Autor/es reacciones

Carlo Maley

Director of the Arizona Cancer Evolution Center and Professor at the University of Arizona (USA)

The thing that surprises me is that evolutionary rate of body size is associated with lower cancer rates. I think it is important if that change in body size is increasing or decreasing body size. If species increase their body size, we would predict there would be some lag time before evolution generated enough cancer defenses to defend the new larger body. In contrast, species that decreased their body size should have inherited stronger than needed defenses, and there should be some evolutionary lag before their defenses decay to equilibrate with their new small size.

In the abstract they say: "Yet, to date, no evidence has been found to support this expectation, and no association has been found between cancer prevalence and body size across species". But that is not true. Their reference 13 from which they got the data shows there is a statistically significant but weak relationship: larger animals get slightly more cancer. They say in their intro that we found an association between body size and neoplasia but not malignancy, but that is wrong. We did find an association with malignancy prevalence, especially when you control for gestation time. They seem to have missed this.

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