World's Oldest Tumor: Researchers Find Evidence Of Rare Growth On Neanderthal [PHOTO]
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The growth was a fibrous dysplasia, a benign bone tumor that still afflicts humans today. The old tumor, found on a rib, marks the earliest known bone tumor on record, beating other tumors by over 100,000 years.
The rib bone, analyzed by researchers from the University of Pennsylvania and the Croatian National History Museum, was excavated in 1899 from the Croatian site Krapina, a place where 876 fossil fragments belonging to several dozen Neanderthals were found. Scientists are not sure why the fossils of the individual Neanderthals were fragmented and scattered, theorizing that they may point to evidence of cannibalism, or that the Neanderthals had been killed and eaten by animals.
Dragutin Gorjanovic-Kramberger, the paleontologist who found the Neanderthal bones in 1899, described his discovery in 1919: "It is perfectly logical to assume that these Neanderthal men, who spent day and night in the open, eating a simple diet, had to be healthy and less prone to illnesses we have today. Accidents were therefore far more common in their struggle to survive and caused injury or even mutilation to the body."
How did this oldest tumor come about, in Neanderthals that weren't smoking cigarettes or being exposed to the other carcinogens of modern life?
"They didn't have pesticides, but they probably were sleeping in caves with burning fires," said David Frayer, an anthropologist at the University of Kansas and the paper's co-author. "They were probably inhaling a lot of smoke from the caves. So the air was not completely free of pollutants--but certainly, these Neanderthals weren't smoking cigarettes."
Janet Monge, a physical anthropologist at the University of Pennsylvania and the paper's lead author, said, "There's lots of evidence of blunt-force trauma where these Neanderthals were hit in the head. There's also evidence of an amputated forearm and arthritis. But this is the earliest evidence of a tumor."
Monge, who has been working with these Neanderthal bones for decades, and her team did x-rays and CT scans of the rib bone. They found a large lesion in the center, which is characteristic of a fibrous dysplasia tumor. The researchers knew it wasn't the result of a fracture, because there was not trauma found on any other part of the rib; it also only protruded from the front of the bone -- and not the back as well, which would be the case if it were the result of trauma.
In either case, though, this discovery is valuable for a simple reason: Tumors, on the whole, are extremely rare in the hominid fossil record. When they occur in any tissue apart from bone, they're unlikely to be preserved, and they also tend to develop during middle age and onwards. Because our ancient ancestors (or in the case of Neanderthals-cousins) typically didn't live past their thirties, they probably developed few cases of cancer or benign tumors.
"One of the important goals of the investigation of our ancestors is to discover aspects of their biology and behavior that provide insights into our present condition," said Alan Mann, one of the paper's researchers. "The discovery of this benign tumor in this collection documents the presence of this pathology well back into our biological history."
Monge said that finding this oldest tumor was particularly important in helping us understand the relationship between Neanderthals and our modern selves.
"This tumor may provide another link between Neandertals and modern peoples, links currently being reinforced with genetic and archaeological evidence," Monge said. "Part of our ancestry is indeed with Neandertals -- we grow the same way in our bones and teeth and share the same diseases."
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