Publications by authors named "Huw J W Thomas"

Abstract: The CAPP2 trial investigated the long-term effects of aspirin and resistant starch on cancer incidence in patients with Lynch syndrome (LS). Participants with LS were randomized double-blind to 30 g resistant starch (RS) daily or placebo for up to 4 years. We present long-term cancer outcomes based on the planned 10-year follow-up from recruitment, supplemented by National Cancer Registry data to 20 years in England, Wales, and Finland.

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Background: Lynch syndrome is associated with an increased risk of colorectal cancer and with a broader spectrum of cancers, especially endometrial cancer. In 2011, our group reported long-term cancer outcomes (mean follow-up 55·7 months [SD 31·4]) for participants with Lynch syndrome enrolled into a randomised trial of daily aspirin versus placebo. This report completes the planned 10-year follow-up to allow a longer-term assessment of the effect of taking regular aspirin in this high-risk population.

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Heritable factors account for approximately 35% of colorectal cancer (CRC) risk, and almost 30% of the population in the UK have a family history of CRC. The quantification of an individual's lifetime risk of gastrointestinal cancer may incorporate clinical and molecular data, and depends on accurate phenotypic assessment and genetic diagnosis. In turn this may facilitate targeted risk-reducing interventions, including endoscopic surveillance, preventative surgery and chemoprophylaxis, which provide opportunities for cancer prevention.

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Purpose: In the general population, increased adiposity is a significant risk factor for colorectal cancer (CRC), but whether obesity has similar effects in those with hereditary CRC is uncertain. This prospective study investigated the association between body mass index and cancer risk in patients with Lynch syndrome (LS).

Patients And Methods: Participants with LS were recruited to the CAPP2 study, in which they were randomly assigned to receive aspirin 600 mg per day or aspirin placebo, plus resistant starch 30 g per day or starch placebo (2 × 2 factorial design).

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Lynch syndrome (LS) is characterised by the development of colorectal cancer, endometrial cancer and various other cancers, and is caused by a mutation in one of the mismatch repair genes: MLH1, MSH2, MSH6 or PMS2. In 2007, a group of European experts (the Mallorca group) published guidelines for the clinical management of LS. Since then substantial new information has become available necessitating an update of the guidelines.

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Many individuals with multiple or large colorectal adenomas or early-onset colorectal cancer (CRC) have no detectable germline mutations in the known cancer predisposition genes. Using whole-genome sequencing, supplemented by linkage and association analysis, we identified specific heterozygous POLE or POLD1 germline variants in several multiple-adenoma and/or CRC cases but in no controls. The variants associated with susceptibility, POLE p.

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Background: Observational studies report that higher intake of dietary fibre (a heterogeneous mix including non-starch polysaccharides and resistant starches) is associated with reduced risk of colorectal cancer, but no randomised trials with prevention of colorectal cancer as a primary endpoint have been done. We assessed the effect of resistant starch on the incidence of colorectal cancer.

Methods: In the CAPP2 study, individuals with Lynch syndrome were randomly assigned in a two-by-two factorial design to receive 600 mg aspirin or aspirin placebo or 30 g resistant starch or starch placebo, for up to 4 years.

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Background: Observational studies report reduced colorectal cancer in regular aspirin consumers. Randomised controlled trials have shown reduced risk of adenomas but none have employed prevention of colorectal cancer as a primary endpoint. The CAPP2 trial aimed to investigate the antineoplastic effects of aspirin and a resistant starch in carriers of Lynch syndrome, the major form of hereditary colorectal cancer; we now report long-term follow-up of participants randomly assigned to aspirin or placebo.

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Objectives: The incidence and prevalence of inflammatory bowel disease (IBD) is increasing throughout Asia. Since the 1950s, there has been substantial migration from South Asia (India, Pakistan, and Bangladesh) to the United Kingdom. The aim of this study was to define the clinical phenotype of IBD in UK South Asians living in North West London, and to compare the results with a white Northern European IBD cohort.

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Genome-wide association studies (GWAS) have identified ten loci harboring common variants that influence risk of developing colorectal cancer (CRC). To enhance the power to identify additional CRC risk loci, we conducted a meta-analysis of three GWAS from the UK which included a total of 3,334 affected individuals (cases) and 4,628 controls followed by multiple validation analyses including a total of 18,095 cases and 20,197 controls. We identified associations at four new CRC risk loci: 1q41 (rs6691170, odds ratio (OR) = 1.

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The British Society of Gastroenterology (BSG) and the Association of Coloproctology for Great Britain and Ireland (ACPGBI) commissioned this update of the 2002 guidance. The aim, as before, is to provide guidance on the appropriateness, method and frequency of screening for people at moderate and high risk from colorectal cancer. This guidance provides some new recommendations for those with inflammatory bowel disease and for those at moderate risk resulting from a family history of colorectal cancer.

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Objectives: Distinguishing between the inflammatory bowel disease (IBD), Crohn's disease (CD), and ulcerative colitis (UC) is important for both management and prognostic reasons. Discrimination using noninvasive techniques could be an adjunct to conventional diagnostics. Differences have been shown between the intestinal microbiota of CD and UC patients and controls; the gut bacteria influence specific urinary metabolites that are quantifiable using proton high-resolution nuclear magnetic resonance (NMR) spectroscopy.

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Background: Observational and epidemiologic data indicate that the use of aspirin reduces the risk of colorectal neoplasia; however, the effects of aspirin in the Lynch syndrome (hereditary nonpolyposis colon cancer) are not known. Resistant starch has been associated with an antineoplastic effect on the colon.

Methods: In a randomized, placebo-controlled trial, we used a two-by-two design to investigate the effects of aspirin, at a dose of 600 mg per day, and resistant starch (Novelose), at a dose of 30 g per day, in reducing the risk of adenoma and carcinoma among persons with the Lynch syndrome.

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This study assessed current practice and methods for improvement in the management of families with hereditary non-polyposis colorectal cancer (HNPCC). HNPCC families registered at five London Genetics Centres and a specialised Colorectal family cancer clinic (CFCC) were identified. Ascertainment of management and outcome details were obtained by scrutiny of patient records and by correspondence with General practitioners (GPs).

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Background & Aims: Lynch syndrome is an autosomal dominant predisposition to colorectal cancer caused by mutations in DNA mismatch repair genes; colorectal cancer risk is high. Few studies have addressed colorectal cancer risk in individuals from dominant families without mismatch repair deficiency. We sought to establish whether these individuals are also at increased risk by examining the incidence of advanced neoplasia during surveillance.

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Objective: To determine to what extent individuals with various family histories of colorectal cancer (from one to three or more affected first degree relatives) benefit from colonoscopic surveillance.

Design: Prospective, observational study of high risk families, followed up over 16 years.

Setting: Tertiary referral family cancer clinic in London.

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Whereas a recent study reported an increased risk of colorectal cancer associated with any HFE germ line mutation (C282Y or H63D), other investigators have concluded there is no increased risk, or that any increase is dependent on polymorphisms in HFE-interacting genes such as the transferrin receptor (TFR). We have established the frequency of HFE mutations in colorectal cancer patients (n = 327) with a family history of the disease and randomly selected controls (n = 322); this design increases greatly the study's power. Genotyping for the TRF S142G polymorphism was also conducted on a large proportion of the study group.

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Colorectal carcinomas develop according to particular genetic pathways, including the chromosomal instability (CIN+), microsatellite instability (MSI+) and MSI- CIN- routes. We have determined the genetic pathway in patients with MYH-associated polyposis (MAP), a syndrome of colorectal adenomas and cancer that results from defective base excision repair (BER). As in previous studies, MAP tumors showed a high frequency of G>T mutations in APC, in accordance with defective BER.

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Aneuploidy is a characteristic of a subset of colorectal tumours. CHEK2 (also known as CHK2) is one of the cell cycle checkpoint genes coding for a family of proteins that sense damage in eukaryotic cells. Germline variation in CHEK2 has recently been shown to confer cancer susceptibility.

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MYH-associated polyposis is a recently described, autosomal recessive condition comprising multiple colorectal adenomas and cancer. This disease is caused by germline mutations in the base excision repair (BER) gene MYH. Genes involved in the BER pathway are thus good candidates for involvement in the pathogenesis of sporadic tumors of the large bowel.

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We have allelotyped a series of 104 Finnish colorectal cancers (CRCs) using 372 polymorphic markers spaced, on average, at 10 cM intervals, and have made a comparison of the differences in the frequency of allelic imbalance (AI) between familial and sporadic cases. Differences in the frequency of allelic imbalance (loss of heterozygosity or amplification) at a number of loci were detected and these were evaluated through analysis of additional series of cancers using specific markers. The most consistent difference was observed at chromosome 20q13.

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Background: Germ-line mutations in the base-excision-repair gene MYH have been associated with recessive inheritance of multiple colorectal adenomas. Tumors from affected persons displayed excess somatic transversions of a guanine-cytosine pair to a thymine-adenine pair (G:C-->T:A) in the APC gene.

Methods: We screened for germ-line MYH mutations in 152 patients with multiple (3 to 100) colorectal adenomas and 107 APC-mutation-negative probands with classic familial adenomatous polyposis (>100 adenomas).

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Background: Small adenomas may be missed during colonoscopy, but chromoscopy has been reported to enhance detection. The aim of this randomized-controlled trial was to determine the effect of total colonic dye spray on adenoma detection during routine colonoscopy.

Methods: Consecutive outpatients undergoing routine colonoscopy were randomized to a dye-spray group (0.

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Background: Endometrial carcinoma is the most common extracolonic malignancy associated with hereditary nonpolyposis colorectal carcinoma syndrome (HNPCC). The risk of endometrial carcinoma in HNPCC mutation carriers is approximately ten times that of the general population, and endometrial ultrasound surveillance to detect early cancer in asymptomatic individuals is recommended by the International Collaborative Group on HNPCC. There is little, if any, published data addressing the effectiveness of surveillance in HNPCC and familial colorectal carcinoma.

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