That’s what data on 2,602 patients, who underwent the screening test and had potentially cancerous polyps removed from their colons, showed. Over 23 years of follow-up, 12 of these patients died, where 25 would have been expected to die in a similar group from the general population — amounting to a 53% lower death rate associated with colonoscopy.

While the benefits of colonoscopy have long been known, previous studies had established only that the test reduced the incidence of colon cancers. By spotting and removing precancerous growths that could develop into tumors, colonoscopy helps stop colon cancer from developing. But whether the test also saves lives has not been entirely clear.

Because not all growths develop into cancers and not all cancers are fatal, some have wondered whether the screen actually lowered patients’ risk of dying from colon cancer or simply removed abnormal lesions. The current study, led by Dr. Sidney Winawer, a gastroenterologist as Memorial Sloan-Kettering Cancer Center, and published in the New England Journal of Medicine, offers strong evidence that it saves lives.

“This study puts that argument to rest,” Dr. David Rothenberger of the University of Minnesota Masonic Cancer Center, who wasn’t involved in the study, told the New York Times.

Documenting that a cancer screen saves lives is critical for justifying its cost and potential complications — not to mention the discomfort. The American Cancer Society (ACS) and the U.S. Preventive Services Task Force currently recommend that people begin screening for colon cancer at age 50. The guidelines do not recommend one type of screen over another — along with colonoscopy, other screening tests include sigmoidoscopy (which scans only the lower third of the colon), virtual colonoscopy, barium enemas and fecal blood tests.

Studies have not yet established whether one screening tool is more accurate or predictive than the others, and the current review did not compare different screening methods. However, a second study published in the same issue of the NEJM found that colonoscopies are more effective at finding polyps than fecal blood tests, revealing 10 times more early cases of disease, which further affirms the advantages of the procedure.

Another key benefit of colonoscopy, experts say, is that it combines screening with treatment: the test involves a thin tube equipped with a camera and a device that can snip off polyps, so doctors can remove suspicious growths during the test.

The results of the current study confirm that despite the discomfort, colon-cancer screening is worth it. “Sure, it’s a pain in the neck. People complain to me all the time, ‘It’s horrible. It’s terrible,’” Winawer told the Associated Press. “But look at the alternative.”

At least patients don’t have to undergo the procedure every year if the initial test is negative. The ACS recommends a colonoscopy every 10 years for those who aren’t at high risk of colon cancer.

Alice Park is a writer at TIME. Find her on Twitter at @aliceparkny. You can also continue the discussion on TIME’s Facebook page and on Twitter at @TIME.