A pleiotropy scan to discover new susceptibility loci for pancreatic ductal adenocarcinoma.

Pleiotropic variants (i.e., genetic polymorphisms influencing more than one phenotype) are often associated with cancer risk. A scan of pleiotropic variants was successfully conducted ten years ago in relation to pancreatic ductal adenocarcinoma susceptibility. However, in the last decade, genetic association studies performed on several human traits have greatly increased the number of known pleiotropic variants. Based on the hypothesis that variants already associated with a least one trait have a higher probability of association with other traits, 61,052 variants reported to be associated by at least one genome wide association study (GWAS) with at least one human trait were tested in the present study consisting of two phases (discovery and validation), comprising a total of 16,055 pancreatic ductal adenocarcinoma (PDAC) cases and 212,149 controls. The meta-analysis of the two phases showed two loci (10q21.1-rs4948550 (P=6.52×10-5) and 7q36.3-rs288762 (P=3.03×10-5) potentially associated with PDAC risk. 10q21.1-rs4948550 shows a high degree of pleiotropy and it is also associated with colorectal cancer risk while 7q36.3-rs288762 is situated 28,558 base pairs upstream of the Sonic Hedgehog (SHH) gene, which is involved in the cell differentiation process and PDAC etiopathogenesis. In conclusion, none of the single nucleotide polymorphisms (SNPs) showed a formally statistically significant association after correction for multiple testing. However, given their pleiotropic nature and association with various human traits including colorectal cancer, the two SNPs showing the best associations with PDAC risk merit further investigation through fine mapping and ad hoc functional studies.

Current approach to hepatobiliary manifestations in inflammatory bowel disease.

Inflammatory bowel disease (IBD), including the two main subtypes - Crohn's disease (CD) and ulcerative colitis (UC) - has a wide range of extra-intestinal manifestations (EIMs) that are major causes of morbidity and disability. The following EIMs can be classified as IBD-associated: mucocutaneous, ocular, pulmonary, renal, genitourinary, hematological, neurological, psychiatric, cardiac and hepatobiliary. The latter include primary sclerosing cholangitis (PSC), cholelithiasis, IgG4 associated cholangiopathy (IAC), autoimmune hepatitis (AIH), non-alcoholic fatty liver disease (NAFLD), hepatitis B and C, and drug-induced hepatotoxicity. The aim of this review is to examine our current knowledge of IBD - associated hepatobiliary EIMs and their treatment.

Clinical significance of activin A and myostatin in patients with pancreatic adenocarcinoma and progressive weight loss.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by progressive weight loss and nutritional deterioration. Several cytokines, such as activin A and myostatin, ligands of the transforming growth factor-ß superfamily, have been shown to influence the pathogenesis of muscle wasting and tumor progression. The aim of our study was to assess the clinical significance of these cytokines in patients with different stages of PDAC. The study included 93 patients: 73 with newly diagnosed PDAC and 20 healthy volunteers as the control group. PDAC patients included 42 diagnosed with non-metastatic pancreatic cancer (stage I - III) and 31 patients with metastatic cancer (stage IV). The peripheral venous blood samples were collected from each patients at the time of cancer diagnosis and plasma concentrations of activin A and myostatin have been measured with an enzyme-linked immunoassay. Forty five patients (61.6%) presented weight loss > 5%, including 24 (57.1%) with stage I - II and 21 (67.7%) with metastatic PDAC (P > 0.05). Plasma levels of activing A were significantly higher in metastatic PDAC patients compared with stage I - III PDAC patients and control group (P < 0.01). The relationship between higher activin A levels and weight loss was also observed (P < 0.05). On the other hand, myostatin was not associated with weight loss in analysed group of patients. In conclusion, the current study demonstrates that high activin A plasma levels at the time of PDAC diagnosis is associated with unintentional weight loss and may be an useful biomarker for identifying patients with metastatic disease. However, further prospective studies are needed to fully explore the clinical significance of myostatin in pathogenesis of progressive weight loss in PDAC patients.

Germline BRCA2 K3326X and CHEK2 I157T mutations increase risk for sporadic pancreatic ductal adenocarcinoma.

Rare truncating BRCA2 K3326X (rs11571833) and pathogenic CHEK2 I157T (rs17879961) variants have previously been implicated in familial pancreatic ductal adenocarcinoma (PDAC), but not in sporadic cases. The effect of both mutations in important DNA repair genes on sporadic PDAC risk may shed light on the genetic architecture of this disease. Both mutations were genotyped in germline DNA from 2,935 sporadic PDAC cases and 5,626 control subjects within the PANcreatic Disease ReseArch (PANDoRA) consortium. Risk estimates were evaluated using multivariate unconditional logistic regression with adjustment for possible confounders such as sex, age and country of origin. Statistical analyses were two-sided with p values <0.05 considered significant. K3326X and I157T were associated with increased risk of developing sporadic PDAC (odds ratio (ORdom ) = 1.78, 95% confidence interval (CI) = 1.26-2.52, p = 1.19 × 10-3 and ORdom = 1.74, 95% CI = 1.15-2.63, p = 8.57 × 10-3 , respectively). Neither mutation was significantly associated with risk of developing early-onset PDAC. This retrospective study demonstrates novel risk estimates of K3326X and I157T in sporadic PDAC which suggest that upon validation and in combination with other established genetic and non-genetic risk factors, these mutations may be used to improve pancreatic cancer risk assessment in European populations. Identification of carriers of these risk alleles as high-risk groups may also facilitate screening or prevention strategies for such individuals, regardless of family history.

Subclinical Inflammation and Endothelial Dysfunction in Patients with Chronic Pancreatitis and Newly Diagnosed Pancreatic Cancer.

BACKGROUND: Recent studies have suggested that various cytokines may be important players in the development and progression of chronic pancreatitis (CP) and pancreatic adenocarcinoma (PC). AIMS: We studied endothelial dysfunction and subclinical inflammation in patients with newly diagnosed pancreatic adenocarcinoma and CP. METHODS: A total of 45 patients were included in the present investigation, 27 with CP and 18 with PC. In addition, the study included 13 age- and body weight-matched healthy subjects served as controls. In all subjects, plasma adiponectin, TNF-alfa, interleukin 6 (IL-6), interleukin 1beta (IL-1ß), E-selectin, thrombomodulin, adhesion molecules ICAM and VCAM, and endothelin-1 were assessed. RESULTS: PC and CP patients as compared with controls had significantly greater plasma adiponectin (13,292 and 12,227 vs 5408 ng/ml; p < 0.0003), TNF-alfa (22.1 and 23.1 vs 13 pg/ml; p < 0.0002), and IL-6 (6.6 and 7.3 vs 3.3 pg/ml; p < 0.0001). Moreover, there was significantly higher concentration of ICAM (931 and 492 vs 290 ng/ml; p < 0.005) and VCAM (1511 and 1080 vs 840 ng/ml; p < 0.01) in PC and CP patients. When PC and CP patients with and without diabetes were considered separately, there was no difference in adiponectin, cytokines, and parameters of endothelial dysfunction. CONCLUSION: In summary, our data indicate that patients with CP and PC express high levels of several cytokines compared with healthy individuals, especially adiponectin, TNF-α and IL-6. Serum TNF-α and ICAM concentrations coordinately increase in advanced CP. Furthermore, especially in PC subjects, elevated markers of endothelial dysfunction are present. This study provides additional evidence that changes in inflammatory cytokine and adhesion molecules in PC and CP are not likely related to endocrine disorders.

Vascular endothelial growth factor (VEGF) genotype and serum concentration in patients with pancreatic adenocarcinoma and chronic pancreatitis.

Vascular endothelial growth factor (VEGF) is necessary for microvasculature development and important for growth and spread of pancreatic tumors. Functional polymorphism of VEGF gene at position C-460T and G+405C may influence VEGF serum level. VEGF gene polymorphisms at position C-460T and G+405C were evaluated in 85 patients with pancreatic adenocarcinoma (PA), 72 - with chronic pancreatitis (CP) and 50 healthy volunteers. VEGF genotypes were studied in DNA isolated from blood samples and serum VEGF concentrations were measured. We found an increased frequency of the homozygous +405C/C VEGF genotype in patients with PA (55.3%) compared with CP (25%) and control group (16%; p<0.01). In contrast, the distribution of genotype and allele frequencies of the -460C/T polymorphism in the PA patients did not differ from those in CP and control groups. Serum levels of VEGF were significantly higher in PA patients (mean level: 441 ± 37.2 pg/ml) compared with CP patients (217 ± 13.6 pg/ml; p<0.001) and control group (137 ± 7.7 pg/ml; p<0.001). No relationship between VEGF serum levels and VEGF gene polymorphisms have been found. Our findings suggest that +405C/C VEGF genotype may contribute to pancreatic carcinogenesis. VEGF serum levels, although elevated in PA patients, are not associated with analysed VEGF polymorphisms.

Tumor necrosis factor alpha and interferon gamma genes polymorphisms and serum levels in pancreatic adenocarcinoma.

Several biochemical pathways can lead to cancer cachexia, one of which involves the elevation of the cytokines, such as tumor necrosis factor alpha (TNF-alpha) and interferon gamma (INF-gamma). It was suggested that TNF-alpha and INF-gamma genes polymorphisms may influence these cytokines serum levels, but published data are still controversial. The aim of our study was to assess the clinical significance of -308G/A TNF-alpha and +874A/T INF-gamma genes polymorphisms as well as TNF-alpha and INF-gamma serum levels in pancreatic adenocarcinoma (PA) and chronic pancreatitis (CP) as regards to healthy volunteers. We studied 41 patients with pancreatic adenocarcinoma, 56 with chronic pancreatitis and 50 healthy volunteers. Peripheral venous blood samples were obtained from all patients for TNF-alpha and INF-gamma serum concentrations measurement. After DNA isolation TNF-alpha and INF-gamma genes polymorphisms have been studied using restriction fragment length polymorphism (RFLP) analysis. Plasma levels of TNF-alpha were significantly higher in PA patients (32.7 pg/ml) compared with CP patients (3.2 pg/ ml) and control group (<1.6 pg/ml; p<0.01). Similarly, plasma levels of INF-gamma in PA patients (12.7 pg/ml) were higher from those in CP and control group (<7.1 pg/ml; p<0.01). In contrast, there were no differences between CP patients and healthy volunteers in INF-gamma levels. We observed a trend toward a correlation between weight loss in PA patients and TNF-alpha serum level (p=0.02). The TNF-alpha and INF-gamma genotype distribution were similar in patients with PA, CP and control group. We have not observed any association between TNF-alpha and INF-gamma serum levels and their genes polymorphisms. Our results suggest that elevated TNF-alpha serum level may have clinical significance in the development of cachexia in PA patients. -308G/A TNF-alpha and +874A/T INF-gamma genes polymorphisms probably do not play important role in pancreatic diseases. Key words: pancreatic adenocarcinoma, tumor necrosis factor alpha, interferon gamma, cytokines, polymorphism.

Usefulness of p16 and K-ras mutation in pancreatic adenocarcinoma and chronic pancreatitis differential diagnosis.

BACKGROUND: The differentiation of chronic pancreatitis (CP) from pancreatic adenocarcinoma (PA) remains a great challenge. The purpose of the study was to compare the prevalence of p16 and K-ras mutation in PA and CP in order to evaluate their usefulness in differential diagnosis of those diseases. METHODS: The study included 44 patients who underwent Whipple resection or distal pancreatectomy for PA (23 subjects) or CP (21 subjects). DNA from pancreatic tissue was analysed for K-ras mutation (codon 12) and p16 mutations with PCR amplifications. RESULTS: The K-ras gene mutation has been shown in 17 (73,9%) cases with pancreatic adenocarcinoma which was significantly more often than in chronic pancreatitis - 9 (42,8%) (p<0,01). Prevalence of p16 mutations in patients with PA was 18 (78,3%) and with CP - 7 (33,3%) (p<0,01). K-ras and p16 mutations together have been observed in 16 (69,6%) cases in patients with PC and only in 3 (14,3%) - with CP (p<0,01). No statistically significant association between K-ras or p16 mutations and tumor size, sex or patient age has been observed. CONCLUSION: It is suggested that simultaneous measurement of K-ras and p16 mutations may provide an additional tool in differential diagnosis of chronic pancreatitis and pancreatic adenocarcinoma.

Experimental studies as an inspiration for clinical investigation.

This study represents an attempt of showing own author's example of using basic research data as an inspiration for the clinical studies. The project evaluates the role of gastrin in colorectal carcinogenesis as well as the differences of its action in proximal and distal colon. Colonocytes were isolated from Fischer-344 rats and incubated for 2 minutes with gastrin (10(-8)M). This treatment resulted with 60-70% rise in tyrosine kinase (Tyr-k) and 150-200% - in phospholipase C activity as regards to basal levels. In vivo infusion of gastrin for 5 days to Fischer-344 rats resulted with 90-150% increase in distal but not proximal colonic mucosal proliferative activity as well as tyrosine phosphorylation of several colonic mucosal proteins. In clinical study, the mean fasting gastrin level in the control group was significantly lower (p<0.01) than in patients with colorectal cancer before surgery. Mean plasma gastrin level in patients with distal tumor yielded 105,31 +/- 12,5 microU/l and was significantly higher than in patients with the proximal tumor site (42, 2 +/- 3,1 microU/l) (p<0,001). We conclude, that Tyr-k is involved in the mechanism of the trophic action of gastrin, particularly in distal colon. The differences in gastrin concentration in patients with distal and proximal tumors may probably contribute to the distinct pathogenesis and biological properties of those cancers.

Prognostic factors in the operative and palliative treatment of pancreatic cancer.

Recent studies have emphasized the importance of patient selection for the surgical resection of pancreatic adenocarcinoma based on reproducible prognostic factors. The aim of the study was to investigate the prognostic factors affecting long-term survival in patients with resectable and nonresectable pancreatic cancer and to evaluate their prognostic value. Forty six patients (25 women, 21 men, aged 44-80) with ductal adenocarcinoma of the pancreas were reviewed. Primary tumor size and regional enlargement of lymph nodes was assessed with enhanced CT scan. 13 patients were treated conservatively, 9 with standard Whipple procedure (pancreatoduodenectomy) and 24 - with palliative surgery. Survival probabilities were computed using univariate Kaplan-Meier analysis. Log-rank test was used to compare survival between groups. Overall median survival was 6 months with a 4 years survival of 2.2%. There was no difference in survival time (ST) between patients aged 65 years or younger and older (p=0.71). MeanST in patients after Whipple procedure was 10.3, after palliative surgery - 9.4 and after conservative treatment - 4.4 months (p<0.05). Thirty-day surgical mortality was 9.4%. ST was significantly longer in patients with tumors 3 cm or less of diameter compared with larger ones (p<0.05). Presenting signs and symptoms, like jaundice, diabetes, alkaline phosphatase, aspartate and alanine aminotransferase elevation and history of cholecystectomy did not have any significant impact on survival. The only significant independent factors improving survival were: operative treatment and tumor size smaller than 3 cm.