Colorectal Cancer Risk (colorectal + cancer_risk)

Distribution by Scientific Domains
Distribution within Medical Sciences


Selected Abstracts


Helicobacter pylori Infection and Colorectal Cancer Risk: A Meta-Analysis

HELICOBACTER, Issue 2 2006
Natalia Zumkeller
Abstract Background:, Several studies suggested an association between Helicobacter pylori infection and colorectal carcinoma or adenoma risk. However, different authors reported quite varying estimates. We carried out a systematic review and meta-analysis of published studies investigating this association and paid special attention to the possibility of publication bias and sources of heterogeneity between studies. Materials and Methods:, An extensive literature search and cross-referencing were performed to identify all published studies. Summary estimates were obtained using random-effects models. The presence of possible publication bias was assessed using different statistical approaches. Results:, In a meta-analysis of the 11 identified human studies, published between 1991 and 2002, a summary odds ratio of 1.4 (95% CI, 1.1,1.8) was estimated for the association between H. pylori infection and colorectal cancer risk. The graphical funnel plot appeared asymmetrical, but the formal statistical evaluations did not provide strong evidence of publication bias. The proportion of variation of study results because of heterogeneity was small (36.5%). Conclusions:, The results of our meta-analysis are consistent with a possible small increase in risk of colorectal cancer because of H. pylori infection. However, the possibility of some publication bias cannot be ruled out, although it could not be statistically confirmed. Larger, better designed and better controlled studies are needed to clarify the situation. [source]


Iron and Colorectal Cancer Risk: Human Studies

NUTRITION REVIEWS, Issue 5 2001
F.A.C.S., Richard L. Nelson M.D
Some reports have associated iron with cancer risk, particularly of the colorectum. This review will focus on the human studies that have investigated this association. Comparative studies were sought in which people with and without colorectal neoplastic lesions, either cancers or adenomatous polyps, were assessed for iron exposure. Iron exposure variables included dietary iron intake, iron vitamin supplementation, body iron stores as measured by ferritin or transferrin saturation, and gene status for hereditary hemochromatosis. Medline was searched for published reports using the key words iron, cancer, colon, rectum, ferritin, transferrin, and hemochromatosis. In addition, the Cochrane Library was searched for relevant studies and several authors were contacted to investigate their awareness of unpublished studies. Studies were categorized by study design and ranked for quality of innovation in design, sample size, and thoroughness of iron status ascertainment. Thirty-three studies were reviewed in 26 publications. Of the larger studies, approximately three-quarters supported the association of iron, in all three strata of exposure, with colorectal neoplasia risk. Because iron is broadly supplemented in the American diet, the benefits of iron supplementation need to be measured against the long-term risks of increased iron exposure, one of which may be increased risk of colorectal cancer. [source]


Colorectal cancer risk in relation to use of acid suppressive medications,

PHARMACOEPIDEMIOLOGY AND DRUG SAFETY, Issue 7 2009
Jessica Chubak PhD, MBHL
Abstract Purpose Acid suppressants are commonly prescribed medications. Laboratory studies suggest a mechanism by which they could increase colorectal cancer (CRC) risk. A few epidemiologic studies have investigated acid suppressant use and CRC risk; none has documented an overall association. We sought to investigate whether acid suppressants are associated with CRC risk. Methods We conducted a case,control study among members of an integrated healthcare delivery system in Washington State. Cases (N,=,641) were diagnosed with CRC between 2000 and 2003; controls (N,=,641) were randomly selected from enrollees and matched to cases on age, sex, and length of enrollment. We used conditional logistic regression to estimate the odds ratios (ORs) and 95% confidence intervals (CI) for CRC associated with the use of any acid suppressive medication, proton pump inhibitors (PPIs) only, histamine receptor antagonists (H2 blockers) only, or both PPIs and H2 blockers in relation to the use of neither PPIs nor H2 blockers. Results Use of PPIs exclusively was modestly associated with an increased risk of CRC, however this finding was consistent with chance and based on a small number of patients exposed (OR,=,1.7; 95%CI,=,0.8, 4.0). H2 blocker use alone was not related to CRC risk (OR,=,0.8; 95%CI,=,0.6, 1.1). Conclusions PPI use may be modestly associated with CRC risk; further research should be conducted in populations with long-term PPI use. Copyright © 2009 John Wiley & Sons, Ltd. [source]


Helicobacter pylori Infection and Colorectal Cancer Risk: A Meta-Analysis

HELICOBACTER, Issue 2 2006
Natalia Zumkeller
Abstract Background:, Several studies suggested an association between Helicobacter pylori infection and colorectal carcinoma or adenoma risk. However, different authors reported quite varying estimates. We carried out a systematic review and meta-analysis of published studies investigating this association and paid special attention to the possibility of publication bias and sources of heterogeneity between studies. Materials and Methods:, An extensive literature search and cross-referencing were performed to identify all published studies. Summary estimates were obtained using random-effects models. The presence of possible publication bias was assessed using different statistical approaches. Results:, In a meta-analysis of the 11 identified human studies, published between 1991 and 2002, a summary odds ratio of 1.4 (95% CI, 1.1,1.8) was estimated for the association between H. pylori infection and colorectal cancer risk. The graphical funnel plot appeared asymmetrical, but the formal statistical evaluations did not provide strong evidence of publication bias. The proportion of variation of study results because of heterogeneity was small (36.5%). Conclusions:, The results of our meta-analysis are consistent with a possible small increase in risk of colorectal cancer because of H. pylori infection. However, the possibility of some publication bias cannot be ruled out, although it could not be statistically confirmed. Larger, better designed and better controlled studies are needed to clarify the situation. [source]


Family history of colorectal cancer: A determinant of advanced adenoma stage or adenoma multiplicity?

INTERNATIONAL JOURNAL OF CANCER, Issue 2 2009
Petra A. Wark
Abstract A family history of colorectal cancer may increase colorectal cancer risk by influencing adenoma growth or enhancing the formation of new lesions. Data of men from the prospective Health Professionals Follow-Up Study who underwent an endoscopy between 1986 and 2004 were used to evaluate whether a family history of colorectal cancer is associated with adenoma multiplicity or advanced adenoma stage (,1 cm, histology with villous component or carcinoma in situ). 21.4% of the 3,881 adenoma patients and 13.9% of the 24,959 adenoma-free men had a first-degree relative with colorectal cancer. Thousand four hundred and ninety-six men were classified as having advanced and 1,507 as having nonadvanced adenomas. Six hundred and twenty-two men had multiple and 1,985 had single adenomas in the distal colon and rectum. A family history of colorectal cancer was similarly associated with advanced and nonadvanced adenomas [multivariable odds ratio (OR) (95% confidence interval): advanced vs. nonadvanced, 0.98 (0.82,1.17), advanced vs. adenoma-free: 1.67 (1.47,1.91), nonadvanced vs. adenoma-free: 1.70 (1.49,1.94)], although potential differences according to adenoma location were seen. A family history of colorectal cancer was more strongly associated with multiple distally located adenomas [odds ratio (95% confidence interval): multiple vs. single, 1.35 (1.09,1.68), multiple vs. no distally located adenomas: 2.02 (1.67,2.44), single vs. no distally located adenomas: 1.49 (1.32,1.68)]. The number of adenomas was also positively associated with a family history of colorectal cancer. Our findings suggest that at the population level, heritable factors may be more important in earlier stages of adenoma formation than at stages of adenoma advancement for at least distally located adenomas. © 2009 UICC [source]


An intron 4 VNTR polymorphism of the endothelial nitric oxide synthase gene is associated with early-onset colorectal cancer

INTERNATIONAL JOURNAL OF CANCER, Issue 7 2009
Chih-Ching Yeh
Abstract Endothelial-derived nitric oxide, which is produced by endothelial nitric oxide synthase (eNOS), may play an important role in colorectal carcinogenesis. However, the putative contribution of common eNOS genetic polymorphisms to colorectal cancer risk remains unknown. We genotyped 3 polymorphisms of eNOS (T-786C, G894T, and intron4b/a) in 727 colorectal adenocarcinoma cases and 736 age- and sex-matched healthy controls in Taiwan. Genotypes of the T-786C and G894T polymorphisms were determined by fluorescence polarization assays and the 27-bp variable number of tandem repeat (VNTR) polymorphism in intron 4 (intron4b/a) was analyzed by PCR. Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Among younger participants (,60 yrs), the intron4a variant genotype was associated with a significantly increased risk of colorectal cancer, compared with the intron4bb genotype (OR = 1.60, 95% CI = 1.04,2.46). In addition, those young individuals bearing a greater number of high-risk genotypes (OR > 1, i.e., CT+TT for T-786C, ba+aa for intron4b/a, and GG for G894T) of eNOS had a higher colorectal cancer risk (ptrend = 0.039). Compared with younger individuals without any putative high-risk genotypes, those with 3 high-risk genotypes had a significantly greater cancer risk (OR = 1.89, 95% CI = 1.04,3.43). Our results suggest that the eNOS intron4b/a polymorphism may contribute to early-onset colorectal cancer risk in the Taiwanese population. © 2008 Wiley-Liss, Inc. [source]


Comment on interaction of hormone replacement therapy with calcium and vitamin D supplementation on colorectal cancer risk

INTERNATIONAL JOURNAL OF CANCER, Issue 7 2009
Ivanka Stajner
No abstract is available for this article. [source]


Oral contraceptive use, hormone replacement therapy, reproductive history and risk of colorectal cancer in women

INTERNATIONAL JOURNAL OF CANCER, Issue 3 2008
Geoffrey C. Kabat
Abstract Evidence from epidemiologic studies suggests a possible role of exogenous and endogenous hormones in colorectal carcinogenesis in women. However, with respect to exogenous hormones, in contrast to hormone replacement therapy, few cohort studies have examined oral contraceptive use in relation to colorectal cancer risk. We used data from a large cohort study of Canadian women enrolled in a randomized controlled trial of breast cancer screening to assess the association of oral contraceptive use, hormone replacement therapy and reproductive factors with risk of colorectal cancer, overall and by subsite within the colorectum. Cancer incidence and mortality were ascertained by linkage to national databases. Among 89,835 women aged 40,59 at enrollment and followed for an average of 16.4 years, we identified 1,142 incident colorectal cancer cases. Proportional hazards models were used to estimate the associations between the exposures of interest and risk of colorectal cancer. Ever use of oral contraceptives at baseline was associated with a modest reduction in the risk of colorectal cancer (hazard ratio 0.83, 95% confidence interval 0.73,0.94), with similar effects for different subsites within the colorectum. No trend was seen in the hazard ratios with increasing duration of oral contraceptive use. No associations were seen with use of hormone replacement therapy (ever use or duration of use) or reproductive factors. Our results are suggestive of an inverse association between oral contraceptive use and colorectal carcinogenesis. However, given the lack of a dose,response relationship and the potential for confounding, studies with more complete assessment of exogenous hormone use throughout the life course are needed to clarify this association. © 2007 Wiley-Liss, Inc. [source]


Coffee consumption and risk of colorectal cancer in a population-based prospective cohort of Japanese men and women

INTERNATIONAL JOURNAL OF CANCER, Issue 6 2007
Kyung-Jae Lee
Abstract We prospectively examined the association between coffee consumption and the risk of developing colorectal cancer in a large population-based cohort study (the JPHC Study) of Japanese men and women. Data were analyzed from a population-based cohort of 96,162 subjects (46,023 men and 50,139 women). A total of 1,163 incident colorectal cancers were identified during the follow-up period, including 763 cases of colon cancer and 400 of rectal cancer. We observed a significant inverse association between coffee consumption and the risk of developing invasive colon cancer among women. Compared with those who almost never consumed coffee, women who regularly consumed 3 or more cups of coffee per day had a RR of 0.44 (95% CI = 0.19,1.04; p for trend = 0.04) after adjustment for potential confounding factors. However, no significant association was found for rectal cancer in women. In men, no significant decrease was observed in any colorectal cancer site. Further, additional analyses on the association of green tea consumption with colorectal cancer risk found no significant association in men or women. These findings suggest that coffee consumption may lower the risk of colon cancer among Japanese women. © 2007 Wiley-Liss, Inc. [source]


Pesticide use and colorectal cancer risk in the agricultural health study

INTERNATIONAL JOURNAL OF CANCER, Issue 2 2007
Won Jin Lee
Abstract We investigated the relationship between agricultural pesticides and colorectal cancer incidence in the Agricultural Health Study. A total of 56,813 pesticide applicators with no prior history of colorectal cancer were included in this analysis. Detailed pesticide exposure and other information were obtained from self-administered questionnaires completed at the time of enrollment (1993,1997). Cancer incidence was determined through population-based cancer registries from enrollment through December 31, 2002. A total of 305 incident colorectal cancers (212 colon, 93 rectum) were diagnosed during the study period, 1993,2002. Although most of the 50 pesticides studied were not associated with colorectal cancer risk, chlorpyrifos use showed significant exposure response trend (p for trend = 0.008) for rectal cancer, rising to a 2.7-fold (95% confidence interval: 1.2,6.4) increased risk in the highest exposure category. Aldicarb was associated with a significantly increased risk of colon cancer (p for trend = 0.001), based on a small number of exposed cases, with the highest exposure category resulting in a 4.1-fold increased risk (95% confidence interval: 1.3,12.8). In contrast, dichlorophenoxyacetic acid showed a significant inverse association with colon cancer but the association was not monotonic. Our findings should be interpreted cautiously since the literature suggesting that pesticides are related to colorectal cancer is limited. Nonetheless the possibility of an association between exposure to certain pesticides and incidence of colorectal cancer among pesticide applicators deserves further evaluation. © 2007 Wiley-Liss, Inc. [source]


Meta-analysis: longitudinal studies of serum vitamin D and colorectal cancer risk

ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 2 2009
L. YIN
Summary Background, In 1980, Garland hypothesized that lower levels of vitamin D resulting from much weaker UV-B radiation at higher latitudes may account for the striking geographical pattern of cancer mortality. Further research has been conducted over the past 20 years. Aim, To perform a systematic review and meta-analysis of longitudinal studies on the association between serum 25 hydroxyvitamin D (25(OH)D) and the risk of colorectal cancer (CRC). Methods, Relevant studies published until September 2008 were identified by systematically searching Ovid Medline, EMBASE, and ISI Web of Knowledge databases and by cross-referencing. Due to the heterogeneity of studies in categorizing serum vitamin D levels, all results were recalculated for an increase of serum 25(OH)D by 20 ng/mL. Summary odds ratios (ORs) were calculated using meta-analysis methods. Results, Overall, eight original articles reporting on the association between serum 25(OH) D and CRC risk were included. In meta-analyses, summary ORs (95% confidence intervals) for the incidence of CRC, colon cancer and rectal cancer associated with an increase of 25(OH)D by 20 ng/mL were 0.57 (0.43,0.76), 0.78 (0.54,1.13) and 0.41 (0.11,1.49). No indication for publication bias was found. Conclusions, Our results support suggestions that serum 25(OH)D is inversely related to CRC risk. [source]


Serum bilirubin and colorectal cancer risk: a population-based cohort study

ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 11 2006
G. N. IOANNOU
Summary Background Bilirubin has antioxidant properties and has been postulated to protect against the development of malignancies. Aim To investigate whether baseline serum bilirubin concentration predicts the incidence of colorectal cancer in a nationally representative sample of the US population. Methods Participants of the first National Health and Nutrition Examination Survey were divided into four groups based on quartiles of baseline serum bilirubin concentration in mg/dL: <0.38 (n = 1410), 0.38 to <0.5 (n = 1287), 0.5 to <0.6 (n = 1048) and ,0.6 (n = 1742). The incidence of colorectal cancer during the following 20 years was determined from hospitalization records and death certificates. Results 110 cases of colorectal cancer-related death or hospitalization were identified among 5487 participants during 88 339 person-years of follow-up (12 per 10 000 person-years). There was no association between baseline serum bilirubin concentration and the incidence of colorectal cancer either in unadjusted analyses or after adjusting for age, gender, ethnicity, smoking, body mass index, alcohol consumption and educational attainment. Conclusions Baseline serum bilirubin concentration did not predict the subsequent incidence of colorectal cancer in this population-based cohort study. [source]


Single nucleotide polymorphisms in the hypoxia-inducible factor-1 gene and colorectal cancer risk

MOLECULAR CARCINOGENESIS, Issue 9 2010
Gudrun Knechtel
Abstract With an incidence of about 300,000 new cases colorectal cancer (CRC) is the second leading cause of cancer-related death in Europe and the United States. Environmental and genetic factors influence CRC risk. Hypoxia-inducible factor-1 (HIF-1), a heterodimeric protein composed of two subunits, HIF-1 alpha and HIF-1 beta, plays a critical role in oxygen homeostasis and is involved in angiogenesis and cell proliferation. The gene for the HIF-1 alpha subunit (HIF1A) carries two common missense mutations,P582S (rs11549465) and A588T (rs11549467),which both have been related to increased trans-activation capacity of HIF1A. In our case,control study we investigated the association between these polymorphisms and CRC risk. We investigated 381 patients with histologically confirmed CRC and 2156 control subjects. HIF1A genotypes were determined by exonuclease (TaqMan) assays. For determination of microvessel density (MVD) tumor sections were stained using a mouse monoclonal antibody recognizing the pan-endothelial marker CD31. In a multivariate logistic regression analysis including age and sex neither the HIF1A 582S allele (Odds ratio: 1.204; 95% confidence interval 0.911,1.592; P,=,0.193) nor the 588T allele was significantly associated with CRC (Odds ratio: 0.851; 95% confidence interval 0.444,1.631; P,=,0.626). However, in an exploratory analysis, the HIF1A 588T allele was associated with tumor localization (P,=,0.016) and tumor size (P,=,0.003). MVD was similar in tumors of patients carrying HIF1A 588T allele and patients without this rare allele. We conclude that functional polymorphisms in the HIF1A gene do not modify CRC risk but maybe associated with clinic-pathological features of the disease. © 2010 Wiley-Liss, Inc. [source]


Dietary patterns and the risk of colorectal cancer and adenomas

NUTRITION REVIEWS, Issue 7 2010
Giorgia Randi
The association of colorectal cancer risk with select foods has been evaluated by dietary pattern analysis. This review of the literature was conducted to thoroughly examine the available evidence for the association between dietary patterns and colorectal cancers and adenomas. A total of 32 articles based on worldwide epidemiological studies were identified. Pattern identification was achieved by exploratory data analyses (principal component, factor, and cluster analyses) in most articles, and only a few used a priori -defined scores. Dietary patterns named as healthy, prudent, fruit and vegetables, fat-reduced/diet foods, vegetable/fish/poultry, fruit/whole grain/dairy, and healthy eating index-2005, recommended food and Mediterranean diet scores were all associated with reduced risk of colorectal cancer and the risk estimates varied from 0.45 to 0.90. In contrast, diets named Western, pork-processed meat-potatoes, meat-eaters, meat and potatoes, traditional patterns, and dietary risk and life summary scores were associated with increased risk of colorectal cancer with risk estimates varying from 1.18 to 11.7. Dietary patterns for adenomas were consistent with those identified for colorectal cancer. [source]


Meat Consumption and Colorectal Cancer: A Review of Epidemiologic Evidence

NUTRITION REVIEWS, Issue 2 2001
Drs. Teresa Norat Ph.D
This article reviews the epidemiologic evidence on colorectal cancer risk and meat consumption from 32 case-control and 13 cohort studies published in English from 1970 to 1999 and retrieved from the Medline database. The results support the hypothesis that meat consumption is associated with a modest increase in colorectal cancer risk. This association, however, seems to have been more consistently found for red meat and processed meat. The studies on cooking methods and meat "doneness" are not consistent and the evidence is not conclusive. [source]


Defining hormone replacement therapy in longitudinal studies: impact on measures of effect

PHARMACOEPIDEMIOLOGY AND DRUG SAFETY, Issue 4 2004
Ilona Csizmadi PhD
Abstract Data from a nested case-control study, designed to examine the effect of hormone replacement therapy (HRT) on colorectal cancer risk, were analyzed to determine the effect of exposure definition on the estimation of risk ratios (RR). A prescription drug plan database was used to ascertain HRT prescriptions dispensed prior to index dates to cases (n,=,3059) and age-matched controls (n,=,12,116). HRT exposure was defined as ,prescription' and ,tablet' counts, ,conjugated estrogen only' and a method based on proportions of minimum exposure to a number of estrogens (SUM-P3 and SUM-P12). The effect of HRT was described with reference to ,ever', <,5 and ,,5 years of HRT use. Conditional logistic regression was used to estimate ORs and 95% confidence intervals (CI). Adjusted ORs for ,ever use' of HRT ranged from 0.72 (95%CI: 0.60,0.88) to 0.86 (95%CI: 0.76,0.99); for <5 years use, from 0.70 (95%CI: 0.56,0.88) to 0.89 (95%CI: 0.78,1.01) and for ,5 year of HRT use, from 0.74 (95%CI: 0.59,0.92) to 0.98 (95%CI: 0.42,2.26). Various methods used to define HRT exposure produce a range of estimated ORs that vary in magnitude similar to results reported in the literature from observational studies investigating the association between HRT and colorectal cancer. Copyright © 2003 John Wiley & Sons, Ltd. [source]


High-risk colorectal adenomas and serum insulin-like growth factors

BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 1 2001
A. G. Renehan
Background: This study investigated the hypothesis that circulating levels of insulin-like growth factor (IGF) I and its main binding protein (IGFBP-3) predict for the presence of colorectal adenomas, surrogate markers of colorectal cancer risk. Methods: Within the Flexi-Scope Trial (healthy volunteers aged 55,64 years), at one study centre, IGF-I and IGFBP-3 levels in serum samples collected prospectively from 442 attendants were measured. Of these, 100 individuals underwent a complete screening colonoscopy. There were 47 normal examinations, while in 11 examinations low-risk adenomas and in 42 examinations high-risk adenomas were identified. Estimates of relative risk (RR) for the adenomatous stages were calculated by means of unconditional logistic regression, adjusting for known risk factors. Results: Mean serum IGF-I and IGFBP-3 levels were similar in individuals with a normal colonoscopy finding and in those with low-risk adenomas. By contrast, the mean(s.d.) serum IGF-I level was increased (190(53) versus 169(54) µg/l; P = 0·06) and the serum IGFBP-3 concentration was significantly decreased (3·22(0·60) versus 3·47(0·62) mg/l; P = 0·05) in individuals with high-risk adenomas compared with levels in those with normal colonoscopy and low-risk adenomas combined. Levels were unaffected by removal of the adenomas. With high-risk adenoma as the dependent factor, regression models demonstrated a significant positive association with IGF-I after controlling for IGFBP-3 (RR per one standard deviation (1s.d.) change 4·39 (95 per cent confidence interval (c.i.) 1·31,14·7); P = 0·02) and, independently, an inverse association with IGFBP-3 after adjustment for IGF-I (RR per 1s.d. change 0·41 (95 per cent c.i. 0·20,0·82); P = 0·01). Conclusion: These findings suggest that circulating IGF-I and IGFBP-3 levels are related to future colorectal cancer risk and, specifically, may predict adenoma progression. © 2001 British Journal of Surgery Society Ltd [source]


Relationships between intestinal polyp formation and fatty acid levels in plasma, erythrocytes, and intestinal polyps in Min mice

CANCER SCIENCE, Issue 12 2008
Kiyonori Kuriki
We have reported that a hyperlipidemic state is characteristic of Apc -deficient Min mice with multiple intestinal polyps. In our earlier case-control study, colorectal cancer risk showed positive relationships with erythrocyte membrane compositions of palmitic and oleic acids, but negative links with linoleic and arachidonic acids. To examine the roles of fatty acids in intestinal polyp formation, levels in plasma, erythrocytes, and intestinal polyps in Min mice were compared with those in wild-type mice. A diet free of eicosapentaenoic and docosahexaenoic acids with antineoplastic effects was fed to all mice from 6 to 15 weeks of age. Fatty acid levels were measured using accelerated solvent extraction and gas,liquid chromatography. Min mice with a hyperlipidemic state and multiple intestinal polyps had elevated values for palmitic and oleic acids in plasma and erythrocytes (at least P < 0.05), and higher plasma level of linoleic acid (P < 0.05). Arachidonic acid was 24.5% lower in erythrocytes (P < 0.0005), but did not differ in plasma. In Min mice, moreover, oleic and arachidonic acids were 1.78 and 1.43 times higher, respectively, in intestinal polyps than in paired normal mucosa (P < 0.05 and P < 0.01, respectively), but linoleic acid was 31.9% lower (P < 0.001). The present study suggests that palmitic, oleic, and arachidonic acids play key roles in intestinal polyp formation, and demonstrates reduced erythrocyte arachidonic acid values of Min mice, in line with our previous findings for patients with sporadic colorectal cancers. (Cancer Sci 2008; 99: 2410,2416) [source]


Association between genetic polymorphisms of the base excision repair gene MUTYH and increased colorectal cancer risk in a Japanese population

CANCER SCIENCE, Issue 2 2008
Hong Tao
The MUTYH gene encodes a DNA glycosylase that can initiate the base excision repair pathway and prevent G:C > T:A transversion by excising adenine mispaired with 8-hydroxyguanine. Biallelic germline mutations of MUTYH have been shown to predict familial and sporadic multiple colorectal adenomas and carcinomas, however, whether there is an association between single nucleotide polymorphisms (SNPs) of MUTYH and sporadic colorectal cancer (CRC) risk has remained unclear. In this study we investigated four MUTYH SNPs, IVS1+11C > T, IVS6+35G > A, IVS10,2A > G, and 972G > C (Gln324His), for an association with increased CRC risk in a population-based series of 685 CRC patients and 778 control subjects from Kyushu, Japan. A statistically significant association was demonstrated between IVS1+11T and increased CRC risk (odds ratio [OR]: 1.43; 95% confidence interval [CI]: 1.012,2.030; P = 0.042) and one of the five haplotypes based on the four SNPs, the IVS1+11T , IVS6+35G , IVS10,2A , 972C (TGAC) haplotype containing IVS1+11T, was demonstrated to be associated with increased CRC risk (OR, 1.43; 95% CI, 1.005,2.029; P = 0.046). Subsite-specific analysis showed that the TGAC haplotype was statistically significantly (P = 0.013) associated with an increased risk of distal colon, but not proximal colon or rectal cancer. Furthermore, IVS1+11C > T was found to be in complete linkage disequilibrium with ,280G > A and 1389G > C (Thr463Thr). The results indicated that Japanese individuals with , 280A/IVS1+11T/1389C genotypes or the TGAC haplotype are susceptible to CRC. (Cancer Sci 2008; 99: 355,360) [source]


Variations in the evaluation of colorectal cancer risk

COLORECTAL DISEASE, Issue 3 2005
R. J. Hodder
Abstract Objectives, To test the variability in estimating cancer risk and demonstrate the consequences that subjectivity has on patient care. Subjects and methods, Forty-three clinicians were each asked to assess 40 symptomatic colorectal referrals. Each clinician was provided with a comprehensive history on the 40 patients. The clinicians graded the referral according to a malignancy risk score, decided on the required first line investigation and the priority of that investigation. The main outcome measures used was accuracy in cancer detection and appropriateness of investigations selected. Results, There was a wide degree of variation among all clinicians grading both benign and malignant disease with the overall correct classification of 54% (P -value of <0.001). On average, the clinicians correctly diagnosed 71.3% of the cancer patients as compared to 44% of the benign patients. Of the cancer patients, 47% were correctly classified as an urgent referral whilst 52% of the benign patients were over classified and graded as an urgent referral. The mean number chosen by clinicians to have a flexible sigmoidoscopy as the appropriate first investigation was 13 (of 40 patients); this was despite the diagnosis being possible in all cases with a flexible sigmoidoscopy. The choice to use full colonic investigation was seen throughout all disciplines. Junior doctors demonstrated the highest tendency choosing full colonic investigation in 92.3%. Consultants and senior grades showed the least tendency to choose full colonic imaging although even here colonoscopy or barium enema represented 48.5%. Conclusion, Subjective assessment of cancer referrals is a significant problem that needs to be confronted. Improvements are needed to resolve the inherent problems of subjectivity and operator bias if uniform quality of patient care and best use of resources is to be achieved. [source]