I'd also like to know what they are basing that on and why the Atkins diet specifically unless they are proceeding on their own misinformation that the Atkins diet is low in fiber. I went to the CNN News website and couldn't find anything recent on colon cancer at all. If it's the old "not enough fiber" issue, studies have been done that showed that those that ate a lot of fiber didn't have any less risk of getting colon cancer than those that ate a low fiber diet and that was no small study..it was based on the Harvard Nurse's study which involved over 88,000 women.
I've heard it said before that eating lots of red meat promotes colon cancer, but I've never seen it conclusively proven in medical trial studies.