What if we stopped trying to cure cancer, and learned how to live with it? That's the provocative question asked by mathematical oncologist Robert Gatenby in an essay published in Nature (subscription required). Gatenby argues that by trying to eradicate tumors with heavy doses of chemotherapy, doctors sometimes end up selecting for drug-resistant cancer cells that can spread rapidly once treatment is halted. Instead, he suggests giving patients moderate doses that aim to stabilize the tumor and prevent its growth. If doctors were guided by this principle, it would change treatment fundamentally, Gatenby says.