Cancer research is ubiquitous. At every school you can find at least a couple researchers who work on some kind of cancer. It's also multi-diciplinary. This means that you can pick just about any area of research and still do something that has to do with oncology.
As for infectuous disease, the same pretty much applies.
I recommend you just apply to schools based on location and overall strength, and see what you get into and what you like.