KRAS mutations are major factors involved in initiation and maintenance of pancreatic tumors. The impact of different mutations on patient survival has not been clearly defined. We screened tumors ...from 171 pancreatic cancer patients for mutations in KRAS and CDKN2A genes. Mutations in KRAS were detected in 134 tumors, with 131 in codon 12 and only 3 in codon 61. The GGT>GAT (G12D) was the most frequent mutation and was present in 60% (80/134). Deletions and mutations in CDKN2A were detected in 43 tumors. Analysis showed that KRAS mutations were associated with reduced patient survival in both malignant exocrine and ductal adenocarcinomas (PDAC). Patients with PDACs that had KRAS mutations showed a median survival of 17 months compared to 30 months for those without mutations (log-rank P = 0.07) with a multivariate hazard ratio (HR) of 2.19 (95%CI 1.09-4.42). The patients with G12D mutation showed a median survival of 16 months (log-rank-test P = 0.03) and an associated multivariate HR 2.42 (95%CI 1.14-2.67). Although, the association of survival in PDAC patients with CDKN2A aberrations in tumors was not statistically significant, the sub-group of patients with concomitant KRAS mutations and CDKN2A alterations in tumors were associated with a median survival of 13.5 months compared to 22 months without mutation (log-rank-test P = 0.02) and a corresponding HR of 3.07 (95%CI 1.33-7.10). Our results are indicative of an association between mutational status and survival in PDAC patients, which if confirmed in subsequent studies can have potential clinical application.
Celotno besedilo
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Molecular sensing in the lingual mucosa and in the gastro-intestinal tract play a role in the detection of ingested harmful drugs and toxins. Therefore, genetic polymorphisms affecting the capability ...of initiating these responses may be critical for the subsequent efficiency of avoiding and/or eliminating possible threats to the organism. By using a tagging approach in the region of Taste Receptor 2R38 (TAS2R38) gene, we investigated all the common genetic variation of this gene region in relation to colorectal cancer risk with a case-control study in a German population (709 controls and 602 cases) and in a Czech population (623 controls and 601 cases). We found that there were no significant associations between individual SNPs of the TAS2R38 gene and colorectal cancer in the Czech or in the German population, nor in the joint analysis. However, when we analyzed the diplotypes and the phenotypes we found that the non-taster group had an increased risk of colorectal cancer in comparison to the taster group. This association was borderline significant in the Czech population, (OR = 1.28, 95% CI 0.99-1.67; P(value) = 0.058) and statistically significant in the German population (OR = 1.36, 95% CI 1.06-1.75; P(value) = 0.016) and in the joint analysis (OR = 1.34, 95% CI 1.12-1.61; P(value) = 0.001). In conclusion, we found a suggestive association between the human bitter tasting phenotype and the risk of CRC in two different populations of Caucasian origin.
Celotno besedilo
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Evidence on the association between vitamin D status and pancreatic cancer risk is inconsistent. This inconsistency may be partially attributable to variation in vitamin D regulating genes. We ...selected 11 vitamin D-related genes (GC, DHCR7, CYP2R1, VDR, CYP27B1, CYP24A1, CYP27A1, RXRA, CRP2, CASR and CUBN) totaling 213 single nucleotide polymorphisms (SNPs), and examined associations with pancreatic adenocarcinoma. Our study included 3,583 pancreatic cancer cases and 7,053 controls from the genome-wide association studies of pancreatic cancer PanScans-I-III. We used the Adaptive Joint Test and the Adaptive Rank Truncated Product statistic for pathway and gene analyses, and unconditional logistic regression for SNP analyses, adjusting for age, sex, study and population stratification. We examined effect modification by circulating vitamin D concentration (≤50, >50 nmol/L) for the most significant SNPs using a subset of cohort cases (n = 713) and controls (n = 878). The vitamin D metabolic pathway was not associated with pancreatic cancer risk (p = 0.830). Of the individual genes, none were associated with pancreatic cancer risk at a significance level of p<0.05. SNPs near the VDR (rs2239186), LRP2 (rs4668123), CYP24A1 (rs2762932), GC (rs2282679), and CUBN (rs1810205) genes were the top SNPs associated with pancreatic cancer (p-values 0.008-0.037), but none were statistically significant after adjusting for multiple comparisons. Associations between these SNPs and pancreatic cancer were not modified by circulating concentrations of vitamin D. These findings do not support an association between vitamin D-related genes and pancreatic cancer risk. Future research should explore other pathways through which vitamin D status might be associated with pancreatic cancer risk.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background: Base excision repair (BER) is a highly conserved essential mechanism for maintaining genome integrity. We examined associations among four well-characterized polymorphisms of BER genes ...(OGG1 Ser326Cys, XRCC1 Arg194Trp, XRCC1 Arg280His, and XRCC1 Arg399Gln) and lung cancer risk. Methods: A total of 2188 patients with lung cancer and 2198 control subjects without lung cancer recruited at 15 centers in six Eastern European countries from February 1998 to October 2002 provided DNA samples for genotype analysis. Genetic polymorphisms were analyzed by the fluorescence 5′ exonuclease and Amplifluor assays. Unconditional multivariable logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). We estimated the false-positive reporting probability (FPRP) for our results by incorporating a range of prior probabilities that specific polymorphisms are associated with lung cancer risk. All statistical tests were two-sided. Results: The overall odds ratio for lung cancer among those with the OGG1 Cys/Cys genotype compared with those with the OGG1 Ser/Ser genotype was 1.34 (95% CI = 0.95 to 1.88); the association was most prominent for adenocarcinoma risk (OR = 1.66, 95% CI = 1.04 to 2.66). Overall, the XRCC1 polymorphisms were not associated with the risk of lung cancer. However, the XRCC1 Arg194Trp and Arg280His variants were each associated with a reduced risk of lung cancer among subjects in the highest quartile of pack-years of smoking compared with common allele homozygotes (ORs of 0.65 95% CI = 0.46 to 0.93 and 0.56 95% CI = 0.36 to 0.86, respectively). The associations between the OGG1 Cys/Cys genotype and adenocarcinoma risk and between XRCC1 Arg194Trp polymorphism and lung cancer risk among heavy smokers remained robust given prior probabilities of 25% (FPRP = 0.238) and 10% (FPRP = 0.276), respectively. Conclusions: Our results do not support a major independent role of BER gene polymorphisms in lung cancer risk. However, we cannot exclude the possibility that the OGG1 Ser326Cys and XRCC1 Arg194Trp polymorphisms play minor roles in lung carcinogenesis.
Several studies have examined leukocyte telomere length (LTL) as a possible predictor for cancer at various organ sites. The hypothesis originally motivating many of these studies was that shorter ...telomeres would be associated with an increase in cancer risk; the results of epidemiologic studies have been inconsistent, however, and suggested positive, negative, or null associations. Two studies have addressed the association of LTL in relation to pancreatic cancer risk and the results are contrasting.
We measured LTL in a prospective study of 331 pancreatic cancer cases and 331 controls in the context of the European Prospective Investigation into Cancer and Nutrition (EPIC).
We observed that the mean LTL was higher in cases (0.59 ± 0.20) than in controls (0.57 ± 0.17), although this difference was not statistically significant (P = 0.07), and a basic logistic regression model showed no association of LTL with pancreas cancer risk. When adjusting for levels of HbA1c and C-peptide, however, there was a weakly positive association between longer LTL and pancreatic cancer risk OR, 1.13; 95% confidence interval (CI), 1.01-1.27. Additional analyses by cubic spline regression suggested a possible nonlinear relationship between LTL and pancreatic cancer risk (P = 0.022), with a statistically nonsignificant increase in risk at very low LTL, as well as a significant increase at high LTL.
Taken together, the results from our study do not support LTL as a uniform and strong predictor of pancreatic cancer.
The results of this article can provide insights into telomere dynamics and highlight the complex relationship between LTL and pancreatic cancer risk.
A higher incidence of stomach cancer in ABO blood type A individuals than in those with blood type O has been known for a long time. We studied this association in relation to Helicobacter pylori ...(Hp) of different cagA status. For our study, we used baseline gastric histopathology data and DNAs from frozen gastric biopsies of 2,077 subjects enrolled in a chemoprevention trial for gastric precancerous lesions in Venezuela. We analyzed six single nucleotide polymorphisms in the ABO gene, and we assessed the presence of the Hp cagA gene. Odds ratios (ORs) for risk of advanced precancerous gastric lesions were calculated using individuals with normal gastric epithelium or non‐atrophic gastritis as a reference. Among individuals carrying a cagA negative Hp infection or no Hp infection, those with blood type A had a lower risk of intestinal metaplasia (IM) and dysplasia than those with blood type O (OR=0.60; 95% CI 0.38–0.94). In carriers of cagA positive Hp strains, individuals with blood type A had a higher risk of IM or dysplasia than those with blood type O (OR=1.42, 95% CI 1.09–1.86) and a higher risk if compared to subjects carrying cagA negative strain and non‐A blood group (OR=3.82, 95% CI=2.80–5.20). The interaction between Hp cagA status and blood type was statistically significant (p=0.0006). We showed that SNPs in the ABO gene, predictive of ABO blood groups, are associated with risk of advanced precancerous gastric lesions in individuals infected with Hp, but the assessment of the risk is strictly dependent on cagA status.
What's new?
Infection with the bacterium H. pylori, which is quite common, can cause stomach cancer. H. pylori comes in several varieties, and those carrying the cagA gene rank among the more dangerous. It is also known that people with blood type A have a higher incidence of stomach cancer. In this paper, the authors investigated the link between blood type allele and H. pylori infection status in assessing risk of stomach cancer. Having type A blood, they found, significantly increases risk of precancerous lesions only in the presence of cagA positive H. pylori infection. In those without H. pylori infections, or infected with a cagA negative strain, blood type A carried less risk of lesions.
Background: Incidence and mortality rates of upper aerodigestive tract cancers in Central Europe are among the highest in
the world and have increased substantially in recent years. This increase is ...likely to be due to patterns of alcohol and tobacco
consumption. Genetic susceptibility to upper aerodigestive tract cancer in relation to such exposures is an important aspect
that should be investigated among populations in this region.
Methods: A multicenter case-control study comprising 811 upper aerodigestive tract cancer cases and 1,083 controls was conducted
in: Bucharest (Romania), Lodz (Poland), Moscow (Russia), Banska Bystrika (Slovakia), and Olomouc and Prague (Czech Republic).
We analyzed six SNPs in three genes related to ethanol metabolism: alcohol dehydrogenase 1B and 1C ( ADH1B, ADH1C ) and aldehyde dehydrogenase 2 ( ALDH2 ).
Results: The ADH1B histidine allele at codon 48 was associated with a decreased risk of upper aerodigestive tract cancer; odds ratios (OR) were
0.36 95% confidence interval (95% CI), 0.17-0.77 for medium/heavy drinkers and 0.57 (95% CI, 0.36-0.91) for never/light
drinkers. Moderately increased risks were observed for the ADH1C 350 Val allele (OR, 1.19; 95% CI, 0.98-1.55) and ADH1C 272 Gln allele (OR, 1.24; 95% CI, 0.98-1.55). Medium/heavy drinkers who were heterozygous or homozygous at ALDH2 nucleotide position 248 were at a significantly increased risk of upper aerodigestive tract cancer (OR, 1.76; 95% CI, 1.13-2.75;
OR, 5.79; 95% CI, 1.49-22.5, respectively), with a significant dose response for carrying variant alleles ( P = 0.0007). Similar results were observed for the ALDH2 +82A>G and ALDH2 −261C>T polymorphisms. When results were analyzed by subsite, strong main effects were observed for squamous cell carcinoma
of the esophagus for all six variants. Among the 30% of the population who were carriers of at least one ALDH2 variant, the attributable fraction among carriers (AF c ) was 24.2% (5.7-38.3%) for all upper aerodigestive tract cancers, increasing to 58.7% (41.2-71.0%) for esophageal cancer.
Among carriers who drank alcohol at least thrice to four times a week, the AF c for having at least one ALDH2 variant was 49% (21.3-66.8%) for all upper aerodigestive tract cancers, increasing to 68.9% (42.9-83.1%) for esophageal cancer.
Conclusions: Polymorphisms in the ADH1B and ALDH2 genes are associated with upper aerodigestive tract cancer in Central European populations and interact substantially with
alcohol consumption. (Cancer Epidemiol Biomarkers Prev 2006;15(4):696–703)
The literature has consistently reported no association between low to moderate alcohol consumption and pancreatic cancer; however, a few studies have shown that high levels of intake may increase ...risk. Most single studies have limited power to detect associations even in the highest alcohol intake categories or to examine associations by alcohol type. We analyzed these associations using 1,530 pancreatic cancer cases and 1,530 controls from the Pancreatic Cancer Cohort Consortium (PanScan) nested case-control study. Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated using unconditional logistic regression, adjusting for potential confounders. We observed no significant overall association between total alcohol (ethanol) intake and pancreatic cancer risk (OR = 1.38, 95% CI = 0.86-2.23, for 60 or more g/day vs. >0 to <5 g/day). A statistically significant increase in risk was observed among men consuming 45 or more grams of alcohol from liquor per day (OR = 2.23, 95% CI = 1.02-4.87, compared to 0 g/day of alcohol from liquor, P-trend = 0.12), but not among women (OR = 1.35, 95% CI = 0.63-2.87, for 30 or more g/day of alcohol from liquor, compared to none). No associations were noted for wine or beer intake. Overall, no significant increase in risk was observed, but a small effect among heavy drinkers cannot be ruled out.
Genetics plays an important role in the susceptibility to sporadic colorectal cancer (CRC). In the last 10 years genome-wide association studies (GWAS) have identified over 40 independent low ...penetrance polymorphic variants. However, these loci only explain around 1‑4% of CRC heritability, highlighting the dire need of identifying novel risk loci. In this study, we focused our attention on the genetic variability of the TAS2R16 gene, encoding for one of the bitter taste receptors that selectively binds to salicin, a natural antipyretic that resembles aspirin. Given the importance of inflammation in CRC, we tested whether polymorphic variants in this gene could affect the risk of developing this neoplasia hypothesizing a role of TAS2R16 in modulating chronic inflammation within the gut.
We performed an association study using 6 tagging SNPs, (rs860170, rs978739, rs1357949, rs1525489, rs6466849, rs10268496) that cover all TAS2R16 genetic variability. The study was carried out on 1902 CRC cases and 1532 control individuals from four European countries.
We did not find any statistically significant association between risk of developing CRC and selected SNPs. However, after stratification by histology (colon vs. rectum) we found that rs1525489 was associated with increased risk of rectal cancer with a (P
of = 0.0071).
Our data suggest that polymorphisms within TAS2R16 gene do not have a strong influence on colon cancer susceptibility, but a possible role in rectal cancer should be further evaluated in larger cohorts.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Pancreatic neuroendocrine tumors (PNETs) are rare neoplasms for which very little is known about either environmental or genetic risk factors. Only a handful of association studies have been ...performed so far, suggesting a small number of risk loci.
To replicate the best findings, we have selected 16 SNPs suggested in previous studies to be relevant in PNET etiogenesis. We genotyped the selected SNPs (rs16944, rs1052536, rs1059293, rs1136410, rs1143634, rs2069762, rs2236302, rs2387632, rs3212961, rs3734299, rs3803258, rs4962081, rs7234941, rs7243091, rs12957119, and rs1800629) in 344 PNET sporadic cases and 2,721 controls in the context of the PANcreatic Disease ReseArch (PANDoRA) consortium.
After correction for multiple testing, we did not observe any statistically significant association between the SNPs and PNET risk. We also used three online bioinformatic tools (HaploReg, RegulomeDB, and GTEx) to predict a possible functional role of the SNPs, but we did not observe any clear indication.
None of the selected SNPs were convincingly associated with PNET risk in the PANDoRA consortium.
We can exclude a major role of the selected polymorphisms in PNET etiology, and this highlights the need for replication of epidemiologic findings in independent populations, especially in rare diseases such as PNETs.
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