We tend to think of cancer as a modern disease. But is it?
That question was explored last week in an article in the New York Times by science writer George Johnson (who worked for the Minneapolis Star many years ago).
“[C]ancer has always been with us,” explains Johnson. “Where scientists disagree,” is on how much it has been amplified by the sweet and bitter fruits of civilization. Over the decades archaeologists have made about 200 possible cancer sightings dating to prehistoric times. But considering the difficulties of extracting statistics from old bones, is that a little or a lot?”
Bolstering the “a little” argument is a study published last October in the journal Nature Reviews: Cancer, which concluded that cancer has been found with “striking rarity” in ancient remains. That rarity suggests that cancers may be “limited to societies that are affected by modern lifestyle issues such as tobacco use and pollution resulting from industrialization,” wrote the study’s authors.
Not so fast, say other experts interviewed by Johnson. Several other factors could account for the paucity of malignant tumors found by archaeologists. To begin with, cancer tends to be a disease of middle and old age, and until relatively recently, many people failed to reach those stages of life. (Most of the skeletons and mummies included in the Nature Reviews: Cancer study were of people who died before the age of 50.)
Furthermore, “sparsity of evidence is not evidence of sparsity,” writes Johnson. Most cancers, for example, originate in the body’s soft organs. Unless a cancer has spread to the bone, archaeologists won’t find it. (A few soft-tissue cancers have been detected in mummified remains, but, as Johnson points out, those “pickings have been slim.”)
So, is cancer a mostly modern disease? Here’s Johnson’s conclusion:
With so little to go on, archaeology may never have a definitive answer. “We can say that cancer certainly existed, and probably in somewhat lower frequency than it does today,” said Arthur C. Aufderheide, emeritus professor of pathology at the University of Minnesota and co-author of the Cambridge Encyclopedia of Human Paleopathology. That may be as certain as we ever can be.
As scientists continue to investigate, there may be comfort in knowing that cancer is not entirely civilization’s fault. In the normal course of life a creature’s cells must be constantly dividing — millions of times a second. Sometimes something will go wrong.
“Cancer is an inevitability the moment you create complex multicellular organisms and give the individual cells the license to proliferate,” said Dr. [Robert A.] Weinberg, [a cancer researcher of the Whitehead Institute for Biomedical Research in Cambridge, Mass.] “It is simply a consequence of increasing entropy, increasing disorder.”
He was not being fatalistic. Over the ages bodies have evolved formidable barriers to keep rebellious cells in line. Quitting smoking, losing weight, eating healthier diets and taking other preventive measures can stave off cancer for decades. Until we die of something else.
“If we lived long enough,” Dr. Weinberg observed, “sooner or later we all would get cancer.”
You can read Johnson’s article here.