When I began reading about paleo-oncology last summer, I came across an estimate by the Czech anthropologist Eugen Strouhal of how many cases of suspected cancer had been found in ancient European skeletons: 176. The number, from a paper published in 1996 in the International Journal of Paleopathology, didn’t include Egyptian mummies or cases from other continents. And by the time I was writing the Times story referred to in my previous post, I had found about 20 more recent discoveries. Adding all of these reports together, I felt safe in concluding that about 200 cases of ancient and prehistoric cancer have been found by archaeologists.
That doesn’t sound like a lot, and some scholars like Luigi Capasso, an Italian anthropologist, have argued that cancer was extremely rare before the environmental assaults that came with industrialization. Others, like Dr. Strouhal, have suggested that the few cases researchers have stumbled across might be the tip of an iceberg — that there is a core rate of cancer that has remained fairly steady since prehistoric times.
The issue can quickly become political, and I was looking for some perspective. Of all the people who lived and died in millennia past, how many can paleo-oncologists possibly have examined? I was surprised to learn that by 1 A.D. the cumulative population of the earth was already approaching 47 billion and had nearly doubled by 1750. (The estimate, obviously very rough, is from a study by Carl Haub of the Population Reference Bureau.) So much for the notion that more people are alive today than have ever walked the earth. Not even close.
The next number I needed was one that, as far as I can see, had not been published before: the total number of human skeletons that have been dug up by archaeologists and made available for scientific study. Two experts I asked arrived independently at the same approximation: About 100,000. That would make the sample size only about 1/10,000th of 1 percent. For palaeo-oncologists it is even smaller than that: only a portion of those skeletons has been systematically examined for bone cancer. That is not much to hang an argument on, and I am left in the same quandary. Is cancer a natural (though unwanted) biological phenomenon, or a Frankensteinian creation of modern times?