Cancer Found in a Dinosaur Fossil: Proof That It Is Not a Man-Made Disease

Day 1 (The History of Cancer in 365 Days Series)

The mistaken belief that cancer is unique to the modern era, or even a disease created by humans, is becoming more common. There is an understandable reason for this misconception: despite major scientific and technological advances, cancer remains a serious health problem, and its global burden continues to grow. Research into cancer biology, its causes and its social effects reveals the disease's complexity; simple solutions are almost impossible. Yet one fact is crystal clear: cancer is neither a modern invention nor an entirely human-caused disease. A widely discussed study published in 2020 demonstrated that cancer dates back millions of years, into paleontological times, and even occurred in dinosaurs. This finding clearly shows that cancer has existed throughout history as a biological reality and a fundamental part of life.

A collaboration led by Canada's Royal Ontario Museum (ROM) and McMaster University resulted in the first discovery and diagnosis of an aggressive malignant bone cancer (osteosarcoma) in a dinosaur. No malignant cancer had previously been documented in dinosaurs. On August 3, 2020, the medical journal The Lancet Oncology published the article.

The severely deformed bone in the fossil, first discovered in 1989 in Alberta's Dinosaur Provincial Park, was initially thought to represent a healing fracture.

During a visit to the Royal Tyrrell Museum in 2017, ROM paleontologist Dr. David Evans, McMaster University Professor of Pathology and Molecular Medicine Dr. Mark Crowther, and osteopathologist Dr. Snezana Popovic noticed the bone's unusual features and decided to investigate further using modern medical techniques.

They assembled a team of experts and medical professionals from several disciplines, including pathology, radiology, orthopedic surgery and paleopathology.

The team reexamined the bones and approached diagnosing cancer in the dinosaur fossil as though they were trying to diagnose a tumor in a human.

Dr. Crowther says, "Diagnosing this type of aggressive cancer in dinosaurs has been difficult and requires medical expertise and multiple levels of analysis for accurate identification."

After carefully examining, documenting and making casts of the bones, the team used powerful three-dimensional CT reconstruction tools to visualize how the cancer had progressed inside the bone.

Using this meticulous process, the researchers diagnosed osteosarcoma.

To confirm the diagnosis, they compared the fossil with a normal fibula from a dinosaur of the same species and a human fibula diagnosed with osteosarcoma.

The fossil specimen belonged to an adult dinosaur with advanced cancer that had probably spread to other body systems. Dr. Evans, an expert on these horned dinosaurs, says, "The shin bone shows an aggressive cancer at an advanced stage. The cancer must have severely impaired the animal and made it highly vulnerable to the fearsome tyrannosaur predators of the time."

"Living in a large, protective herd may have allowed this plant-eating dinosaur to survive longer than it otherwise could have with such a devastating disease."

Osteosarcoma is a bone cancer that usually occurs in the second or third decade of life.

It arises through disordered bone growth and spreads rapidly both within the bone where it originates and to other organs, most commonly the lungs.

Dr. Seper Ekhtiari, an orthopedic surgeon at McMaster University, says, "It is both fascinating and inspiring to see an interdisciplinary effort similar to the one we use to diagnose and treat osteosarcoma in our patients lead to the first diagnosis of osteosarcoma in a dinosaur."

"This discovery reminds us of the biological links shared across the animal kingdom and strengthens the theory that osteosarcoma affects bones when and where they grow most rapidly."

The study aims to establish a new standard for diagnosing uncertain diseases in dinosaur fossils and opens the door to more precise and definitive diagnoses.

Drawing connections between human diseases and those of the past will help scientists better understand the evolution and genetics of various diseases.

Evidence of many other diseases we share with dinosaurs and other extinct animals may still be present in museum collections, waiting to be reexamined with modern analytical techniques.