SCIENCE: Report Affirms Lifesaving Role of Colonoscopy. “In patients tracked for as long as 20 years, the death rate from colorectal cancer was cut by 53 percent in those who had the test and whose doctors removed precancerous growths, known as adenomatous polyps, researchers reported on Wednesday in The New England Journal of Medicine. The test examines the inside of the intestine with a camera-tipped tube.”