The Colonoscopy is an Effective Prevention Tool Against Colorectal Cancer
Previous studies have suggested that colonoscopies were only beneficial for finding cancers on the left side of the colon, the region more easily reached during the procedure. New research contends that while the test does detect more cancers on that side, it remained substantial for also finding adenomas on the right and is an effective tool for the protection against colon cancer.
Screening Can Substantially Reduce Risk of Colorectal Cancer
Dr. Hermann Brenner and colleagues from the German Cancer Research Center enrolled 3,620 patients for a study – 1,688 with colorectal cancer and 1,932 healthy controls. The participants, all aged 50 or older) were asked if they had had a colonoscopy during the previous 10 years (1,023 had at least one) and their medical records were analyzed.
Overall, for those who had undergone colonoscopy, the risk for any colorectal cancer was reduced by 77%. Risk reduction was essentially the same among men and women, at all stages of cancer, and across ages.
As seen in previous studies, there was a larger reduction in risk for left-sided colorectal cancer (84%), but the risk reduction in right-sided cancer was still significant at 56%. According to Dr. Brenner, his findings contrast that published in a 2008 issue of the Journal of the American Medical Association in which a Canadian study found no protection from deaths from right-sided colorectal cancer.
According to the American Cancer Society, colorectal cancer is the third most common cancer diagnosed in both men and women in the United States with over 142,000 new cases found each year. The overall lifetime risk for developing colorectal cancer is about 1 in 19.
The colonoscopy is the standard and preferred method of screening for colorectal cancers, but there are also other methods available such as a flexible sigmoidoscopy and a fecal occult blood test.
Beginning at age 50, both men and women at average risk for developing colorectal cancer should be screened based upon their doctor’s recommendations. People at higher risk, including those with a personal or family history of cancer or polyps, should be screened earlier and more often.
Regular screenings can often find colorectal cancer early, when it is most likely to be curable, or may prevent the disease by removing benign polyps before they have a chance to turn into cancer.
Brenner H, et al "Protection from colorectal cancer after colonoscopy: A population-based, case-control study" Ann Intern Med 2011; 154: 22-30.
Weinberg DS "Colonoscopy: What does it take to get it 'right'?" Ann Intern Med 2011; 154: 68-69.
Soetikno RM et al “Prevalence of nonpolypoid (flat and depressed) colorectal neoplasms in asymptomatic and symptomatic adults”,JAMA. 2008;299:1027-1035.