TNM staging of foregut (neuro)endocrine tumors: a consensus proposal including a grading system

The need for standards in the management of patients with endocrine tumors of the digestive system prompted the European Neuroendocrine Tumor Society (ENETS) to organize a first Consensus Conference, which was held in Frascati (Rome) and was based on the recently published ENETS guidelines on the diagnosis and treatment of digestive neuroendocrine tumors (NET). Here, we report the tumor-node-metastasis proposal for foregut NETs of the stomach, duodenum, and pancreas that was designed, discussed, and consensually approved at this conference. In addition, we report the proposal for a working formulation for the grading of digestive NETs based on mitotic count and Ki-67 index. This proposal, which needs to be validated, is meant to help clinicians in the stratification, treatment, and follow-up of patients.

Adjuvant chemoradiotherapy and chemotherapy in resectable pancreatic cancer: a randomised controlled trial

BACKGROUND

The role of adjuvant treatment in pancreatic cancer remains uncertain. The European Study Group for Pancreatic Cancer (ESPAC) assessed the roles of chemoradiotherapy and chemotherapy in a randomised study.

METHODS

After resection, patients were randomly assigned to adjuvant chemoradiotherapy (20 Gy in ten daily fractions over 2 weeks with 500 mg/m(2) fluorouracil intravenously on days 1-3, repeated after 2 weeks) or chemotherapy (intravenous fluorouracil 425 mg/m(2) and folinic acid 20 mg/m(2) daily for 5 days, monthly for 6 months). Clinicians could randomise patients into a two-by-two factorial design (observation, chemoradiotherapy alone, chemotherapy alone, or both) or into one of the main treatment comparisons (chemoradiotherapy versus no chemoradiotherapy or chemotherapy versus no chemotherapy). The primary endpoint was death, and all analyses were by intention to treat. Findings 541 eligible patients with pancreatic ductal adenocarcinoma were randomised: 285 in the two-by-two factorial design (70 chemoradiotherapy, 74 chemotherapy, 72 both, 69 observation); a further 68 patients were randomly assigned chemoradiotherapy or no chemoradiotherapy and 188 chemotherapy or no chemotherapy. Median follow-up of the 227 (42%) patients still alive was 10 months (range 0-62). Overall results showed no benefit for adjuvant chemoradiotherapy (median survival 15.5 months in 175 patients with chemoradiotherapy vs 16.1 months in 178 patients without; hazard ratio 1.18 [95% CI 0.90-1.55], p=0.24). There was evidence of a survival benefit for adjuvant chemotherapy (median survival 19.7 months in 238 patients with chemotherapy vs 14.0 months in 235 patients without; hazard ratio 0.66 [0.52-0.83], p=0.0005). Interpretation This study showed no survival benefit for adjuvant chemoradiotherapy but revealed a potential benefit for adjuvant chemotherapy, justifying further randomised controlled trials of adjuvant chemotherapy in pancreatic cancer.

TNM staging of neoplasms of the endocrine pancreas: results from a large international cohort study

BACKGROUND

Both the European Neuroendocrine Tumor Society (ENETS) and the International Union for Cancer Control/American Joint Cancer Committee/World Health Organization (UICC/AJCC/WHO) have proposed TNM staging systems for pancreatic neuroendocrine neoplasms. This study aims to identify the most accurate and useful TNM system for pancreatic neuroendocrine neoplasms.

METHODS

The study included 1072 patients who had undergone previous surgery for their cancer and for which at least 2 years of follow-up from 1990 to 2007 was available. Data on 28 variables were collected, and the performance of the two TNM staging systems was compared by Cox regression analysis and multivariable analyses. All statistical tests were two-sided.

RESULTS

Differences in distribution of sex and age were observed for the ENETS TNM staging system. At Cox regression analysis, only the ENETS TNM staging system perfectly allocated patients into four statistically significantly different and equally populated risk groups (with stage I as the reference; stage II hazard ratio [HR] of death = 16.23, 95% confidence interval [CI] = 2.14 to 123, P = .007; stage III HR of death = 51.81, 95% CI = 7.11 to 377, P < .001; and stage IV HR of death = 160, 95% CI = 22.30 to 1143, P < .001). However, the UICC/AJCC/WHO 2010 TNM staging system compressed the disease into three differently populated classes, with most patients in stage I, and with the patients being equally distributed into stages II-III (statistically similar) and IV (with stage I as the reference; stage II HR of death = 9.57, 95% CI = 4.62 to 19.88, P < .001; stage III HR of death = 9.32, 95% CI = 3.69 to 23.53, P = .94; and stage IV HR of death = 30.84, 95% CI = 15.62 to 60.87, P < .001). Multivariable modeling indicated curative surgery, TNM staging, and grading were effective predictors of death, and grading was the second most effective independent predictor of survival in the absence of staging information. Though both TNM staging systems were independent predictors of survival, the UICC/AJCC/WHO 2010 TNM stages showed very large 95% confidence intervals for each stage, indicating an inaccurate predictive ability.

CONCLUSION

Our data suggest the ENETS TNM staging system is superior to the UICC/AJCC/WHO 2010 TNM staging system and supports its use in clinical practice.

European experts consensus statement on cystic tumours of the pancreas

Cystic lesions of the pancreas are increasingly recognized. While some lesions show benign behaviour (serous cystic neoplasm), others have an unequivocal malignant potential (mucinous cystic neoplasm, branch- and main duct intraductal papillary mucinous neoplasm and solid pseudo-papillary neoplasm). European expert pancreatologists provide updated recommendations: diagnostic computerized tomography and/or magnetic resonance imaging are indicated in all patients with cystic lesion of the pancreas. Endoscopic ultrasound with cyst fluid analysis may be used but there is no evidence to suggest this as a routine diagnostic method. The role of pancreatoscopy remains to be established. Resection should be considered in all symptomatic lesions, in mucinous cystic neoplasm, main duct intraductal papillary mucinous neoplasm and solid pseudo-papillary neoplasm as well as in branch duct intraductal papillary mucinous neoplasm with mural nodules, dilated main pancreatic duct >6mm and possibly if rapidly increasing in size. An oncological partial resection should be performed in main duct intraductal papillary mucinous neoplasm and in lesions with a suspicion of malignancy, otherwise organ preserving procedures may be considered. Frozen section of the transection margin in intraductal papillary mucinous neoplasm is suggested. Follow up after resection is recommended for intraductal papillary mucinous neoplasm, solid pseudo-papillary neoplasm and invasive cancer.

Identification of a cold shock transcriptional enhancer of the Escherichia coli gene encoding nucleoid protein H-NS

The hns (27 min) gene encoding the 15.4-kDa nucleoid protein H-NS was shown to belong to the cold shock regulon of Escherichia coli, its expression being enhanced 3- to 4-fold during the growth lag that follows a shift from 37 degrees C to 10 degrees C. A 110-base-pair (bp) DNA fragment containing the promoter of hns fused to a promoterless cat gene (hns-cat fusion) conferred a similar cold shock response to the expression of chloramphenicol acetyltransferase (CAT) activity in vivo and in coupled transcription-translation systems prepared with extracts of cold-shocked cells. Extracts of the same cells produce a specific gel shift of the 110-bp DNA fragment and this fragment, immobilized on a solid support, specifically retains a single 7-kDa protein present only in cold-shocked cells that was found to be identical to F10.6 (CS7.4), the product of cspA. This purified protein, which is homologous to human DNA-binding protein YB-1, recognizes some feature of the 110-bp promoter region of hns and acts as a cold shock transcriptional activator of this gene since it stimulates the expression of CAT activity and of cat transcription in in vitro systems programmed with plasmid DNA carrying the hns-cat fusion.

Thermoregulation of Shigella and Escherichia coli EIEC pathogenicity. A temperature-dependent structural transition of DNA modulates accessibility of virF promoter to transcriptional repressor H-NS

The expression of plasmid-borne virF of Shigella encoding a transcriptional regulator of the AraC family, is required to initiate a cascade of events resulting in activation of several operons encoding invasion functions. H-NS, one of the main nucleoid-associated proteins, controls the temperature-dependent expression of the virulence genes by repressing the in vivo transcription of virF only below a critical temperature (approximately 32 degrees C). This temperature-dependent transcriptional regulation has been reproduced in vitro and the targets of H-NS on the virF promoter were identified as two sites centred around -250 and -1 separated by an intrinsic DNA curvature. H-NS bound cooperatively to these two sites below 32 degrees C, but not at 37 degrees C. DNA supercoiling within the virF promoter region did not influence H-NS binding but was necessary for the H-NS-mediated transcriptional repression. Electrophoretic analysis between 4 and 60 degrees C showed that the virF promoter fragment, comprising the two H-NS sites, undergoes a specific and temperature-dependent conformational transition at approximately 32 degrees C. Our results suggest that this modification of the DNA target may modulate a cooperative interaction between H-NS molecules bound at two distant sites in the virF promoter region and thus represents the physical basis for the H-NS-dependent thermoregulation of virulence gene expression.

Serous cystic neoplasm of the pancreas: a multinational study of 2622 patients under the auspices of the International Association of Pancreatology and European Pancreatic Club (European Study Group on Cystic Tumors of the Pancreas)

OBJECTIVES

Serous cystic neoplasm (SCN) is a cystic neoplasm of the pancreas whose natural history is poorly known. The purpose of the study was to attempt to describe the natural history of SCN, including the specific mortality.

DESIGN

Retrospective multinational study including SCN diagnosed between 1990 and 2014.

RESULTS

2622 patients were included. Seventy-four per cent were women, and median age at diagnosis was 58 years (16-99). Patients presented with non-specific abdominal pain (27%), pancreaticobiliary symptoms (9%), diabetes mellitus (5%), other symptoms (4%) and/or were asymptomatic (61%). Fifty-two per cent of patients were operated on during the first year after diagnosis (median size: 40 mm (2-200)), 9% had resection beyond 1 year of follow-up (3 years (1-20), size at diagnosis: 25 mm (4-140)) and 39% had no surgery (3.6 years (1-23), 25.5 mm (1-200)). Surgical indications were (not exclusive) uncertain diagnosis (60%), symptoms (23%), size increase (12%), large size (6%) and adjacent organ compression (5%). In patients followed beyond 1 year (n=1271), size increased in 37% (growth rate: 4 mm/year), was stable in 57% and decreased in 6%. Three serous cystadenocarcinomas were recorded. Postoperative mortality was 0.6% (n=10), and SCN's related mortality was 0.1% (n=1).

CONCLUSIONS

After a 3-year follow-up, clinical relevant symptoms occurred in a very small proportion of patients and size slowly increased in less than half. Surgical treatment should be proposed only for diagnosis remaining uncertain after complete workup, significant and related symptoms or exceptionally when exists concern with malignancy. This study supports an initial conservative management in the majority of patients with SCN.

TRIAL REGISTRATION NUMBER

IRB 00006477.

Management of complications after pancreaticoduodenectomy in a high volume centre: results on 150 consecutive patients

Pancreaticoduodenectomy (PD) is still a difficult procedure with significant morbidity. We report 150 consecutive PDs performed during a 3-year period. All the cases have been prospectively evaluated with regard to the surgical outcome. Mortality in this series was 3/150 (2%) with a re-operation rate of 5/150 (3.3%); surgical complications were experienced in 57/150 (38%). The most frequent complications were collections in 25/150 (16.6%) and pancreatic fistulas in 16/150 (10.7%). The majority of these complications were conservatively managed: only one abscess and one fistula due to an anastomotic dehiscence required re-operation. The complication most responsible for mortality was haemorrhage secondary to arterial pseudoaneurysms in patients with severe post-operative pancreatitis. The continued high morbidity of PDs is compensated by the ability to treat complications non-operatively, resulting in a surgical risk that should now be considered medium to low in high volume centres.

Pancreatic insufficiency after different resections for benign tumours

BACKGROUND

Pancreatic resections for benign diseases may lead to long-term endocrine/exocrine impairment. The aim of this study was to compare postoperative and long-term results after different pancreatic resections for benign disease.

METHODS

Between 1990 and 1999, 62 patients underwent pancreaticoduodenectomy (PD), 36 atypical resection (AR) and 64 left pancreatectomy (LP) for benign tumours. Exocrine and endocrine pancreatic function was evaluated by 72-h faecal chymotrypsin and oral glucose tolerance test.

RESULTS

The incidence of pancreatic fistula was significantly higher after AR than after LP (11 of 36 versus seven of 64; P = 0.028). The long-term incidence of endocrine pancreatic insufficiency was significantly lower after AR than after PD (P < 0.001). Exocrine insufficiency was more common after PD (P < 0.001) and LP (P = 0.009) than after AR. The probability of developing both endocrine and exocrine insufficiency was higher for PD and LP than for AR (32, 27 and 3 per cent respectively at 1 year; 58, 29 and 3 per cent at 5 years; P < 0.001).

CONCLUSION

Different pancreatic resections are associated with different risks of developing long-term pancreatic insufficiency. AR represents the best option in terms of long-term endocrine and exocrine function, although it is associated with more postoperative complications.

Prognostic factors at diagnosis and value of WHO classification in a mono-institutional series of 180 non-functioning pancreatic endocrine tumours

BACKGROUND

Non-functioning pancreatic endocrine tumours (NF-PETs) are an aggressive gastroenteropancreatic neoplasm. The present study assessed survival, value of World Health Organisation (WHO) classification and prognostic utility of clinicopathological parameters at diagnosis.

PATIENTS AND METHODS

From 1990 to 2004, 180 patients with NF-PETs were entered in a prospective database, and predictors of prognosis were tested in uni- and multivariate models.

RESULTS

There were 25 (14%) benign lesions, 38 (21%) neoplasms of uncertain behaviour, 100 well-differentiated carcinomas (56%) and 17 poorly differentiated carcinomas (9%). Radical resection was possible in 93 cases (51.6%). Overall 5-, 10- and 15-year survival rates were 67%, 49.3% and 32.8%, respectively, and were significantly higher in radically resected patients (93%, 80.8% and 65.2%, respectively; P < 0.00001). By multivariate analysis, poor differentiation [hazard ratio (HR) 7.3; P = 0.0001], nodal metastases (HR 3.05; P = 0.02), liver metastases (HR 3.29; P = 0.003), K(i)-67 >5% (HR 2.5; P = 0.012) and weight loss (HR 3.06; P = 0.001) were significantly associated with mortality.

CONCLUSION

This study confirms the good long-term survival of patients with NF-PETs and the prognostic value of WHO classification, liver metastases, poor differentiation, Ki-67, nodal metastases and weight loss. These latter two parameters have a prognostic value similar to that of liver metastases and Ki-67.

Alcohol and smoking as risk factors in chronic pancreatitis and pancreatic cancer

The aim of this study was to compare alcohol and smoking as risk factors in the development of chronic pancreatitis and pancreatic cancer. We considered only male subjects: (1) 630 patients with chronic pancreatitis who developed 12 pancreatic and 47 extrapancreatic cancers; (2) 69 patients with histologically well documented pancreatic cancer and no clinical history of chronic pancreatitis; and (3) 700 random controls taken from the Verona polling list and submitted to a complete medical check-up. Chronic pancreatitis subjects drink more than control subjects and more than subjects with pancreatic cancer without chronic pancreatitis (P<0.001). The percentage of smokers in the group with chronic pancreatitis is significantly higher than that in the control group [odds ratio (OR) 17.3; 95% CI 12.6-23.8; P<0.001] and in the group with pancreatic carcinomas but with no history of chronic pancreatitis (OR 5.3; 95% CI 3.0-9.4; P<0.001). In conclusion, our study shows that: (1) the risk of chronic pancreatitis correlates both with alcohol intake and with cigarette smoking with a trend indicating that the risk increases with increased alcohol intake and cigarette consumption; (2) alcohol and smoking are statistically independent risk factors for chronic pancreatitis; and (3) the risk of pancreatic cancer correlates positively with cigarette smoking but not with drinking.

Efficacy of octreotide in the prevention of complications of elective pancreatic surgery. Italian Study Group

A placebo-controlled double-blind multicentre study, with randomization into parallel groups, was performed to determine whether perioperative subcutaneous administration of octreotide 0.1 mg every 8 h reduces the rate of complications specifically related to pancreatic surgery. In all, 252 patients were evaluated (153 men, 99 women; mean(s.e.m.) age 53.1(0.8) years) who had pancreatic or periampullary tumour or other duodenal disease (157 patients) or chronic pancreatitis (95) and were undergoing elective pancreatic resection (100 Whipple's procedure, 60 distal resection, 12 others), pancreaticojejunostomy (66) or enucleation of pancreatic lesions (14). The proportion of patients with complications was significantly lower in the group treated with octreotide than in the placebo group (15.6 versus 29.2 per cent, P = 0.01). Octreotide thus appears to reduce substantially the risk of complications related to elective pancreatic surgery. Moreover, treatment acceptability was high.

The oligomeric structure of nucleoid protein H-NS is necessary for recognition of intrinsically curved DNA and for DNA bending

Escherichia coli hns, encoding the abundant nucleoid protein H-NS, was subjected to site-directed mutagenesis either to delete Pro115 or to replace it with alanine. Unlike the wild-type protein, hyperproduction of the mutant proteins did not inhibit macromolecular syntheses, was not toxic to cells and caused a less drastic compaction of the nucleoid. Gel shift and ligase-mediated circularization tests demonstrated that the mutant proteins retained almost normal affinity for non-curved DNA, but lost the wild-type capacity to recognize preferentially curved DNA and to actively bend non-curved DNA, a property of wild-type H-NS demonstrated here for the first time. DNase I foot-printing and in vitro transcription experiments showed that the mutant proteins also failed to recognize the intrinsically bent site of the hns promoter required for H-NS transcription autorepression and to inhibit transcription from the same promoter. The failure of the Pro115 mutant proteins to recognize curved DNA and to bend DNA despite their near normal affinity for non-curved DNA can be attributed to a defect in protein-protein interaction resulting in a reduced capacity to form oligomers observed in vitro and by a new in vivo test based on functional replacement by H-NS of the oligomerization domain (C-domain) of bacteriophage lambda cI repressor.

Enucleation of pancreatic neoplasms

BACKGROUND

Standard resections for benign and borderline neoplasms of the pancreas are associated with a significant risk of long-term functional impairment, whereas enucleation preserves healthy parenchyma and pancreatic function. The aim of this study was to evaluate postoperative and long-term oncological and functional results after pancreatic enucleation.

METHODS

Data collected prospectively from 61 consecutive patients who underwent pancreatic enucleation were analysed.

RESULTS

There were no deaths. A clinically significant pancreatic fistula was reported in 14 patients (23 per cent), and five patients (8 per cent) had a further operation for fistula-related complications. The most common indication for surgery was endocrine neoplasm (38 patients; 62 per cent) and two patients (3 per cent) had a final histopathological diagnosis of malignant neoplasm. At a median follow-up of 61 months no patient had developed tumour recurrence or exocrine insufficiency. Two elderly patients developed non-insulin-dependent diabetes.

CONCLUSION

Enucleation is an effective procedure for the radical treatment of benign and borderline neoplasms of the pancreas, with good long-term outcomes.

Clinicopathological features and treatment of intraductal papillary mucinous tumour of the pancreas

BACKGROUND

The surgical strategy in patients with a pancreatic intraductal papillary mucinous tumour (IPMT) is still controversial. In this study the pathological findings in a series of patients were used to rationalize surgical choice.

METHODS

Fifty-one patients with IPMT were observed between 1988 and 1998 and treated by pancreatic resection. Factors evaluated included symptoms, tumour site, type of operation, histological findings and resection margins, tumour stage, follow-up and survival.

RESULTS

Pancreaticoduodenectomy was the most frequent surgical treatment (33 patients; 65 per cent), followed by left pancreatectomy (ten), total pancreatectomy (five) and middle pancreatectomy (three). Histological assessment revealed the tumour to be an adenoma in 13 patients (25 per cent), a borderline tumour in ten (20 per cent) and a carcinoma in 28 (55 per cent), 19 of which were invasive. Mild to moderate dysplasia was present at the resection margin in 20 specimens (41 per cent), and carcinoma in one. Local recurrence was observed in four patients (8 per cent), all of whom underwent a second resection. The 3-year actuarial survival rate for benign and malignant disease was 94 and 69 per cent respectively (P = 0.03).

CONCLUSION

These results suggest that resection should be the treatment for IPMT. Management of the resection margin could be crucial in avoiding tumour recurrence.

Pancreatic tumours: molecular pathways implicated in ductal cancer are involved in ampullary but not in exocrine nonductal or endocrine tumorigenesis

Alterations of K- ras, p53, p16 and DPC4/Smad4 characterize pancreatic ductal cancer (PDC). Reports of inactivation of these latter two genes in pancreatic endocrine tumours (PET) suggest that common molecular pathways are involved in the tumorigenesis of pancreatic exocrine and endocrine epithelia. We characterized 112 primary pancreatic tumours for alterations in p16 and DPC4 and immunohistochemical expression of DPC4. The cases included 34 PDC, 10 intraductal papillary-mucinous tumours (IPMT), 6 acinar carcinomas (PAC), 5 solid-pseudopapillary tumours (SPT), 16 ampulla of Vater cancers (AVC) and 41 PET. All tumours were also presently or previously analysed for K- ras and p53 mutations and allelic loss at 9p, 17p and 18q. Alterations in K- ras, p53, p16 and DPC4 were found in 82%, 53%, 38% and 9% of PDC, respectively and in 47%, 60%, 25% and 6% of AVC. Alterations in these genes were virtually absent in PET, PAC or SPT, while in IPMT only K- ras mutations were present (30%). Positive immunostaining confirmed the absence of DPC4 alterations in all IPMT, SPT, PAC and PET, while 47% of PDC and 38% of AVC were immunonegative. These data suggest that pancreatic exocrine and endocrine tumourigenesis involves different genetic targets and that among exocrine pancreatic neoplasms, only ductal and ampullary cancers share common molecular events.

The virF promoter in Shigella: more than just a curved DNA stretch

In the human enteropathogen Shigella transcription of virF, the primary regulator of the invasion functions, is strictly temperature-dependent and is antagonistically mediated by H-NS and FIS, which bind to specific sites on the virF promoter. Here we report on the relevance of DNA geometry to the thermoregulation of virF and demonstrate that the virF promoter hosts a major DNA bend halfway between two H-NS sites. The bent region has been mutagenized in vitro to mimic temperature-induced changes of DNA curvature. Functional analysis of curvature mutants and of promoter constructs in which the two H-NS sites are phased-out by a half-helix turn reveals that modifying the spatial relationships between these sites severely affects the interaction of H-NS with the virF promoter, as well as its in vivo and in vitro temperature-dependent activity. The role of promoter curvature as thermosensor is also compatible with the present observation that, with increasing temperature, the virF bending centre moves downstream at a rate having its maximum around the transition temperature, abruptly unmasking a binding site for the transcriptional activator FIS.

Lethal overproduction of the Escherichia coli nucleoid protein H-NS: ultramicroscopic and molecular autopsy

The Escherichia coli hns gene, which encodes the nucleoid protein H-NS, was deprived of its natural promoter and placed under the control of the inducible lambda PL promoter. An hns mutant yielding a protein (H-NS delta 12) with a deletion of four amino acids (Gly112-Arg-Thr-Pro115) was also obtained. Overproduction of wild-type (wt) H-NS, but not of H-NS delta 12, resulted in a drastic loss of cell viability. The molecular events and the morphological alterations eventually leading to cell death were investigated. A strong and nearly immediate inhibition of both RNA and protein synthesis were among the main effects of overproduction of wt H-NS, while synthesis of DNA and cell wall material was inhibited to a lesser extent and at a later time. Upon cryofixation of the cells, part of the overproduced protein was found in inclusion bodies, while the rest was localized by immunoelectron microscopy to the nucleoids. The nucleoids appeared condensed in cells expressing both forms of H-NS, but the morphological alterations were particularly dramatic in those overproducing wt H-NS; their nucleoids appeared very dense, compact and almost perfectly spherical. These results provide direct evidence for involvement of H-NS in control of the organization and compaction of the bacterial nucleoid in vivo and suggest that it may function, either directly or indirectly, as transcriptional repressor and translational inhibitor.

Functional characterization and regulation of gadX, a gene encoding an AraC/XylS-like transcriptional activator of the Escherichia coli glutamic acid decarboxylase system

The Escherichia coli chromosome contains two distantly located genes, gadA and gadB, which encode biochemically undistinguishable isoforms of glutamic acid decarboxylase (Gad). The Gad reaction contributes to pH homeostasis by consuming intracellular H(+) and producing gamma-aminobutyric acid. This compound is exported via the protein product of the gadC gene, which is cotranscribed with gadB. Here we demonstrate that transcription of both gadA and gadBC is positively controlled by gadX, a gene downstream of gadA, encoding a transcriptional regulator belonging to the AraC/XylS family. The gadX promoter encompasses the 67-bp region preceding the gadX transcription start site and contains both RpoD and RpoS putative recognition sites. Transcription of gadX occurs in neutral rich medium upon entry into the stationary phase and is increased at acidic pH, paralleling the expression profile of the gad structural genes. However, P(T5)lacO-controlled gadX expression in neutral rich medium results in upregulation of target genes even in exponential phase, i.e., when the gad system is normally repressed. Autoregulation of the whole gad system is inferred by the positive effect of GadX on the gadA promoter and gadAX cotranscription. Transcription of gadX is derepressed in an hns mutant and strongly reduced in both rpoS and hns rpoS mutants, consistent with the expression profile of gad structural genes in these genetic backgrounds. Gel shift and DNase I footprinting analyses with a MalE-GadX fusion protein demonstrate that GadX binds gadA and gadBC promoters at different sites and with different binding affinities.

Incidence of cancer in the course of chronic pancreatitis

OBJECTIVE

Chronic pancreatitis patients appear to present an increased incidence of pancreatic cancer. The aim of the study was to compare the incidence of cancer, whether pancreatic or extrapancreatic, in our chronic pancreatitis cases with that in the population of our region.

METHODS

We analyzed 715 cases of chronic pancreatitis with a median follow-up of 10 yr (7287 person-years); during this observation period they developed 61 neoplasms, 14 of which were pancreatic cancers. The cancer incidence rates were compared, after correction for age and gender, with those of a tumour registry.

RESULTS

We documented a significant increase in incidence of both extrapancreatic (Standardized Incidence Ratio [SIR], 1.5; 95% confidence interval [CI], 1.1-2.0; p <0.003) and pancreatic cancer (SIR, 18.5; 95% CI, 10-30; p <0.0001) in chronic pancreatitis patients. Even when excluding from the analysis the four cases of pancreatic cancer that occurred within 4 yr of clinical onset of chronic pancreatitis, the SIR is 13.3 (95% CI, 6.4-24.5; p <0.0001). If we exclude these early-onset cancers, there would appear to be no increased risk of pancreatic cancer in nonsmokers, whereas in smokers this risk increases 15.6-fold.

CONCLUSIONS

The risks of pancreatic and nonpancreatic cancers are increased in the course of chronic pancreatitis, the former being significantly higher than the latter. The very high incidence of pancreatic cancer in smokers probably suggests that, in addition to cigarette smoking, some other factor linked to chronic inflammation of the pancreas may be responsible for the increased risk.

Controlled clinical trial of pefloxacin versus imipenem in severe acute pancreatitis

BACKGROUND & AIMS

Antibiotic prophylaxis in severe pancreatitis has recently yielded promising clinical results, with imipenem significantly reducing the incidence of infected necrosis compared with an untreated control group. On the bases of pefloxacin's spectrum of action and pancreatic penetration, we investigated whether such drugs represent a valid alternative to imipenem.

METHODS

In a multicenter study, 60 patients with severe acute pancreatitis with necrosis affecting at least 50% of the pancreas were randomly allocated to receive intravenous treatment for 2 weeks with pefloxacin, 400 mg twice daily (30 patients), or imipenem, 500 mg three times daily (30 patients), within 120 hours of onset of symptoms. Age, sex, body weight, Ranson and Apache II scores, C-reactive protein, etiology, and time from onset of symptoms to treatment were well matched in the two groups.

RESULTS

The incidences of infected necrosis and extrapancreatic infections were 34% and 44%, respectively, in the pefloxacin group and 10% and 20% in the imipenem group. Imipenem proved significantly more effective in prevention of pancreatic infections (P </= 0.05). Mortality was not significantly different in the two groups.

CONCLUSIONS

Despite its theoretical potential, pefloxacin is inferior to imipenem in the prevention of infections associated with severe pancreatitis.

Systematic review of resection of primary midgut carcinoid tumour in patients with unresectable liver metastases

BACKGROUND

Surgery for small intestinal neuroendocrine tumours (SI-NETs) is limited by metastatic disease in most patients. However, resection of the primary lesion alone has been advocated in patients with unresectable liver metastases. The present systematic review investigated the value of surgical resection of the primary lesion in patients with unresectable metastatic disease.

METHODS

MEDLINE was searched for studies reporting the outcome of patients with SI-NETs and unresectable liver metastases where there was an explicit comparison between resection of the primary lesion alone and no resection. The primary outcome was overall survival. Secondary outcomes were progression-free survival, treatment-related mortality and relief of symptoms.

RESULTS

Meta-analysis was not possible, but six studies were analysed qualitatively to highlight useful information. Possible confounders in these studies were the inclusion of patients with other primary tumour sites, unknown primary tumour or non-metastatic disease. Bearing in mind these limitations, there was a clear trend towards longer survival in patients who underwent surgical resection in all studies; their median overall survival ranged from 75 to 139 months compared with 50-88 months in patients who did not have resection. The difference between the two groups was statistically significant in three studies. Data on symptomatic improvement were scarce and did not suggest a clear benefit of surgery. Surgery-related mortality seemed low.

CONCLUSION

Available data suggest a possible benefit of resection of the primary lesion in patients with unresectable liver metastases, but the studies have several limitations and the results should therefore be considered with caution.