MATTAWA, Grant County — Luis Martinez was still trying to figure out how to tell his 11-year-old son that his cancer might be back when his phone rang. He squinted to make out the name of his son’s soccer coach. The coach wanted to know if Luis could drive his son, Rooney, to a tournament in Seattle, three hours away. A last-minute dropout meant their team suddenly had a chance to compete against the best players in the state. Luis closed his eyes.