According to some recent research, cancer looks more like early multi-cellular life than a mutation of modern cellular structures:
According to Lineweaver, this suggests that cancer is an atavism, or an evolutionary throwback.
“Unlike bacteria and viruses, cancer has not developed the capacity to evolve into new forms. In fact, cancer is better understood as the reversion of cells to the way they behaved a little over one billion years ago, when humans were nothing more than loose-knit colonies of only partially differentiated cells.
“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.