In a paper titled, “Adaptive Therapy,” published 10 years ago(!), authors R.A. Gatenby et al. proposed a radically different approach to chemotherapy. The traditional approach to chemotherapy is to use the most potent drug against a cancer and to give as much of it as possible to wipe out the cancer completely. Kind of mafia-style, “kick it while it’s down, and then drive a truck over it as well.” In reality, cancer is made up of billions of cells. Perhaps 99.99% of the cells are vulnerable to the chemotherapy “du jour.” So the tumor shrinks dramatically in response to the treatment. But then the 0.001% of cells that are RESISTANT to the drug are suddenly left all alone – “where is everyone?” Now all the resources, like oxygen, blood flow, energy molecules like glucose are available to a very few number of surviving cancer cells. The tumor then grows back in a few months, and is now completely resistant to that fabulous chemotherapy drug which wiped out the original cancer (but not quite). The radically different goal of adaptive therapy is to maintain the tumor at its initial size. Let the various cancer cells compete with each other for the limited resources. So if the tumor grows, crank up the chemo a little; if the tumor shrinks, dial it down a bit. Adaptive therapy was tried in mice with cancer. The mice treated with the traditional approach experienced an impressive initial shrinkage of the tumor, but then it grew back aggressively and killed the mouse, all in a short time. The mice treated with adaptive therapy survived indefinitely with a tumor that stayed reasonably small.