A study recently published in the South African Journal of Science shows that a fossilized foot bone found in South Africa displays the oldest example of malignant cancer. Recovered from the Swartkrans cave site in South Africa, the fossil dates back 1.7 million years and shows "osteosarcoma," an aggressive form of bone cancer. The diagnosis was made through 3-D imaging methods, and the fossilized bone appears to have belonged to an ancient human. The researchers said the cancer most probably affected the individual's ability to walk or run.

"Modern medicine tends to assume that cancers and tumors in humans are diseases caused by modern lifestyles and environments," said Edward Odes, from the University of Witwatersrand, South Africa, as reported by New Scientist. He said the findings suggest that humans have suffered from cancer for many more years than researchers previously thought. "The expression of malignant osteosarcoma in the Swartkrans specimen indicates that while an upsurge in the incidence of malignancy correlates with modern lifestyles, there is no reason to suspect that primary bone tumors would have been any less frequent in ancient specimens. Such tumors are not related to lifestyle and often occur in younger individuals. As such, malignancy has a considerable antiquity in the fossil record, as evidenced by this specimen."

The Swartkrans cave site is on UNESCO's World Heritage List. A previous study found a tumor in a human fossil dating back 120,000 years.