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PubMed · 9369968

Colon polyps.

A L Watne
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Abstract

Colon polyps may be single or multiple, noninherited or inherited, histologically may vary from inflammatory, hamartomatous, neurogenic, or adenomatous, and may be benign or malignant. The various recognized syndromes are discussed including their clinical presentation, malignant potential, and associated tumors. Recognition of these clinical syndromes will allow the clinician to categorize the patient and the relative risk. The discussion goes into the genetic studies identifying the adenomatous polyposis coli gene on chromosome 5 q21 and the identification of mutations arising in the DNA repair genes (MSA2, MLH1, PMSI, and M52) in the HNPCC syndrome. This identified two divergent pathologies, both involving "multiple hits" with mucosal cells going from normal to adenoma-dysplasia-carcinoma. The understanding of the multiple hit concept with the adenoma-dysplasia-carcinoma progression will aid in the further understanding of the broad neoplastic process.

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AdenomaAdenomatous Polyposis ColiChromosomes, Human, Pair 5Colonic PolypsColorectal Neoplasms, Hereditary NonpolyposisDNA RepairGardner SyndromeGenes, p53HamartomaHumansMutationNeoplasm InvasivenessPeutz-Jeghers SyndromeJournal ArticleReview

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BibTeXRIS

A L Watne. 1997. Colon polyps.. https://doi.org/10.1002/(sici)1096-9098(199711)66%3A3%3C207%3A%3Aaid-jso10%3E3.0.co%3B2-z

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PubMed1999

Calcium supplements for the prevention of colorectal adenomas. Calcium Polyp Prevention Study Group.

BACKGROUND AND METHODS: Laboratory, clinical, and epidemiologic evidence suggests that calcium may help prevent colorectal adenomas. We conducted a randomized, double-blind trial of the effect of supplementation with calcium carbonate on the recurrence of colorectal adenomas. We randomly assigned 930 subjects (mean age, 61 years; 72 percent men) with a recent history of colorectal adenomas to receive either calcium carbonate (3 g [1200 mg of elemental calcium] daily) or placebo, with follow-up colonoscopies one and four years after the qualifying examination. The primary end point was the proportion of subjects in whom at least one adenoma was detected after the first follow-up endoscopy but up to (and including) the second follow-up examination. Risk ratios for the recurrence of adenomas were adjusted for age, sex, lifetime number of adenomas before the study, clinical center, and length of the surveillance period. RESULTS: The subjects in the calcium group had a lower risk of recurrent adenomas. Among the 913 subjects who underwent at least one study colonoscopy, the adjusted risk ratio for any recurrence of adenoma with calcium as compared with placebo was 0.85 (95 percent confidence interval, 0.74 to 0.98; P=0.03). The main analysis was based on the 832 subjects (409 in the calcium group and 423 in the placebo group) who completed both follow-up examinations. At least one adenoma was diagnosed between the first and second follow-up endoscopies in 127 subjects in the calcium group (31 percent) and 159 subjects in the placebo group (38 percent); the adjusted risk ratio was 0.81 (95 percent confidence interval, 0.67 to 0.99; P=0.04). The adjusted ratio of the average number of adenomas in the calcium group to that in the placebo group was 0.76 (95 percent confidence interval, 0.60 to 0.96; P=0.02). The effect of calcium was independent of initial dietary fat and calcium intake. CONCLUSIONS: Calcium supplementation is associated with a significant - though moderate - reduction in the risk of recurrent colorectal adenomas.

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