A new study suggests that 40 percent of all colorectal cancers might be prevented if people underwent regular colonoscopy screening.
The new research also supports existing guidelines that recommend that people with an average risk of colorectal cancer should have a colonoscopy every 10 years.
The study, from Harvard School of Public Health (HSPH), helps address previous uncertainty about the effectiveness of colonoscopy in reducing colorectal cancer incidence and mortality-particularly among people with cancer that originates in the proximal, or upper part of the colon.
"Colonoscopy is the most commonly used screening test in the US but there was insufficient evidence on how much it reduces the risk of proximal colon cancer and how often people should undergo the procedure," Shuji Ogino, co-senior author and associate professor in the Department of Epidemiology at HSPH, said.
"Our study provides strong evidence that colonoscopy is an effective technique for preventing cancers of both distal and proximal regions of the colorectum, while sigmoidoscopy alone is insufficient for preventing proximal cancer," the researcher said.
The study is published in the New England Journal of Medicine.
