The first generation of a stool DNA test to identify early colorectal cancer has limitations, as per a Mayo Clinic-led study reported in the Oct. 7, 2008, issue of Annals of Internal Medicine Results did not corroborate findings of an earlier multicenter study that showed stool DNA testing was more accurate than fecal blood testing for colorectal cancer detection. *........

Patients who undergo a complete negative colonoscopy have a reduced occurence rate of colorectal cancer, confirms a study published in Clinical Gastroenterology and Hepatology However, in the proximal colon, the incidence reduction of colorectal cancer following complete negative colonoscopy differs in magnitude and timing. The reduction of colorectal cancer is observed in about half of the 14 follow-up years and for the most part occurs after just seven years of follow-up. Clinical Gastroenterology and Hepatology is the official journal of the American Gastroenterological Association (AGA) Institute........

Scientists at NorthShore University HealthSystem (NorthShore) and Northwestern University have discovered that fiber optic technology can for the very first time effectively measure blood levels in the colonic lining (mucosa) in humans, thus having potential applications for analyzing risk of colon cancer........

Demonstrating that despite the large number of cancer-causing genes already identified, a number of more remain to be found, researchers at Dana-Farber Cancer Institute have linked a previously unsuspected gene, CDK8, to colon cancer. The discovery of CDK8's role in cancer was made possible by new tools for assessing the activity of specific genes, say the authors of the new study. As these tools are further improved, the stream of newly discovered cancer genes is expected to increase, providing new avenues for treatment, the authors suggest. The findings are being published as an advanced online publication by the journal Nature on Sept. 14........

The absence or inactivation of the RUNX3 gatekeeper gene paves the way for the growth and development of colon cancer, Singapore researchers report in the Sept. issue of the journal Cancer Cell Prior studies have shown that RUNX3 plays a role in gastric, breast, lung and bladder cancers. The inactivation of RUNX3 occurs at a very early stage of colon cancer, as per the Singapore scientists' studies with human tissue samples and animal models........

Colorectal adenomas, the precursor polyps in virtually all colorectal cancers, occur infrequently in younger adults, but the rate sharply increases after age 50. Additionally, African Americans have a higher rate of proximal, or right-sided, polyps, and may have a worse prognosis for survival if the polyps become malignant. Therefore, the results of this study further emphasize the importance of colonoscopies, which view the entire colon, for the prevention of colorectal cancer beginning at age 50. The results of this study, which represents the largest investigation, by several-fold, of this kind, were published in Clinical Gastroenterology and Hepatology, the official journal of the American Gastroenterological Association (AGA) Institute........

Eventhough colorectal cancer screening tests are proven to reduce colorectal cancer mortality, only about half of U.S. men and women 50 and older receive the recommended tests, as per a report in the July 2008 issue of Cancer Epidemiology, Biomarkers and Prevention, a journal of the American Association for Cancer Research........

A probe so sensitive that it can tell whether or not a cell living within the human body is veering towards cancer development may revolutionize how future colonoscopies are done, say scientists from the Mayo Clinic in Jacksonville, Fla. Investigators have observed that technology known as a high resolution confocal endomicroscopy probe system can determine whether a colon polyp is non-malignant (not premalignant) - without having to remove it for examination by a pathologist........

A new study being presented at the American Society of Clinical Oncology meeting in Chicago (Abstract #4020), may change therapy practice in about 25 percent of colon cancer patients and is the basis for proposed changes to the way colorectal cancers will be staged. This new study, using National Cancer Institute (NCI) SEER population-based statistic registries from 1992 to 2004, and phase III clinical trial data, shows that outcomes of patients with positive nodes (Stage III) in colorectal cancer interact, to a greater extent than previously thought, with how deeply the cancer penetrates the bowel wall........

A gene mutation responsible for the most common form of inherited colon cancer is older and more common than formerly believed, as per a recent study. The findings provide a better understanding of the spread and prevalence of the American Founder Mutation, a common cause in North America of Lynch syndrome, a hereditary cancer syndrome that greatly increases a persons risk for developing cancers of the colon, uterus and ovaries........

Smoking puts older women at significant risk for loss of DNA repair proteins that are critical for defending against development of some colorectal cancers, as per research from a team led by Mayo Clinic scientists. In a study being presented at the annual meeting of the American Association for Cancer Research (AACR), the scientists observed that women who smoked were at increased risk for developing colorectal tumors that lacked some or all of four proteins, known as DNA mismatch repair (MMR) proteins. These proteins keep cells lining the colon and rectum healthy because they recognize and repair genetic damage as well as mistakes that occur during cell division........

Some colon cancers are destined to spread to the liver and other parts of the body, whereas others are successfully treated by surgical removal of the tumor. Now, Howard Hughes Medical Institute researchers have observed that the ability of a colon tumor to metastasize arises early in its development........

Case Western Reserve University School of Medicine scientists published a study in the March 7th issue of The American Journal of Human Genetics identifying the hereditary components of colorectal cancer (CRC.) Identification of Susceptibility Genes for Cancer in a Genome-wide Scan: Results from the Colon Neoplasia Sibling Study is the first large linkage study of families with CRC and colon polyps in the country. Because only five percent of CRC cases are due to known gene defects, this NIH-funded study is designed to identify the remaining CRC-related susceptibility genes. The team built on a prior study which identified a specific region on chromosome 9q that harbors a CRC susceptibility gene. Upon review of a whole genome scan of all chromosome pairs in 194 families, the scientists were able to identify additional CRC gene regions on chromosomes 1p, 15q, and 17p........

New consensus colorectal cancer guidelines released recently state for the first time that the primary goal of colorectal cancer screening is cancer prevention. Prior guidelines have given equal weight to tests for detecting cancer and preventing cancer. By removing polyps from the large bowel, colonoscopy is the only screening test that also prevents colorectal cancer........

5-fluorouracil (5-FU) is a common chemotherapeutical drug. It exerts its antitumor effect through competitive thymidylate synthase (TS) inhibition. Thymidylate synthase (TS) catalyses deoxyuridine-5-monophosphate (dUMP) to 2-deoxythymydine-5-monophosphate (dTMP). It is the only de novo source of thymidylate, an essential precursor of DNA biosynthesis. In the 5-untranslated region of TS gene, there a unique tandem repeated sequence. There are three predominant genotypes of TS: (1) Homozygous with two tandem repeats (2R/2R); (2) homozygous with three tandem repeats (3R/3R); (3) heterozygous with both alleles (2R/3R). It was reported that TS genes with the triple repeats have higher expression activity than those with double repeats in vitro and in vivo........

New data revealing decreasing trends in cancer deaths in the United States overall, and in colorectal cancer deaths in particular, highlight the remarkable benefits of colorectal cancer screening tests, but the lifesaving potential of these tests is unrealized for a number of Americans as per experts from the American College of Gastroenterology. Racial minorities, uninsured Americans and even Medicare patients who should be tested are not being screening appropriately, and other recent studies reveal that they are diagnosed with more advanced cancers in comparison to patients with private insurance........