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

This article describes a study in which four trace elements (Se, Mn, Cu, and Fe) were analyzed in the blood serum of the patients with colorectal cancer from the Moravian region of the Czech Republic. Atomic absorption spectrometry with graphite furnace atomization was used for analysis of selenium and manganese and with flame atomization for analysis of copper and iron. The observed serum concentrations in adenocarcinoma colorectal patients of selenium were significantly lower (41:8 +/- 11.6 microg/L) and those of manganese (16.3 +/- 4.5 microg/L) and iron (2.89 +/- 1.23 mg/L) were significantly higher as compared to the age-matched control group. Copper serum content (0.95 +/- 0.28 mg/L) did not significantly differ as compared to healthy population.
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PMID:Serum levels of selenium, manganese, copper, and iron in colorectal cancer patients. 1133 May 16

Some reports have associated iron with cancer risk, particularly of the colorectum. This review will focus on the human studies that have investigated this association. Comparative studies were sought in which people with and without colorectal neoplastic lesions, either cancers or adenomatous polyps, were assessed for iron exposure. Iron exposure variables included dietary iron intake, iron vitamin supplementation, body iron stores as measured by ferritin or transferrin saturation, and gene status for hereditary hemochromatosis. Medline was searched for published reports using the key words iron, cancer, colon, rectum, ferritin, transferrin, and hemochromatosis. In addition, the Cochrane Library was searched for relevant studies and several authors were contacted to investigate their awareness of unpublished studies. Studies were categorized by study design and ranked for quality of innovation in design, sample size, and thoroughness of iron status ascertainment. Thirty-three studies were reviewed in 26 publications. Of the larger studies, approximately three-quarters supported the association of iron, in all three strata of exposure, with colorectal neoplasia risk. Because iron is broadly supplemented in the American diet, the benefits of iron supplementation need to be measured against the long-term risks of increased iron exposure, one of which may be increased risk of colorectal cancer.
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PMID:Iron and colorectal cancer risk: human studies. 1166 42

There is increasing evidence that excess dietary iron may be a risk factor for colorectal cancer. However, the majority of animal studies looking at possible mechanism have used unrealistically high concentrations of iron. The current study was designed to test whether chronic exposure to high levels of iron fortification affects the free radical generating capacity of the lumenal contents, mucosal lipid peroxidation and crypt cell proliferation. Rats were fed diets containing either 29 mg/kg or 102 mg/kg of elemental iron for 6 mo. The free radical generating capacity of lumenal contents was assessed using an in vitro assay. Crypt cell proliferation rate was measured in tissues taken from the cecum and colon, with the remaining tissue being used for the assessment of lipid peroxidation. Chronic feeding of iron did not increase crypt cell proliferation rate in either the colon or cecum, but it was associated with an increase in free radical generating capacity in the colon and increased lipid peroxidation, particularly in the cecum. These results may be relevant to epidemiological evidence showing that dietary iron is associated with the risk of proximal colon cancer in humans.
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PMID:Chronic exposure to high levels of dietary iron fortification increases lipid peroxidation in the mucosa of the rat large intestine. 1169 20

The oral contraceptive pill is one of the most extensively studied medications ever prescribed. The health benefits are numerous and outweigh the risks of their use. Definitive evidence exists for protection against ovarian and endometrial cancers, benign breast disease, pelvic inflammatory disease requiring hospitalization, ectopic pregnancy, and iron-deficiency anemia. It has also been suggested that oral contraceptives may provide a benefit on bone mineral density, uterine fibroids, toxic shock syndrome, and colorectal cancer. Minimal supportive evidence exists for oral contraceptives protecting against the development of functional ovarian cysts and rheumatoid arthritis. Treatment of medical disorders with oral contraceptives is an "off-label" practice. Dysmenorrhea, irregular or excessive bleeding, acne, hirsutism, and endometriosis-associated pain are common targets for oral contraceptive therapy. Most patients are unaware of these health benefits and therapeutic uses of oral contraceptives, and they tend to overestimate their risk. Counseling and education are necessary to help women make well-informed health-care decisions and improve compliance.
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PMID:Noncontraceptive benefits and therapeutic uses of the oral contraceptive pill. 1172 71

Long-term ulcerative colitis (UC) patients are at increased risk for developing colorectal cancer. In order to develop strategies for preventing UC-associated carcinogenesis, we studied the effect of the antioxidant N-acetylcysteine (NAC) on UC-associated cancer development in a mouse model. Female C57BL/6J mice were subjected to long-term administration of dextran sulfate sodium (DSS) in the drinking fluid and 2-fold iron-enriched AIN76A diet, with or without NAC. In the DSS-plus-2-fold iron positive control group, gross tumor incidence was 88.5% (23/26 mice) after 12 DSS cycles (1 DSS cycle = 7 day DSS treatment period followed by 10 day recovery period). The tumor multiplicity was 2.1 +/- 0.2 tumors/tumor-bearing mouse, and the tumor volume was 0.054 +/- 0.019 cm3. With 0.2% NAC administration, tumor incidence was significantly reduced (68%, 17/25 mice; P < 0.05), as was the tumor multiplicity (1.5 +/- 0.1 tumors/tumor-bearing mouse; P < 0.05). The tumor volume was lower (0.014 +/- 0.004 cm3), but not significantly decreased. The proliferation index was significantly decreased in non-cancerous epithelia (48.5 +/- 6.0% vs 32.0 +/- 3.7%; P < 0.05), but not in tumor cells. NAC significantly induced apoptosis in both non-cancerous epithelia and colorectal adenocarcinoma. The number of cells immunostained-positive for nitrotyrosine was markedly decreased in the non-cancerous mucosa of NAC-treated mice (102.4 +/-16.6 positive cells/mm2 mucosa vs 53.6 +/- 14.9 cells/mm2; P < 0.05). In addition, the number of inducible nitric oxide synthase (iNOS)-positive inflammatory cells in the non-cancerous mucosa of the distal colon was markedly decreased by NAC. This study indicates that the antioxidant NAC has the potential to serve as a preventive agent for UC-associated colorectal cancer, possibly via inhibition of cellular proliferation and nitrosative stress-caused cellular damage.
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PMID:Inhibition of chronic ulcerative colitis-associated colorectal adenocarcinoma development in a murine model by N-acetylcysteine. 1208 21

According to literature the gastroenterologic consultations for iron-deficiency anemia are quite frequent. The aim was the evaluation of the part played by gastrointestinal examinations for the diagnosis of iron-deficiency anemia. There were 115 patients admitted in the Medical Clinic between 1998-1999, with iron-deficiency anemia in the absence of macroscopic bleeding who carried out upper or lower endoscopy. A digestive lesion which account for iron deficiency anemia was identified in 35% of the cases. In the upper digestive tract there were 60%, in decreasing order of frequency: peptic ulcer, gastric cancer, erosive gastritis, angiodysplasia. In the lower digestive tract were 35% of the cases (colorectal cancer, polyps, angiodysplasia and hemorrhoids). In 5% of the cases there were found synchronization of the digestive tract lesions. So the digestive tract examination is worth doing because it establishes the diagnosis in 35% of the cases with few symptoms. The digestive tract lesions are more frequent in the upper tract, but they are more severe in the lower digestive tract. The possibility of the synchronization of lesions proves the necessity of carrying out the complete examination of the whole digestive tract.
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PMID:[The examination of the digestive tract in patients with iron-deficiency anemia]. 1208 59

The chronic inflammatory bowel disease ulcerative colitis (UC) occurs commonly in the US and other Western countries, but its etiology is unknown. An association between UC and an elevated risk for colorectal cancer is well established. UC-associated colorectal carcinogenesis is probably driven by chronic inflammation, but the mechanism is unclear. The morphological development of UC-associated cancer differs from that of its sporadic counterpart. Similarly, detailed molecular analyses have indicated that whereas many of the genetic alterations observed in sporadic colon cancers also occur in UC-associated neoplasms, the timing and frequency of those changes in the setting of UC are different. These histological and molecular signatures may very well be reflective of an inflammation-driven carcinogenesis process in UC patients. Studies in animal models of UC have helped to shed light on the mechanisms of inflammation-driven colorectal carcinogenesis. The available evidence suggests that DNA damage caused by oxidative stress in the characteristic damage-regeneration cycle is a major contributor to colorectal cancer development in UC patients. Based on this concept, iron over-nutrition is proposed as a risk factor and dietary antioxidants as protective factors for UC and associated carcinogenesis.
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PMID:Oxidative stress and ulcerative colitis-associated carcinogenesis: studies in humans and animal models. 1266 92

The relationship between high dietary iron intake, mutations of the HFE gene, and iron status, and their effects on human health are reviewed. Prolonged high dietary intakes of iron are unlikely to result in iron overload in the general population. Homozygotes for the C282Y mutation of the HFE gene have elevated body iron levels. Heterozygotes have normal iron stores but some may be at increased risk for cardiovascular disease. There is no convincing evidence that elevated iron status increases the risk of coronary heart disease or type 2 diabetes, but high iron intakes may increase the risk of colorectal cancer. The dietary levels of iron associated with health risks in different HFE genotypes must be determined.
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PMID:Health implications of iron overload: the role of diet and genotype. 1267 37

Many N-nitroso compounds (NOC) are carcinogens. In this controlled study of 21 healthy male volunteers, levels of NOC on a high (420 grams) red meat diet were significantly greater (P = 0.001) than on a low (60 grams) meat diet but not significantly greater when an equivalent amount of vegetable protein was fed. An 8-mg supplement of haem iron also increased fecal NOC (P = 0.006) compared with the low meat diet, but 35-mg ferrous iron had no effect. Endogenous N-nitrosation, arising from ingestion of haem but not inorganic iron or protein, may account for the increased risk associated with red meat consumption in colorectal cancer.
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PMID:Haem, not protein or inorganic iron, is responsible for endogenous intestinal N-nitrosation arising from red meat. 1275 Feb 50

A prospective randomized trial was used to determine iron concentrations in intestinal cancer tissue and colorectum polyps. We investigated the possible difference between the concentrations of iron, ferritin, albumin, and hemoglobin in the serum of patients with colorectal cancer and polyps. We also determined the relationship between the iron and ferritin levels in cancer tissue, the localization of neoplasms, and the stage of their development. The study comprises 67 patients with colorectum cancer and 42 patients with colon and rectum polyps. The metal was determined by using the total-reflection X-ray fluorescence (TRXRF) method. The mean concentration of iron in colorectal cancer equaled 46.1 microg/g of the tissue and was higher than in the case of polyps (43.2 microg/g). The mean serum iron level in patients with colorectal cancer was statistically lower than in the serum of patients with polyp and in the control group (54.5, 91.3, and 108.0 microg/g, respectively). The determined average concentration of ferritin in the serum of patients with colorectal cancer equaled 60.4 microg/g and was statistically lower than the level of this enzyme in the serum of patients with polyps (85.2 microg/g) and in the control group (102.0 microg/g). There was no difference between the serum albumin and hemoglobin concentrations in patients with colorectal cancer, polyps, and the control. There was no difference in the levels of iron and ferritin depending on the location of the neoplasm and the stage of its development. Also, there was no difference between the concentrations of iron in the cancer tissue of malignant and benign tumors after taking into consideration sex and age of patients. During the examination we determined significantly higher concentrations of iron in the cancer tissue and not in the polyp. The low levels of iron in the serum of patients with malignant tumor may increase colorectal cancer risk.
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PMID:Iron concentrations in intestinal cancer tissue and in colon and rectum polyps. 1455 96


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