Any discussion on cancer is very incomplete without an acknowledgement that pre-civilization cancer was much more rare, and in some hunter-gatherer societies almost unknown. Good Calories Bad Calories has a good discussion of this and other health issues in some remote areas. Some members of those societies lived into old age, and some members of our society get cancer at young ages. Along these lines, I would be very interested in reading about cancer rates of animals in natural environments. One must assume that the talk of mice getting cancer is referring to lab mice.
A better question (and maybe the one you are asking) is how would we know if someone outside of civilisation actually had cancer. You have to draw on various sources of evidence. It is possible to see evidence of health issues in skeletons, the most obvious example pertinent to this discussion might be something like bone cancer. The most convincing evidence on the issue is observational. It comes from people from civilization documenting populations that are hunter-gatherers or pastoralist and sometimes partly subsistence agriculturalists. As mentioned, there is a discussion of this type of evidence in GCBC by Gary Taubes. Doctors from civilisation would go to the frontier, deal with disease in the frontier populations, and note an extraordinary lack of disease in the native populations. The best documented groups are various groups in Africa, the Inuit, and some Pacific islanders like the Kitavans. Finding a case of cancer in an Inuit was worthy of publication in a journal. In the case of the Kitavans a researcher actually went there specifically to study their health. There was not a single overweight individual that had lived on the island their whole life. There were (a few) ~100 year old individuals without any sign of disease. They could recount the one time in their populations recent history that it appeared that someone from the island had cancer. People there (that don't die from accidents) presumably die from infections, not from cancer and other degenerative diseases.
That's really interesting, thanks for sharing that. I always assumed that before modern medicine identified cancer, people thought that they were dying of other diseases & what not when in reality they had cancer. Is there any way that scientists can figure out if people from centuries ago died from cancer (excluding bone cancer)?
It is all a very vague science to try to look back in time. Centuries is not that long ago, and one can try to assume that remote indigenous populations are still similar. Lets assume we are talking thousands if not tens of thousands of years ago. There are a lot of things that scientists can try to interpret from skeletal and other bone remains, only some of them that would be a direct link to cancer. This is a good overview of some of the science that goes on for that in a context that is relevant to the discussion at hand: http://wholehealthsource.blogspot.com/2009/03/paleopathology...
Personally I am convinced that cancer is just one of many degenerative health issues. If you follow that line of reasoning, than the frequency of degenerative issues in skeletal remains are likely related to the frequency of cancer and any other degenerative health issue. As one example, if you simply see caries (cavities) in the remains of the teeth, that would also mean cancer was more likely to occur. (very healthy indigenous cultures have almost no cavities). Obviously this is very loose logic, and certain groups are more likely to have certain issues that are more or less likely to show up in skeletal remains, but I believe the general principle is sound.
We can inspect the skeletons and determine if there was cancer present. I have also read that it was largely non-existent in paleolithic cultures, indicating agricultural products and lifestyle, but I'd like to see further confirmation of this.
