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Query: UMLS:C0699790 (colon cancer)
 28,837 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The frequency of colorectal cancer increased during the first half of the twentieth century, but for the last four decades, it appears to have stabilized. Today, the average American has a 5 percent probability of developing colorectal cancer during a 70-year life span. The majority of cases occur in persons aged greater than 50 years; the incidence increases up to age 75 years, after which there is a decline. Etiology is unknown; however, environment, genetics, and carcinogens have been implicated. Genetic relations of skin tags, colon polyps, and colon cancer are a matter of ongoing research. If such relations could be established, it could provide clinicians with a possible additional marker for persons at increased risk of colorectal adenoma and adenocarcinoma. Two cases are presented with a brief review of the literature.
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PMID:Skin tags--a marker for colon polyps? 237 57

Fecal intestinal flora in patients with colon adenoma showed significant decrease of Bifidobacterium. A tendency of decrease of Bifidobacterium and increase of Clostridium-other was shown in adenomas with higher degree atypia, but no definite tendency could be found concerning its size. Compared with the control group, patients with colon cancer showed significant increase of Clostridium-other and decrease tendency of Bifidobacterium which was not relevant to its percentage of total circum ference involved by the cancer. From the above findings, it is suggested that tumor growth or malignant transformation has relation to Bifidobacterium and Clostridium-other.
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PMID:[Fecal intestinal flora in patients with colon adenoma and colon cancer]. 238 24

A biomarker of increased risk for colon cancer is abnormally high proliferation of colonic epithelial cells. The authors developed an in vitro assay that measures the ability of human colonic epithelial cells that are in progressive stages of abnormal development to respond to direct application of calcium as the chloride in tissue culture medium. Incorporation of 3H-thymidine and autoradiography in situ was employed to measure the number of proliferating cells cultured at 0.1 mM CaCl2, the optimum level for growth, and 2.2 to 5 mM, both levels achievable in the colonic lumen. Abnormal cell proliferation was reduced in biopsies from 13 of 14 patients without familial polyposis but at increased risk for colon cancer because of previous colonic neoplasms or familial association; in cells from three of four asymptomatic individuals in familial polyposis families at risk for that disease; and in cells of three of ten patients symptomatic with familial polyposis. Growth of tubular adenoma cells from two of seven familial polyposis patients was also inhibited by calcium. Growth inhibition was not observed in more advanced colon tumors including eight adenomas, either villotubular or villous, and five carcinomas. These findings indicate heterogeneity within the familial polyposis phenotype for the normal cellular response to growth inhibition by calcium, and a further loss of response to calcium as these cells progress toward malignancy.
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PMID:Heterogeneity in the response of familial polyposis epithelial cells and adenomas to increasing levels of calcium in vitro. 254 88

Ornithine decarboxylase (ODC) catalyzes the formation of putrescine from ornithine, which is the first step in the pathway of mammalian polyamine biosynthesis. Tissue activity levels of ODC have been suggested to be a marker of risk for colorectal cancer in hereditary polyposis and in adenoma formers. We analyzed ODC activity in rectal and sigmoid colon mucosal biopsies obtained at 10 cm and at 30 cm in 40 healthy, colon cancer risk factor-free adults following three endoscopic preparation regimens: 1) no special preparation; 2) two phosphate enemas; and 3) "Colyte" lavage preparation 12 hr previously. Levels of ODC, measured in fresh tissue, were approximately twofold higher for enema preparation vs. no preparation (for log-transformed data: sigmoid, P less than 0.0001; rectum, P = 0.0001) and for enema preparation vs. lavage (sigmoid, P = 0.0002; rectum, P = 0.008). Lavage and no preparation ODC levels were not significantly different. ODC activity levels ranged from 0.00 to 352.96 pmol/mg/hr.
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PMID:Colon ornithine decarboxylase activity following standard endoscopy preparation regimens. 255 65

Molecular genetic studies of tumor-specific allele loss, originally associated primarily with research regarding childhood hereditary cancers such as retinoblastoma and Wilms' tumors, only lately have been recognized as a relatively fast and fruitful way of locating cancer genes on human chromosomes. To date, over 25 different cancers have been tied to a gene (or genes) on a specific chromosome when this method has been used. During the past year alone, this approach has permitted detection of three genes involved in either hereditary or sporadic colorectal cancers. These three genes, located on chromosomes 5q, 17p, and 18q, are believed to belong to the newly described tumor suppressor (or growth suppressor) gene class, whose effects are opposite those of activated cellular oncogenes, which promote uncontrolled cell growth. Present studies, however, have not shown losses of any of these tumor suppressor genes to be correlated with the presence of activated ras genes in colorectal adenomas or carcinomas. During progression from adenoma to carcinoma, ras gene mutations and 5q allelic deletions are likely to be earlier events, whereas allelic losses from chromosomes 18q and 17p seem to occur more often in advanced tumors. Involvement of the genes on 5q (FAP) and 18q (Lynch syndrome II) in hereditary colon cancer syndromes is supported by linkage studies, but their respective roles (as well as that of the gene on 17p) in familial and sporadic colorectal cancer remain to be precisely defined. Probable isolation of these three genes by molecular cloning within the next few years will help elucidate their specific biologic functions. It will also permit early detection, and thus prevention, of some familial colon cancers (such as FAP), and possibly allow DNA marker-based separation of different colon cancer subtypes of similar histologic appearance.
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PMID:Molecular genetic studies of colon cancer. 264 66

The purpose of this experiment was to study sequential histogenesis of colonic epithelial tumours in the dimethylhydrazine (DMH) induced rat colon cancer model. Seventy outbred female Wistar rats treated with DMH (40 mg/kg, subcutaneously weekly for five weeks) were killed and autopsied in batches of 10 every five weeks from the 10th to 40th weeks from first treatment. The resulting 378 colonic lesions were assigned to benign or malignant categories using each of three standard histopathological thresholds of malignancy: alpha, the transition from dysplasia to intraepithelial carcinoma; beta, invasion through the crypt basement membrane; and gamma, invasion through the muscularis mucosae. These comprised 79 'benign' and 299 'malignant' or 273 'benign' and 141 'malignant' lesions depending on the threshold (alpha or gamma) assigned (p less than 0.001). Decreasing ratios of pre-threshold to post-threshold lesions between 15 and 40 weeks (alpha, 2.0 to 0.051; beta, 3.5 to 0.57; gamma, 8.0 to 0.87) provide some support for an 'adenoma-carcinoma' progression for each. Comparison of time-dependent prevalence curves confirms that the alpha threshold (cyto-architecture) is qualitatively different from the beta and gamma thresholds (invasion), showing that the adenoma-carcinoma and de novo hypotheses need not be mutually exclusive. The time-dependent prevalence data support de novo origin of some carcinomas, as well as at least two other modes of accrual for neoplastic lesions.
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PMID:Comparison of the significance of three histopathological thresholds of malignancy in experimental colorectal tumours. 275 8

Rectal mucosa from normal controls (n = 25) and tumor tissue and rectal mucosa from patients with colorectal cancer (n = 38) and adenoma (n = 35) were biopsied via colonoscopy. Ornithine decarboxylase (ODC) activity was determined in order to study the role of promoters in the process of colorectal carcinogenesis. ODC activity of cancer tissue was significantly higher than that of adenoma tissue. Normal mucosal ODC activity in rectum and sigmoid colon was 2 to 4 times higher than that in the proximal colon. Moreover, rectal mucosal ODC activity was significantly higher in patients with cancer or adenoma than that in normal controls. When ODC activity is regarded as an index of promoter, the possibility is suggested that cancer and adenoma developed in similar mucosa of the large bowel. Furthermore, ODC activity in colon cancer was significantly higher than that in rectal cancer. This suggests the possibility that TPA type promoter assumes a greater role in the process of carcinogenesis of colon cancer than that of rectal cancer.
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PMID:[A study of ornithine decarboxylase activity in tumor tissue and rectal mucosa in patients with colorectal cancer or adenoma]. 279 55

In vitro tetraploidy (IVT) in cultures of skin fibroblasts was compared with tumor DNA ploidy, as determined by flow cytometry on paraffin-embedded material, in 99 patients with colorectal neoplasm. In 63 patients with non-heritable carcinoma we found a significant correlation between the number of aneuploid stemlines in the tumor and IVT in the fibroblast culture. Furthermore, tumor aneuploidy was significantly correlated to the size of the tetraploid subpopulation in the fibroblasts. There was no correlation between aneuploidy and Dukes's stage or the degree of differentiation. In 36 patients with adenoma no correlation between tumor aneuploidy and fibroblast IVT was demonstrated, whereas the number of tumor stemlines was significantly correlated to histopathologic stage and grade of dysplasia. IVT in cultured skin fibroblasts, which has been reported to reflect a genetic predisposition to colorectal cancer in heritable colon cancer syndromes, thus seems to be relevant also for the understanding of tumor formation and progression in the 'non-heritable' type of colorectal cancer.
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PMID:Association between tumor DNA aneuploidy and in vitro tetraploidy of skin fibroblasts in patients with colorectal neoplasms. 281 41

Over a period of six years a total of 407 patients with polyps of the gastrointestinal tract were examined by gastroscopy and coloscopy and the findings analysed retrospectively. Among patients with colon polyps 10.5% were found also to have polypoid gastric lesions, among those with adenoma of the colon the prevalence was 11.7%. Only 2.4% of simultaneously diagnosed gastric lesions were found to be malignant or premalignant, a figure similar to the population average. But in patients with more than ten polyps of the colon both the prevalence of polypoid gastric changes and the significance of polyps with respect to precancerous lesions were clearly increased. On the other hand, in patients with epithelial polyps and/or glandular cysts colon polyps were found in 45%, in 42% with precancerous changes (adenoma). Thus patients with epithelial gastric polyps and glandular cysts probably constitute a group with a real additional risk of colon carcinoma. Regular coloscopy will thus reveal precancerous changes (adenoma) in the colon of 42% of such patients; coloscopic polypectomy will be an effective prophylactic measure against carcinoma of the colon.
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PMID:[Are stomach polyps an indicator of colonic carcinoma and colonic polyps an indicator of stomach carcinoma?]. 282 97

An autopsy case of glioblastoma multiforms of the pons with a colon cancer, a rectal carcinoid, a renal adenoma and three gastric leiomyomas in a 81-year-old-woman is reported with a statistical analysis on multiple primary cancers associated with primary brain tumors as reported in the Japan autopsy annuals. Out of 329, 705 autopsy cases from 1975 to 1984 in the Japan autopsy registry, double cancers and triple cancers that included a primary brain tumor amounted to 123 cases (0.037%) and 12 cases (0.0036%), respectively. Other sites for primary cancers were the thyroid (23%), the stomach (15%), the lungs (12%), and the colon (10%) in that order of frequency.
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PMID:[An autopsy case of triple primary cancers consisting of glioblastoma multiforme of the pons, colon cancer and rectal carcinoid--a statistical analysis of cases of brain tumor combined with other primary cancers in Japan autopsy annuals]. 282 42


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