 11.7 years.

CONCLUSIONS

Surgical cytoreduction in NET patients has low morbidity and mortality rates and results in prolonged survival. We believe that surgical cytoreduction should play a major role in the care of patients with NETs.

Surgical Treatment of NEN of Small Bowel: A Retrospective Analysis

BACKGROUND

Neuroendocrine Neoplasms of the small intestine have been noticed more frequently over the past 35 years. They constitute about 25% of all NENs and 29% of all tumors of the small intestine. Due to the predominantly indolent nature and overall good prognosis, the benefit of surgical treatment is still debated.

METHODS

In a retrospective study, data of 83 surgically treated patients with neuroendocrine neoplasms of the small intestine, 48 males and 35 females with a median age of 62 years (range 25-86 years) were analyzed. Patient data were documented in the MaDoc database for neuroendocrine tumors of the University Medical Center of Mainz. IBM SPSS Statistics 20 was used for statistical analysis. Kaplan-Meier survival curves and Log-Rank tests, censoring patients at the time of last follow-up, were used to compare the overall survival depending on potential prognostic factors (stage, grade, surgical treatment).

RESULTS

At the time of diagnoses, the most common clinical symptoms were abdominal pain (n = 31, 37.3%), bowel obstruction (n = 11, 13.3%), bowel perforation and peritonitis (n = 3, 3.6%), gastrointestinal bleeding (n = 9, 10.8%), weight loss (n = 11, 13.3%), and carcinoid syndrome (n = 27, 32.5%). 65 patients (78.3%) had lymph node metastasis and in 58 patients (69.9%) distant metastasis were present. Segmental bowel resection (44) was the most common surgical procedure, followed by right hemi-colectomy (32) and explorative laparotomy (7). In most patients (78.9%), lymphadenectomy (systematic/selective) was performed. The 5-year survival of patients who underwent a systematic or a selective lymphadenectomy differed significantly (82.2 vs. 40.0%). The overall 3-, 5-, and 10-year survival rates were 88.2, 80.3, and 71.0%, respectively.

CONCLUSION

Mesenteric lymph node metastases are almost invariably present and have significant impact on patients' prognosis. Systematic lymphadenectomy prevents complications and improves the survival. Early surgical treatment should be the goal in order to prevent complications.

Gastroenteropancreatic Well-Differentiated Grade 3 Neuroendocrine Tumors: Review and Position Statement

: In 2010, the World Health Organization (WHO) classification of neuroendocrine neoplasms was reviewed and validated the crucial role of the proliferative rate. According to the WHO classification 2010, gastroenteropancreatic neuroendocrine neoplasms are classified as well-differentiated neuroendocrine tumors (NETs) of grade 1 or 2 in up to 84%, or poorly differentiated neuroendocrine carcinomas in 6%-8%. Neuroendocrine carcinomas are of grade G. Recently, a proportion of neuroendocrine tumors presenting a number of mitoses or a Ki-67 index higher than 20% and a well-differentiated morphology have been identified, calling for a new category, well-differentiated grade 3 NET (NET G-3). Studies that have reported the characteristics of neuroendocrine neoplasms have identified more well-differentiated NET G-3 than neuroendocrine carcinomas. The main localizations of NET G-3 are the pancreas, stomach, and colon. Treatment for NET G-3 is not standardized and is balanced between G-1/2 neuroendocrine tumor and neuroendocrine carcinoma treatments. In nonmetastatic neuroendocrine tumors, the European and American guidelines recommended a surgical resection for localized neuroendocrine neoplasm, irrespective of the tumor grading. In NET G-3, chemotherapy is the benchmark if the main treatment goal is reduction of the tumor mass, particularly if it would allow a secondary surgery. In the present work, we review the epidemiology and make recommendations for the management of NET G-3.

IMPLICATIONS FOR PRACTICE

Neuroendocrine tumors presenting a number of mitoses or a Ki-67 index higher than 20% and a well-differentiated morphology have been identified and named well-differentiated grade 3 neuroendocrine tumors (NET G-3). The main localizations of NET G-3 are the pancreas, stomach, and colon. The prognosis is worse than that for NET G-2. In nonmetastatic NET G-3, surgery appeared to be the first option. The chemotherapy regimen in pancreatic NET G-3 should be in line with that implemented in NET G-1/2 when the Ki-67 index is below 55% and should be in line with that implemented for neuroendocrine carcinoma when Ki-67 is above 55%.

Toward a Preoperative Classification of Lymph Node Metastases in Patients with Small Intestinal Neuroendocrine Tumors in the Era of Intestinal-Sparing Surgery

INTRODUCTION

In patients with small intestinal neuroendocrine tumors (siNETs), surgical resection of the primary tumor and associated mesenteric lymph nodes (LNs) is recommended, but is not well standardized and can be risky in patients with superior mesenteric vessel involvement.

OBJECTIVE

We aimed to evaluate the correlation between the length of resected small bowel and the number of removed LNs, and to propose a preoperative morphological classification of siNET-associated LNs.

METHODS

The records of patients operated on for siNETs at two expert centers between August 2005 and November 2013 were analyzed. Two specialist radiologists reviewed the preoperative imaging and classified mesenteric LNs into five stages according to their proximity to the trunk and/or branches of the superior mesenteric artery.

RESULTS

72 patients were included. The mean number of removed LNs was 12 ± 15 and the length of removed small intestine was 53 ± 43 cm. No correlation existed between the length of small bowel resection and the number of removed LNs. Overall, 9 (12%), 13 (18%), 36 (50%), 14 (19%) and 0 patients were classified into LN stages 0, I, II, III and IV. The correlation rate between the two observers was 0.98. Patients with LN stage III (hardly resectable) had more removed LNs than those with LN stages 0, I or II (easily removable).

CONCLUSION

Optimal lymphadenectomy is not always associated with extended small bowel resection. In the era of small bowel-sparing surgery, the preoperative classification of mesenteric LNs could help to standardize the surgical management of patients with siNETs.

Retrograde Stenting Under Transmesenteric Angiographic Guidance of an Occluded Superior Mesenteric Vein to Treat Life-Threatening Hemorrhage

Midgut carcinoid tumors (MCTs) are responsible for a range of mesenteric vascular complications and may rarely manifest with gastrointestinal (GI) hemorrhage. Endovascular approaches are particularly useful for this population, as surgery is often technically difficult. We report a case of life-threatening upper GI bleeding in a 50-year-old man previously diagnosed with an MCT in the small bowel mesentery. Computed tomography angiogram revealed an MCT obstructing the superior mesenteric vein (SMV) associated with multiple large collateral vessels. The patient underwent retrograde stenting of the obstructed SMV using a combined open and endovascular approach to successfully terminate the persistent GI bleeding.

Adjuvant intraoperative post-dissectional tumor bed chemotherapy-A novel approach in treating midgut neuroendocrine tumors

BACKGROUND

Midgut neuroendocrine tumor (NET) patients are often diagnosed at an advanced stage with extensive mesenteric lymph node and liver metastasis. Even with skillful surgical dissection, macro and microscopic residual disease at the dissection site remains a possibility. We hypothesize these potential tumor residuals in mesenteric lymph node dissection beds can be eliminated safely by a local application of 5-fluorouracil (5-FU). We describe a novel technique invented by the author to treat these micro and macro residuals.

METHODS

Retrospectively, charts of 62 consecutive midgut NET patients with boggy mesenteric lymphadenopathy who underwent cytoreductive debulking surgeries from 1/2007 to 12/2009 were reviewed. A total of 32 patients received an intraoperative application of 5-FU saturated gelfoam strips secured into the mesenteric defect following the extensive lymphadenectomy. A total of 30 untreated patients served as a control.

RESULTS

The 5-year survival after cytoreductive surgeries was 22/32 (68.8%) for the treated group, vs. 20/30 (66.7%) for the control. Six patients (6/32, 18.8%) among the study group required additional debulking surgeries, vs. 16 patients (16/30, 53.3%) in the control group. Upon reoperation, loco-regional recurrence was noted in 9 of the 16 patients (56.3%) in the control group, vs. only 2/6 (33.3%) of treated patients. Overall, local recurrence rate is 6.25% (2/32) in the treated group vs. 30% (9/30) in the control group. Post-op complication rates are similar in the two arms.

CONCLUSIONS

Intraoperative application of chemotherapy is a safe and effective adjuvant to reduce local recurrence and the need of reoperation by the tumoricidal or tumorstatic effects of 5-FU on any potential microscopic residual disease after extensive cytoreductive surgeries in advanced stage NET patients with mesenteric lymph node metastasis. It provides patients with sustained, slow releasing, high dose of 5-FU within the surgical bed with a negligible side effect profile. Further studies are required to evaluate its effect on long term survival.

A review on management discussions of small intestinal neuroendocrine tumors ‘midgut carcinoids’

European Neuroendocrine Tumor Society staging, together with the Ki67 grading system, has appeared as superior for classification of neuroendocrine tumors (NET). The management of small intestinal NET (SI-NET) has been overall controversial. Mesenteric metastases occur also with the smallest SI-NET, and the majority of patients risk to ultimately progress with liver metastases. 68Gallium (somatostatin receptor)/PET/CT has appeared as most sensitive for imaging, and fluorodeoxyglucose-PET is recommended to identify lesions with high proliferation. Our treatment policy for SI-NET is to initiate somatostatin analog treatment, and in order to prevent abdominal complications we recommend early intestinal resection for removal of primary tumors and clearance of lymph node metastases. Liver metastases are liberally treated by resection (or ablation), as this can efficiently palliate carcinoid syndrome-associated symptoms.

Rural-urban disparities in incidence and outcomes of neuroendocrine tumors: A population-based analysis of 6271 cases

BACKGROUND

Despite their rising incidence, neuroendocrine tumors (NETs) remain a poorly understood disease. Living in a rural area (RA) affects the incidence and outcomes of other types of cancer. This study compared the incidence and outcomes of NETs for patients in RAs and patients in urban areas (UAs).

METHODS

A population-based cohort study of patients with NETs in Ontario, Canada from 1994 to 2011 was conducted. An RA was defined as any community with a population < 10,000 and outside the commuting zone of a metropolitan area. Incidence, advanced stage at presentation, distant recurrence-free survival (dRFS), and overall survival (OS) were compared between patients who lived in RAs and patients who lived in UAs with univariate and multivariate regression analyses.

RESULTS

The cohort included 6271 patients diagnosed with NETs, of whom 13.5% (n = 846) resided in RAs. The incidence of NETs was higher in RAs at 3.01 per 100,000 per year versus UAs at 2.82 per 100,000 per year (relative rate, 1.10; P = .04). RA living was not associated with an advanced stage at presentation (odds ratio, 1.15; 95% confidence interval, 0.96-1.38). Patients who lived in RAs had worse 10-year dRFS (62.8% vs 65.9%, P = .03) and OS (44.6% vs 48.8%, P = .004). RAs were independently associated with decreased OS (hazard ratio, 1.16; 95% confidence interval, 1.04-1.30).

CONCLUSIONS

Patients are more commonly diagnosed with NETs in RAs, but they do not present at more advanced stages in comparison with patients diagnosed in UAs. Patients living in RAs experience worse cancer recurrence and OS, and this is possibly related to variations in socioeconomic status, rural environmental factors, and access to specialized health care.

Modified liver-free multivisceral transplantation for a metastatic small bowel neuroendocrine tumor: a case report

Neuroendocrine tumors originating from the small bowel frequently metastasize to the lymph nodes and/or liver. Although surgical extirpation of the primary tumor and locoregional metastases epitomizes the management of patients with such tumors, this is not always possible with conventional surgical techniques. Nonresectable, slow-growing tumors involving the mesenteric root represent a generally accepted indication for deceased donor intestinal and multivisceral transplantation. Furthermore, vascularized sentinel forearm flaps offer opportunities for monitoring graft rejection and tailoring immunosuppression regimens. Here, we report the first documented case of modified liver-free multivisceral transplantation preceded by neoadjuvant 177-lutetium peptide receptor radionuclide therapy in a patient with a small bowel neuroendocrine tumor and extensive lymph node metastases in the mesenterium. At a follow-up of 21 months the patient is biochemically and radiologically disease-free.

Updating the surgical management of peritoneal carcinomatosis in patients with neuroendocrine tumors

Well-differentiated digestive neuroendocrine tumors (NET) are a heterogeneous group of neoplasms usually associated with slow growth but a high rate of metastases, including peritoneal carcinomatosis (PC). Herein, we aimed to comprehensively review the current knowledge of PC in terms of implications for the management and prognosis of patients with NET, including the latest studies and expert statements. NET-derived PC concerns about 17% of NET patients and up to 30% of those with small intestine primary NET. It has an independent pejorative prognostic impact. The extent of PC in NET patients and its severity can be expressed by analogy to other malignancies. However, it must be placed in the context of NET disorders, which usually vary from other PC-related malignancies. Recently, a gravity PC score was proposed by a consensus European Neuroendocrine Tumor Society (ENETS) expert group, but it requires validation. In addition, the form of peritoneal involvement (nodular or fusiform/infiltrative) might influence its prognosis and management. Aggressive surgical management seems justified for subsets of NET-related PC but requires careful selection of the candidates most likely to benefit. Cytoreductive surgery prolongs survival, especially when the peritoneal lesions are completely resected. Too little is known about the benefit of hyperthermic intraperitoneal chemotherapy for NET-derived PC, but if it confers an advantage, it would have to be counterbalanced by its high morbidity.

Reappraisal of lymphatic mapping for midgut neuroendocrine patients undergoing cytoreductive surgery

BACKGROUND

We previously reported that midgut neuroendocrine tumors (NETs) often develop alternative lymphatic drainage owing to lymphatic obstructions from extensive mesenteric lymphadenopathy, making intraoperative lymphatic mapping mandatory. We hypothesize that this innovative approach needs a longer term validation.

METHODS

We updated our results by reviewing 303 patients who underwent cytoreduction from November 2006 to October 2011. Of these patients, 112 had lymphatic mappings and 98 were for midgut NET primaries. Among them, 77 mappings were for the initial cytoreduction and 35 were for reexploration and further cytoreduction. The operative findings, pathology reports, and long-term surgical outcomes were reviewed.

RESULTS

Lymphatic mapping changed traditional resection margins in 92% of patients. Of the 35 patients who underwent reexploration without initial mapping, 19 (54%) showed a recurrence at or near the anastomotic sites. In contrast, none of the 112 mapped patients had shown signs of recurrence in a 1- to 5-year follow-up. Additionally, 20 of 45 ileocecal valves (44.4%) were spared in patients whose tumors were at the terminal ileum that, traditionally, would call for a right hemicolectomy.

CONCLUSION

With a longer follow-up, lymphatic mapping has proven to be a safe and effective way to prevent local recurrences and preserve the ileocecal valve for selected patients.

Exploring the rising incidence of neuroendocrine tumors: a population-based analysis of epidemiology, metastatic presentation, and outcomes

BACKGROUND

An increased incidence of neuroendocrine tumors (NETs) has been reported worldwide, but the reasons underlying this rise have not been identified. By assessing patterns of metastatic presentation, this study sought to examine the epidemiologic characteristics of NETs and the contribution of early-stage detection to the rising incidence.

METHODS

A population-based retrospective cohort study was conducted with prospectively maintained databases linked at the Institute for Clinical Evaluative Sciences. Adult patients with a NET diagnosis from 1994 to 2009 in Ontario, Canada were included. The main outcomes included the overall and site-specific incidence, proportion of metastatic disease, overall survival (OS), and recurrence-free survival (RFS).

RESULTS

Five thousand six hundred nineteen NET cases were identified. The incidence of NETs increased from 2.48 to 5.86 per 100,000 per year. Metastases were found in 20.8% at presentation and in another 38% after the initial diagnosis. The proportion of metastases at presentation decreased from 1994 to 2009 (from 29% to 13%). Therefore, although the incidence of all NETs increased, the overall incidence of metastases did not change (0.63-0.69 per 100,000 per year). The 10-year OS rate was 46.5%, and the RFS rate was 64.6%. In addition to the primary tumor site, independent predictors of worse OS included an advanced age (P < .0001), male sex (P < .0001), a low socioeconomic status (P < .0001), and rural living (P = 0.049).

CONCLUSIONS

The incidence of NETs has markedly increased over the course of 15 years. This is the first study to provide evidence suggesting that the increase in the incidence of NETs may be due to increased detection. In addition to tumor characteristics, low income and rural residency portend worse survival for patients with NETs.

GEP-NETS update: a review on surgery of gastro-entero-pancreatic neuroendocrine tumors

The incidence of neuroendocrine tumors (NETs) has increased in the last decades. Surgical treatment encompasses a panel of approaches ranging from conservative procedures to extended surgical resection. Tumor size and localization usually represent the main drivers in the choice of the most appropriate surgical resection. In the presence of small (<2 cm) and asymptomatic nonfunctioning NETs, a conservative treatment is usually recommended. For localized NETs measuring above 2 cm, surgical resection represents the cornerstone in the management of these tumors. As they are relatively biologically indolent, an extended resection is often justified also in the presence of advanced NETs. Surgical options for NET liver metastases range from limited resection up to liver transplantation. Surgical choices for metastatic NETs need to consider the extent of disease, the grade of tumor, and the presence of extra-abdominal disease. Any surgical procedures should always be balanced with the benefit of survival or relieving symptoms and patients' comorbidities.

Ki67 proliferation index, hepatic tumor load, and pretreatment tumor growth predict the antitumoral efficacy of lanreotide in patients with malignant digestive neuroendocrine tumors

BACKGROUND

An antiproliferative effect of somatostatin analogs was recently demonstrated.

AIM

To identify factors associated with tumor control in a group of patients with well-differentiated malignant digestive neuroendocrine tumors treated with lanreotide.

METHODS

A retrospective study was conducted in 68 patients treated with lanreotide alone, with progression-free survival as the primary endpoint. The role of the following factors was searched for by univariate and multivariate analyses: age, sex, mode of discovery, site of the primary tumor, metastatic spread, Ki67 proliferation index, uptake on somatostatin receptor scintigraphy, pretreatment tumor growth, extent of liver involvement, resection of primary tumor, previous treatments, and tumor markers.

RESULTS

Tumor progression was observed in 39/68 patients (57.4%). Median progression-free survival was 29 months. On multivariate analysis, a Ki67 proliferation index of up to 5% [hazard ratio (HR)=0.262, P=0.009], pretreatment stability (HR=0.241, P=0.008), and hepatic tumor load of up to 25% (HR=0.237, P=0.004) were significantly associated with disease stability under lanreotide therapy.

CONCLUSION

In patients with well-differentiated malignant digestive neuroendocrine tumors, Ki67 proliferation index of up to 5%, stable disease before treatment, and low-to-moderate hepatic tumor involvement (≤ 25%) are associated with tumor control during lanreotide treatment. These data if confirmed in prospective trials will help in rationalizing the use of somatostatin analogs with antiproliferative intent.

Neuroendocrine tumor disease: an evolving landscape

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) represent a heterogenous group of tumors arising from a variety of neuroendocrine cell types. The incidence and prevalence of GEP-NENs have markedly increased over the last three decades. Symptoms are often absent in early disease, or vague and nonspecific even in advanced disease. Delayed diagnosis is thus common. Chromogranin A is the most commonly used biomarker but has limitations as does the proliferative marker Ki-67%, which is often used for tumor grading and determination of therapy. The development of a multidimensional prognostic nomogram may be valuable in predicting tumor behavior and guiding therapy but requires validation. Identification of NENs that express somatostatin receptors (SSTR) allows for SSTR scintigraphy and positron emission tomography imaging using novel radiolabeled compounds. Complete surgical resection of limited disease or endoscopic ablation of small lesions localized in stomach or rectum can provide cure; however, the majority of GEP-NENs are metastatic (most frequently the liver and/or mesenteric lymph nodes) at diagnosis. Selected patients with metastatic disease may benefit from advanced surgical techniques including hepatic resection or liver transplantation. Somatostatin analogs are effective for symptomatic treatment and exhibit some degree of antiproliferative activity in small intestinal NENs. There is a place for streptozotocin, temozolomide, and capecitabine in the management of pancreatic NENs, while new agents targeting either mTOR (everolimus) or angiogenic (sunitinib) pathways have shown efficacy in these lesions.

Ileal volvulus and its association with carcinoid tumours

Small bowel volvulus is a rare cause of bowel obstruction in the Western World. It is often divided into primary and secondary causes. This report presents a case of secondary ileal volvulus with underlying carcinoid tumour.

Cervical and upper mediastinal lymph node metastasis from gastrointestinal and pancreatic neuroendocrine tumors: true incidence and management

BACKGROUND

The incidence, clinical importance, and optimal management of cervical and upper mediastinal lymph node metastasis from gastrointestinal and pancreatic neuroendocrine tumors (NETS) are largely unknown. Historically, cervical nodes have been regarded as asymptomatic and ignored. We hypothesized that these lesions have clinical implications and should be removed surgically.

STUDY DESIGN

Consecutive (111)In pentetreotide scans (OctreoScan) performed at our institution from May 2008 to October 2010 were reviewed to determine the incidence of cervical and upper mediastinal lymph node metastases among patients with gastrointestinal and pancreatic NETs. The charts of surgically treated patients were reviewed to evaluate the clinical importance of these metastases and the subsequent outcomes of their surgical treatment.

RESULTS

A total of 161 NET patients presented with positive OctreoScans. Fourteen patients (8.7%) scanned positive for cervical and upper mediastinal lymph node metastasis. Nine patients underwent surgical exploration; 8 had successful removal of their metastatic nodes. Seven had clinical symptoms that resolved after surgery.

CONCLUSIONS

Cervical and upper mediastinal lymph node metastases from gastrointestinal and pancreatic NETs were seen in up to 8.7% of patients. In the past, these metastases were assumed to be insignificant and ignored. Our study clearly demonstrates that most, if not all, such metastases are symptomatic and their clinical implications should not be overlooked. Notably, these metastases can be easily and safely resected using radioguided surgery.

Radioguided exploration facilitates surgical cytoreduction of neuroendocrine tumors

INTRODUCTION

Radioguided exploration (RGS) can be an important tool to direct the cytoreduction of neuroendocrine tumors (NETs). The selection of the proper radiolabeled isotope, the dose, and the time interval between isotope injection and exploration are the major factors that lead to the successful use of this technique.

METHODS

Data on 43 patients who underwent RGS of their NET at our facility (Ochsner Medical Center-Kenner) was collected. These cases were reviewed to determine the optimal radiopharmaceutical, dose, and interval between injection and exploration.

RESULTS

The isotopes used were (99)technetium sulfur colloid in three patients, (123)I metaiodobenzylguanidine ((123)I-MIBG) in six patients, and (111)In-pentreotide in 30 abdominal NET patients and in four patients undergoing neck and mediastinum explorations. In 29 of 30 (111)In-pentreotide-guided abdominal explorations (five of which were re-explorations, all successful), the gamma detector was determined to be "helpful". In the four neck and mediastinum explorations, the gamma probe was deemed "essential" for completing a quick, safe, and minimally invasive procedure. (123)I-MIBG injection, in contrast, was useful in only one patient. The optimal dose and interval between injection and exploration of (111)In-pentreotide were discovered to be 6 mCi injected 7 days prior to the planned exploration.

CONCLUSION

Radioguided exploration is a useful tool to guide the cytoreduction of NETs. The correct choice of radiopharmaceutical, its dose, and the interval between injection and exploration are critical for obtaining optimal results.

PET-Guided Surgery - High Correlation between Positron Emission Tomography with 11C-5-Hydroxytryptophane (5-HTP) and Surgical Findings in Abdominal Neuroendocrine Tumours

Positron emission tomography (PET) with 11C-labeled 5-hydroxytryptophane (5-HTP) is a sensitive technique to visualize neuroendocrine tumours (NETs), due to high intracellular uptake of amine-precursors like L-dihydroxyphenylalanine (L-DOPA) and 5-HTP. NETs are often small and difficult to localize in spite of overt clinical symptoms due to hormonal excess. In our study, 38 consecutive NET patients underwent 11C-5-HTP-PET and morphological imaging by CT within 12 weeks prior to surgery. Surgical, histopathological and 5-HTP PET findings were correlated. 11C-5-HTP-PET corresponded to the surgical findings in 31 cases, was false negative in six, and true negative in one case resulting in 83.8% sensitivity and 100% specificity. Positive predicted value was 100%. In 11 patients 11C-5-HTP-PET was the only imaging method applied to localize the tumour. Thus, we could demonstrate that functional imaging by 11C-5-HTP-PET in many cases adds vital preoperative diagnostic information and in more than every fourth patient was the only imaging method that will guide the surgeon in finding the NET-lesion. Although the present results demonstrates that 11C-5-HTP may be used as an universal NET tracer, the sensitivity to visualize benign insulinomas and non functioning pancreatic NETs was lower.

[Extent of resection for neuroendocrine tumors of the small intestine]

Neuroendocrine tumors of the small intestine have been diagnosed with increasing frequency over the past 35 years and presently account for approximately 2% of all gastrointestinal neoplasms. While most of these tumors are discovered incidentally during emergency laparotomy or in the clinical setting of unknown primary cancer with hepatic metastases, the growing awareness of this rare entity and improved diagnostic methods promote earlier diagnosis. The classical carcinoid syndrome with flush, diarrhea and cardiac strain is observed only in 20-30% of patients. The clinical symptoms necessitate a special preoperative preparation of the patient including evaluation of cardiac function.Prospective studies assessing the efficacy of surgical treatment strategies for neuroendocrine neoplasms of the small intestine do not exist. However, retrospective studies have demonstrated that curative as well as palliative resection of the primary tumor improves the prognosis and the quality of life of patients. Besides limited resection of the small bowel in order to avoid postoperative short bowel syndrome an effective clearance of the regional lymph nodes is essential. A primary tumor site in the terminal ileum requires dissection of the lymph nodes on the right side of the ileocolic artery which usually implies an additional resection of the right colon. In cases of a primary tumor site located in the lower ileum up to the distal jejunum, a cone-shaped resection of the mesenterium of the small bowel with extension of lymphadenectomy into adjacent segments with preservation of vascularization is performed.

Relapse factors for ileal neuroendocrine tumours after curative surgery: a retrospective French multicentre study

AIM

To evaluate the characteristics of postoperative relapse, predictive factors and time to relapse after curative surgery for well-differentiated neuroendocrine tumours of the ileum, without hepatic or other distant metastases.

METHODS

Clinical data of patients entered into the Groupe d'étude des Tumeurs Endocrines database were collected and analysed retrospectively to identify factors predictive of relapse.

RESULTS

Among 100 patients followed for a median of 56.5 (range 1-290) months, 42 relapsed after a median follow-up of 57.5 (range 6-176) months, with liver lesions in 27 (64.3%). Median disease-free survival (Kaplan-Meier) was 88 months (95% confidence interval 72-115). Disease-free survival was shorter for emergency surgery patients (p<0.01), patients with distant mesenteric lymph-node metastases (p<0.01), with fortuitous diagnosis (p=0.02), with tumour diameter >20mm (p=0.02), and those with multiple tumours (p=0.07). Multivariate analysis retained emergency surgery (odds-ratio 4.04 [95% confidence interval 2.01-8.11]), distant mesenteric lymph-node metastases (odds-ratio 2.53 [95% confidence interval 1.22-5.25]), and multiple tumours (odds-ratio 2.14 [95% confidence interval 1.01-4.50]), as being significantly associated with relapse.

CONCLUSION

Patients who underwent emergency surgery, with distant mesenteric lymph-node metastases or with multiple ileal tumours relapsed earlier. Closer monitoring for the patients with these risk factors may be required.

Surgical treatment of gastrointestinal neuroendocrine tumors

INTRODUCTION

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are uncommon but clinically challenging and fascinating tumors. GEP-NETs present as either functional or as nonfunctional tumors. Functional tumors are commonly associated with a specific hormonal syndrome directly related to a hormone secreted by the tumor, like gastrinomas with a Zollinger-Ellison syndrome or carcinoid syndrome in patients with neuroendocrine tumors (NET) of the ileum. Nonfunctional tumors do not secrete a hormone resulting in a clinical syndrome.

METHODS

The natural course of GEP-NETs is highly variable. Small, benign neoplasms such as 90% of all insulinomas or gastric endocrine tumors type 1 are readily curable by surgical resection; however, most other GEP-NETs have a much less favorable prognosis. Patients with completely resected tumors generally have a good prognosis, and an aggressive surgical approach in patients with advanced disease may also prolong survival.

CONCLUSIONS

This review focuses on the current standards of surgical treatment of gastric endocrine tumors, NETs of the pancreas (PNET) and NETs of the ileum. Although the evidence level is low in many instances due to the lack of randomized controlled trials, important treatment recommendations can be given.

Partial abdominal evisceration and intestinal autotransplantation to resect a mesenteric carcinoid tumor

Background

Midgut carcinoids are neuroendocrine tumors that commonly metastasize to the intestinal mesentery, where they predispose to intestinal obstruction, ischemia and/or congestion. Because of their location, many mesenteric carcinoid tumors are deemed unresectable due to the risk of uncontrollable bleeding and prolonged intestinal ischemia.

Case Presentation

We report the case of a 60-year-old male with a mesenteric carcinoid tumor obstructing his superior mesenteric vein, resulting in intestinal varices and severe recurrent GI bleeds. While his tumor was thought to be unresectable by conventional techniques, it was successfully resected using intestinal autotransplantation to safely gain access to the tumor. This case is the first described application of this technique to carcinoid tumors.

Conclusions

Intestinal autotransplantation can be utilized to safely resect mesenteric carcinoid tumors from patients who were not previously thought to be surgical candidates. We review the literature concerning both carcinoid metastases to the intestinal mesentery and the use of intestinal autotransplantation to treat lesions involving the mesenteric root.

Carcinoid tumors of the gastrointestinal tract

The gastrointestinal tract is the largest neuroendocrine system in the body. Carcinoid tumors are amine precursor uptake decarboxylase (APUD) omas that arise from enterochromaffin cells throughout the gut. These tumors secrete discrete bioactive substances producing characteristic immunohistochemical patterns. Most tumors are asymptomatic and detected at late stages. Hepatic metastases are commonly responsible for carcinoid syndrome. The small bowel is the most common location of carcinoids. Computed tomography scan and magnetic resonance imaging are useful in the detection of these tumors. The measurement of bioactive amines is the initial diagnostic test. Various treatment options, including somatostatin analogs, interferon, chemotherapy, surgery, hepatic artery chemoembolization, and surgery have emerged in the past two decades. However, the incidence and prevalence of carcinoid tumors has increased, while mean survival time has not changed significantly. The lack of standardized classification, federal support, and an incomplete understanding of the complications of this disease are some of the impediments to progress in treatment.

Placebo-controlled, double-blind, prospective, randomized study on the effect of octreotide LAR in the control of tumor growth in patients with metastatic neuroendocrine midgut tumors: a report from the PROMID Study Group

PURPOSE

Somatostatin analogs are indicated for symptom control in patients with gastroenteropancreatic neuroendocrine tumors (NETs). The ability of somatostatin analogs to control the growth of well-differentiated metastatic NETs is a matter of debate. We performed a placebo-controlled, double-blind, phase IIIB study in patients with well-differentiated metastatic midgut NETs. The hypothesis was that octreotide LAR prolongs time to tumor progression and survival.

PATIENTS AND METHODS

Treatment-naive patients were randomly assigned to either placebo or octreotide LAR 30 mg intramuscularly in monthly intervals until tumor progression or death. The primary efficacy end point was time to tumor progression. Secondary end points were survival time and tumor response. This report is based on 67 tumor progressions and 16 observed deaths in 85 patients at the time of the planned interim analysis.

RESULTS

Median time to tumor progression in the octreotide LAR and placebo groups was 14.3 and 6 months, respectively (hazard ratio [HR] = 0.34; 95% CI, 0.20 to 0.59; P = .000072). After 6 months of treatment, stable disease was observed in 66.7% of patients in the octreotide LAR group and 37.2% of patients in the placebo group. Functionally active and inactive tumors responded similarly. The most favorable effect was observed in patients with low hepatic tumor load and resected primary tumor. Seven and nine deaths were observed in the octreotide LAR and placebo groups, respectively. The HR for overall survival was 0.81 (95% CI, 0.30 to 2.18).

CONCLUSION

Octreotide LAR significantly lengthens time to tumor progression compared with placebo in patients with functionally active and inactive metastatic midgut NETs. Because of the low number of observed deaths, survival analysis was not confirmatory.

Fibrosis and carcinoid syndrome: from causation to future therapy

Carcinoid tumors are part of a heterogeneous group of gastrointestinal and pancreatic endocrine tumors that are characterized by their capacity to produce and secrete hormones, 5-hydroxytryptamine, tachykinins and other mediators. These substances are thought to be responsible for the collection of symptoms, which include diarrhea, flushing and wheezing, that is known as carcinoid syndrome. Fibrosis that occurs either local to or distant from the primary tumor is one of the hallmarks of carcinoid tumors that originate from the midgut. The fibrotic process can occur in the mesentery as a desmoplastic response and may lead to obstruction of the small bowel, but it can also occur in the lungs, skin or retroperitoneum. Importantly, up to one-third of patients develop cardiac valvulopathy. One or more products that are secreted by the tumor and enter into the circulation are likely to have a role in this process. This Review discusses the incidence and prevalence of fibrosis in carcinoid syndrome and explores evidence to date for causative agents, in particular the roles of 5-hydroxytryptamine and elements of the downstream signaling pathway. Improved understanding of the etiology of carcinoid-tumor-related fibrosis may lead to better treatments for this condition than those we currently have.

Diagnosis and treatment of metastatic disease to the liver

A number of cancers present with synchronous or metachronous hepatic metastases. Historically, many of these patients were considered unresectable and were treated with either systemic chemotherapy or supportive care. Today, a variety of options exist for the management of hepatic metastases. Newer agents for systemic therapy continue to be introduced and are providing improved progression-free and overall survival and increased resectability of liver metastases. However, complete surgical resection of isolated hepatic metastases remains the optimal management for these patients. Surgical interventions can be offered to patients with hepatic-only metastases. Hepatic artery chemotherapy represents an adjunct for those patients undergoing resection and can improve survival. This benefit may be even more pronounced when combined with systemic chemotherapy. Newer generation biologic agents can improve results. New therapeutic modalities to treat lesions that are unresectable include ablative techniques such as radiofrequency ablation (RFA) and cryoablation. This article will examine modalities of diagnosis of hepatic metastases and highlight the data regarding hepatic resection for metastases of several types of primary cancers, the rationale for, and efficacy of, hepatic arterial chemotherapy, in both the postoperative adjuvant setting and in unresectable liver disease, and review the current literature for ablative techniques in the treatment of liver metastases.

Surgery on neuroendocrine tumours

Neuroendocrine tumours of the gastrointestinal tract and pancreas present a major challenge to physicians in their recognition and treatment requirements, and surgical treatment of these tumours has become increasingly important for symptom palliation and survival. For some carcinoid tumours the extent of surgery may depend on tumour size. Midgut carcinoid is the most common cause of the carcinoid syndrome, requiring surgery for primary and mesenteric tumours to minimize the risk for abdominal complications but also for removal of liver metastases to palliate hormonal symptoms. Among endocrine pancreatic tumours, insulinoma and gastrinoma often cause severe symptoms of hormone excess despite their inconspicuous size, but they can be successfully removed with improved pre- and intraoperative localization. Other tumours--glucagonoma, VIPoma, and non-functioning endocrine pancreatic tumours--are often large or metastasizing, but generally require surgical debulking to alleviate hormonal symptoms and have favourable survival.

Carcinoid tumors

Carcinoid tumors can present a difficult diagnostic and therapeutic dilemma. Despite their reputation as indolent tumors, they frequently metastasize and can cause significant symptomatology. The only curative therapy remains surgical resection. The prognosis and treatment of carcinoids vary based on location and histology, and therapy must be tailored to each patient.

Tumours of the midgut (jejunum, ileum and ascending colon, including carcinoid syndrome)

(Neuro-)endocrine tumours of the gastrointestinal tract are also called 'carcinoids'. (Neuro-)endocrine midgut tumours can be categorized according to their clinical behaviour. Most tumours are non-functioning. Functioning tumours are responsible for the carcinoid syndrome. The carcinoid syndrome is almost uniquely associated with midgut carcinoids. Symptoms of the carcinoid syndrome are caused by an excess of biogenic amines, peptides and other factors in the circulation. The typical symptoms of the carcinoid syndrome are diarrhoea, flushing, and carcinoid heart disease. Carcinoid heart disease involves the tricuspid and pulmonary valves and the endocardium. Serum chromogranin A and urinary excretion of 5-hydroxy-indoleacetic acid (5-HIAA) are biochemical markers. Carcinoid tumours express large numbers of high-affinity somatostatin receptors. These can bind the currently available octapeptide somatostatin analogues. In inoperable patients, biotherapy with somatostatin analogues and interferon-alpha is the treatment of choice. Somatostatin analogues and interferon-alpha significantly improve symptoms.

Midgut carcinoid tumours: surgical treatment and prognosis

Midgut carcinoids originating in the small intestine are the most common cause of the carcinoid syndrome. These tumours typically progress slowly and have an extended disease course, and although they often present with metastases at diagnosis, surgical treatment has become increasingly important for their management. Surgery should include efforts to remove mesenteric metastases, which may cause severe long-term abdominal complications with typical fibrotic intestinal entrapment and small-bowel ischaemia due to compression of mesenteric vessels. Attempts should also be made to surgically remove or ablate liver metastases, since this may provide considerable palliation of the carcinoid syndrome. For patients with the carcinoid syndrome surgery is combined with continuous biotherapy with long-acting somatostatin analogues, which may alleviate symptoms and stabilize disease or slow progression. Favourable survival and appreciable quality of life can be expected with this combined treatment, even in patients with advanced midgut carcinoids.