John Shoemaker's prostate cancer diagnosis in 2006 launched the self-described "data-driven" former tech executive on a months-long research project. By the time the 62-year-old landed in Dr. Peter Carroll's office, he knew a great deal about prostate cancer and the nation's top experts who treat it. Still, he was startled to hear Carroll's advice: Track your cancer closely, but don't treat it until necessary. Almost 17 years later, Shoemaker remains on active surveillance and his disease has not progressed. "The strongest, most positive thing I can say is it hasn't affected me at all," he says. "I have lived exactly the same life I would've lived if I hadn't been diagnosed."