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Query: UMLS:C0009402 (colorectal cancer)
 53,228 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Colorectal cancer appears as a continuous process, starting with the normal cells and progressively growing towards malignancy. The aim of this review is to focus on the stages of that transformation and the means available for reducing the risk of this particular cancer. Although genetic factors have been identified, dietary pattern, the presence of inflammatory bowel disease and adenomas seem to play the most important role in the occurrence of colorectal cancer. The prevention of colorectal cancer should include changes in dietary habits, resection of adenomatous polyps as well as early detection of cancer. Studies testing these approaches are few and so far, none has proven effective in improving survival.
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PMID:Natural history of the colorectal cancer. 808 Oct 42

A review is given of methods and results of screening for colorectal cancer in average-risk and high-risk groups. Possible methods are digital rectal exploration, endoscopic examination, barium enemas, faecal occult blood tests, tumour markers like carcinoembryonic antigen, Ca-19-9, and others, and gene markers. Final results of large randomized population studies with faecal occult blood tests are expected within the next few years, but it will probably be necessary to add flexible sigmoidoscopy to achieve a major reduction in mortality from colorectal cancer in average-risk persons. Recommendations for screening in high-risk groups are proposed, but strong support for these guidelines are still missing, an exception being first-degree relatives of individuals with familial adenomatous polyposis; the other high-risk groups include members of hereditary non-polyposis colorectal cancer families, relatives of patients with sporadic colorectal cancer, patients with colorectal adenomas, patients with previous colorectal cancer, and patients with inflammatory bowel disease.
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PMID:[Screening for colorectal neoplasms. A review and recommendations]. 825 20

Cost-benefit analysis for colorectal cancer-screening of asymptomatic patients has been discussed controversially. In patients with genetic predisposition for colorectal cancer, adenomatous polyps or resected cancer as well as inflammatory bowel disease in contrast the incidence of new cancer can be lowered by endoscopic surveillance. Newer techniques from molecular biology will in the near future permit to detect patients at risk with higher certitude and at an earlier time.
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PMID:[Is there progress in preventive screening for colorectal carcinoma?]. 838 86

A prospective study was performed to determine the incidence of colorectal neoplasia and inflammatory bowel disease in patients with benign anorectal disease. Over a three-year period, 102 consecutive patients who presented with hemorrhoids, fissure, fistula-in-ano, anorectal abscess, and anal condylomata and who did not have gastrointestinal symptoms underwent colonoscopy. The mean age of all patients was 53.5 years; males out-numbered females 1.6:1. No patient was found to have inflammatory bowel disease. Ten of 102 (9.8 percent) were found to have a neoplastic lesion (nine adenomas and one adenocarcinoma). Patients found to have a neoplastic lesion tended to be older (61 years vs. 52.7 years; P = 0.06). Neoplasia was found in 4 of 21 (19 percent) with a family history of colorectal cancer and in 6 of 81 (7.4 percent) without a family history (P = 0.24). Patients presenting with outlet-type bleeding were not found to have a higher detection of neoplasia. The specific type of anorectal disease present was not associated with an increased risk for colorectal neoplasia. Our study suggests that benign anorectal disease and colorectal neoplasia may coexist. Anorectal disease is not predictive of neoplasia. The decision to perform colonoscopy should be based on age, gastrointestinal symptoms, and other risk factors.
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PMID:Colonoscopy in patients with benign anorectal disease. 845 64

Fecal alpha 1-antitrypsin measurement may be of value for the detection of colorectal neoplasia and is compared with the HemoQuant test in 119 subjects with either a screen-positive Hemoccult result (N = 78) or iron-deficiency anaemia (N = 41). Nineteen patients were found to have colorectal cancer, 35 had colorectal adenomatous polyps, 5 had inflammatory bowel disease, and 60 had no detected cause of occult blood loss. Of the cancer patients, 63% (12/19) were detected by fecal alpha 1-antitrypsin and 63% (12/19) by HemoQuant. Of the adenomas > 1 cm in diameter 33% (7/23) were detected by fecal alpha 1-antitrypsin and 26% (6/23) by HemoQuant. There was a poor correlation between fecal alpha 1-antitrypsin and HemoQuant results for colorectal cancers (r = 0.37, P > 0.05), and combining the tests, the sensitivity for colorectal cancer was increased to 84% (16/19). Fecal protein loss, as measured using alpha 1-antitrypsin, appears to involve largely different mechanisms from that of blood loss from colorectal cancers.
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PMID:Fecal alpha 1-antitrypsin detection of colorectal neoplasia. An evaluation using HemoQuant. 853 6

Events of reproductive life, such as parity and age at menarche, have been found in some but not all studies to be associated with risk for colorectal cancer in females. Because adenomatous polyps (adenomas) are precursors of colorectal cancer, we investigated whether reproductive variables were associated with colorectal adenomas. We conducted a case-control study among patients examined in three colonoscopy practices in New York City (NY, United States) from 1986 to 1988. Adenoma cases (n = 128) were defined as women who had an adenoma detected at the index colonoscopy with no history of inflammatory bowel disease, adenomas, or cancer. Controls (n = 283) were women with a normal index colonoscopy and no history of inflammatory bowel disease, adenomas, or cancer. The adjusted odds ratio (OR) for the association of early menarche (age less than 13 years) with adenomas was 0.6 (95 percent confidence interval = 0.4-0.9). Parity, history of spontaneous or induced abortion, infertility, type of menopause, age at menopause, use of oral contraceptives, and use of menopausal hormone replacement therapy were not associated statistically significantly with adenoma risk, although some possible trends were observed. Our findings do not implicate reproductive events, nulliparity, or overexposure to estrogens or to menstrual cycles as mechanisms of increased risk for colorectal neoplasia.
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PMID:Reproductive risk factors for colorectal adenomatous polyps (New York City, NY, United States). 858 Feb 99

In recent years, many health claims have been made about dietary and supplemental fiber. However, some reports (eg, those regarding oat bran) have been controversial. A review of scientifically rigorous studies shows that fiber has some preventive or therapeutic benefits in irritable bowel syndrome, diverticulosis, colorectal cancer, diabetes, and hypercholesterolemia. However, it appears to have no direct benefit in patients with inflammatory bowel disease, gallstones, or obesity. The United States has one of the lowest per capita intakes of fiber in the world. Therefore, increasing daily fiber intake either through diet or with supplements is recommended for most Americans. Consumer interest groups should lobby for more fiber-enriched foods. The challenge for education and healthcare professionals alike is to remold the nation's interest in and understanding of dietary fiber.
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PMID:Benefits of dietary fiber. Myth or medicine? 863 64

In a population study for colorectal neoplasia possible relationships were sought between faecal occult bleeding and clinical findings. Samples were taken from three different stools, collected during biennial screening from 1985 to 1994 in the age group 45-75 years at the beginning of the study. A total of 943 persons had positive Haemoccult-II (H-II) tests in at least one of the five screening rounds, and 87% had a complete colonoscopy. Of the 20,672 persons accepting initial screening, 1% had a positive test, the figure increasing to 1.8% during the fifth screen. The degree of positivity (1-3 slides) decreased with time. Positive tests were most frequent in men. Predictive values (PVpos) for colorectal cancer (CRC) increased with increasing number of positive slides from 6 to 31%. The average PVpos decreased from 17% during the initial screen to 8% during the fifth. Average PVpos for possible precursors (adenomas) varied from 40% at the beginning to 33% at the end. PVpos for CRC and inflammatory bowel disease increased when visible blood in the stools was present. Marcoumar increased PVpos for adenomas. Colorectal examination in the 943 persons revealed 114 persons with CRC and further 377 with adenomas. Early CRC (Dukes' stage A) was detected in 46 of the 114 with CRC, a more favourable distribution than that found in symptomatic patients. The study defined a group of people with a high risk of colorectal neoplasia, with a good prognosis, out of a group who had been selected at random from a normal population.
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PMID:Possible causes of a positive Haemoccult-II test in a population screening study for colorectal neoplasia. 881 7

The development of colorectal cancer is the most serious long-term problem faced by patients with extensive ulcerative colitis and Crohn's colitis, with an incidence 20-fold higher and an average age of onset 20 years younger than colorectal cancer in the general population. This report summarizes the epidemiology, pathology, and recent advances in the molecular pathogenesis of colorectal cancer in inflammatory bowel disease and of its acknowledged precursor, mucosal dysplasia. It also reviews the rationale behind the use of endoscopic surveillance for dysplasia as a means of reducing cancer mortality, as well as some of the issues involved in its effective implementation.
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PMID:Colorectal cancer in idiopathic inflammatory bowel disease. 894 11

There is an increased risk of colorectal cancer in patients who have had an attack of chronic ulcerative colitis, and there is evidence to suggest that patients with Crohn's disease are also at risk. It is difficult to give a precise estimate of the increased danger that patients with inflammatory bowel disease have over the normal population because published results are inconsistent. Twenty years ago patients with long-standing extensive ulcerative colitis were often advised to undergo proctocolectomy to protect against the development of cancer, but since then most physicians have adopted a policy of regular colonoscopic surveillance in an attempt to detect early cancer or pre-cancer. When published studies of surveillance results are critically analyzed, it appears that relatively little benefit accrues from this approach. Better methods of surveillance are needed to determine which individuals with chronic ulcerative colitis are most likely to develop cancer.
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PMID:Screening and surveillance of ulcerative colitis. 899 18


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