Using this model, you might expect that larger organisms would undergo more gene mutation, and thus be more prone to cancer. Yet this is not true, Aktipis noted. In work carried out during a yearlong residence at the Berlin Institute for Advanced Study, she traced cancer incidence across different multicellular species, including blood cancers and melanoma in clams and mollusks. As multicellular life evolved, she discovered, so did the ability of organisms to restrict the incidence of cellular cheating.

“What was required is that life solve this problem of cellular cheating,” she said.

Cancer cells evolve to exploit the ecology of the body, while the body evolves to suppress invasions. Aktipis cited the evolution of the TP53 gene, which regulates cells and suppresses tumors. Larger organisms such as elephants have more copies of TP53 (twenty times that of humans) to deal with their body size.

“We actually have an amazing multilayer system of cellular cheater detection,” she said. “You can think of these mechanisms as the cellular conscience, the cell moderating itself.” The upshot, she added, is that bodies have a “collective cellular intelligence” that has evolved to keep cancer incidence lower than it would otherwise be. These defenses, like cancer itself, are a fundamental consequence of multicellularity.

One possible path for future research, she said, would be to allow that cancer is genetically inevitable and concentrate on managing it.  While the disease isn’t likely to be eradicated altogether, new treatments can bolster “cheater detection systems” and increase the body’s ability to fight invasions.

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For example, researchers are now finding that non-steroidal inflammatory drugs can slow down the mutation rate and reduce the progression of esophageal cancer. Most exciting, Aktipis said, is a new form of adaptive therapy that has been found to control cancers in mice and has seen promising trials in humans. In this case, tumors are treated with drugs only when they are actively growing and are otherwise left alone; this approach keeps drug-resistant cells from taking over.

Such “evolutionarily informed treatments” may offer the greatest hope for cancer treatment, she said.

Aktipis’ lecture was sponsored by the Harvard Museum of Natural History, the Peabody Museum of Archaeology and Ethnology, and the Harvard Museums of Science and Culture.