Scientists found aggressive cancer tumors in a 1.7 million-year-old foot bone.

According to the researchers from the University of Witwatersrand's Evolutionary Studies Institute and the South African Center for Excellence in Paleosciences, the benign tumor was found in a fossilized foot bone suspected to belong to a bipedal hominin - early ancestor of modern-day humans, which was discovered in the Swartkrans cave outside of Johannesburg, South Africa.

In the first study, which was published in the South African Journal of Science, the researchers identified the cancer in the foot bone as an osteosarcoma, an aggressive form of cancer that commonly affects younger individuals in modern humans and results to early death if untreated.

"Due to its preservation, we don't know whether the single cancerous foot bone belongs to an adult or child, nor whether the cancer caused the death of this individual, but we can tell this would have affected the individuals' ability to walk or run," Dr. Bernhard Zipfel, Witswatersrand scientist and co-author of the study, said in a press release. "In short, it would have been painful."

In an accompanying study by the research team, which was published in the same journal, the scientists also discovered the oldest known tumor in human fossil record in Malapa cave near Johannesburg. The tumor, which was non-cancerous, was found in the vertebrae of an Australopithecus sediba child - about eight or nine years old upon death - and dated almost two million years back.

Prior to the discovery, the oldest hominin tumor was found in the rib of a Neanderthal, which dated back to about 120,000 years old.

The researchers used a new method known as micro-CT imaging in discovering the tumor. The technique allowed researchers to examine the insides of the fossil in detailed 2D and 3D images, DigitalTrends reports.

"Modern medicine tends to assume that cancers and tumors in humans are diseases caused by modern lifestyles and environments," Edward Odes, Witswatersrand scientist and co-author of both studies, said in the same statement.

"Our studies show the origins of these diseases occurred in our ancient relatives millions of years before modern industrial societies existed."