U.S. researchers have proven that removing precancerous polyps during patient colonoscopies reduces the death from colon cancer, according to media reports Thursday quotting the New England Journal of Medicine. After a study of more than 2,600 patients who had precancerous polyps removed during colonoscopies between 1980 and 1990, scientists found that removing theprecancerous polyps, known as adenomas, during a colonoscopy can reduce the risk of death from colorectal cancer by half. It can take years for a tiny adenoma to grow large and become malignant, said Dr. William Katkov, a gastroenterologist at Saint John’s Health Center in Santa Monica. The U.S. Preventive Services Task Force recommends that most people begin getting regular colonoscopies at age 50. Those suffering changes in bowel habits, blood in the stool or anemia may need to begin screening even sooner, Katkov said. About 140,000 cases of colorectal cancer are diagnosed in the United States each year, resulting in about 49,000 deaths, according to the National Cancer Institute. Colorectal cancer is the third most common cancer worldwide. Scientists recommends screening for people age 50 to 75 years but people often find the tests unpleasant. \"This study is showing both a reduction in colon cancer incidence and colon cancer deaths by removing the adenomas, and it\'s a long-term effect\" said Ann Zauber of the Memorial Sloan-Kettering Cancer Center in New York, chief author of the long-term evaluation of polyp removal in a telephone interview. \"This is reassuring for people to come in for screening.\"