An international team of researchers have discovered the most ancient evidence of cancer and bony tumors in a foot bone dated to approximately 1.7 million years ago from the site of Swartkrans.

The discovery, described in two separate paper published in the South African Journal of Science, suggest that cancers in humans can be dated back to deep prehistory.

"Modern medicine tends to assume that cancers and tumours in humans are diseases caused by modern lifestyles and environments. Our studies show the origins of these diseases occurred in our ancient relatives millions of years before modern industrial societies existed," said Edward Odes, a Wits doctoral candidate and lead author of the cancer paper, and co-author on the tumor paper, in a statement.

At present, the researchers don't know the exact species to which the bone belongs to, but they believe that it belongs to a hominin, a bipedal human relative. The discovered foot bone is a metatarsal. The researchers identified the cancer to be an osteosarcoma, an aggressive from of cancer known to affect younger individuals in modern human and can usually lead to early death if left untreated. The researchers are uncertain whether the cancer is the cause of death of the individual, but they are sure that the cancer might affect its ability to walk or run.

In the other paper, the researchers described the oldest tumor to be ever found in the human fossil record. A benign neoplasm was found in the vertebrae of a two million-year old Australopithecus sediba child. Previously, the oldest possible hominin tumor was found in the rib of a 120,000 year-old Neanderthal.

The discovery of the tumor baffled the researchers because it was found in the back, which is a extremely rare place for the disease to develop in humans, and it happens to a child. This made the discovery as the first evidence of a tumor in a young individual in the whole human fossil record.

Their findings clearly suggest that the cancers and tumors are not a disease of modernity and the history of these disease are much more complex than previously thought.