NEW HAVEN, Conn. (WTNH) — A new study out of Norway suggests that the benefits of using a colonoscopy as a cancer screening tool have been overestimated — but an expert at the Yale Cancer Center still urges people to get one.

“We have a lot of data that’s really pointing towards a very significant decrease in colorectal cancer since we started screening in the United States, and actually some other places in Western Europe,” said Dr. Xavier Llor, the director of colorectal cancer screening at the center. “We don’t consider a single study. We look at the body of the literature, and when you see the body of the literature, that’s very favorable to colorectal cancer screening. But even looking at this paper on its own, a decrease of death rate by 50%, that’s humongous already.”

The study, published in the New England Journal of Medicine, states that only 42% of people who were invited to get a colonoscopy actually got one. The procedure has been touted as the best way to catch, and even prevent, colorectal cancer.

For those who received one, the study said that there was a 18% lower risk of getting colorectal cancer, but no difference in the risk of dying of cancer.

Llor stressed that the majority of literature still shows that there are benefits to colorectal cancer screening.