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

Because patients with ulcerative colitis have an increased long-term risk of colorectal cancer, colonoscopic surveillance with multiple biopsies is commonly performed for histopathological detection of dysplasia to select high-risk patients for prophylactic colectomy. Improved differentiation between neoplastic vs. nonneoplastic changes is needed because active inflammation may cause significant misinterpretation of nonneoplastic reactive/regenerative changes in the epithelium. We investigated whether the expression of proliferative antigens is correlated with various degrees of epithelial dysplasia and inflammatory changes in biopsy specimens from patients with long-standing ulcerative colitis. Colorectal biopsy specimens from patients undergoing colonoscopic surveillance were analyzed immunohistochemically using two types of monoclonal antibodies: MIB-1 against Ki-67 and NCL-PCNA against proliferating cell nuclear antigen for structural, active inflammatory, and dysplastic changes. Specimens from patients without inflammatory bowel disease or neoplasia were used as controls; these showed no increased proliferation. However, increased staining with the MIB-1 monoclonal antibody was detected in 9% of the specimens from patients with long-standing ulcerative colitis without active inflammation or dysplasia; this was significantly more common in specimens indefinite for dysplasia, probably positive (24%), and in those with definite dysplasia of low (47%) or high grade (67%; P = 0.008). For increased PCNA staining, there was a non-significant correlation (P = 0.30) with increasing degrees of dysplasia. Increased MIB-1 immunostaining was found in 50% and increased PCNA immunostaining in 75% of the specimens displaying mild inflammation. Both antibodies had a 100% increased staining in specimens with moderate or severe inflammation. Increased proliferation as expressed by MIB-1 is thus better correlated with increasing degree of dysplasia than is PCNA. Neither staining method is able to differentiate neoplastic from inflammatory epithelial changes. However, in the absence of active inflammation, immunostaining for MIB-1 may be a valuable adjunct in the confirmation of dysplastic epithelial changes in long-standing ulcerative colitis, particularly in the indefinite changes category.
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PMID:Increased expression of proliferative Ki-67 nuclear antigen is correlated with dysplastic colorectal epithelium in ulcerative colitis. 1036 56

This article provides an in-depth review of the radiologic and endoscopic imaging techniques used in the evaluation and management of inflammatory bowel disease (IBD). The use of imaging studies to diagnose IBD and to differentiate ulcerative colitis from Crohn's disease is discussed. The evaluation of suspected complications associated with IBD, including strictures and fistulous disease, as well as surveillance for colorectal cancer are also addressed.
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PMID:Imaging modalities in inflammatory bowel disease. 1037 74

Patients with inflammatory bowel disease (IBD) are at increased risk for developing cancer of the gastrointestinal tract, particularly colorectal cancer. Because of the relative rarity of IBD in the general population, it has been difficult to quantify this risk. Efforts to reduce the risk have included both prophylactic surgery and endoscopic screening programs. Because of the potential impact on quality of life and life expectancy, the optimal strategy for reducing this risk has not been defined. This article reviews the current literature relating to the risk of cancer for patients with IBD and methods to reduce this risk.
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PMID:Cancer risk in patients with inflammatory bowel disease. 1037 77

A germline sequence alteration at codon 1307 of the APC gene (I1307K) has been reported in 6-7% of the Ashkenazi Jewish population in the United States. This alteration is believed to predispose the APC gene to a secondary mutation at the same locus, resulting in an increased risk of colorectal carcinoma. There is an increased risk of colorectal carcinoma in patients with inflammatory bowel disease (IBD), a relatively large proportion of whom are Ashkenazi Jews. We therefore sought to determine whether the I1307K sequence variant occurred in the germline DNA of IBD patients. To our surprise, we found this sequence in only two of 267 patients with IBD (0.7%), occurring in only 1.5% of Jewish IBD patients. The I1307K sequence variant was not found in 67 patients with esophageal cancer, 53 patients with gastric carcinoma (13 MSI-H and 44 MSI-negative), or ten patients with sporadic MSI-H colon cancer. These findings suggest that the I1307K sequence is relatively rare in the germline of Jewish as well as non-Jewish IBD patients. It does not appear to contribute to the increased colorectal cancer risk present in these patients.
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PMID:Low prevalence of the APC I1307K sequence in Jewish and non-Jewish patients with inflammatory bowel disease. 1044 54

Endogenously formed nitrogen and oxygen free radicals are believed to be involved in human cancer etiology. Plasma nitrate/nitrite originates from endogenous nitric oxide production in fasting humans, decrease in superoxide scavenger activity (SSA), and free sulfhydryl groups (SH) reflects the amount of superoxide anion generated, and nitrotyrosine is believed to be formed by the interaction of tyrosine and peroxynitrite in vivo. The aim of the current study was to measure plasma nitrate/ nitrite, SSA, and SH in 69 patients (mean age +/- standard deviation, 66 +/- 11 years) with colorectal carcinoma. Nitrotyrosine was measured from both the plasma and tumor tissues in 32 patients. All patients had adenocarcinoma of the colon or rectum. Twenty-five patients were classified as stage B according to Dukes classification as modified by Astler-Coller, 13 were classified as stage C, and 31 patients were classified as stage D. To determine whether the changes are specific for colorectal cancer, 20 patients with active inflammatory bowel disease (IBD; mean age, 52 +/- 18 years) and 30 healthy volunteers, who served as control subjects (mean age, 48 +/- 11 years), were studied. Plasma nitrate/nitrite was measured by the modified Griess method, SSA was measured by an electron/spin resonance spin trapping method, free SH was measured by Ellman's method, and the presence of nitrotyrosine in the plasma and tumor tissue was detected by high performance liquid chromatography (HPLC) using C- 18-derivatized silica (5 microm) column (C18S, Crestpaque, New York, NY, USA) and at a wavelength of 274 nm. Patients with colorectal carcinoma and with active IBD had a significantly higher plasma nitrate/ nitrite level (51.2 +/- 26.2 microm and 56.0 +/- 14.6 microm versus. 29.6 +/- 6.3 microm; p < 0.01), and a lower SSA level (39 +/- 11.5 U/g protein and 52.0 +/- 18.9 U/g protein versus. 88 +/- 25.1 U/g protein; p < 0.05) and SH level (7.7 +/- 3.89 microm protein and 6.4
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PMID:Evidence of in vivo peroxynitrite formation in patients with colorectal carcinoma, higher plasma nitrate/nitrite levels, and lower protection against oxygen free radicals. 1063 9

Colorectal Cancer (CRC) fulfills all the criteria for a successful screening: i) it is a frequent tumor associated with serious morbidity and mortality; ii) recognition and treatment of premalignant lesions or early tumor stages improves prognosis and lowers its incidence, respectively. During recent years, our understanding of the biology, diagnosis and therapy of adenomas and CRCs led to the identification of risk factors. Based on these, screening strategies differ for individuals with average risk (age > or = 50 years, no risk factors) and individuals with increased risk for CRC development (positive personal history [CRC, colorectal adenomas, inflammatory bowel disease]; positive family history [CRC, colorectal adenomas, hereditary syndromes]). The currently available strategies aimed at prevention and early detection of CRCs (past history, family history, rectal digital examination, fecal occult blood testing, endoscopy) are discussed and recommendations for their implementation are formulated.
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PMID:[Screening for prevention and early detection of colorectal carcinoma]. 1066 79

Patients with long-standing inflammatory bowel disease have an increased risk for colorectal carcinoma. Microsatellite instability occurs in colonic neoplasms and has been reported in colonic tissues from patients with ulcerative colitis. Patients with Crohn's disease also have an increased risk for colorectal cancer, although it is lower than that associated with ulcerative colitis. This study was designed to determine whether microsatellite instability occurs in Crohn's disease, and whether it occurs with similar frequency to that observed in ulcerative colitis. In all, 177 tissue samples from 33 patients with Crohn's disease were evaluated for microsatellite alterations. Microsatellite instability occurred in five different tissue samples from one of 33 Crohn's disease patients. Four of the five tissue samples showed microsatellite instability at more than one locus. We conclude that microsatellite instability is less common in Crohn's disease than ulcerative colitis and may reflect differences in cancer risk between these two forms of inflammatory bowel disease.
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PMID:Microsatellite instability is uncommon in intestinal mucosa of patients with Crohn's disease. 1071 55

The first case of cancer in inflammatory bowel disease (IBD) was reported at The Mount Sinai Hospital in 1925 in a patient with ulcerative colitis (UC). In 1956, carcinoma of the jejunum was described in a patient with regional enteritis (Crohn's disease [CD]). IBD cancers are preceded by dysplasia, and the relative risk increases with duration of the IBD. CD cancers are more proximally distributed than are UC cancers. Both tend to occur at the site of the overt disease and both develop at earlier ages (47 UC, 50 CD) than in the de novo colorectal cancer (70 years). The absolute cumulative colon cancer frequencies (8% UC, 7% CD) are identical after 20 years, emphasizing the importance of regular surveillance in both types of IBD. Moreover, the increased risk of colon cancer exists in patients with CD even when CD is confined to the small bowel, and patients with IBD have increased risks of developing extraintestinal and reticuloendothelial tumors in both CD and UC, as well as ano-vulval and malignant melanoma in CD. Colitic colorectal cancers are often diffuse, extensive, multiple and right-sided with insidious presentation. The prognosis is no worse after operation than that of de novo colon cancer. Most small bowel cancers in CD are adenocarcinomas, rather than sarcomas, and present at a younger age, more diffusely and more distally than de novo cancers, usually making them undiagnosable at a curable early stage; indeed, two-thirds present with intestinal obstruction. Strictures of the colon are common in patients with IBD, and they have a 10-fold risk for colon cancer, 30-fold for UC, and 6-fold for CD. The risk increases with disease duration. The indications for surgery are absolute, relative and incidental, and the procedures include segmental resection, total proctocolectomy, subtotal colectomy and palliative procedures.
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PMID:Cancer in inflammatory bowel disease. 1082 8

Colorectal cancer (CRC) is the third most common cancer in the world, and mortality has remained the same for the past 50 years, despite advances in diagnosis and treatment. Because significant numbers of patients present with advanced or incurable stages, patients with pre-malignant lesions (adenomatous polyps) that occur as result of genetic inheritance or age should be screened, and patients with long-standing inflammatory bowel disease should undergo surveillance. There are different risk groups for CRC, as well as different screening strategies. It remains to be determined which screening protocol is the most cost-effective for each risk catagory. The objective of screening is to reduce morbidity and mortality in a target population. The purpose of this review is to analyze the results of the published CRC screening studies, with regard to the measured reduction of morbidity and mortality, due to CRC in the studied populations, following various screening procedures. The main screening techniques, used in combination or alone, include fecal occult blood tests, flexible sigmoidoscopy, and colonoscopy. Evidence from the published literature on screening methods for specific risk groups is scanty and frequently does not arise from controlled studies. Nevertheless, data from these studies, combined with recent advances in molecular genetics, certainly lead the way to greater efficacy and lower cost of CRC screening.
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PMID:Colorectal cancer screening. 1088 Oct 77

Although there is a great deal of information concerning the risk factors for colorectal cancer, progress has been slow in determining methods of chemoprevention. In part this is because colorectal cancer consists of a series of events over 10-15 years or more, which affects only 3-5% of the population. Risk markers for use in patient selection are needed to decrease the sample size needed. In addition, there is a need to identify intermediate endpoints of success to decrease the follow-up time. Clinical markers of risk are a history of colorectal adenomas and of inflammatory bowel disease. Molecular markers include a number of genetic markers and enzyme polymorphisms.
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PMID:Molecular and clinical risk markers in colon cancer trials. 1088 68


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