Wildlife Wednesdays: The Study of Elephants and Cancer

Elephants are large creatures but surprisingly have a very low risk of cancer. It is a phenomenon that became popular by Oxford University epidemiologists, Richard Peto. In what is called "Peto's paradox" which is defined that larger animals have low incidences of cancer, despite have more cells with the potential to mutate. “Elephants are 100 times the size of people,” says senior co-author Dr. Joshua Schiffman. “They should all be dropping dead of cancer and going extinct. But they have less cancer.”

Researchers from the University of Utah and Arizona State University spent several years looking into what kind of protections elephants have against the disease. "Most people have two copies of a gene that codes for p53, a protein Schiffman calls the “guardian of the genome.” People with Li-Fraumeni, a hereditary cancer predisposition syndrome, have only one working copy to code for the superhero protein that can jump in to repair damage or kill off a cell on its way to becoming cancerous. Without that genomic guardian swooping in to save the day, Schiffman said, people with Li-Fraumeni Syndrome have a nearly 100 percent risk of developing cancer in their lifetime.

So back to elephants, they have 40 copies of the gene that makes p53 and 38 with some variation that occurred over evolution that reminds in their DNA. It was then theorized that elephants p53 would repair cells at a higher rate than humans. That was not exactly the case with the study. The repair rate was similar, but in elephants, the genome guardian ramped up its other method of attack: cell death. For the elephants, Schiffman said, “it is so important that we don’t develop cancer that, instead of trying to fix it, where cells might go on to divide and turn into cancer, we need the ultimate protection, getting rid of the damaged cell completely." the article goes onto mention.