Study Shows Colonoscopy is Far Better In
Detecting Colon Cancer
A study, conducted by the Department of Veterans Affairs in Portland, Oregon concluded that colonoscopy is far superior to sigmoidoscopy and the fecal blood test, two other common tests for colon.
Colonoscopy involves the use of a flexible, lighted tube that lets a doctor see the sedated patient's entire colon and immediately remove any growths. Experts consider colonoscopy the "gold standard" test for colon cancer, the nation's No.2 cancer killer. But the procedure is expensive. It costs at least $1000. So, experts had been trying to establish with more certainty which method really is the best.
Colonoscopy is considered 95 percent accurate and is recommended by the American Cancer Society every 10 years, starting at age 50 for people who are not at high risk for colon cancer.
Sigmoidoscopy, which costs $100 to $200, uses a less-sophisticated viewing tube and cannot probe the colon's top two-thirds, where growths become more common, dangerous and hard to detect with age.
The fecal blood test looks for blood in patient's stool. It can be accomplished with a simple stool test and is the least expensive of the three. The latest results show that it is also the least accurate in detecting colon cancer.
Of the 306 veterans in whom colonoscopy detected tumors or precancerous growths, fecal blood test detected 73 (23.9% of the total) and sigmoidoscopy detected 215 (70.3%). Together, fecal blood test and Sigmoidoscopy detected only 232 cases (75.8%) out of the 306, missing 1 in every four cases detected by colonoscopy.
Medical guidelines generally call for annual testing for blood in a patient's stool and, every five years, a sigmoidoscopy, or examination of the lower colon, both starting at age 50. Some guidelines recommend colonoscopy as a routine test; others recommend it only for people who run a high risk of colon cancer, such as those with a family history of it, those who have had previous growths, or those who show signs of cancer during the stool test or a sigmoidoscopy.
"Colonoscopy currently is the best available test that we have," said Dr. David A. Lieberman, who led the study as chief of gastroenterology at the Portland Veterans Affairs Medical Center in Oregon. It makes a case for at least considering colonoscopy as a screening test beginning at age 60.
Colorectal cancer this year will kill an estimated 56,700 Americans and will be diagnosed in 135,400 others, according to the American Cancer Society.
Source: New England Journal of Medicine, Associated Press