Ellie,
I agree with the above post from kalaoamom. Many small studies have demonstrated MCP to increase cancer cell death (apoptosis) especially in prostate cancer. I am including a link to one of many abstracts on PubMed.
http://www.ncbi.nlm.nih.gov/pubmed/17513886
Modified citrus pectin is also a great soluble fiber and there is little/no risk in including it in the diet. Many foods naturally contain pectin. I believe supplements have their place but I always ask my patients to look at their diets first because we
know that diet/lifestyle changes reduce cancer risk.