I, for one, am quite aware of "the facts" about animal testing. Here are three of the assumptions that I question when I think about animal testing:
1) human life has more worth than non-human life
2) humans are meant to conquer death and live forever
3) humans are supposed to "play god" by messing with Life
If you admit that you have (consciously or unconsciously) made any of these assumptions, then maybe you could explore them by questioning your own bias.
1) Humans are superior: When faced with this assumption, I can only ask: Who told you this? (No great omniscient being told us this. We humans told ourselves that we were superior.) Prove it. (You can't.)
2) Humans are meant to conquer death: This is an interesting assumption. Questions: How old do you think humans SHOULD live? What DO you want to die of? Aren't diseases part of the life cycle?
3) Humans should "play god": This doesn't have to have a religious connotation. What makes us think we are responsible enough and knowledgeable enough to tinker with a system so intricate and balanced as the Life-process that keeps this place running?
These are a few of the assumptions that remain unaddressed when people insist that testing on animals is right and good. Dying is a scary thing for most people (I include myself in there.) I don't want to suffer lots before I die. Nor do I want any of my loved ones to suffer greatly before they die. I hope they all have long and lovely lives. BUT humans are not meant to live forever. Some of my loved ones (maybe myself) will die rather young. Some of us will suffer immeasurably before we die. That is sure scary. But I can at least admit that some of these things (dying and suffering) are part of life. What is not "part of life" is the utilitarian imposition of suffering and death on other life forms. Testing for cancer research is no more acceptible than testing for cosmetics. Each is an example of our species' arrogant assumption that we are superior and that the planet and its inhabitants are part of our "toolbox", designed solely for our use.