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1.
J Natl Compr Canc Netw ; 17(9): 1089-1099, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31487678

RESUMO

BACKGROUND: Chemotherapy underuse in elderly patients (aged ≥75 years) with colon cancer has been reported in previous studies. However, these studies were mostly registry-based and limited in their potential to consider underlying reasons of such undertreatment. This study aimed to evaluate patient and hospital determinants of chemotherapeutic treatment in patients with stage III colon cancer, with a particular focus on age and underlying reasons for nontreatment of elderly patients. METHODS: A total of 629 patients with stage III colon cancer who were diagnosed in 2003 through 2012 and recruited into a population-based study in the Rhine-Neckar region of Germany were included. Information on sociodemographic and lifestyle factors, comorbidities, and treatment was collected from patient interviews and physicians. Patient (with an emphasis on age) and hospital factors were evaluated for their associations with administration of adjuvant chemotherapy overall and of oxaliplatin specifically using multivariable logistic regression. RESULTS: Administration of chemotherapy decreased from 94% in patients aged 30 to 64 years to 51% in those aged ≥75 years. A very strong decline in chemotherapy use with age persisted even after comprehensive adjustment for multiple patient factors-including comorbidities-and hospital factors and was also seen among patients without any major comorbidities. Between 2005 and 2008, and 2009 and 2012, chemotherapy administration in patients aged ≥75 years decreased from 60% to 41%. Among chemotherapy recipients, old age was also strongly associated with higher odds of nonadministration of oxaliplatin. The 2 most commonly reported reasons for chemotherapy nonreceipt among the study population were patient refusal (30%) and old age (24%). CONCLUSIONS: Age was the strongest predictor of chemotherapy underuse, irrespective of comorbidities and even in patients without comorbidities. Such underuse due just to older age in otherwise healthy patients deserves increased attention in clinical practice to ensure that elderly patients also get the best possible care. Patients' refusal as the most frequent reason for chemotherapy nonreceipt also warrants further investigation to exclude misinformation as underlying cause.

2.
Int J Cancer ; 2019 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-31495913

RESUMO

Colorectal cancer is the second most common cause of cancer-related death globally, with marked differences in prognosis by disease stage at diagnosis. We studied circulating metabolites in relation to disease stage to improve the understanding of metabolic pathways related to colorectal cancer progression. We investigated plasma concentrations of 130 metabolites among 744 stage I-IV colorectal cancer patients from ongoing cohort studies. Plasma samples, collected at diagnosis, were analysed with liquid chromatography-mass spectrometry using the Biocrates AbsoluteIDQ™ p180 kit. We assessed associations between metabolite concentrations and stage using multinomial and multivariable logistic regression models. Analyses were adjusted for potential confounders as well as multiple testing using false discovery rate (FDR) correction. Patients presented with 23%, 28%, 39% and 10% of stage I-IV disease, respectively. Concentrations of sphingomyelin C26:0 were lower in stage III patients compared to stage I patients (pFDR  < 0.05). Concentrations of sphingomyelin C18:0 and phosphatidylcholine (diacyl) C32:0 were statistically significantly higher, while citrulline, histidine, phosphatidylcholine (diacyl) C34:4, phosphatidylcholine (acyl-alkyl) C40:1 and lysophosphatidylcholines (acyl) C16:0 and C17:0 concentrations were lower in stage IV compared to stage I patients (pFDR  < 0.05). Our results suggest that metabolic pathways involving amongst others citrulline and histidine, implicated previously in colorectal cancer development, may also be linked to colorectal cancer progression. This article is protected by copyright. All rights reserved.

3.
Int J Cancer ; 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31483856

RESUMO

We critically examined existing approaches for the estimation of the excess familial risk of cancer which can be attributed to identified common genetic risk variants and propose an alternative, more straightforward approach for calculating this proportion using well-established epidemiological methodology. We applied the underlying equations of the traditional approaches and the new epidemiological approach for colorectal cancer (CRC) in a large population-based case-control study in Germany with 4,447 cases and 3,480 controls, who were recruited from 2003 to 2016 and for whom interview, medical and genomic data were available. Having a family history of CRC (FH) was associated with a 1.77-fold risk increase in our study population (95% CI 1.52-2.07). Traditional approaches yielded estimates of the FH-associated risk explained by 97 common genetics variants from 9.6% to 23.1%, depending on various assumptions. Our alternative approach resulted in smaller and more consistent estimates of this proportion, ranging from 5.4% to 14.3%. Commonly employed methods may lead to strongly divergent and possibly exaggerated estimates of excess familial risk of cancer explained by associated known common genetic variants. Our results suggest that familial risk and risk associated with known common genetic variants might reflect two complementary major sources of risk. This article is protected by copyright. All rights reserved.

4.
Nutrients ; 11(9)2019 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-31484340

RESUMO

A pro-coagulative state is related to increased risk of cardiovascular diseases but also certain cancers. Since experimental and smaller human studies suggest that diet, physical activity, and body weight may all affect coagulation, we evaluated associations between these lifestyle factors and hemostatic biomarkers in a population-based study. Cross-sectional baseline data from 2267 randomly selected participants of EPIC-Heidelberg (age range 35-65 years) was used. Fibrinogen, glycoprotein IIb/IIIa, P-selectin, thrombomodulin (TM), and thrombopoietin (TPO) were measured in baseline plasma samples. A score reflecting adherence to the World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) recommendations for cancer prevention was created. Associations between the WCRF/AICR score as well as its individual components and hemostatic biomarkers were analyzed by linear regression models. Multivariable-adjusted geometric means (95% confidence intervals) of TM and TPO were higher with greater adherence to the WCRF/AICR recommendations (TM, lowest vs. highest score category: 2.90 (2.7,3.1) vs. 3.10 (2.9,3.3) ng/mL, plinear trend = 0.0001; TPO: 328 (302,356) vs. 348 (321,378) pg/mL, plinear trend = 0.0007). These associations were driven by lower alcohol and meat consumption among persons with higher WCRF/AICR scores. Our results indicate that lifestyle factors favorably affect TM and TPO, two hemostatic factors implicated in chronic disease development.

5.
Am J Gastroenterol ; 114(9): 1520-1530, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31464746

RESUMO

OBJECTIVES: Many risk scores have been proposed to predict presence of advanced colorectal neoplasms, but a comprehensive comparison conducted in the same population is sparse. The aim of this study was to evaluate and directly compare the diagnostic performance of published risk prediction models for advanced colorectal neoplasms. METHODS: Data were drawn from 2 cohorts of subjects undergoing screening colonoscopy in Germany, i.e., KolosSal (n = 16,195) and BliTz (n = 7,444). Absolute risks and relative risks were generated for the presence of at least 1 advanced neoplasm, taking the lowest risk group as the reference group. Performance of risk models was assessed by the area under the receiver operating characteristic curve (AUC) and compared by the net reclassification improvement. RESULTS: The 2 cohorts included 1,917 (11.8%) and 848 (11.4%) participants with advanced neoplasm, respectively. Absolute risks were mostly between 5% and 10% among participants in the lowest risk group and between 15% and 20% among participants in the highest risk group, and relative risks mostly ranged from 2.0 to 4.0 across the risk models in both cohorts. The AUCs ranged from 0.58 to 0.65 in KolosSal and from 0.57 to 0.61 in BliTz for all risk scores. Compared to models with lower AUC, classification was significantly improved in most models with higher AUC. DISCUSSION: Risk models for advanced colorectal neoplasms generally yielded modest discriminatory power, despite some variation in performance between models. Future studies should evaluate the performance of these risk models in racially diverse populations and investigate possible extensions, such as combination with polygenic risk scores.

6.
Cancer Prev Res (Phila) ; 12(9): 617-630, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31289028

RESUMO

Monitoring population-level colonoscopy and sigmoidoscopy use is crucial to estimate the future burden of colorectal cancer and guide screening efforts. We conducted a systematic literature search on colonoscopy and sigmoidoscopy use, published between November 2016 and December 2018 in the databases PubMed and Web of Science to update previous reviews and analyze time trends for various countries. In addition, we used data from the German and European Health Interview Surveys and the National Health Interview Survey to explore recent time trends for Germany and the US, respectively. The literature search yielded 23 new articles: fourteen from the US and nine from Australia, Canada, England, Germany, Saudi Arabia, and South Korea. Colonoscopy use within 10 years was highest and, apart from the youngest age groups eligible for colorectal cancer screening, kept increasing to levels close to 60% in the US and Germany. A recent steep increase was also observed for South Korea. Limited data were available on sigmoidoscopy use; regional studies from the US suggest that sigmoidoscopy has become rarely used. Despite high uptake and ongoing increase in the US, Germany, and South Korea, use of colonoscopy and sigmoidoscopy has either remained low or essentially unknown for the majority of countries.

7.
Clin Epigenetics ; 11(1): 109, 2019 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-31340858

RESUMO

BACKGROUND: Results of previous studies on the association of the CpG island methylator phenotype (CIMP) with colorectal cancer (CRC) prognosis were inconsistent and mostly based on different CIMP definitions. The current study aimed to comprehensively investigate the associations between DNA methylation on genes previously used to define CIMP status with CRC survival. RESULTS: Patients with CRC followed up for a median of 5.2 years were divided into a study cohort (n = 568) and a validation cohort (n = 308). DNA methylation was measured in tumor tissue using the Illumina Infinium HumanMethylation450 BeadChip and restricted to 43 genes used to define CIMP status in previous studies. Cox proportional hazard regression models were used to estimate adjusted hazard ratios (HR) and 95% confidence intervals (CI) of survival after CRC, including adjustment for tumor stage, microsatellite instability, and BRAF mutation status. In the study cohort, ten CpG sites were identified to be associated with CRC survival. Seven of these ten CpG sites were also associated with CRC survival in the validation cohort and were used to construct a prognostic score. CRC patients with a prognostic score of the lowest methylation level showed poorer disease-specific survival compared with patients with the highest methylation level in both the study cohort and the validation cohort (HR = 3.11 and 95% CI = 1.97-4.91, and HR = 3.06 and 95% CI = 1.71-5.45, respectively). CONCLUSIONS: A CpG panel consisting of seven CpG sites was found to be strongly associated with CRC survival, independent from important clinical factors and mutations associated with CIMP. Further studies are required to confirm these findings.

8.
BMC Cancer ; 19(1): 681, 2019 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-31296182

RESUMO

BACKGROUND: Competing molecular classification systems have been proposed to complement the TNM staging system for a better prediction of survival in colorectal cancer (CRC). However, validation studies are so far lacking. The aim of this study was to validate and extend previously published molecular classifications of CRC in a large independent cohort of CRC patients. METHODS: CRC patients were recruited into a population-based cohort study (DACHS). Molecular subtypes were categorized based on three previously published classifications. Cox-proportional hazard models, based on the same set of patients and using the same confounders as reported by the original studies, were used to determine overall, cancer-specific, or relapse-free survival for each subtype. Hazard ratios and confidence intervals, as well as Kaplan-Meier plots were compared to those reported by the original studies. RESULTS: We observed similar patterns of worse survival for the microsatellite stable (MSS)/BRAF-mutated and MSS/KRAS-mutated subtypes in our validation analyses, which were included in two of the validated classifications. Of the two MSI subtypes, one defined by additional presence of CIMP-high and BRAF-mutation and the other by tumors negative for CIMP, BRAF and KRAS-mutations, we could not confirm associations with better prognosis as suggested by one of the classifications. For two of the published classifications, we were able to provide results for additional subgroups not included in the original studies (men, other disease stages, other locations). CONCLUSIONS: External validation of three previously proposed classifications confirmed findings of worse survival for CRC patients with MSS subtypes and BRAF or KRAS mutations. Regarding MSI subtypes, other patient characteristics such as stage of the tumor, may influence the potential survival benefit. Further integration of methylation, genetic, and immunological information is needed to develop and validate a comprehensive classification that will have relevance for use in clinical practice.

9.
Int J Cancer ; 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31291471

RESUMO

In October 2002, screening colonoscopy was added to the German colorectal cancer (CRC) screening program as an alternative to fecal occult blood test (FOBT). We aimed to evaluate the change in CRC screening use after introduction of the dual screening offer and to assess determinants of screening use. Data were drawn from a population-based cohort study initiated during 2000-2002 in Germany (n = 5,845, age range at recruitment: 50-75 years). We conducted both cross-sectional and longitudinal analyses to obtain uptake rates of CRC screening based on four waves of data. Age-group specific proportions of participants having had FOBT within 2 years remained essentially unchanged at 61-67% between 2000 and 2002 (1st wave) and 2005-2007 (3rd wave). The proportions of participants having undergone screening colonoscopy within 10 years increased from 23-29% to 46-57%, leading to a substantial overall increase in being up-to-date with CRC screening from 66-68% to 77-80%. In 2008-2010 (4th wave), FOBT use declined and colonoscopy use continued to increase. Obesity was significantly associated with lower prevalence of being up-to-date with FOBT (odds ratio [OR] at 8-year follow-up 0.68; 95% confidence interval [CI], 0.58-0.80) and screening colonoscopy (OR, 0.73; 95% CI, 0.62-0.86). Also, smokers were less likely to have ever used FOBT (OR, 0.54; 95% CI, 0.40-0.75) or colonoscopy (OR, 0.75; 95% CI, 0.63-0.90) compared to nonsmokers. After the introduction of dual screening offer, the overall adherence to CRC screening steeply increased, mainly due to an increase in screening colonoscopy uptake. Screening tests kept being underused by obese people and smokers who are at elevated CRC risk.

10.
Nat Med ; 25(7): 1054-1056, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31160815

RESUMO

Microsatellite instability determines whether patients with gastrointestinal cancer respond exceptionally well to immunotherapy. However, in clinical practice, not every patient is tested for MSI, because this requires additional genetic or immunohistochemical tests. Here we show that deep residual learning can predict MSI directly from H&E histology, which is ubiquitously available. This approach has the potential to provide immunotherapy to a much broader subset of patients with gastrointestinal cancer.

11.
Int J Cancer ; 2019 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-31209889

RESUMO

Interindividual differences in DNA repair systems may play a role in modulating the individual risk of developing colorectal cancer. To better ascertain the role of DNA repair gene polymorphisms on colon and rectal cancer risk individually, we evaluated 15,419 single nucleotide polymorphisms (SNPs) within 185 DNA repair genes using GWAS data from the Colon Cancer Family Registry (CCFR) and the Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO), which included 8,178 colon cancer, 2,936 rectum cancer cases and 14,659 controls. Rs1800734 (in MLH1 gene) was associated with colon cancer risk (p-value = 3.5 × 10-6 ) and rs2189517 (in RAD51B) with rectal cancer risk (p-value = 5.7 × 10-6 ). The results had statistical significance close to the Bonferroni corrected p-value of 5.8 × 10-6 . Ninety-four SNPs were significantly associated with colorectal cancer risk after Binomial Sequential Goodness of Fit (BSGoF) procedure and confirmed the relevance of DNA mismatch repair (MMR) and homologous recombination pathways for colon and rectum cancer, respectively. Defects in MMR genes are known to be crucial for familial form of colorectal cancer but our findings suggest that specific genetic variations in MLH1 are important also in the individual predisposition to sporadic colon cancer. Other SNPs associated with the risk of colon cancer (e.g., rs16906252 in MGMT) were found to affect mRNA expression levels in colon transverse and therefore working as possible cis-eQTL suggesting possible mechanisms of carcinogenesis.

14.
Int J Cancer ; 2019 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-31037736

RESUMO

Alcohol consumption is an established risk factor for colorectal cancer (CRC). However, while studies have consistently reported elevated risk of CRC among heavy drinkers, associations at moderate levels of alcohol consumption are less clear. We conducted a combined analysis of 16 studies of CRC to examine the shape of the alcohol-CRC association, investigate potential effect modifiers of the association, and examine differential effects of alcohol consumption by cancer anatomic site and stage. We collected information on alcohol consumption for 14,276 CRC cases and 15,802 controls from 5 case-control and 11 nested case-control studies of CRC. We compared adjusted logistic regression models with linear and restricted cubic splines to select a model that best fit the association between alcohol consumption and CRC. Study-specific results were pooled using fixed-effects meta-analysis. Compared to non-/occasional drinking (≤1 g/day), light/moderate drinking (up to 2 drinks/day) was associated with a decreased risk of CRC (odds ratio [OR]: 0.92, 95% confidence interval [CI]: 0.88-0.98, p = 0.005), heavy drinking (2-3 drinks/day) was not significantly associated with CRC risk (OR: 1.11, 95% CI: 0.99-1.24, p = 0.08) and very heavy drinking (more than 3 drinks/day) was associated with a significant increased risk (OR: 1.25, 95% CI: 1.11-1.40, p < 0.001). We observed no evidence of interactions with lifestyle risk factors or of differences by cancer site or stage. These results provide further evidence that there is a J-shaped association between alcohol consumption and CRC risk. This overall pattern was not significantly modified by other CRC risk factors and there was no effect heterogeneity by tumor site or stage.

15.
Epigenetics ; 14(5): 477-493, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30931802

RESUMO

Involvement of sex hormones in colorectal cancer (CRC) development has been linked to oestrogen receptor ß (ERß). Expression of ERß is found reduced in tumour tissue and inversely related to mortality. However, mechanisms are not well understood. Our study aimed to detect differentially methylated genes associated with ERß expression, which could point to mechanisms by which ERß could influence risk and prognosis of CRC. Epigenome-wide DNA methylation profiling was performed using Illumina HumanMethylation450k BeadChip arrays in two independent tumour sample sets of CRC patients recruited in 2003-2010 by the German DACHS study (discovery cohort n = 917, replication cohort n = 907). ERß expression was measured using immunohistochemistry and scored as negative, moderate and high. Differentially methylated CpG sites and genomic regions were determined using limma in the R-package RnBeads. For the comparison of tumours with moderate/high ERß versus negative expression, differentially methylated CpG sites were identified but not confirmed by replication. Comparing tumours of high with tumours of negative ERß expression revealed 2,904 differentially methylated CpG sites of which 403 were replicated (FDR adjusted p-value<0.05). Replicated CpGs were annotated to genes such as CD36, HK1 or LRP5. A survival analysis indicates that 30 of the replicated CpGs are also associated with overall survival (FDR-adjusted p-value<0.05). The regional analysis identified 60 differentially methylated promotor regions. The epigenome-wide analysis identified both novel genes as well as genes already implicated in CRC. Follow-up mechanistic studies to better understand the regulatory role of ERß could inform potential targets for improving treatment or prevention of CRC.

16.
Cancer Epidemiol Biomarkers Prev ; 28(7): 1221-1227, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31015200

RESUMO

BACKGROUND: While enhanced platelet activation and a procoagulant state may drive lung cancer progression and metastases, less is known about their role in earlier phases of cancer development. Thus, we evaluated whether prediagnostic biomarkers of platelet activation and coagulation are related to the risk of lung cancer in the prospective EPIC-Heidelberg Study using a case-cohort design. METHODS: Levels of fibrinogen, soluble glycoprotein (sGP) IIb/IIIa, soluble P-selectin (sP-selectin), soluble thrombomodulin (sTM), and thrombopoietin (TPO) were measured in baseline plasma samples of a random subcohort (n = 2,480) and incident cases of lung cancer (n = 190). Multivariable-adjusted Cox proportional hazards regression analyses were used to obtain HRs of lung cancer across quartiles of biomarker levels. RESULTS: Fibrinogen [HR highest vs. lowest quartile: 1.91 (95% confidence interval: 1.09-3.34)] and sP-Selectin [HR: 2.51 (1.39-4.52)] were significantly associated with lung cancer risk in multivariable adjusted Cox regression models. Adding both biomarkers to the established PLCOm2012 algorithm, which alone showed a C-statistic of 0.788, led to a slight increment in lung cancer risk prediction, with a C-statistic of 0.814. CONCLUSION: Our findings indicate that enhanced platelet activation and a procoagulative state contribute to lung carcinogenesis. IMPACT: The current prospective study supports the hypothesis of increased coagulation being a possible driver of lung carcinogenesis, as strong positive associations were found between two procoagulative markers, sP-Selectin and fibrinogen, with lung cancer risk. Both biomarkers could improve lung cancer risk prediction, but external validation of the results is needed.

17.
Prev Med ; 123: 333-340, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30946858

RESUMO

An increasing number of countries have recently introduced colorectal cancer (CRC) screening programs. Typically, one specific screening exam, such as fecal occult blood test (FOBT) or flexible sigmoidoscopy, is offered as a primary screening test. We aimed to assess trends in FOBT and colonoscopy use in Germany following the introduction of the offer of screening colonoscopy as an alternative to FOBT in 2002. We used data from 4052 control participants aged 50-79 years recruited during 2003-2016 for a population-based case-control study in Germany. Prevalence of FOBT and colonoscopy lifetime and recent use was analyzed and trends over time were examined. The percentage of all respondents who had ever undergone a colonoscopy (for either screening or diagnostic purpose) increased markedly over time from 44.6% in 2003-2005 to 57.5% in 2013-2016 (p < 0.0001). Large increases were also observed for colonoscopy use within 10 years (from 38.0% to 52.8%, p < 0.0001), whereas FOBT uptake within one to two years declined from 54.0% to 33.3%. By 2013-2016, 67.2% of respondents either had an FOBT within one to two years or a colonoscopy within 10 years, and this percentage had remained relatively stable over time. This study demonstrates a large increase in colonoscopy utilization since colonoscopy was included as an alternative primary screening test, which was accompanied by a substantial decline in FOBT use. Although the overall adherence to CRC screening recommendations remained stable, the substantial shift of share from FOBT to colonoscopy is expected to yield more protection against CRC incidence and mortality.

18.
Nutrients ; 11(3)2019 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-30871032

RESUMO

Although flavonoid phytoestrogens have been suggested to be associated with reduced risk of colorectal cancer (CRC), their influence on CRC prognosis remains uncertain. A population-based cohort of 2051 patients diagnosed with stage I⁻III CRC in southwest Germany in 2003⁻2010 were followed for five years. Post-diagnostic serum concentration of genistein and luteolin were measured using Ultra-Performance Liquid Chromatography with mass spectrometry. Multivariable Cox regression analysis was conducted to calculate the Hazard Ratios (HRs) and 95% confidence interval (CI) for the association between flavonoids concentration and overall morality, CRC-specific mortality, CRC recurrence, and disease-free survival (DFS). Median (interquartile range) serum concentration of genistein and luteolin was 11.90 ng/µL (10.08⁻14.13) and 7.20 ng/µL (6.40⁻8.16), respectively. Neither serum genistein nor luteolin was associated with CRC prognosis. There was no clear evidence of departure from linearity. However, the association might be differential by adjuvant chemotherapy. Associations pointed towards lower risk in patients who received chemotherapy and higher risk in those without chemotherapy for overall mortality regarding serum genistein (P-interaction = 0.02) and correspondingly for CRC recurrence (P-interaction: 0.03) and DFS (P-interaction: 0.01) with respect to luteolin. Our study provides little evidence that serum genistein and luteolin are associated with colorectal cancer prognosis. Future studies are warranted to evaluate the potential interaction with adjuvant chemotherapy.


Assuntos
Neoplasias Colorretais/sangue , Genisteína/sangue , Luteolina/sangue , Fitoestrógenos/sangue , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Neoplasias Colorretais/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
19.
Hum Genet ; 138(4): 307-326, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30820706

RESUMO

Genome-wide association studies have reported 56 independently associated colorectal cancer (CRC) risk variants, most of which are non-coding and believed to exert their effects by modulating gene expression. The computational method PrediXcan uses cis-regulatory variant predictors to impute expression and perform gene-level association tests in GWAS without directly measured transcriptomes. In this study, we used reference datasets from colon (n = 169) and whole blood (n = 922) transcriptomes to test CRC association with genetically determined expression levels in a genome-wide analysis of 12,186 cases and 14,718 controls. Three novel associations were discovered from colon transverse models at FDR ≤ 0.2 and further evaluated in an independent replication including 32,825 cases and 39,933 controls. After adjusting for multiple comparisons, we found statistically significant associations using colon transcriptome models with TRIM4 (discovery P = 2.2 × 10- 4, replication P = 0.01), and PYGL (discovery P = 2.3 × 10- 4, replication P = 6.7 × 10- 4). Interestingly, both genes encode proteins that influence redox homeostasis and are related to cellular metabolic reprogramming in tumors, implicating a novel CRC pathway linked to cell growth and proliferation. Defining CRC risk regions as one megabase up- and downstream of one of the 56 independent risk variants, we defined 44 non-overlapping CRC-risk regions. Among these risk regions, we identified genes associated with CRC (P < 0.05) in 34/44 CRC-risk regions. Importantly, CRC association was found for two genes in the previously reported 2q25 locus, CXCR1 and CXCR2, which are potential cancer therapeutic targets. These findings provide strong candidate genes to prioritize for subsequent laboratory follow-up of GWAS loci. This study is the first to implement PrediXcan in a large colorectal cancer study and findings highlight the utility of integrating transcriptome data in GWAS for discovery of, and biological insight into, risk loci.


Assuntos
Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/genética , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Polimorfismo de Nucleotídeo Único , Estudos de Casos e Controles , Neoplasias Colorretais/epidemiologia , Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Frequência do Gene , Estudo de Associação Genômica Ampla/estatística & dados numéricos , Humanos , Valor Preditivo dos Testes , Prognóstico , Fatores de Risco
20.
Int J Cancer ; 145(5): 1221-1231, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-30665271

RESUMO

Colorectal cancer is known to arise from multiple tumorigenic pathways; however, the underlying mechanisms remain not completely understood. Metabolomics is becoming an increasingly popular tool in assessing biological processes. Previous metabolomics research focusing on colorectal cancer is limited by sample size and did not replicate findings in independent study populations to verify robustness of reported findings. Here, we performed a ultrahigh performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) screening on EDTA plasma from 268 colorectal cancer patients and 353 controls using independent discovery and replication sets from two European cohorts (ColoCare Study: n = 180 patients/n = 153 controls; the Colorectal Cancer Study of Austria (CORSA) n = 88 patients/n = 200 controls), aiming to identify circulating plasma metabolites associated with colorectal cancer and to improve knowledge regarding colorectal cancer etiology. Multiple logistic regression models were used to test the association between disease state and metabolic features. Statistically significant associated features in the discovery set were taken forward and tested in the replication set to assure robustness of our findings. All models were adjusted for sex, age, BMI and smoking status and corrected for multiple testing using False Discovery Rate. Demographic and clinical data were abstracted from questionnaires and medical records.

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