Many thanks to Cynthia Beall for flagging up this interesting Scientific American piece about the discovery of an osteosarcoma in the toe bone of an as yet unidentified hominin discovered in the Swartkrans Cave and dated to around 1.7 million years ago. The source paper is from the South African Journal of Science. Popular accounts of this find – such as the SciAm piece – seem to find it really interesting that cancer has been found in such an old specimen, citing an orthodox view that much cancer is the direct result of modern life-styles typified by obesity, cigarette and alcohol use, and environmental carcinogens. However, while these factors have increased the incidence of cancer, as has relative longevity, it remains the case that cancer will always occur wherever and whenever cells are dividing. That is, after all, why long-lived massive animals like elephants and whales have multiple copies of the tumour suppressor gene p53. Given the acknowledged occurrence of cancer throughout the animal kingdom it should not come as a surprise when ultra-modern 3-D imaging exposes it in our ancestors. As the paper’s authors say in the Abstract: “The expression of malignant osteosarcoma in the Swartkrans specimen indicates that whilst the upsurge in malignancy incidence is correlated with modern lifestyles, there is no reason to suspect that primary bone tumours would have been any less frequent in ancient specimens. Such tumours 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.”
For anyone interested there is another popular piece about this discovery, and a twin discovery of bone cancer in a specimen of Australopithecus sediba, in Physorg which has a link to the second paper in SAJC.