"'Advanced' metazoan life of the form we now know, i.e. organisms with cell specialization and organ differentiation, was preceded by colonies of eukaryotic cells in which cellular cooperation was fairly rudimentary, consisting of networks of adhering cells exchanging information chemically, and forming self-organized assemblages with only a moderate division of labor," they write.

According to Lineweaver, this suggests that cancer is an atavism, or an evolutionary throwback.

“We think that the tumours that develop in cancer patients today take the same form as these simple cellular structures did more than a billion years ago,” he said.

In a way, the genes that controlled this early multi-cellular form of life are like a computer operating system's 'safe mode', and when there are failures or mutations in the more recent genes that manage the way cells specialise and interact to form the complex life of today, then the earlier level of programming takes over.

Their notion is in contrast to a prevailing theory that cancer cells are 'rogue' cells that evolve rapidly within the body, overcoming the normal slew of cellular defences.

However, Davies and Lineweaver point out that cancer cells are highly cooperative with each other, if competing with the host's cells. This suggests a pre-existing complexity that is reminiscent of early multicellular life.

They also point out that cancers' manifold survival mechanisms are predictable, and unlikely to emerge spontaneously through evolution within each individual in such a consistent way.

The good news is that this means combating cancer is not necessarily as complex as if the cancers were rogue cells evolving new and novel defence mechanisms within the body.