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

The relationship of adenoma to carcinoma of the colon and rectum in individuals of families with nonpolyposis hereditary carcinoma of the colon and rectum syndrome is uncertain. In five families with hereditary carcinoma of the colon and rectum, the medical records of 39 patients who had 50 instances of carcinoma of the colon and rectum develop were studied. Six instances of disease were found in adenomas: Dukes' A in two; Dukes' B in three, and Dukes' C in one. The malignant polyp was the only neoplastic lesion in the colon in five of these instances. In only 12 of the patients (31 per cent) were adenomas (seven patients) or secondary disease (five patients) ever found. These data suggest that while uncommon adenomas are precursor lesions for malignant neoplasms in patients with carcinoma of the colon and hereditary carcinoma of the colon and rectum syndrome.
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PMID:Adenomas are precursor lesions for malignant growth in nonpolyposis hereditary carcinoma of the colon and rectum. 394 Apr 11

Colonoscopy is a valuable and frequently used method in the evaluation of colonic neoplasia. Flow cytometry is a technique that can be used to diagnose malignancy. In this study, flow cytometry was used to evaluate colonoscopic biopsies taken from patients with suspected colonic neoplasia. Nineteen colonic biopsies were obtained and evaluated by this technique. Aneuploidy was demonstrated in six patients with carcinoma of the colon. In addition, abnormal DNA histograms were noted in two premalignant conditions (colonic adenoma and inflammatory bowel disease). The results show that flow cytometry can be applied to colonic biopsies and suggest that it may be of use in the diagnosis of malignant and premalignant conditions of the colon.
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PMID:Evaluation of colonic neoplasia by flow cytometry of endoscopic biopsies. 396 54

The results of this multicentre autopsy study emphasize the relationship between the prevalence of adenomas and the incidence of large-bowel cancer. The highest proportion of autopsies with adenomas was observed in the area with the highest incidence of large-bowel cancer. The segmental distribution of adenomas within the colon was found to be similar to the site distribution of cancer. However, the lowest proportion of adenomas was found in the rectum, the segment in which cancer is most frequent. The latter finding suggests that either the adenoma-carcinoma sequence is a less important pathway in the pathogenesis of rectal cancer, or that more rectal than colonic adenomas become malignant. The high proportion of hyperplastic polyps in the rectum, and statistically significant regional differences following the same patterns as the incidence of rectal cancer suggest that there could be at least an indirect relationship between hyperplastic polyps and cancer of the rectum. Adenomas of both colon and rectum were more frequent in men than in women, contrary to findings with colon cancer. However, as for colon cancer, the sex ratio of adenomas changed with age, from slightly below unity in persons under 65, to above unity for those aged 65 and over. A major difficulty that emerged was the histological identification of "polyps" because of the degree of autolysis of epithelial cells in the mucous membrane, and this difficulty largely contributed to the poor consistency of histological reporting. Regular consistency surveys of histological preparations should be recommended in any type of multicentre study in which histological examination is included.
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PMID:Prevalence of polyps in an autopsy series from areas with varying incidence of large-bowel cancer. 401 11

The incidence and types of unusual nuclear structures (UNS) were examined based on the observation of randomly photographed 1,919 nuclei in total from the normal epithelium, dysplasia, Peutz-Jeghers type polyp, adenoma and carcinoma of the large bowel. These nuclear structures were classified as filamentous, granular and vesicular inclusions, and invaginated structures were also taken into consideration. Although all types of UNS were found in the normal epithelium, carcinoma cells had the most numerous UNS, especially of the invaginated type. The possible process of nuclear inclusion (NI) formation was discussed in connection with malignant transformation of colo-rectal epithelial cells.
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PMID:Nuclear changes in colo-rectal epithelium with special reference to nuclear inclusions in carcinoma, dysplasia, adenoma and Peutz-Jeghers polyps. 402 86

Among about 20.000 patients who had a gastroscopy in a period of 6 years, 92 had gastric mucosal polyposis, diagnosed by endoscopy and histology, an incidence of 0.46%. Eight patients with an age average of 38 years had familial gastrointestinal adenomatosis, in six of them the criteria of Gardner's disease were fulfilled. The remaining 84 patients had an average age of 62 years. In patients with more than ten polyps the sex ratio (female to male) was 3.9:1. In 56 patients without familial gastrointestinal adenomatosis, coloscopy and(or) proctosigmoidoscopy was performed. In 18 there were polyps in the colon, in three an invasive carcinoma in an adenoma. In three further patients extensive carcinoma of the colon (in two with stenosis) was found. These observations suggest that patients with gastric mucosal polyposis have a higher incidence of colon polyps and carcinoma.
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PMID:[Gastric mucosal polyps--an irrelevant finding? Studies on the incidence and clinical significance]. 614 21

Adenoma formation in the colon has been shown to be initiated by an alteration in the genetic make-up which controls the repopulation of the mucosa. This defect is recognized primarily by an upward displacement of the major zone of DNA synthesis within one or a few crypts. Progression to a microadenoma involves an elevation of cell proliferation within these glands and may be hastened by mucosal responses to environmental and dietary factors which enhance cell turnover. The high proliferative activity of epithelial cells within these select crypts allows the unmasking of the neoplastic genotype and the expansion of these cells with a proliferative advantage. Continued rapid cell proliferation within the adenoma either indigenous to the excrescence or fueled additionally by luminal conditions may contribute to the evolution of a malignant genotype, the establishment of a severely dysplastic clone and ultimately to the production of invasive colon cancer.
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PMID:Adenomas: preneoplastic events, growth and development in man and experimental systems. 634 73

We examined the cytosolic estrogen receptor (ER) level in tumor tissue from 77 patients: 36 meningiomas, 20 gliomas (12 glioblastomas, 2 cerebellar astrocytomas, 2 ependymomas, and 4 medulloblastomas), 8 neurinomas, 7 pituitary adenomas (2 prolactin-producing adenomas, 1 growth hormone-producing adenoma, and 4 nonfunctioning adenomas), and 6 metastatic brain tumors (1 from breast cancer, 4 from lung cancers, and 1 from colon cancer). Nuclear ER levels were assayed in 11 meningiomas and 2 glioblastomas. ER was determined by the dextran-coated charcoal method and calculated by Scatchard analysis. Cytosolic ER was detected in 100% of the pituitary adenomas, 50% of the meningiomas, 50% of the metastatic brain tumors, 25% of the neurinomas, and 15% of the gliomas. In gliomas, only medulloblastomas had ER activity. Nuclear ER was found in three premenopausal women with meningioma. The dissociation constant of the ER complex was, in each case, less than 10(-9) M. These observations suggest that some brain tumors may be responsive to estrogen via the cellular ER.
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PMID:Estrogen receptors in brain tumors. 650 47

Peanut lectin (PNA) has a specificity for the disaccharide beta-D-Gal-(1 leads to 3)-D-GalNac which is the purported antigenic determinant for the T blood group antigen (TAg). This TAg is considered the immediate precursor of the MN blood group substance. In normal colonic epithelium, PNA binds to the supranuclear (stalk) portion of epithelial cells. This corresponds to the detection of beta-DGal-(1 leads to 3)-D-GalNac in nascent oligosaccharide chains in the Golgi cisternae prior to addition of terminal sialic acid. Colonic carcinomas bind PNA in the "region" of the glycocalyx or in the apical portion of the cell, which represents incomplete glycoprotein synthesis. Eighty-two percent of tubular adenomas, 80% of villous adenomas, and 91% of adenomas with in situ cancer expressed PNA in a supranuclear distribution, reminiscent of normal colonic epithelium. This stalk distribution was seen in goblet cells. Twenty-five percent of tubular adenomas, 43% of villous adenomas and 60% of adenomas with in situ cancer (adenoma portion) expressed PNA in an apical cytoplasmic and/or glycocalyx pattern among nonmucinous columnar cells. In 80% of the cases, the in situ cancer itself expressed PNA in an apical cytoplasmic and/or glycocalyx pattern. Fetal and most colon cancer cells fail to produce mucin goblets and make incomplete glycoproteins. The cytologic localization of TAg by PNA corresponds to the cells' ability to produce mucin goblets. Most adenomas consist of goblet cells, localize TAg to the stalk, and probably make complete MN glycoprotein as does normal colonic epithelium. However, in adenomas, nonmucinous columnar cells localize TAg to the apical cytoplasm and/or glycocalyx region and represent incomplete blood group glycoprotein synthesis.
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PMID:Peanut lectin-binding sites in polyps of the colon and rectum. Adenomas, hyperplastic polyps, and adenomas with in situ carcinoma. 665 97

Among the different polypous lesions the adenoma does have special importance because of the adenoma-carcinoma sequence. A carcinoma of the colon should be diagnosed only when atypical epithelial formations can be found infiltrating the submucosa. The diagnosis of different stages of the adenoma-carcinoma sequence can definitely be established only by histological investigation of the polyp, which has been taken out completely. Endoscopic polypectomy has today a definite place in therapy of colorectal carcinoma, if selection criteria are strict, histological technique perfect, and postoperative follow-up regularly.
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PMID:[Pathologic anatomy of polypoid processes of the colon and rectum]. 668 Apr 13

A new multihit model of carcinogenesis is developed for use in evaluating age-specific cancer incidence rates in human populations. The model allows for some heterogeneity in both risk (perhaps genetic) and pathway (number of hits). Fitting the model yields estimates of (1) levels of effect of background exposure to environmental agents, (2) tumor growth times after initiation of a malignant cell, and (3) relative sizes of high-risk groups in a human population. Maximum likelihood procedures are used to fit the model to the polyposis coli data of Veale and the colon cancer incidence data from the Third National Cancer Survey. Model estimates may be verified in some cases by review of independent data in the literature and results have both theoretical and practical implications. Findings are generally consistent with the adenoma-carcinoma etiologic sequence postulated by Hill, Morson and Bussey with one exception. A large proportion of the population may be at risk of four-hit colon tumors following a non-adenoma etiologic sequence.
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PMID:The multihit model of carcinogenesis: etiologic implications for colon cancer. 672


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