In 1950, a diagnosis of cancer was all but a death sentence. Mortality rates only got worse, and as late as 1986, an article in the New England Journal of Medicine lamented: "We are losing the war against cancer." Cancer is one of humankind's oldest and most persistent enemies; it has been called the existential disease. But we are now entering a new, and more positive, phase in this long campaign. While cancer has not been cured --...