Surveillance for pancreatic cancer in high-risk individuals.

Background: Surveillance of individuals at high risk of pancreatic ductal adenocarcinoma (PDAC) and its precursors might lead to better outcomes. The aim of this study was to determine the prevalence and outcomes of PDAC and high-risk neoplastic precursor lesions among such patients participating in surveillance programmes. Methods: A multicentre study was conducted through the International CAncer of the Pancreas Screening (CAPS) Consortium Registry to identify high-risk individuals who had undergone pancreatic resection or progressed to advanced PDAC while under surveillance. High-risk neoplastic precursor lesions were defined as: pancreatic intraepithelial neoplasia (PanIN) 3, intraductal papillary mucinous neoplasia (IPMN) with high-grade dysplasia, and pancreatic neuroendocrine tumours at least 2 cm in diameter. Results: Of 76 high-risk individuals identified in 11 surveillance programmes, 71 had undergone surgery and five had been diagnosed with inoperable PDAC. Of the 71 patients who underwent resection, 32 (45 per cent) had PDAC or a high-risk precursor (19 PDAC, 4 main-duct IPMN, 4 branch-duct IPMN, 5 PanIN-3); the other 39 patients had lesions thought to be associated with a lower risk of neoplastic progression. Age at least 65 years, female sex, carriage of a gene mutation and location of a lesion in the head/uncinate region were associated with high-risk precursor lesions or PDAC. The survival of high-risk individuals with low-risk neoplastic lesions did not differ from that in those with high-risk precursor lesions. Survival was worse among patients with PDAC. There was no surgery-related mortality. Conclusion: A high proportion of high-risk individuals who had surgical resection for screening- or surveillance-detected pancreatic lesions had a high-risk neoplastic precursor lesion or PDAC at the time of surgery. Survival was better in high-risk individuals who had either low- or high-risk neoplastic precursor lesions compared with that in patients who developed PDAC.

Antecedentes: Se podrían obtener mejores resultados con el seguimiento de individuos de alto riesgo para adenocarcinoma ductal pancreático (pancreatic ductal adenocarcinoma, PDAC) y lesiones precursoras. El objetivo de este estudio fue determinar la prevalencia y los resultados del PDAC y de las lesiones precursoras de alto riesgo neoplásico en pacientes que participaron en programas de seguimiento. Métodos: Se llevó a cabo un estudio multicéntrico a través del registro internacional del consorcio CAPS (Common Automotive Platform Standard) para identificar a las personas de alto riesgo que se habían sometido a una resección pancreática o habían progresado a PDAC avanzado mientras estaban en seguimiento. Se definieron como lesiones neoplásicas precursoras de alto riesgo la neoplasia intraepitelial pancreática de tipo 3 (PanIN­3), la neoplasia papilar mucinosa intraductal (intraductal papillary mucinous neoplasia, IPMN) con displasia de alto grado y los tumores neuroendocrinos pancreáticos (pancreatic neuroendocrine tumours, PanNET) de ≥ 2 cm de diámetro. Resultados: De 76 individuos con lesiones de alto riesgo identificados en 11 programas de seguimiento, 71 fueron tratados quirúrgicamente y 5 fueron diagnosticados de un PDAC inoperable. De las 71 resecciones, 32 (45%) tenían PDAC o una lesión precursora de alto riesgo (19 PDAC, 4 IPMN de conducto principal, 4 IPMN de rama secundaria y 5 PanIN­3). Los otros 39 pacientes tenían lesiones que se consideraron asociadas con un menor riesgo de progresión neoplásica. La edad ≥ 65 años, el sexo femenino, el ser portador de una mutación genética y la localización de la lesión en la cabeza/proceso uncinado fueron factores asociados a las lesiones precursoras de alto riesgo o al PDAC. No hubo diferencias en la supervivencia de individuos de alto riesgo con lesiones neoplásicas de bajo riesgo frente a aquellos que presentaron lesiones precursoras de alto riesgo. La supervivencia fue peor en los pacientes con PDAC. No hubo mortalidad relacionada con la cirugía. Conclusión: Un elevado porcentaje de individuos de alto riesgo que se sometieron a resección quirúrgica tras la detección de lesiones pancreáticas en el seguimiento tenían una lesión precursora neoplásica de alto riesgo o un PDAC. La supervivencia fue mejor en individuos de alto riesgo que tenían lesiones precursoras neoplásicas de bajo o alto riesgo en comparación con aquellos pacientes que habían desarrollado un PDAC.

Validation of histomolecular classification utilizing histological subtype, MUC1, and CDX2 for prognostication of resected ampullary adenocarcinoma.

BACKGROUND: Outcomes for ampullary adenocarcinomas are heterogeneous, and numerous methods of categorisation exist. A histomolecular phenotype based on histology, caudal-type homeodomain transcription factor 2 (CDX2) staining and Mucin 1 (MUC1) staining has recently been tested and validated in two cohorts. We attempt to validate this classification in a large patient population. METHODS: Tissue samples from 163 patients with resected ampullary adenocarcinoma were classified based on histology and immunohistochemical expression of CDX2 and MUC1. A pancreaticobiliary histomolecular classification (PB) was defined as a sample with pancreaticobiliary histology, positive MUC1 and negative CDX2 expression. RESULTS: There were 82 deaths; median follow-up of 32.4 months; and median overall survival of 87.7 (95% CI 42.9-109.5) months. PB comprised 28.2% of the cases. Factors associated with overall survival were histological subtype (P=0.0340); T1/2 vs T3/4 (P=0.001); perineural (P<0.0001) and lymphovascular (P=0.0203) invasion; and histomolecular intestinal histomolecular phenotype (INT) vs PB phenotype (106.4 vs 21.2 months, P<0.0001). Neither MUC1 nor CDX2 was statistically significant, although MUC1 positivity defined as ⩾10% staining was significant (P=0.0023). In multivariate analysis, age (HR 1.03), PB phenotype (HR 2.26) and perineural invasion (PNI; HR 2.26) were associated with poor survival. CONCLUSIONS: The prognostic ability of histomolecular phenotype has been validated in an independent cohort of ampullary adenocarcinoma patients.

Incidence of contrast-induced nephropathy in kidney transplant recipients.

UNLABELLED: Contrast-induced nephropathy (CIN) is responsible for one-third of acute kidney injuries (AKI) in the hospital setting. The incidence of CIN varies from 3% to 30%, depending on the preexisting risk factors, with higher incidence noted with diabetes mellitus, chronic kidney disease, and older age. Though CIN risk factors are common in kidney transplant recipients (KTRs), data about incidence of CIN in this population are sparse. METHODS: We retrospectively analyzed 124 consecutive patients transplanted at our center between January 2002 and December 2013 and received iodinated intravascular contrast with stable kidney function prior to contrast administration. CIN was defined as either an absolute rise in serum creatinine of ≥ 0.5 mg/dL or a ≥ 25% drop in estimated glomerular filtration rate (eGFR) after contrast administration. RESULTS: Seven of 124 (5.64%) patients developed CIN. Kidney function returned to baseline in 5 of the 7 patients within 3 weeks. In 2 patients serum creatinine remained elevated due to recurrent AKI episodes from other causes. Dialysis was not required in any patient. Calcineurin inhibitors (CNIs) were being used in 95% patients at the time of contrast administration. Diabetes mellitus, baseline serum creatinine, age, race, gender, and the use of ACE inhibitor, angiotensin receptor blocker, diuretic, or prophylaxis with intravenous hydration ± N-acetylcysteine did not affect the incidence of CIN. CONCLUSION: Incidence of CIN in KTRs was low in our study (5.6%), much less than previously reported. This low incidence may be related to the high baseline eGFR (>70 mL/min/1.73 m(2)) and use of hypo-osmolar contrast in our patients. In KTRs with baseline eGFR >70 mL/min, the incidence of CIN is low despite the concurrent use of nephrotoxic CNI.

Tumour epithelial vimentin expression and outcome of pancreatic ductal adenocarcinomas.

PURPOSE: Tumour epithelial vimentin expression is a marker of mesenchymal differentiation and may be a useful marker of carcinomas with more aggressive behaviour. The aim of this study was to determine the extent and prognostic significance of vimentin expression in pancreatic ductal adenocarcinomas. METHODS: Vimentin expression was detected by immunohistochemistry on tissue microarrays of surgically resected pancreatic ductal adenocarcinomas from 387 patients. The percentage of vimentin-immunolabelled neoplastic cells was correlated with outcome and with clinico-pathological factors using the Kaplan-Meier method and Cox multivariate survival models. RESULTS: In all, 45% of primary pancreatic adenocarcinomas contained neoplastic cells that expressed vimentin, and in 27.5% of the cancers >10% of cells expressed vimentin. Vimentin expression was correlated with poor histological differentiation. By both uni- and multivariate survival analysis, neoplastic vimentin expression (P<0.01, HR 1.52, 95% confidence interval 1.14-2.04) was an indicator of a shorter postsurgical survival independent of other clinico-pathological variables. CONCLUSION: The presence of vimentin-expressing tumour epithelial cells in surgically resected pancreatic adenocarcinomas independently predicted a shorter postsurgical survival.

A novel mutation of STK11/LKB1 gene leads to the loss of cell growth inhibition in head and neck squamous cell carcinoma.

To investigate whether genetic alteration of the STK11 (serine/threonine kinase 11)/LKB1 tumor-suppressor gene is involved in the carcinogenesis of head and neck squamous cell carcinoma (HNSCC), the entire encoding exons and flanking intronic sequences of the STK11/LKB1 gene were analysed with direct genomic sequencing of 15 HNSCC specimens. A novel missense mutation with presumed loss of heterozygosity (LOH) and 10 polymorphisms were identified in these samples. The novel mutation of STK11/LKB1 at nucleotide position 613 G --> A, which causes the amino-acid substitution from alanine to threonine at residue 205 within the catalytic kinase domain, was identified in cell line RPMI 2650. To further determine whether this point mutation affects the gene function, constructs of the wild type and A205T mutant of the STK11/LKB1 gene expression vectors were created and transfected into RPMI 2650 cells. Our results showed that the reintroduction of the wild-type but not the mutant STK11/LKB1 construct into RPMI 2650 cells induced suppression of the cell growth. The mutation also affected the kinase activity of the Stk11/Lkb1 protein. This led us to conclude that the A205T point mutation of the STK11/LKB1 gene produces functionally inactive proteins. This is the first described mutation of the STK11/LKB1 gene in HNSCC. While the mutation frequency of the STK11/LKB1 gene in HNSCC remains to be determined in future studies, our data strongly suggests that STK11/LKB1 is involved in the carcinogenesis of HNSCC.

Aberrant methylation of the Human Hedgehog interacting protein (HHIP) gene in pancreatic neoplasms.

Hedgehog pathway overactivity has been implicated in the development of a variety of human cancers. The Human Hedgehog interacting protein (HHIP), a negative regulator of hedgehog signaling, has been shown to be underexpressed in pancreatic cancers. In this study we determined if the HHIP gene is a target for genetic and epigenetic alterations. While no mutations of HHIP were identified, we found complete methylation of the HHIP promoter CpG island in three pancreatic cancer cell lines, and partial hypermethylation in 13/17 (80%) pancreatic cancer cell lines, 35/75 (46%) primary pancreatic cancers and 14/18 (78%) pancreatic cancer xenografts, but no methylation in 13 normal pancreata. In pancreatic cancer cell lines, complete methylation was associated with absent or reduced HHIP expression by real-time RT-PCR. HHIP expression could be restored in methylated cell lines using epigenetic modifier drugs. Restoring the expression of HHIP in pancreatic cancer cells by 5-aza-2'-deoxycytidine led to a decrease in Gli reporter activity, consistent with downregulation of Hedgehog signaling. These results indicate in some pancreatic adenocarcinomas that HHIP is epigenetically inactivated by promoter methylation, and its silencing could contribute to the increased Hedgehog signaling observed in pancreatic neoplasms.

Aberrant methylation of suppressor of cytokine signalling-1 (SOCS-1) gene in pancreatic ductal neoplasms.

The suppressor of cytokine signalling-1 (SOCS-1) gene is frequently silenced in human hepatocellular carcinoma by aberrant methylation. The aim of this study was to determine if SOCS-1 is inactivated in pancreatic ductal neoplasms, and to investigate if aberrant methylation of this gene affected the Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway. Aberrant methylation in the CpG island of the SOCS-1 gene was detected in six of 19 (31.6%) human pancreatic cancer cell lines using methylation-specific PCR, and was associated with a loss or reduction of gene expression in five of the six methylated cell lines. Thirteen of 60 pancreatic ductal adenocarcinomas (21.7%) and two of 34 intraductal papillary mucinous neoplasms (IPMNs) (5.9%) had methylated SOCS-1. In contrast, SOCS-1 methylation was not seen in pancreatic normal ductal epithelia (zero out of 15), in pancreatic intraepithelial neoplasia (PanINs) (zero out of 49) or in the IPMNs without infiltrating cancer (zero out of 20). 5-Aza-2'-deoxycytidine treatment of the SOCS-1-methylated pancreatic cancer cell lines led to restoration of SOCS-1 gene expression. Interleukin-6, which has been shown to act through the JAK/STAT pathway to increase cell growth, induced modest time and dose-dependent cell proliferation in a SOCS-1-methylated cell line (PL10, P=0.015) but not in two unmethylated cell lines. These results indicate that loss of SOCS-1 gene is associated with transcriptional silencing and may have growth-promoting effects, and that its methylation is a useful marker of pancreatic cancer.

Mesothelin is overexpressed in the vast majority of ductal adenocarcinomas of the pancreas: identification of a new pancreatic cancer marker by serial analysis of gene expression (SAGE).

PURPOSE: Effective new markers of pancreatic carcinoma are urgently needed. In a previous analysis of gene expression in pancreatic adenocarcinoma using serial analysis of gene expression (SAGE), we found that the tag for the mesothelin mRNA transcript was present in seven of eight SAGE libraries derived from pancreatic carcinomas but not in the two SAGE libraries derived from normal pancreatic duct epithelial cells. In this study, we evaluate the potential utility of mesothelin as a tumor marker for pancreatic adenocarcinoma. EXPERIMENTAL DESIGN: Mesothelin mRNA expression was evaluated in pancreatic adenocarcinomas using reverse-transcription PCR (RT-PCR) and in situ hybridization, whereas mesothelin protein expression was evaluated by immunohistochemistry. RESULTS: Using an online SAGE database (http://www.ncbi.nlm.gov/SAGE), we found the tag for mesothelin to be consistently present in the mesothelioma, ovarian cancer, and pancreatic cancer libraries but not in normal pancreas libraries. Mesothelin mRNA expression was confirmed by in situ hybridization in 4 of 4 resected primary pancreatic adenocarcinomas and by RT-PCR in 18 of 20 pancreatic cancer cell lines, whereas mesothelin protein expression was confirmed by immunohistochemistry in all 60 resected primary pancreatic adenocarcinomas studied. The adjacent normal pancreas in these 60 cases did not label, or at most only rare benign pancreatic ducts showed weak labeling for mesothelin. CONCLUSIONS: Mesothelin is a new marker for pancreatic adenocarcinoma identified by gene expression analysis. Mesothelin overexpression in pancreatic adenocarcinoma has potential diagnostic, imaging, and therapeutic implications.

The SMAD4 protein and prognosis of pancreatic ductal adenocarcinoma.

PURPOSE: SMAD4 (also called Dpc4) is a tumor suppressor in the TGF-beta signaling pathway that is genetically inactivated in approximately 55% of all pancreatic adenocarcinomas. We investigated whether prognosis after surgical resection for invasive pancreatic adenocarcinoma is influenced by SMAD4 status. EXPERIMENTAL DESIGN: Using immunohistochemistry, we characterized the SMAD4 protein status of 249 pancreatic adenocarcinomas resected from patients who underwent pancreaticoduodenectomy (Whipple resection) at The Johns Hopkins Hospital, Baltimore, MD, between 1990 and 1997. The SMAD4 gene status of 56 of 249 (22%) pancreatic carcinomas was also determined. A multivariate Cox proportional hazards model assessed the relative risk of mortality associated with SMAD4 status, adjusting for known prognostic variables. RESULTS: Patients with pancreatic adenocarcinomas with SMAD4 protein expression had significantly longer survival (unadjusted median survival was 19.2 months as compared with 14.7 months in patients with pancreatic cancers lacking SMAD4 protein expression; P = 0.03). This SMAD4 survival benefit persisted after adjustment for prognostic factors including tumor size, margins, lymph node status, pathological stage, blood loss, and use of adjuvant chemoradiotherapy. The relative hazard of mortality for cancers lacking SMAD4 after adjusting for other prognostic factors was 1.36 (95% confidence interval, 1.01-1.83; P = 0.04). CONCLUSION: Patients undergoing Whipple resection for pancreatic adenocarcinoma survive longer if their cancers express SMAD4.

STK11/LKB1 Peutz-Jeghers gene inactivation in intraductal papillary-mucinous neoplasms of the pancreas.

Despite the growing awareness of intraductal papillary-mucinous neoplasms (IPMNs) of the pancreas among clinicians, the molecular features of IPMNs have not been well characterized. Previous reports suggest that inactivation of the STK11/LKB1, a tumor-suppressor gene responsible for Peutz-Jeghers syndrome (PJS), plays a role in the pathogenesis of gastrointestinal hamartomas as well as several cancers, including pancreatic adenocarcinoma. Using polymerase chain reaction amplification of five microsatellite markers from the 19p13.3 region harboring the STK11/LKB1 gene, we analyzed DNA from 22 IPMNs for loss of heterozygosity (LOH). LOH at 19p13.3 was identified in 2 of 2 (100%) IPMNs from patients with PJS and 5 of 20 (25%) from patients lacking features of PJS (7 of 22, 32% overall). Sequencing analysis of the STK11/LKB1 gene in these IPMNs with LOH revealed a germline mutation in one IPMN that arose in a patient with PJS and a somatic mutation in 1 of the 20 sporadic IPMNs. None of the 22 IPMNs showed hypermethylation of the STK11/LKB1 gene. These results suggest that the STK11/LKB1 gene is involved in the pathogenesis of some IPMNs.

Identification and characterization of differentially methylated CpG islands in pancreatic carcinoma.

To identify CpG islands differentially methylated in pancreatic adenocarcinoma, we used methylated CpG island amplification (MCA) coupled with representational difference analysis. Of 42 CpG islands identified by MCA/representational difference analysis, 7 CpG islands [methylated in carcinoma of the pancreas (MICP)] were differentially methylated in a panel of eight pancreatic cancer cell lines compared with normal pancreas. In a larger panel of 75 pancreatic adenocarcinomas, these 7 MICPs (ppENK, Cyclin G, ZBP, MICP25, 27, 36, and 38) were methylated in 93, 3, 9, 15, 48, 19, and 41% of cancers, respectively, by methylation-specific PCR but not in any of 15 normal pancreata. In pancreatic cancer cell lines, methylation of ppENK, a gene with known growth suppressive properties, was associated with transcriptional silencing that was reversible with 5-aza-2'-deoxycytidine treatment. Relationships between the methylation patterns of pancreatic adenocarcinomas and their clinicopathological features were also determined. Larger pancreatic cancers and those from older patients (P = 0.017) harbored more methylated loci than smaller tumors and those from younger patients (P = 0.017). ppENK, MICP25, and 27 were variably methylated in normal gastric, duodenal, and colonic mucosae. These data indicate that aberrant methylation of ppENK and its transcriptional repression is a common event in pancreatic carcinogenesis.

Familial pancreatic cancer.

Pancreatic cancer is the fourth leading cause of cancer death in both men and women in the United States and will be responsible for an estimated 28,900 deaths in 2001. Relatively little is known of its etiology, and the only well-established risk factor is cigarette smoking. Studies over the past 3 decades have shown that 4%-16% of patients with pancreatic cancer have a family history of the disease. A small fraction of this aggregation can be accounted for in inherited cancer syndromes, including familial atypical multiple-mole melanoma, Peutz-Jeghers syndrome, hereditary breast-ovarian cancer, hereditary pancreatitis, and hereditary nonpolyposis colorectal cancer. These syndromes arise as a result of germline mutations in the BRCA2, pl6 (familial atypical multiple-mole melanoma), mismatch repair (hereditary nonpolyposis colorectal cancer), and STK11 (Peutz-Jeghers syndrome) genes. In addition, hereditary plays a role in predisposing certain patients with apparently sporadic pancreatic cancer. Many patients with pancreatic cancers caused by a germline mutation in a cancer-causing gene do not have a pedigree that is suggestive of a familial cancer syndrome. A recent prospective analysis of the pedigrees in the National Familial Pancreatic Tumor Registry found that individuals with a family history of pancreatic cancer in multiple first-degree relatives have a high risk of pancreatic cancer themselves. The identification of such high-risk individuals will help clinicians target screening programs and develop preventive interventions with the hope of reducing the mortality of pancreatic cancer in these families.

Molecular pathology of pancreatic cancer.

Until recently, pancreatic cancer was a poorly understood disease. Research in the past decade has shown conclusively, however, that pancreatic cancer is primarily genetic in nature. Inactivation with a variety of tumor-suppressor genes such as p16, DPC4, and p53, coupled with activation of oncogenes such as K-ras, are a few of the mutations that trigger the growth of cancerous cells. Understanding these mutations is critical to a better understanding of familial pancreatic cancer and to the development of gene-based screening tests and therapies. In this article, we review the genetic alterations identified in pancreatic cancer and provide examples of how this information can be applied to patient care.

Soluble adhesion molecules in inflammatory bowel disease.

BACKGROUND: Soluble adhesion molecules are elevated in a number of inflammatory conditions. AIMS: To investigate the correlation of soluble intercellular adhesion molecule-1 (sICAM-1) and sE-selectin with the activity of inflammatory bowel disease (IBD). METHODS: sICAM-1 and sE-selectin were measured by an enzyme-linked immunosorbent assay (ELISA) in 53 patients with ulcerative colitis (UC) and 38 patients with Crohn's disease (CD). RESULTS: Patients with active UC and CD had significantly higher sICAM-1 than patients with inactive disease and controls. Patients with pancolitis had significantly higher levels than patients with distal colitis. There was a significant difference in sE-selectin levels between patients with active CD and control sICAM-1. sE-selectin did not correlate with the Harvey Bradshaw index (HBI). C-reactive protein (CRP) and microalbuminuria were better markers than sICAM-1 or sE-selectin which correlated with serum tumour necrosis factor (TNF)-alpha. CONCLUSION: sICAM-1 and sE-selectin are elevated in the serum of patients with IBD but CRP and microalbuminuria reflect clinical disease activity more accurately. This study does not support the routine use of soluble adhesion molecules as disease activity markers in IBD.

Discovery of new markers of cancer through serial analysis of gene expression: prostate stem cell antigen is overexpressed in pancreatic adenocarcinoma.

Serial analysis of gene expression (SAGE) can be used to quantify gene expression in human tissues. Comparison of gene expression levels in neoplastic tissues with those seen in nonneoplastic tissues can, in turn, identify novel tumor markers. Such markers are urgently needed for highly lethal cancers like pancreatic adenocarcinoma, which typically presents at an incurable, advanced stage. The results of SAGE analyses of a large number of neoplastic and nonneoplastic tissues are now available online, facilitating the rapid identification of novel tumor markers. We searched an online SAGE database to identify genes preferentially expressed in pancreatic cancers as compared with normal tissues. SAGE libraries derived from pancreatic adenocarcinomas were compared with SAGE libraries derived from nonneoplastic tissues. Three promising tags were identified. Two of these tags corresponded to genes (lipocalin and trefoil factor 2) previously shown to be overexpressed in pancreatic carcinoma, whereas the third tag corresponded to prostate stem cell antigen (PSCA), a recently discovered gene thought to be largely restricted to prostatic basal cells and prostatic adenocarcinomas. PSCA was expressed in four of the six pancreatic cancer SAGE libraries, but not in the libraries derived from normal pancreatic ductal cells. We confirmed the overexpression of the PSCA mRNA transcript in 14 of 19 pancreatic cancer cell lines by reverse transcription-PCR, and using immunohistochemistry, we demonstrated PSCA protein overexpression in 36 of 60 (60%) primary pancreatic adenocarcinomas. In 59 of 60 cases, the adjacent nonneoplastic pancreas did not label for PSCA. PSCA is a novel tumor marker for pancreatic carcinoma that has potential diagnostic and therapeutic implications. These results establish the validity of analyses of SAGE databases to identify novel tumor markers.

Increased urinary nitrite, a marker of nitric oxide, in active inflammatory bowel disease.

BACKGROUND: Nitric oxide (NO) production is increased in inflammatory bowel disease (IBD), and measurement of NO metabolites may be useful for monitoring disease activity. AIMS AND OBJECTIVES: To characterise urinary nitrite levels, a stable metabolite of NO, in IBD and to evaluate its potential as a marker of disease activity. METHODS: Twelve-hour urinary nitrites were measured by the microplate assay method in 46 patients with IBD (active; n = 32). Urinary samples from 16 healthy individuals served as controls. RESULTS: Increased levels of urinary nitrites were found in patients with active IBD compared with those with inactive IBD. Twenty-eight out of 32 patients (87.5%) with active IBD had detectable levels of nitrite in their urine as compared with 2/14 (14.3%) patients with inactive IBD. None of the 16 healthy controls had detectable urinary nitrite. Twelve-hour urinary nitrite in active compared with inactive IBD: 5 0.7 versus 0.1+/-0.04 micromol (P < 0.05). There was good correlation between urinary nitrite and some markers of disease activity in IBD such as C-reactive protein and microalbuminuria but not with erythrocyte sedimentation rate. CONCLUSIONS: Increased levels of nitrite were detected in urine of patients with active IBD, consistent with increased NO synthesis. This simple assay may be exploited as a potential marker of disease activity in IBD.

Increased risk of incident pancreatic cancer among first-degree relatives of patients with familial pancreatic cancer.

It has been estimated that familial aggregation and genetic susceptibility play a role in as many as 10% of patients with pancreatic cancer (PC). The quantified prospective risk of PC among first-degree relatives of PC patients has not been investigated. Families enrolled in the National Familial Pancreas Tumor Registry (NFPTR) prior to September 1, 1998 were followed to estimate the risk and incidence of PC among first-degree relatives of patients with PC. Analyses were performed separately on kindreds with at least two first-degree relatives with PC (familial pancreatic carcinoma (PC); n = 150) at the time the kindred was enrolled in the NFPTR and on kindreds without a pair of affected first-degree relatives (sporadic PC; n = 191). A subanalysis was performed on familial PC kindreds containing three or more affected members at the time of enrollment in the NFPTR (n = 52). Risk was estimated by comparing observed new cases of PC during the observation period with expected numbers based on the United States population-based Surveillance, Epidemiology and End Results program data. Incidence was estimated using person-years risk analyses. During the observational period, six incident PCs developed in the first-degree relatives: two in the sporadic PC kindreds, and four in the familial PC kindreds. The PC risk in the sporadic PC kindreds was not significantly greater than expected [observed/expected = 6.5 (95% CI = 0.78-23.3)] with an incidence rate of 24.5/10(5)/ year. There was a significantly increased 18-fold risk (95% CI = 4.74-44.5) of PC among first-degree relatives in familial PC kindreds, with an incidence of 76.0/10(5)/year. In the subset of familial PC kindreds with three or more affected family members at the time of enrollment, there was a 57-fold (95% CI = 12.4-175) increased risk of PC and an incidence of 301.4/10(5)/year compared with the Surveillance, Epidemiology and End Result age-adjusted incidence of PC in the U.S. (8.8/10(5)/year). When stratified by age, the risk was largely confined to relatives over the age of 60. This study is the first analysis of incident PC occurring in familial PC kindreds. The risk and incidence of PC is exceptionally high among at-risk first-degree relatives in familial PC kindreds in which at least three first-degree relatives have already been diagnosed with PC. Familial PC kindreds are a reasonable high-risk group for PC screening and chemoprevention research.

Nuclear localization of Dpc4 (Madh4, Smad4) in colorectal carcinomas and relation to mismatch repair/transforming growth factor-beta receptor defects.

The tumor-suppressor protein Dpc4 (Smad4, Madh4) regulates gene expression. On binding of an extracellular ligand of the extensive transforming growth factor (TGF) superfamily to its cognate receptor complex, latent cytoplasmic Dpc4 is activated and translocated into the nucleus to function as part of various DNA-binding transcriptional activator complexes. The most relevant ligand/receptor pair to control the tumor suppressive function of Dpc4 remains uncertain, but is usually assumed to be TGF-beta and its heteromeric receptor. We exploited a fortuitous experiment of nature to directly test this hypothesis: the TGF-beta type II receptor gene is inactivated by mutation in nearly all colorectal carcinomas having microsatellite instability, as seen in hereditary nonpolyposis colorectal cancer (HNPCC) and in sporadic medullary colorectal cancers. Using a specific and sensitive immunohistochemical label for Dpc4, we examined nuclear localization of Dpc4 in 13 HNPCC, six medullary, and 41 sporadic nonmedullary colorectal carcinomas. In agreement with published rates, two (5%) of 41 sporadic tumors showed complete loss of Dpc4 protein, indicative of genetic inactivation. All 13 HNPCC and six medullary tumors had intact cytoplasmic and nuclear Dpc4 localization. The TGFBR2 gene was sequenced in three of the cancers from patients with HNPCC, and all of these harbored inactivating mutations. The specificity of the immunohistochemical assay was demonstrated in xenograft tumors of syngeneic cell lines that differed in DPC4 genetic status because of an engineered gene knockout. Thus, nuclear localization of Dpc4 can be maintained in cells with inactivated TGF-beta type II receptors, suggesting the persistence of tumor-suppressive action of an upstream signaling input, most likely a ligand/receptor complex distinct from TGF-beta. Identification of the relevant input would be expected to have implications for the understanding of tumorigenesis and the design of rational biological therapy.