Dennis J. Ahnen

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The nonsteroidal anti-inflammatory drug sulindac is known to inhibit chemical carcinogenesis in rodent models and cause regression of adeno mas in patients with adenomatous polyposis coli. Sulindac is a prodrug that is metabolized to a pharmacologically active sulfide derivative that potently inhibits prostaglandin synthesis. Recent studies, however, have(More)
BACKGROUND In developed countries, the lifetime risk of developing colorectal cancer (CRC) is 5%, and it is the second leading cause of death from cancer. The presence of family history is a well established risk factor with 25-35% of CRCs attributable to inherited and/or familial factors. The highly penetrant inherited colon cancer syndromes account for(More)
BACKGROUND Carriers of germline mutations in DNA mismatch repair (MMR) genes have a high risk of colorectal cancer (CRC), but the modifiers of this risk are not well established. We estimated an association between body mass index (BMI) in early adulthood and subsequent risk of CRC for carriers and, as a comparison, estimated the association for(More)
BACKGROUND Recent genome-wide studies identified a risk locus for colorectal cancer at 18q21, which maps to the SMAD7 gene. Our objective was to confirm the association between SMAD7 SNPs and colorectal cancer risk in the multi-center Colon Cancer Family Registry. MATERIALS AND METHODS 23 tagging SNPs in the SMAD7 gene were genotyped among 1,592(More)
There is consensus internationally that research participants should be offered the opportunity to receive clinically relevant genetic information identified through research, but there is little empirical peer-reviewed work documenting this process. We report the experience of conducting genetic research with nearly 35,000 participants in the Colon Cancer(More)
The cytochrome P450 2C9 enzyme (CYP2C9) is involved in metabolism of endogenous compounds, drugs, and procarcinogens. Two common nonsynonymous polymorphisms in CYP2C9 are associated with reduced enzyme activity: CYP2C9*2 (rs1799853, R144C) and CYP2C9*3 (rs1057910, I359L). We investigated whether CYP2C9 genotype was associated with risk of colorectal adenoma(More)
Inflammatory cytokines in the colonic microenvironment have been shown to increase with advance colorectal cancer disease state. However, the contribution of inflammatory cytokines to pre-malignant disease, such as the formation of adenomas, is unclear. Using the Milliplex® MAP Human Cytokine/ Chemokine Magnetic Bead Panel Immunoassay, serum cytokine and(More)
Prior studies suggest cigarette smoking is associated with 1.5- to twofold increased risk of colorectal adenomas and possibly a higher risk of serrated polyps. Further clarification of risk differences between adenomas and serrated polyps is needed with regard to co-occurrence and polyp location. We conducted a combined analysis of conventional adenoma and(More)
BACKGROUND Regular use of nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with a decreased mortality from colorectal cancer (CRC). NSAIDs induce apoptotic cell death in colon cancer cells in vitro and inhibit growth of neoplastic colonic mucosa in vivo however, the biochemical mechanisms required for these growth inhibitory effects are not well(More)
BACKGROUND Constipation, a low fiber diet, sedentary lifestyle and gravidity are commonly assumed to increase the risk of hemorrhoids. However, evidence regarding these factors is limited. We examined the association between commonly cited risk factors and the prevalence of hemorrhoids. METHODS We performed a cross sectional study of participants who(More)