Colonoscopy is a more reliable method for detecting colorectal tumors in women as against the method of flexible sigmoidoscopy, which misses 65 per cent of advanced colorectal lesions, a study published in
The New England Journal of Medicine has said.
The study compared the results of colonoscopy on 1463 women between the ages of 50 year and 79 years with those that underwent flexible sigmoidoscopy. Out of these 1463 women, 240 had a family history of colon cancer.
Researchers found that the colonoscopy reported advanced abnormal growth of cells, also called neoplasia, in around 5 per cent of women (72 women), as against less than 2 per cent (around 25 women), reported by flexible sigmoidoscopy.
“In our opinion, colonoscopy is the preferred method of colorectal cancer screening in women. All our data until now has been based on men. What this data shows is it’s a lot worse in women,” said Dr Philip Schoenfeld of the University of Michigan, the lead author of the study, which was funded by National Cancer Institute.
Both colonoscopy and flexible sigmoidoscopy use a lighted tube to see the colon on a video screen. But colonoscopy examines the entire colon, whereas flexible sigmoidoscopy looks only at the distal colon, the part of the colon that lies close to the rectum. The latter was found to miss detecting pre-cancerous growths in almost two-thirds of women. This failure rate was twice as high as that seen in men.
In the United States, most colon cancer screening in done through colonoscopy. Hence, the study might not have major implications. But in other countries where flexible sigmoidoscopy is more popular, doctors might want to consider the results of the study, the researchers said.
The third leading cause of death in women, colon cancer is likely to affect around 73,470 American women in 2005. About 27,750 are likely to die of it this year.
