Earliest Evidence of Bone Tumor Discovered in Neanderthal Fossil

With increasing exposure to toxins, pollution, radiation and addiction to unhealthy diets, it is quite common to see modern-day humans suffering with various chronic diseases. However, the same environmental conditions didn't exist during the time of our ancient ancestors, and researchers have thought it highly unlikely to trace the possibility of chronic diseases like cancer among them.

But researchers at the University of Kansas have produced an extraordinary finding, where they have traced the evidence of cancer in prehistoric populations. This is the first case of bone tumor that has been traced in the ribs of a Neanderthal specimen.

The study shows that like modern-day humans, even Neanderthals suffered from cancer, a leading cause of death worldwide. The evidence of bone cancer, also known as fibrous dysplasia, was found in the rib of a 120,000-year-old Neanderthal from the Krapina rock shelter, based 34 miles north of what is currently known as Zagreb, Croatia.

"It's evidence that Neandertals suffered tumors, that they were susceptible to the same kinds of diseases that we seen in modern humans," David Frayer, professor of anthropology at the University of Kansas, who co-authored the paper, said in a press statement. "Before this the earliest tumor in bone that we've seen goes back to an Egyptian mummy. So this is 100,000 years older than the previous tumor that had been found. There is no evidence of cancer older than this in the human fossil record."

The site from which the rib bone was excavated had nearly 876 other Neanderthal fossil fragments belonging to several individuals who died 120,000 years ago. Researchers therefore are not sure whether the tumor was from a male or female. They had no idea how old the adult was and at what time he or she died, nor the cause of death.

Based on the nuclear DNA of several Neanderthals, the researchers know that a certain set of unique genes were passed to modern humans. The rib bone they discovered is a 30-millimeter-long piece belonging to the left rib which had a fresh break. This break leads to a cavity that is 18 millimeters in length and 7.6 millimeters wide.  

On analyzing the bone with the help of radiography and CT scans, researchers learnt that the tumor was linked with fibrous dysplasia, which is abnormal bone growth, where fibrous bone tissue replaces the normal bone.

The study details will be published in the forthcoming edition of PLOS One.