Researchers have reported of the first confirmed finding of an osteosarcoma in dinosaurs, specifically a specimen of Centrosaurus apertus.
Osteosarcoma is a primary bone malignancy. It has a worldwide incidence of 3.4 cases per million people per year. The incidence of osteosarcoma in humans, peaks in the second decade of life. Researchers believe this is due to the increase in bone growth velocity at this age. Our understanding of the cause, genetic aberrations, oncogenic events and evolutionary history of osteosarcoma is poor. As a result, this has limited further advances in genome-informed targeted therapies.
Palaeopathology (study of ancient diseases) in dinosaurs is often limited due to loss of soft tissues and varying states of fossil preservation. In addition, diagnosis is further limited by hesitation to destructively analyse dinosaur bones as they are unique and rare. Scientists have previously reported a case of a metastatic malignancy in a dinosaur (thought to be a Ewing’s sarcoma-like reaction). However, the authors did not confirm this diagnosis histologically.
A confirmed finding in dinosaurs
In a study, published in The Lancet Oncology, researchers report findings of an osteosarcoma in a specimen of Centrosaurus apertus. This is a herbivorous ceratopsian (horned) dinosaur from the Dinosaur Park Formation (Canada) which dates back approximately 77·0–75·5 million years ago. The team confirmed the diagnosis using gross, radiographic and histological analysis. Experts in musculoskeletal oncology and human pathology performed the analysis. They compared their analyses to a confirmed case of human osteosarcoma and a normal Centrosaurus fibula.
Researchers were able to confirm the diagnosis based on morphological, radiological and histological criteria. They found that the gross, radiographic and histological appearance of the dinosaur fibula was very similar to the known human osteosarcoma, despite the lack of preserved soft tissue structures in the dinosaur fibula. They also noted that the extensive invasion of the cancer throughout the bone suggests that it may have persisted for a long period of time in the animal’s life and may have also invaded other body systems.
These findings indicate the value of a multimodal analysis to facilitate identification of additional illnesses and injuries in ancient species. This evidence also shows that malignancies are persistent within evolutionary history of organisms.
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