I concede I was probably inaccurate in my statement about evolution and the species level; note, however, that I disagree with people who believe that the gene is the unit of evolutionary selection (I would refine it to say "functional region" rather than gene because I believe that mutations in enhancers and other transcriptional activators play a bigger role in evolution that mainstream science).

On to your second reply: I basically agree. We're mostly arguing about where that certain point is. Problem is: cancer is a disease that is closely tied to many necessary functional parts of multicellular organisms.

In a sense cancer is what gets people who weren't got by something more acute earlier, and probably evolution is addressing the more acute issues with a higher priority.