The genetic difference between Humans and chimpanzees is about 1.2% and yet noone would argue that they are the same species. When the dna from a cancer biopsy shows a 6% genetic variance between a person's cancer and it's host? That's a seperate and distinct species, boys and girls. The various cancers are predatory seperate organisms that prey upon Humans who's immune systems have been weakened. Like lions hanging around the watering hole looking to see which gazelles or water buffalo are limping.