Panagiotis Drymousis

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

BACKGROUND Over the last decade laparoscopic pancreatic surgery (LPS) has emerged as an alternative to open pancreatic surgery (OPS) in selected patients with neuroendocrine tumours (NET) of the pancreas (PNET). Evidence on the safety and efficacy of LPS is available from non-comparative studies. OBJECTIVES This study was designed as a meta-analysis of studies which allow a comparison of LPS and OPS for resection of PNET. METHODS Studies conducted from 1994 to 2012 and reporting on LPS and OPS were reviewed. Studies considered were required to report on outcomes in more than 10 patients on at least one of the following: operative time; hospital length of stay (LoS); intraoperative blood loss; postoperative morbidity; pancreatic fistula rates, and mortality. Outcomes were compared using weighted mean differences and odds ratios. RESULTS Eleven studies were included. These referred to 906 patients with PNET, of whom 22% underwent LPS and 78% underwent OPS. Laparoscopic pancreatic surgery was associated with a lower overall complication rate (38% in LPS versus 46% in OPS; P < 0.001). Blood loss and LoS were lower in LPS by 67 ml (P < 0.001) and 5 days (P < 0.001), respectively. There were no differences in rates of pancreatic fistula, operative time or mortality. CONCLUSIONS The nature of this meta-analysis is limited; nevertheless LPS for PNET appears to be safe and is associated with a reduced complication rate and shorter LoS than OPS.

Is octreotide beneficial in patients undergoing pancreaticoduodenectomy? Best evidence topic (BET)

A best evidence topic was written according to a structured protocol. The question addressed was whether the prophylactic administration of somatostatin or somatostatin analogues in patients undergoing pancreaticoduodenectomy (Whipples procedure) is beneficial in terms of improved surgical outcomes, reduced morbidity or reduced mortality. A total of 118 papers were found using the reported searches of which 5 represented the best evidence (1 meta-analysis, 1 systematic review and 3 randomized control trials). The authors, date, journal, study type, population, main outcome measures and results were tabulated. There is evidence that the perioperative administration of somatostatin or somatostatin analogues reduces biochemical incidence of pancreatic fistula but, it is still unclear if there is a beneficial effect in the incidence of clinically significant pancreatic fistula. Further adequately powered trials with low risk of bias are necessary. From the available data, somatostatin or somatostatin analogues have no effect on mortality post Whipples. Interestingly, there are only limited data available on the cost-benefit and financial constraints imposed by this treatment, an issue that has only been addressed in a few studies.

Glucagon receptor gene mutations with hyperglucagonemia but without the glucagonoma syndrome.

Pancreatic neoplasms producing exclusively glucagon associated with glucagon cell hyperplasia of the islets and not related to hereditary endocrine syndromes have been recently described. They represent a novel entity within the panel of non-syndromic disorders associated with hyperglucagonemia. This case report describes a 36-year-old female with a 10 years history of non-specific abdominal pain. No underlying cause was evident despite extensive diagnostic work-up. More recently she was diagnosed with gall bladder stones. Abdominal ultrasound, computerised tomography and magnetic resonance imaging revealed no pathologic findings apart from cholelithiasis. Endoscopic ultrasound revealed a 5.5 mm pancreatic lesion. Fine needle aspiration showed cells focally expressing chromogranin, suggestive but not diagnostic of a low grade neuroendocrine tumor. OctreoScan(®) was negative. Serum glucagon was elevated to 66 pmol/L (normal: 0-50 pmol/L). Other gut hormones, chromogranin A and chromogranin B were normal. Cholecystectomy and enucleation of the pancreatic lesion were undertaken. Postoperatively, abdominal symptoms resolved and serum glucagon dropped to 7 pmol/L. Although H and E staining confirmed normal pancreatic tissue, immunohistochemistry was initially thought to be suggestive of alpha cell hyperplasia. A count of glucagon positive cells from 5 islets, compared to 5 islets from 5 normal pancreata indicated that islet size and glucagon cell ratios were increased, however still within the wide range of normal physiological findings. Glucagon receptor gene (GCGR) sequencing revealed a heterozygous deletion, K349_G359del and 4 missense mutations. This case may potentially represent a progenitor stage of glucagon cell adenomatosis with hyperglucagonemia in the absence of glucagonoma syndrome. The identification of novel GCGR mutations suggests that these may represent the underlying cause of this condition.

Incidence of Second Primary Malignancies in Patients with Neuroendocrine Tumours

Background: An association between neuroendocrine tumours (NET) and increased risk of developing second primary malignancies (SPM) has been recognised. Methods: This was a retrospective review of our institutional prospectively maintained database of NET patients. We identified patients who had been diagnosed with both neuroendocrine and any additional malignancies via examination of patient notes. Results: Clinical data for 169 patients were analysed. After exclusion of patients known to have hereditary tumour predisposition syndromes, 29 SPM were identified in 26 patients (15.38%), the commonest being colorectal (n = 6), breast and renal carcinomas (both n = 5). SPM were classified as previous, synchronous or subsequent relative to NET diagnosis. Rates of SPM in pancreatic and small-bowel NET patients were comparable (15.7 vs. 19.6%, p = 0.78). A person-year methodology was used to compare observed numbers of SPM against expected values generated from age- and sex-specific incidence tables, with standardised incidence ratios (SIR) and 95% confidence intervals (CI) calculated. SPM incidence was significantly elevated in the synchronous subset (SIR 2.732, CI 1.177-5.382) whilst significantly fewer NET patients had a cancer history compared to the general population (SIR 0.4, CI 0.241-0.624). No overall differences were evident between observed and expected incidences of subsequent SPM (SIR 0.36, CI 0.044-1.051). The incidence of synchronous colorectal cancers was markedly elevated (SIR 13.079, CI 4.238-30.474). Conclusions: Our data support the use of colonoscopy in the diagnostic work-up of NET patients in anticipation of a colorectal SPM. The mechanistic underpinnings of this clinical phenomenon require further genetic investigation, and consideration of this knowledge in patient management pathways is warranted.

Goblet cell carcinomas of the appendix: rare but aggressive neoplasms with challenging management

Goblet cell carcinomas (GCC) are a rare, aggressive sub-type of appendiceal tumours with neuroendocrine features, and controversy exists with regards to therapeutic strategy. We undertook a retrospective review of GCC patients surgically treated at two tertiary referral centres. Clinical and histopathological data were extracted from a prospectively maintained database. Survival analyses utilised Kaplan–Meier methodology. Twenty-one patients were identified (9 females). Median age at diagnosis was 55 years (range 32–77). There were 3, 6 and 9 grade 1, 2 and 3 tumours, respectively. One, 10, 5 and 5 patients had stage I, II, III and IV disease at diagnosis, respectively. There were 8, 10 and 3 Tang class A, B and C tumours, respectively. Index operation was appendectomy (n = 12), right hemicolectomy (n = 6) or resections including appendix/right colon, omentum and the gynaecological system (n = 3). Eight patients underwent completion right hemicolectomy. Surgery for recurrence included small bowel resection (n = 2), debulking with peritonectomy and heated intraperitoneal chemotherapy, and hysterectomy and bilateral salpingo-oophorectomy (all n = 1). Median follow-up was 30 months (range 2.5–123). One-, 3- and 5-year OS was 79.4, 60 and 60%, respectively. Mean OS (1-, 3-, and 5-year OS) for Tang class A, B and C tumours were 73.1 months (85.7, 85.7, 51.4%), 83.7 months (all 66.7%) and 28.5 months (66.7, 66.7%, not reached), respectively. Chromogranin A/B and 68Ga-DOTATATE PET/CT were not useful in follow-up, but CEA, CA 19-9, CA 125 and 18F-FDG PET/CT identified tumour recurrence. GCC must be clearly discriminated from relatively indolent appendiceal neuroendocrine neoplasms. 18F-FDG PET/CT and CEA/CA19-9/CA 125 are useful in detecting recurrence of GCC.

Surgical Management of Patients with Neuroendocrine Neoplasms of the Appendix: Appendectomy or More?

Background: Appendiceal neuroendocrine neoplasms (ANEN) are mostly indolent tumours treated effectively with simple appendectomy. However, controversy exists regarding the necessity of oncologic right hemicolectomy (RH) in patients with histologic features suggestive of more aggressive disease. We assess the effects of current guidelines in selecting the surgical strategy (appendectomy or RH) for the management of ANEN. Methods/Aims: This is a retrospective review of all ANEN cases treated over a 14-year period at 3 referral centres and their management according to consensus guidelines of the European and the North American Neuroendocrine Tumor Societies (ENETS and NANETS, respectively). The operation performed, the tumour stage and grade, the extent of residual disease, and the follow-up outcomes were evaluated. Results: Of 14,850 patients who had appendectomies, 215 (1.45%) had histologically confirmed ANEN. Four patients had synchronous non-ANEN malignancies. One hundred and ninety-three patients had index appendectomy. Seventeen patients (7.9%) had lymph node metastases within the mesoappendix. Forty-nine patients underwent RH after appendectomy. The percentages of 30-day morbidity and mortality after RH were 2 and 0%, respectively. Twelve patients (24.5%) receiving completion RH were found to have lymph node metastases. Two patients had liver metastases, both of them synchronous. The median follow-up was 38.5 months (range 1-143). No patient developed disease recurrence. Five- and 10-year overall survival for all patients with ANEN as the only malignancy was both 99.05%. Conclusions: The current guidelines appear effective in identifying ANEN patients at risk of harbouring nodal disease, but they question the oncological relevance of ANEN lymph node metastases. RH might present an overtreatment for a number of patients with ANEN.

12th Annual ENETS Conference for the Diagnosis and Treatment of Neuroendocrine Tumor Disease. March 11-13, 2015, Barcelona, Spain: Abstracts

Multidisciplinary Team (MDT) in Neuroendocrine Tumor (NET) Management : Results from the First Global NET Patient (pt) Survey - A Collaboration between the International Neuroendocrine Cancer Alliance (INCA) and Novartis PharmaceuticalsRadioembolization with 90Y-Labelled Resin Microspheres in Patients with Liver Metastases from Neuroendocrine TumorsIncremental Benefit of Preoperative Endoscopic Ultrasound for the Detection of Pancreatic Neuroendocrine Tumors : A Meta-AnalysisSmall intestinal neuroendocrine tumors (SI-NETs) originate from serotonin-producing enterochromaffin (EC) cells in the intestinal mucosa. Somatostatin analogs (SSAs) are mainly used to control hormonal secretion and tumor growth. However, the molecular mechanisms leading to the control of SI-NETs are unknown. Although microRNAs (miRNAs) are post transcriptional regulators deeply studied in many cancers, are not well-defined in SI-NETs. We adopted a two-pronged strategy to investigate SSAs and miRNAs: first, to provide novel insights into how SSAs control NET cells, and second, to identify an exclusive SI-NET miRNA expression, and investigate the biological functions of miRNA targets.To accomplish the first aim, we treated CNDT2.5 cells with octreotide for 16 months. Affymetrix microarray was performed to study gene variation of CNDT2.5 cells in the presence or absence of octreotide. The study revealed that octreotide induces six genes, ANXA1, ARHGAP18, EMP1, GDF15, TGFBR2 and TNFSF15.To accomplish the second aim, SI-NET tissue specimens were used to run genome-wide Affymetrix miRNA arrays. The expression of five miRNAs (miR-96, -182, -183, -196a and -200a) was significantly upregulated in laser capture microdissected (LCM) tumor cells versus LCM normal EC cells, whereas the expression of four miRNAs (miR-31, -129-5p, -133a and -215) was significantly downregulated in LCM tumor cells. We also detected nine tissue miRNAs in serum samples, showing that the expression of five miRNAs is significantly increased in SSA treated patients versus untreated patients. Conversely, SSAs do not change miRNA expression of four low expressed miRNAs. Silencing miR-196a expression was used to investigate functional activities in NET cells. This experimental approach showed that four miR-196a target genes, HOXA9, HOXB7, LRP4 and RSPO2, are significantly upregulated in silenced miR-196a NET cells.In conclusion, ANXA1, ARHGAP18, EMP1, GDF15, TGFBR2 and TNFSF15 genes might regulate cell growth and differentiation in NET cells, and play a role in an innovative octreotide signaling pathway. The global SI-NET miRNA profiling revealed that nine selected miRNAs might be involved in tumorigenesis, and play a potential role as novel markers for follow-up. Indeed, silencing miR-196a demonstrated that HOXA9, HOXB7, LRP4 and RSPO2 genes are upregulated at both transcriptional and translational levels.