The research is part of a larger project examining various types of cancer screening. The researchers looked at the experiences of nearly 35,000 people -- aged 55 to 74 -- who underwent two sigmoidoscopies over a period of three to five years.
The alternative procedure increased the number of times that colon cancer or benign tumors were detected by roughly one-third. Physicians detected signs of trouble in about 38 per 1,000 persons after the first screening, and that number grew to almost 50 per 1,000 persons after both screenings.
The detected cancers were in the early stages 80 percent of the time.
While the new study has some limitations, it will help researchers as they try to figure out how often people should get sigmoidoscopies, said Newcomb.
After the age of 50, the American Cancer Society recommends a flexible sigmoidoscopy once every five years or a colonoscopy every 10 years. Other tests are also available, and the organization recommends them at different intervals.
For more about colon cancer, try the U.S. National Library of Medicine.
SOURCES: Joel L. Weissfeld, M.D., MPH, associate professor, epidemiology, University of Pittsburgh; Polly A. Newcomb, Ph.D., MPH, head, Cancer Prevention Program, Fred Hutchinson Cancer Research Center, Seattle; Jan. 31, 2012, Journal of the National Cancer Institute
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