Scientists suggest that cancer is man-made (2010)

We definitely have evidence of cancer being present in the animal kingdom (that includes humans) deep into the fossil record so I might suggest that they are mistaken.

Pruitt, S. (2019, February 11). "How Old Is Cancer? At Least as Old as the Start of the Dinosaurs, Fossil Shows." HISTORY.

https://www.history.com/news/cancer-dinosaur-fossil-earliest...