ABSTRACT
While cancer’s incidence dramatically increases with age and is exacerbated by mismatch, it is fundamentally different from other diseases because it is a corruption of the normal cellular processes that occur within us. We explore the hallmarks of cancer and then show how these hallmarks are deviations from the “rules” of multicellularity. We also see how cancer has been found across multicellular life. In addition, we explore the apparent paradox: given that cancers share common hallmarks, why is each one so different? Another paradox (Peto’s paradox) is the lack of correlation between the size of an organism and its cancer risk: big organisms with many more cellular divisions do not get cancer more often than smaller ones. We explore why elephants have low cancer risk. We then turn to other animals that have unusually high or unusually low cancer risk. These comparative oncology studies could reveal insight into lowering cancer risk in humans. Evolutionary genetics can also be useful in distinguishing between the genetic changes (drivers) that contribute to cancer and those along for the ride. We look at tradeoffs between genetic risk of cancer and neurodegenerative diseases. We also explore two evolutionary approaches to cancer: adaptative oncogenesis (as an explanation for why cancer risk increases dramatically with age) and adaptive therapy (an approach to treatment).
