I seem to recall some discussion of this stuff here a few years ago. At that time there were a few studies that were encouraging, especially if you happened to be a mouse. I am glad to see that human trials are proceeding.
Here's a nicely-written review of some of the research as of ten years ago:Modified citrus pectin anti-metastatic properties: one bullet, multiple targets
For those of you who like to rush out and try everything new and exciting, or the more cautious types who insist on more mature research but suspect they may be mice, you can buy the stuff from Amazon. It's slightly expensive as supplements go but as a cancer treatment it's dirt cheap. At the dose mentioned in reachout's study (roughly 15g a day, taken as 3 5g doses) it costs four or five bucks a day as a bulk powder and about
twice that if you prefer it in capsule form.