Thomas M. Gress

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

4508 Background: Octreotide is currently used for the control of symptoms in patients with gastroenteropancreatic neuroendocrine tumors (NETs). However, the ability of long-acting somatostatin analogues to control the growth of well-differentiated metastatic NETs is a matter of debate. The analysis of the first randomized, double-blind, placebo-controlled, multicenter, phase IIIb study of octreotide LAR in patients with metastatic NETs of the midgut is presented. METHODS Treatment-naïve patients with histologically confirmed locally inoperable or metastasized well-differentiated NETs and a Karnofsky index >60 were randomized to receive either octreotide LAR 30 mg/month (mo) or placebo for 18 mos, or until tumor progression or death. The primary endpoint was median time to tumor progression. Secondary endpoints included objective tumor response rate (WHO criteria), measured every 3 mos, as well as symptom control and overall survival. This was a planned interim analysis using the Lan-DeMets error spending approach. RESULTS Eighty-five patients (n=43 octreotide LAR; n=42 placebo) have been enrolled to date and data from 67 patients with tumor progressions and 16 deaths (n=7 octreotide LAR; n=9 placebo) are included here. Median time to tumor progression in the octreotide LAR and placebo groups were 14.3 mos and 6 mos, respectively (HR: 0.34; 95% CI: 0.20-0.59; P=0.000072). After 6 mos of treatment, stable disease was seen in 67% and 37.2% of patients treated with octreotide LAR and placebo, respectively. Due to the low number of observed deaths, median survival time could not be estimated. CONCLUSIONS Octreotide LAR significantly lengthens median time to tumor progression compared with placebo in patients with metastatic NETs of the midgut. Patients treated with octreotide LAR had a 66% risk reduction of tumor progression compared with patients receiving placebo. Octreotide LAR demonstrates substantial tumor control and shows a more favorable antiproliferative response than placebo as two-thirds of patients treated with octreotide LAR achieved stable disease at 6 mos. [Table: see text].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.

Stromal biology and therapy in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDA) is an almost uniformly lethal disease. One explanation for the devastating prognosis is the failure of many chemotherapies, including the current standard of care therapy gemcitabine. Although our knowledge of the molecular events underlying multistep carcinogenesis in PDA has steadily increased, translation into more effective therapeutic approaches has been inefficient over the last several decades. Evidence for this innate resistance to systemic therapies was recently provided in an accurate mouse model of PDA by the demonstration that chemotherapies are poorly delivered to PDA tissues because of a deficient vasculature. This vascular deficiency correlated with the presence of a dense stromal matrix that is a prominent histological hallmark of PDA tumours. Therapeutic targeting of stromal cells decreased the stroma from pancreatic tumours, resulting in increased intratumoral perfusion and therapeutic delivery of gemcitabine. Stromal cells contained within the PDA tumour microenvironment therefore represent an additional constituent to neoplastic cells that should be critically evaluated for optimal therapeutic development in preclinical models and early clinical trials.

Genetic profile of 22 pancreatic carcinoma cell lines. Analysis of K-ras, p53, p16 and DPC4/Smad4.

Abstract. The K-ras, p53, p16 and DPC4 genes are among those most frequently altered in pancreatic ductal carcinoma. We analyzed 22 cell lines for alterations in these genes by direct sequence analysis and methylation-specific polymerase chain reaction. These cell lines showed mutations in K-ras and p53 at frequencies of 91% and 95%, respectively. Alterations in p16INK4a were found in all cases and included nine homozygous deletions, seven mutations and promoter methylation in six cases. Eight cell lines (36%) had an alteration of DPC4, including one mutation and seven homozygous deletions. The most typical mutational profile involved K-ras, p53, and p16INK4a, concurrently aberrated in 20 cases (91%). Eight cell lines had alterations in all four genes. Inactivation of DPC4 was always accompanied by alteration of all of the other three genes. This comprehensive data regarding the cumulative genetic alterations in pancreatic carcinoma cell lines will be of great value for studies involving drug sensitivity or resistance that may be associated with inactivation of a particular gene or molecular pathway.

Chymotrypsin C (CTRC) variants that diminish activity or secretion are associated with chronic pancreatitis.

Chronic pancreatitis is a persistent inflammatory disease of the pancreas, in which the digestive protease trypsin has a fundamental pathogenetic role. Here we have analyzed the gene encoding the trypsin-degrading enzyme chymotrypsin C (CTRC) in German subjects with idiopathic or hereditary chronic pancreatitis. Two alterations in this gene, p.R254W and p.K247_R254del, were significantly overrepresented in the pancreatitis group, being present in 30 of 901 (3.3%) affected individuals but only 21 of 2,804 (0.7%) controls (odds ratio (OR) = 4.6; confidence interval (CI) = 2.6–8.0; P = 1.3 × 10−7). A replication study identified these two variants in 10 of 348 (2.9%) individuals with alcoholic chronic pancreatitis but only 3 of 432 (0.7%) subjects with alcoholic liver disease (OR = 4.2; CI = 1.2–15.5; P = 0.02). CTRC variants were also found in 10 of 71 (14.1%) Indian subjects with tropical pancreatitis but only 1 of 84 (1.2%) healthy controls (OR = 13.6; CI = 1.7–109.2; P = 0.0028). Functional analysis of the CTRC variants showed impaired activity and/or reduced secretion. The results indicate that loss-of-function alterations in CTRC predispose to pancreatitis by diminishing its protective trypsin-degrading activity.

Long-term outcomes of autoimmune pancreatitis: a multicentre, international analysis

Objective Autoimmune pancreatitis (AIP) is a treatable form of chronic pancreatitis that has been increasingly recognised over the last decade. We set out to better understand the current burden of AIP at several academic institutions diagnosed using the International Consensus Diagnostic Criteria, and to describe long-term outcomes, including organs involved, treatments, relapse frequency and long-term sequelae. Design 23 institutions from 10 different countries participated in this multinational analysis. A total of 1064 patients meeting the International Consensus Diagnostic Criteria for type 1 (n=978) or type 2 (n=86) AIP were included. Data regarding treatments, relapses and sequelae were obtained. Results The majority of patients with type 1 (99%) and type 2 (92%) AIP who were treated with steroids went into clinical remission. Most patients with jaundice required biliary stent placement (71% of type 1 and 77% of type 2 AIP). Relapses were more common in patients with type 1 (31%) versus type 2 AIP (9%, p<0.001), especially those with IgG4-related sclerosing cholangitis (56% vs 26%, p<0.001). Relapses typically occurred in the pancreas or biliary tree. Retreatment with steroids remained effective at inducing remission with or without alternative treatment, such as azathioprine. Pancreatic duct stones and cancer were uncommon sequelae in type 1 AIP and did not occur in type 2 AIP during the study period. Conclusions AIP is a global disease which uniformly displays a high response to steroid treatment and tendency to relapse in the pancreas and biliary tree. Potential long-term sequelae include pancreatic duct stones and malignancy, however they were uncommon during the study period and require additional follow-up. Additional studies investigating prevention and treatment of disease relapses are needed.

ENETS Consensus Guidelines for the Management of Patients with Neuroendocrine Neoplasms from the Jejuno-Ileum and the Appendix Including Goblet Cell Carcinomas

a Division of Hepatology and Gastroenterology, Department of Internal Medicine, Campus Virchow-Klinikum, Charite-Universitatsmedizin Berlin, Berlin , Germany; b Department of Pathology, Universitatsspital, Zurich , Switzerland; c Division of General Surgery, Department of Surgery, Medical University of Vienna, Vienna , Austria; d Department of Endocrinology and Metabolism, Hadassah University Hospital, Jerusalem , Israel; e Department of Internal Medicine, Philipps University, Marburg , Germany; f Hopital Sirio Libanes, Centro de Oncologia, Sao Paulo , Brazil; g Department of Radiology, Campus Virchow-Klinikum, Charite, University Medicine Berlin, Berlin , Germany; h Department of Oncology, Institut Catala d’Oncologia (IDIBELL), Barcelona , Spain; i Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, University of Oxford, Oxford , UK

StellaTUM: current consensus and discussion on pancreatic stellate cell research

The field of pancreatic stellate cell (PSC) biology is very young, as the essential in-vitro tools to study these cells (ie, methods to isolate and culture PSC) were only developed as recently as in 1998. Nonetheless, there has been an exponential increase in research output in this field over the past decade, with numerous research groups around the world focusing their energies into elucidating the biology and function of these cells. It is now well established that PSC are responsible for producing the stromal reaction (fibrosis) of two major diseases of the pancreas—chronic pancreatitis and pancreatic cancer. Despite exponentially increasing data, the methods for studying PSC remain variable. Although within individual laboratories methods are consistent, different methodologies used by various research groups make it difficult to compare results and conclusions. This article is not a review article on the functions of PSC. Instead, members of the Pancreatic Star Alliance (http://www.pancreaticstaralliance.com) discuss here and consolidate current knowledge, to outline and delineate areas of consensus or otherwise (eg, with regard to methodological approaches) and, more importantly, to identify essential directions for future research. Hepatic stellate cells (HSC) were first described by Karl von Kupffer in 1876; however, similar cells in the pancreas were first observed in the 1980s.1–3 In 1998, Apte et al 4 and Bachem et al 5 isolated and cultured PSC.4 5 In the normal pancreas, PSC are located in close proximity to the basal aspect of pancreatic acinar cells. In sections immunostained for the marker desmin (a cytoskeletal protein), quiescent PSC can be seen as cells with a central cell body and long cytoplasmic projections extending along the base of adjacent acinar cells similar to that of pericytes in the mammary gland. …

Role of actin and myosin in the control of paracellular permeability in pig, rat and human vascular endothelium

1. We have investigated the endothelial actomyosin system with particular emphasis on its possible role in actively opening a paracellular route for permeability. 2. Actin and myosin comprised 16% of total endothelial protein with a molar actin/myosin ratio of 16.2 which is close to the actin/myosin ratio of muscle (studies on freshly isolated pig pulmonary arterial endothelial cells, PAEC). 3. By immunocytochemistry at the light and electron microscope levels the bulk of actin and myosin was colocalized in close vicinity to the intercellular clefts of both micro‐ and macrovascular endothelial cells in situ and in vitro. 4. Calcium‐ionophore‐induced rise in permeability of human umbilical venous endothelial cells (HUVEC) and PAEC monolayers grown on filters in a two‐chamber permeability system was caused by opening of intercellular gaps. Gap formation depended on the rise in intracellular Ca2+ and could be blocked by the calmodulin‐binding drugs trifluperazine (TFP) and W7. 5. In skinned monolayers of cultured PAEC and in isolated sheets of HUVEC gap formation was shown to require ATP and occurred only when free myosin binding sites were available on endothelial actin filaments (experiments with myosin subfragment 1 modified by N‐ethylmaleimide, S1‐NEM). 6. These experiments suggest that actin and myosin in endothelial cells play a central role in regulating the width of the intercellular clefts, thereby controlling the paracellular pathway of vascular permeability.

Five years of prospective screening of high-risk individuals from families with familial pancreatic cancer

Objective: Familial pancreatic cancer (FPC) accounts for approximately 3% of all pancreatic cancer (PC) cases. It has been suggested that high-risk individuals (HRIs) should be offered a screening programme. Aim: To evaluate the diagnostic yield of a prospective screening programme in HRIs from families with FPC over a period of 5 years. Methods: HRIs of families with FPC of the National German Familial Pancreatic Cancer Registry (FaPaCa) were counselled and enrolled in a prospective, board-approved PC screening programme. Screening included clinical examination, laboratory tests, endoscopic ultrasound (EUS) and MRI with magnetic resonance cholangiopancreaticography (MRCP) and MR angiography. Results: Between June 2002 and December 2007, 76 HRIs of families with FPC took part in the screening programme with a total of 182 examination visits. Twenty-eight patients revealed abnormalities in EUS (n = 25) and/or MR/MRCP (n = 12). In 7 patients fine needle aspiration cytology was performed. Operative pancreatic explorations were performed in 7 individuals, resulting in limited resections in 6 cases. Histopathological examination of the resected specimens showed serous oligocystic adenomas (n = 3), pancreatic intraepithelial neoplasia 1 (PanIN1) lesions with lobular fibrosis (n = 1), PanIN2 lesions (n = 1) and PanIN1 lesion plus a gastric type intraductal papillary mucinous neoplasm (IPMN) (n = 1). Conclusions: In FPC an EUS/MR/MRCP-based screening programme leads to the detection of potential precursor lesions of PC. However, the yield of an extensive screening programme is low, especially since the tumourigenic value of low grade PanIN lesions is not yet defined. Taking into account the enormous psychological stress for the tested individual and the high costs, a general PC screening in HRIs is not justified.

The N34S mutation of SPINK1 (PSTI) is associated with a familial pattern of idiopathic chronic pancreatitis but does not cause the disease

Background: Mutations in the PRSS1 gene explain most occurrences of hereditary pancreatitis (HP) but many HP families have no PRSS1 mutation. Recently, an association between the mutation N34S in the pancreatic secretory trypsin inhibitor (SPINK1 or PSTI) gene and idiopathic chronic pancreatitis (ICP) was reported. It is unclear whether the N34S mutation is a cause of pancreatitis per se, whether it modifies the disease, or whether it is a marker of the disease. Patients and methods: A total of 327 individuals from 217 families affected by pancreatitis were tested: 152 from families with HP, 108 from families with ICP, and 67 with alcohol related CP (ACP). Seven patients with ICP had a family history of pancreatitis but no evidence of autosomal dominant disease (f-ICP) compared with 87 patients with true ICP (t-ICP). Two hundred controls were also tested for the N34S mutation. The findings were related to clinical outcome. Results: The N34S mutation was carried by five controls (2.5%; allele frequency 1.25%), 11/87 (13%) t-ICP patients (p=0.0013 v controls), and 6/7 (86%) affected (p<0.0001 v controls) and 1/9 (11%) unaffected f-ICP cases. N34S was found in 4/108 affected HP patients (p=0.724 v controls), in 3/27 (11%) with wild-type and in 1/81 (1%) with mutant PRSS1, and 4/67 ACP patients (all p>0.05 v controls). The presence of the N34S mutation was not associated with early disease onset or disease severity. Conclusions: The prevalence of the N34S mutation was increased in patients with ICP and was greatest in f-ICP cases. Segregation of the N34S mutation in families with pancreatitis is unexplained and points to a complex association between N34S and another putative pancreatitis related gene.