Cancer is a Scourge Most Ancient

Reconstruction of Pappochelys rosinae or grandfather turtle. Attribution: Rainer Schoch [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)], via Wikimedia Commons
The first words that come to mind when people hear “Triassic” are likely dinosaur or maybe ginkgo or possibly even phytoplankton, but probably not cancer. For all that we have learned about how cancer develops based on the efforts of numerous research scientists, this disease is not solely a modern affliction. In fact, cancer has deep roots in the past. From several thousand year old human mummies to fossils millions of years old, cancer has left evidence of its presence in the historical record. Yes, even in the era of dinosaurs, cancer existed.

Cancer is usually a soft-tissue-based malady, but occasionally, it can also be found on bones, altering the bone’s surface and leaving unmistakable signs. Alterations like those observed on the femur of a 240-million-year-old shell-less stem-turtle found in modern-day Germany and described in JAMA Oncology.

Researchers examined the surface of the reptilian left femur with a stereo microscope and generated interior images using virtual sections from a micro computerized tomography (CT) scan. The micro CT X-ray scans were combined into a 3D reconstruction of the bone. Even a visual inspection could spot the roughened, pocked areas of the fossil’s left femur, indicating something had happened to the bone.

The diagnosis 240 million years after the stem-turtle died and became fossilized: Periosteal osteosarcoma. This conclusion was based on several characteristics seen in the radiography, including the large, broad attachment to the cortical bone (meaning not a bone spur), the sharp, spiny outgrowths on the mass, no involvement with structures deeper in the bone and the wrinkled texture of the area affected. As it turns out, the surface bone tumor was noted by Haridy et al. as one of the oldest known examples of cancer found in an aminiote, vertebrate animals that include birds, reptiles, dinosaurs and mammals.

The Triassic stem-turtle in which this bone cancer was found is called Pappochelys rosinae. Pappochelys means grandfather turtle in reference to the fossil as a recently discovered link between turtles and the main group of reptiles such as lizards and snakes. In this case, grandfather could also refer to the osteosarcoma found on the fossil skeleton, demonstrating that cancer is far from a recent phenomenon and has been present in vertebrates for millions of years.

Reference
Haridy, Y., Witzmann, F., Asbach, P., Schoch, R.R., Fröbisch, N. and Rothschild, B.M. (2019) Triassic cancer–Osteosarcoma in a 240-million-year-old stem-turtle. JAMA Oncol. doi: 10.1001/jamaoncol.2018.6766

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Sara Klink

Technical Writer at Promega Corporation
Sara is a native Wisconsinite who grew up on a fifth-generation dairy farm and decided she wanted to be a scientist at age 12. She was educated at the University of Wisconsin—Parkside, where she earned a B.S. in Biology and a Master’s degree in Molecular Biology before earning her second Master’s degree in Oncology at the University of Wisconsin—Madison. She has worked for Promega Corporation for more than 15 years, first as a Technical Services Scientist, currently as a Technical Writer. Sara enjoys talking about her flock of entertaining chickens and tries not to be too ambitious when planning her spring garden.

One thoughtful comment

  1. Hi Sarah, there is a fascinating discussion on the ancient nature of cancer in Paul Davies’ new book “The Demon In The Machine”. He refers to cancer as an atavistic phenotype. Here is what he says:

    “the fact that cancer is so widespread among species point to an ancient evolutionary origin. The common ancestor of, say, humans and flies dates back 600 million years ago, while the broader categories of cancer-susceptible organisms have points of convergence over 1 billion years ago.

    The implication is that cancer has been around for as long as there have been multicelled organisms….our view of cancer is that it is not a product of damage but a systematic response to a damaging environment- a primitive cellular defence mechanism. Cancer is a cell’s way of coping with a bad place. It may be triggered by mutations, but its root cause is the self-activation of a very old and deeply embedded toolkit of emergency survival procedures…cancer is a default state in which a cell under threat runs on its ancient core functionality, thereby preserving its vital functions of which proliferation is the most ancient, most vial and most protected. …

    Because cancer is deeply integrated into the logic of mulcicellular life, its ancient mechanisms are highly conserved and fiercely protected, combating it proves a formidable challenge” (pp. 132-138)

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