The rise of cancer in humans is often attributed to modern lifestyles. But two recent discoveries in fossils in South Africa show that cancer has been a part of life for millions of years. Scientists and researchers collectively have published their findings in the South African Journal of Science.
The old foot bone, dating from approximately 1.7 million years ago, shows the extent of expansion of osteosarcoma, or primary bone cancer, beyond the surface of the bone. (Image: Patrick Randolph-Quinney, UCLan)
Stressful, hurried, modern lifestyles are often associated with the rise of cancer in humans. But two recent discoveries in South Africa – one on a foot bone dated approximately 1.7 million years ago, the other a tumour in the back of a child – turns that theory on its head.
A team of scientists from the University of the Witwatersrand’s Evolutionary Studies Institute and the South African Centre for Excellence in PalaeoSciences, working with international researchers, recently published papers in the South African Journal of Science on the discoveries of evidence of cancer and bony tumours in fossils.
The foot bone was found at a site in Swartkrans. It pushes back the oldest date for cancer from recent history to prehistory. The bone belonged to a hominin, or bipedal human relative, said the scientists.
“Modern medicine tends to assume that cancers and tumours in humans are diseases caused by modern lifestyles and environments,” said Edward Odes, a Wits doctoral candidate and lead author of the cancer paper, and a co-author on the tumour paper.
“Our studies show the origins of these diseases occurred in our ancient relatives millions of years before modern industrial societies existed.”
Scientists identified the metatarsal, or foot bone, as having an osteosarcoma, an aggressive form of cancer usually affecting younger people today. If not treated, it results in death.
The cancer would have affected the individual’s ability to walk or run, said Dr Bernhard Zipfel, a Wits scientist and an expert on the foot and locomotion of early human relatives. “In short, it would have been painful.”
Watch the experts explain their discoveries:
An accompanying paper, published in the same journal, identified the oldest tumour in a human fossil dating from almost 2 million years ago. Scientists found a benign neoplasm in the vertebrae of the well-known Australopithecus sediba child, Karabo, found at the Malapa site.
The top row shows the surface rendered image volume. The bottom row shows partially transparent image volume with the segmented boundaries of the lesion rendered solid pink. Volume data derived from phase contrast X-ray synchrotron microtomography. A: right lateral view. B: superior view. C: posterior view. (Image: Paul Tafforeau, ESRF)
“Not only has there been an assumption that these sorts of cancers and tumours are diseases of modernity, which these fossils clearly demonstrate they are not, but that we as modern humans exhibit them as a consequence of living longer, yet this rare tumour is found in a young child,” said Prof Lee Berger, a co-author of both papers and the leader of the Malapa project, where the fossil vertebra was found.
He is the research professor in Human Evolution and the Public Understanding of Science at the Institute for Human Evolution, School of GeoSciences, at Wits.
“The history of these types of tumours and cancers is clearly more complex than previously thought,” Berger said.
— Lee Berger (@LeeRberger) August 1, 2016
Dr Patrick Randolph-Quinney, senior lecturer in biological and forensic anthropology at the UK’s University of Central Lancashire (UCLan), said the finding in Australopithecus sediba was fascinating not only because it was found in the back, which was rare, but also that it was found in a child. “This in fact is the first evidence of such a disease in a young individual in the whole of the fossil human record.”
The cancer and tumour were diagnosed using the best technology available from various institutions, including the European Synchrotron Research Facility in Grenoble, France; medical CT (or computed tomography) at the Charlotte Maxeke Hospital in Johannesburg; and the micro-CT facility at the Nuclear Energy Corporation of South Africa at Pelindaba.
Dr Jacqueline Smilg, a radiologist at Charlotte Maxeke Hospital, was also a co-author of both papers. She participated in the clinical diagnoses of each discovery. Researchers in the country were at the forefront of using various X-ray modalities to discover fresh details about ancient human relatives, she said.
“This is another good example of how the modern clinical sciences and the science of palaeoanthropology are working together in South Africa and with international collaborators to advance our understanding of diseases in both the past and the present,” she said.