<a href="http://news.bbc.co.uk/1/hi/health/3149062.stm">Red meat 'cancer threat'</a> (Link BBC news)
<a href="http://news.google.com/news?num=30&hl=en&edition=us&q=cluster:reuters%2ecom%2fnewsArticle%2ejhtml%3ftype%3dhealthNews%26storyID%3d3527289">Here are more articles</a> (Link to google results)
And it's not related to any of the usual suspects like fat. It is a molecule that is found in higher levels in red meat but also is lower or undetectable levels in poultry, fish, and vegetables. The molecule is not produced by humans but is found in tumors, and it has been shown that the molecule can be absorbed by the body. So far I think the link between this molecule and tumors is speculation.