I thought this would be about allometric scaling of organs. But if we're on the topic of metabolism, I wonder what the rate of cancer is for shrews vs. elephants, once the metabolism and lifespan are somehow accounted for.
This isn't my area of expertise, but my understanding is that elephants have many more copies of TP53, a gene that plays a critical role in regulating the cell cycle (and thus uncontrolled growth that may occur in cancer).
One of the linked papers also states that there was no correlation between body size and cancer in their experiments.
https://www.nature.com/news/how-elephants-avoid-cancer-1.185...