Brown-Assisted Trial Finds New Colorectal Screening Procedure Is Accurate and Less InvasiveSeptember 18, 2008PROVIDENCE, R.I. [Brown University] - More patients stand to benefit from a comprehensive, less invasive method to accurately detect colorectal cancer and precancerous polyps, a multicenter study involving Brown University and institutions nationwide has found. The method, called computerized tomographic (CT) colonography, employs virtual reality technology to produce two- or three-dimensional visualizations that permit a thorough and minimally invasive evaluation of the entire colon and rectum. The procedure is comparable to standard colonoscopy, which uses a long, flexible tube with a camera to view the lining of the colon, in its ability to accurately detect problems and could serve as an initial screening exam for colorectal cancer. The results of the American College of Radiology Imaging Network (ACRIN) National CT Colonography Trial are published in this week's issue of the New England Journal of Medicine.
The goal of the trial was to assess the accuracy of CT colonography, also known as virtual colonoscopy, using conventional colonoscopy as the gold standard. The ACRIN trial, funded by the National Cancer Institute (NCI), enrolled more than 2,600 patients at 15 sites nationwide. "I think this is going to be a definitive study when it comes to establishing that CT colonography has a place in the armamentarium of modalities for colorectal cancer screening," said Constantine Gatsonis, a biostatistics professor and director of the Center for Statistical Sciences at Brown. "It says that basically from here on, the question is how to implement CT colonography in screening programs." The center's faculty and staff provide methodological leadership to ACRIN, design studies, and monitor and analyze the data. The center's Meridith Blevins, Mei-Hsiu Chen, Ilana Gareen, Ben Herman, and Alicia Toledano contributed to the ACRIN trial. "CT colonography could be adopted into the mainstream of clinical practice as a primary option for colorectal cancer screening. We hope that this additional, less-invasive option for cancer screening will lead more people to get screened and will ultimately result in fewer deaths from colorectal cancer," said ACRIN National CT Colonography Trial principal investigator C. Daniel Johnson, M.D., of the Mayo Clinic in Scottsdale, Ariz. Colorectal cancer is the third most frequently diagnosed cancer and second leading cause of cancer death in men and women in the United States. Although screening recommendations vary somewhat, many recommend that adults aged 50 and older in the general population receive a colonoscopy every 10 years or more frequently, depending on known risk factors. Yet, despite the known benefits of screening, studies indicate that the majority of Americans age 50 and older are not being screened for the disease. "Previous single-site studies had indicated that CT colonography held promise in screening for colorectal cancer due to its accuracy, safety, cost-effectiveness, and patient acceptability. However, validation of the technique across multiple centers and radiologists was needed to provide more evidence of the exam's viability," said Chen, who led the statistical analysis at the Brown center. "The ACRIN trial has now validated that CT colonography could serve as an initial screening exam for the population in which screening is indicated." In the ACRIN trial, CT colonography was found to be highly accurate for the detection of intermediate and large polyps. Ninety percent of the polyps 1 centimeter or larger were detected by CT colonography. Even polyps as small as one half centimeter were detected by CT colonography with a high degree of accuracy. Since most colon cancers develop from polyps, and screening to find and remove these polyps can prevent colon cancer, an opportunity exists to save lives with early detection. "There are clearly clinical settings in which CT colonography, colonoscopy, or both tests in combination offer distinct advantages. The most important advice we can give to patients is to get screened. How they get screened should be an individual decision based upon discussions between patients and their providers," said gastroenterologist and study author Paul Limburg, M.D., Mayo Clinic in Rochester, Minn. Study participants had to be at least 50 years old, scheduled for a screening colonoscopy, and not have received a colonoscopy in the last five years. Each participant had a CT colonography followed by a colonoscopy, with 99 percent of both exams accomplished on the same day. Participants scheduled for a screening colonoscopy were recruited with assistance from gastroenterologists at each participating site. Preparation for CT colonography and colonoscopy both involve taking solutions to clear and cleanse the colon. Brown University | |||||||||||||||||
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Related Colonography Current Events and Colonography News Articles CT colonography offers 1-stop screening for cancer and osteoporosis New research reveals that computed tomography (CT) colonography, also known as virtual colonoscopy, has the potential to screen for two diseases at once-colorectal cancer and osteoporosis, both of which commonly affect adults over age 50. Surgical Removal of Small Colon Polyps is Costly and Unnecessary Polypectomy (the surgical removal of polyps by colonoscopy) of small polyps found during CT colonography is costly and unnecessary according to a study performed at the University of Wisconsin School of Medicine and Public Health in Madison, WI. Is CT-colonoscopy a valuable tool to detect colorectal cancer? CTC (virtual colonoscopy) is a thin slice CT scan of the abdomen after adequate bowel preparation and colon insufflation in which data are reconstructed providing axial, multiplanar, and endoluminal views, in order to visualize internal colonic wall. AGA Institute statement: Data support CT colonography as viable colorectal cancer screening option Death from colorectal cancer is highly preventable with effective screening and early detection. Many screening options are available, each with advantages and disadvantages, but half of eligible patients still do not participate in colorectal cancer screening. ASGE encourages patients to speak to their doctor about colorectal cancer screening options Results of the National CT Colonography Trial, published in the September 18 issue of the New England Journal of Medicine, show improvements in the technology's ability to diagnose intermediate- to large-sized polyps in the colon, but this method of testing is not as effective in diagnosing small polyps Health groups issue updated colorectal cancer screening guidelines The American Cancer Society, the American College of Radiology, and the U.S. Multi-Society Task Force on Colorectal Cancer (a group that comprises representatives from the American College of Gastroenterology, American Gastroenterological Association, and American Society for Gastrointestinal Endoscopy) have released the first-ever joint consensus guidelines for colorectal cancer screening. AGA supports new guidelines favoring tests that prevent colorectal cancer New consensus colorectal cancer guidelines released today state for the first time that the primary goal of colorectal cancer screening is cancer prevention. Previous 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. New guidelines update recommendations on colorectal cancer screening A new guideline on colorectal cancer screening released today by an expert group representing a broad spectrum of health care organizations, including the American College of Gastroenterology (ACG), the American Society for Gastrointestinal Endoscopy (ASGE) and the American Cancer Society (ACS), offers recommendations for various alternatives for colorectal cancer detection and states a strong preference for screening tests that can prevent colorectal cancer. CT colonography detects wide-range of extracolonic abnormalities in elderly patients CT colonography (CTC), when used in elderly patients, can detect a high number of new and significant abnormalities outside the colon (including cirrhosis and tumors) and is well tolerated, according to a recent study conducted by researchers at St. James's University Hospital in Leeds, United Kingdom (UK). Minority patients prefer optical colonoscopy for colorectal cancer screening The clinical importance of colorectal cancer screening is well established, however the majority of eligible people do not undergo screening tests. More Colonography Current Events and Colonography News Articles |
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