Regular Colonoscopies May Reduce Risk for Colon Cancer by 40 Percent

Regular colonoscopies may reduce risk for colorectal cancer by up to 40 percent, according to a study released Wednesday.

A new study from the Harvard School of Public Health confirmed that 40 percent of all colorectal cancers can be prevented if people underwent regular colonoscopy screenings. According to the National Cancer Institute, 102,480 people will be diagnosed with colon cancer in the U.S. this year, and another 40,340 will learn they have rectal cancer.

About 50,830 people are expected to die from colorectal cancer this year, making it the second-leading cause of cancer deaths in the U.S. Colorectal cancer usually starts from abnormal growths known as precancerous polyps, so experts recommend that people get screened regularly. One way to get examined for the disease is to have a colonoscopy.

During the procedure, doctors use a tool called an endoscope with a tiny camera attached to take a look at the entire large intestine and part of the small intestine. The patient often has to be sedated. Doctors can remove any questionable polyps if they see them during the exam.

"Colonoscopy is the most commonly used screening test in the U.S., but there was insufficient evidence on how much it reduces the risk of proximal colon cancer and how often people should undergo the procedure," co-senior author Dr. Shuji Ogino, associate professor in the Department of Epidemiology at Harvard School of Public Health, said in a press release.

"Our study provides strong evidence that colonoscopy is an effective technique for preventing cancers of both distal [left] and proximal [right] regions of the colorectum." Furthermore, the study found that a less-invasive alternative to colonoscopy -- a sigmoidoscopy -- is not as effective at preventing cancer in the proximal or right side of the colon.