Reacción a "Study shows that larger species do develop more cases of cancer, disproving Peto's paradox"

The study used data we collected and analyzed for our Cancer Discovery manuscript, although they took a different analysis approach.

Overall, I think the implications are very similar that what has already been reported. Despite the title, they do report evidence of Peto’s Paradox: animals that evolved large body size rapidly do have lower malignancy rates. It’s possible to have a paradox related to body mass and cancer across some species, as Sir Richard Peto originally observed when comparing mice and men, but not others. Peto’s paradox does exist, but maybe not across all species.

One limitation of this study is that the sample sizes for each species that was analyzed here was highly variable. Differences in sample size should be accounted for. 

This study supports our efforts to identify enhanced mechanisms of cancer defense across species by exploring animals that develop less cancer than expected based on their size. Specifically, it confirms our previous findings that elephants exhibit lower cancer rates than predicted, as demonstrated through an analysis of Asian elephants. Our published research documenting cancer in elephants found that African elephants, the larger of the two species, exhibit even lower rates of neoplasia and malignancy than Asian elephants. These findings reinforce our ongoing work to identify and functionally validate enhanced cancer defense mechanisms and translate them into therapeutic strategies to improve outcomes for human cancer patients.

Overall, identifying species that evolved enhanced mechanisms of cancer defense holds tremendous promise for future preventative and treatment strategies for human cancer.