The guidelines regarding colon cancer recommend that average-risk patients undergo a colonoscopy every 10 years, even if their previous colonoscopy results were negative. However, until recently, there has been limited evidence to support this recommendation.
To address this lack of evidence, investigators studied 1.25 million individuals aged 50 to 75 who were considered to have average risk for developing colon cancer. Average risk entails an absence of the following: a personal history of colorectal cancer or of certain types of polyps, a family history of colon cancer, a personal history of inflammatory bowel disease, a confirmed or suspected hereditary colorectal cancer syndrome, or a personal history of radiation to the abdomen or pelvic area.
The results, published in JAMA Internal Medicine, revealed that the average-risk patient who received a negative colonoscopy result had a 46% lower colon cancer risk and was 88% less likely to die due to related causes compared with the average-risk patient who did not receive a colonoscopy screening.
"Our study shows that following a colonoscopy with normal findings, there is a reduced risk of developing and dying from colorectal cancer for at least 10 years," stated the study's principal investigator, Jeffery Lee, MD, Kaiser Permanente gastroenterologist and research scientist in the Division of Research. "These findings suggest that physicians can feel confident following the guideline-recommended 10-year rescreening interval after a negative colonoscopy in which no colorectal cancer or polyps were found. There is now solid evidence supporting that recommendation."
During a time when colon cancer is the third leading cause of cancer-related death in the United States, this study can reassure physicians that following the guidelines is safe.
"This large study is the first with a high enough number of average-risk individuals to evaluate cancer risks after colonoscopy examinations, compared with no screening," commented the study's senior author, Douglas Corley, MD, PhD, Kaiser Permanente gastroenterologist and research scientist with the Division of Research. "Such information provides greater certainty regarding the appropriate timing for rescreening after a negative colonoscopy."
For More Information
Lee JK, Jensen CD, Levin TR, et al (2018). Long-term risk of colorectal cancer and related deaths after a colonoscopy with normal findings. JAMA Intern Med. [Epub ahead of print] DOI:10.1001/jamainternmed.2018.5565
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