New Guidelines Update Recommendations on Colorectal Cancer Screening
Strong Preference for Tests That Can Prevent Colon Cancer, Including Colonoscopy
March 5, 2008 – 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. The ASGE and the ACG are members of the U.S. Multi-Society Task Force on Colorectal Cancer and were participants in the guideline development process.
“What distinguishes these new guidelines is an emphasis on the importance and value of preventing colorectal cancer, which GI physicians applaud,” said Amy E. Foxx-Orenstein, D.O., FACG, president of the ACG.
“We know that 50 percent of Americans who should be getting screening for this largely preventable disease are not,” said Grace H. Elta, M.D., FASGE, president of the ASGE. “The data show that screening saves lives and efforts to increase colon cancer awareness and screening will help patients through earlier detection.”
Both the ASGE and the ACG want the public to be aware that the guideline’s stated preference for tests that prevent colorectal cancer supports the groups’ longstanding positions that colonoscopy is the preferred screening strategy for colorectal cancer. Because of its excellent sensitivity in detecting polyps and its potential for removing them and breaking the sequence of polyp to cancer in a single diagnostic and therapeutic intervention, colonoscopy is one of the most powerful preventive tools in clinical medicine.
Several tests are among the recommended alternatives including stool tests that detect colorectal cancer but not its precursor, colon polyps, and structural examinations of the colon by endoscopic procedures such as flexible sigmoidoscopy and colonoscopy, as well as radiological examinations by either barium enema or CT colonography, also known as “virtual colonoscopy.” The new guideline recognizes that for flexible sigmoidoscopy, barium enema and CT colonography, a follow-up colonoscopy will be required if anything suspicious is discovered.
Dr. Foxx-Orenstein of ACG added, “All of us on the front lines of battling colorectal cancer welcome this thorough review of the evidence regarding all the various screening modalities. While the evidence suggests that there are some limitations to all of the tests, the College sees significant strengths in the proven benefits of visualizing pre-cancerous growths and removing them in a single examination during colonoscopy.”
According ACG’s Dr. Foxx-Orenstein, “We congratulate the American Cancer Society and the other group participants on the publication of these guidelines which required so much collegiality and scientific exchange to navigate areas where clinically there still exists much controversy and uncertainty.”
Dr. Elta added, “It is our greatest hope that these new guidelines will contribute to the increased use of colorectal cancer screening tests to reduce the incidence of colorectal cancer, and thereby save lives.”
About Colorectal Cancer
Each year nearly 150,000 people are diagnosed with colon cancer and almost 50,000 die from the disease annually in the United States. Colorectal cancer, also known as colon cancer, is the third most commonly diagnosed cancer in men and women and the second leading cause of cancer-related deaths in the United States. Many of those deaths could be prevented with earlier detection. The five-year relative survival rate for people whose colon cancer is treated in an early stage is greater than 90 percent. Unfortunately, only 39 percent of colon cancers are found at that early stage. Once the cancer has spread to nearby organs or lymph nodes, the five-year relative survival rate decreases dramatically.
Colonoscopy utilizes direct visualization of the entire colon to detect pre-cancerous growths, including smaller polyps, even below 1 cm. This test allows removal of suspicious polyps without surgery at the time of the exam. Three studies have shown that colonoscopy prevents about 80 percent of colorectal cancers from developing by removing pre-cancerous polyps. Colorectal cancer screening’s effect on early detection and prevention through polypectomy has been identified as a main contributing factor for the declining rates of colorectal cancer incidence and deaths from the disease.
About CT Colonography
CT colonography technology requires the same cathartic bowel preparation and restricted diet as colonoscopy. The test requires insertion of a tube in the rectum and insufflation of the abdomen with air or gas while patients are awake. It does not provide the opportunity to remove polyps or suspicious lesions. There are unresolved questions about radiation risks and identifying small or flat polyps. CT colonography may be useful for those who refuse, who cannot undergo, or who have failed prior colonoscopy.
The Need to Follow-up Suspicious Findings
The management of any findings from stool tests, barium enema exams, or CT colonography is an important part of a screening program using these tests:
- For any of the stool tests, a positive finding will require a follow-up colonoscopy.
- For flexible sigmoidoscopy, patients who have adenomas discovered at sigmoidoscopy should undergo colonoscopy, based on evidence suggesting that patients who have an adenoma of any size in the distal colon (visible during the exam which only views part of the colon) are at increased risk for advanced neoplasia proximally (higher up in the colon beyond the reach of the sigmoidoscope.)
- For CT colonography, the new guideline reflects that the risk for patients whose largest polyps are smaller than 5 mm is low, but for polyps over 5 mm in size, a follow-up by colonoscopy is recommended.
About the American College of Gastroenterology
Founded in 1932, the American College of Gastroenterology (ACG) is an organization with an international membership of more than 10,000 individuals from 80 countries. The College is committed to serving the clinically oriented digestive disease specialist through its emphasis on scholarly practice, teaching and research. The mission of the College is to serve the evolving needs of physicians in the delivery of high quality, scientifically sound, humanistic, ethical, and cost-effective health care to gastroenterology patients. To learn more about the College and its mission, visit www.acg.gi.org.
About the American Society for Gastrointestinal Endoscopy
Founded in 1941, the mission of the American Society for Gastrointestinal Endoscopy (ASGE) is to be the leader in advancing patient care and digestive health by promoting excellence in gastrointestinal endoscopy. ASGE, with more than 10,000 physician members worldwide, promotes the highest standards for endoscopic training and practice, fosters endoscopic research, recognizes distinguished contributions to endoscopy, and is the foremost resource for endoscopic education. Visit www.asge.org and www.screen4coloncancer.org for more information.
Endoscopy is performed by specially-trained physicians called endoscopists using the most current technology to diagnose and treat diseases of the gastrointestinal tract. Using flexible, thin tubes called endoscopes, endoscopists are able to access the human digestive tract without incisions via natural orifices. Endoscopes are designed with high-intensity lighting and fitted with precision devices that allow viewing and treatment of the gastrointestinal system. In many cases, screening or treatment of conditions can be delivered via the endoscope without the need for further sedation, treatment or hospital stay.