Abstract

Peto’s paradox is the disconnect between individual risk of cells to develop malignancy and the absence of a strong increase in cancer incidence with body mass across species. Recently small increases of cancer incidence with body mass across species have been interpreted as a falsification of Peto’s paradox. I argue this is a misinterpretation as it is the predicted incredible scale of the increase in cancer incidence with body mass that led to Peto’s paradox. The relevance for the biology of cancer and ageing of Peto’s paradox is off the scale and remains a highly valid paradigm of study.